diff --git a/appveyor.yml b/appveyor.yml
index 433d391b16..bbd35ed160 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -14,6 +14,7 @@ environment:
 
 branches:
   only:
+  - openapi-required-and-nullable-properties # TODO: remove
   - master
   - openapi
   - develop
diff --git a/src/JsonApiDotNetCore.OpenApi.Client/ApiException.cs b/src/JsonApiDotNetCore.OpenApi.Client/ApiException.cs
index 1224308af9..cc7cdc8104 100644
--- a/src/JsonApiDotNetCore.OpenApi.Client/ApiException.cs
+++ b/src/JsonApiDotNetCore.OpenApi.Client/ApiException.cs
@@ -15,7 +15,7 @@ public sealed class ApiException : Exception
 
     public IReadOnlyDictionary<string, IEnumerable<string>> Headers { get; }
 
-    public ApiException(string message, int statusCode, string? response, IReadOnlyDictionary<string, IEnumerable<string>> headers, Exception innerException)
+    public ApiException(string message, int statusCode, string? response, IReadOnlyDictionary<string, IEnumerable<string>> headers, Exception? innerException)
         : base($"{message}\n\nStatus: {statusCode}\nResponse: \n{response ?? "(null)"}", innerException)
     {
         StatusCode = statusCode;
diff --git a/src/JsonApiDotNetCore.OpenApi.Client/IJsonApiClient.cs b/src/JsonApiDotNetCore.OpenApi.Client/IJsonApiClient.cs
index a994d78a0e..5cb98a7b9a 100644
--- a/src/JsonApiDotNetCore.OpenApi.Client/IJsonApiClient.cs
+++ b/src/JsonApiDotNetCore.OpenApi.Client/IJsonApiClient.cs
@@ -5,14 +5,19 @@ namespace JsonApiDotNetCore.OpenApi.Client;
 public interface IJsonApiClient
 {
     /// <summary>
-    /// Ensures correct serialization of attributes in a POST/PATCH Resource request body. In JSON:API, an omitted attribute indicates to ignore it, while an
-    /// attribute that is set to "null" means to clear it. This poses a problem because the serializer cannot distinguish between "you have explicitly set
-    /// this .NET property to null" vs "you didn't touch it, so it is null by default" when converting an instance to JSON. Therefore, calling this method
-    /// treats all attributes that contain their default value (<c>null</c> for reference types, <c>0</c> for integers, <c>false</c> for booleans, etc) as
-    /// omitted unless explicitly listed to include them using <paramref name="alwaysIncludedAttributeSelectors" />.
+    /// <para>
+    /// Calling this method ensures that attributes containing a default value (<c>null</c> for reference types, <c>0</c> for integers, <c>false</c> for
+    /// booleans, etc) are omitted during serialization, except for those explicitly marked for inclusion in
+    /// <paramref name="alwaysIncludedAttributeSelectors" />.
+    /// </para>
+    /// <para>
+    /// This is sometimes required to ensure correct serialization of attributes during a POST/PATCH request. In JSON:API, an omitted attribute indicates to
+    /// ignore it, while an attribute that is set to "null" means to clear it. This poses a problem because the serializer cannot distinguish between "you
+    /// have explicitly set this .NET property to null" vs "you didn't touch it, so it is null by default" when converting an instance to JSON.
+    /// </para>
     /// </summary>
     /// <param name="requestDocument">
-    /// The request document instance for which this registration applies.
+    /// The request document instance for which default values should be omitted.
     /// </param>
     /// <param name="alwaysIncludedAttributeSelectors">
     /// Optional. A list of expressions to indicate which properties to unconditionally include in the JSON request body. For example:
@@ -30,7 +35,7 @@ public interface IJsonApiClient
     /// An <see cref="IDisposable" /> to clear the current registration. For efficient memory usage, it is recommended to wrap calls to this method in a
     /// <c>using</c> statement, so the registrations are cleaned up after executing the request.
     /// </returns>
-    IDisposable RegisterAttributesForRequestDocument<TRequestDocument, TAttributesObject>(TRequestDocument requestDocument,
+    IDisposable WithPartialAttributeSerialization<TRequestDocument, TAttributesObject>(TRequestDocument requestDocument,
         params Expression<Func<TAttributesObject, object?>>[] alwaysIncludedAttributeSelectors)
         where TRequestDocument : class;
 }
diff --git a/src/JsonApiDotNetCore.OpenApi.Client/JsonApiClient.cs b/src/JsonApiDotNetCore.OpenApi.Client/JsonApiClient.cs
index 219ac04353..f119396747 100644
--- a/src/JsonApiDotNetCore.OpenApi.Client/JsonApiClient.cs
+++ b/src/JsonApiDotNetCore.OpenApi.Client/JsonApiClient.cs
@@ -3,6 +3,7 @@
 using JetBrains.Annotations;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Serialization;
+using SysNotNull = System.Diagnostics.CodeAnalysis.NotNullAttribute;
 
 namespace JsonApiDotNetCore.OpenApi.Client;
 
@@ -23,7 +24,7 @@ protected void SetSerializerSettingsForJsonApi(JsonSerializerSettings settings)
     }
 
     /// <inheritdoc />
-    public IDisposable RegisterAttributesForRequestDocument<TRequestDocument, TAttributesObject>(TRequestDocument requestDocument,
+    public IDisposable WithPartialAttributeSerialization<TRequestDocument, TAttributesObject>(TRequestDocument requestDocument,
         params Expression<Func<TAttributesObject, object?>>[] alwaysIncludedAttributeSelectors)
         where TRequestDocument : class
     {
@@ -39,13 +40,14 @@ public IDisposable RegisterAttributesForRequestDocument<TRequestDocument, TAttri
             }
             else
             {
-                throw new ArgumentException($"The expression '{selector}' should select a single property. For example: 'article => article.Title'.");
+                throw new ArgumentException(
+                    $"The expression '{nameof(alwaysIncludedAttributeSelectors)}' should select a single property. For example: 'article => article.Title'.");
             }
         }
 
-        _jsonApiJsonConverter.RegisterRequestDocument(requestDocument, new AttributeNamesContainer(attributeNames, typeof(TAttributesObject)));
+        _jsonApiJsonConverter.RegisterDocument(requestDocument, new AttributeNamesContainer(attributeNames, typeof(TAttributesObject)));
 
-        return new AttributesRegistrationScope(_jsonApiJsonConverter, requestDocument);
+        return new RequestDocumentRegistrationScope(_jsonApiJsonConverter, requestDocument);
     }
 
     private static Expression RemoveConvert(Expression expression)
@@ -67,38 +69,38 @@ private static Expression RemoveConvert(Expression expression)
 
     private sealed class JsonApiJsonConverter : JsonConverter
     {
-        private readonly Dictionary<object, AttributeNamesContainer> _alwaysIncludedAttributesPerRequestDocumentInstance = new();
-        private readonly Dictionary<Type, ISet<object>> _requestDocumentInstancesPerRequestDocumentType = new();
-        private bool _isSerializing;
+        private readonly Dictionary<object, AttributeNamesContainer> _alwaysIncludedAttributesByRequestDocument = new();
+        private readonly Dictionary<Type, ISet<object>> _requestDocumentsByType = new();
+        private SerializationScope? _serializationScope;
 
         public override bool CanRead => false;
 
-        public void RegisterRequestDocument(object requestDocument, AttributeNamesContainer attributes)
+        public void RegisterDocument(object requestDocument, AttributeNamesContainer alwaysIncludedAttributes)
         {
-            _alwaysIncludedAttributesPerRequestDocumentInstance[requestDocument] = attributes;
+            _alwaysIncludedAttributesByRequestDocument[requestDocument] = alwaysIncludedAttributes;
 
             Type requestDocumentType = requestDocument.GetType();
 
-            if (!_requestDocumentInstancesPerRequestDocumentType.ContainsKey(requestDocumentType))
+            if (!_requestDocumentsByType.ContainsKey(requestDocumentType))
             {
-                _requestDocumentInstancesPerRequestDocumentType[requestDocumentType] = new HashSet<object>();
+                _requestDocumentsByType[requestDocumentType] = new HashSet<object>();
             }
 
-            _requestDocumentInstancesPerRequestDocumentType[requestDocumentType].Add(requestDocument);
+            _requestDocumentsByType[requestDocumentType].Add(requestDocument);
         }
 
-        public void RemoveAttributeRegistration(object requestDocument)
+        public void RemoveRegistration(object requestDocument)
         {
-            if (_alwaysIncludedAttributesPerRequestDocumentInstance.ContainsKey(requestDocument))
+            if (_alwaysIncludedAttributesByRequestDocument.ContainsKey(requestDocument))
             {
-                _alwaysIncludedAttributesPerRequestDocumentInstance.Remove(requestDocument);
+                _alwaysIncludedAttributesByRequestDocument.Remove(requestDocument);
 
                 Type requestDocumentType = requestDocument.GetType();
-                _requestDocumentInstancesPerRequestDocumentType[requestDocumentType].Remove(requestDocument);
+                _requestDocumentsByType[requestDocumentType].Remove(requestDocument);
 
-                if (!_requestDocumentInstancesPerRequestDocumentType[requestDocumentType].Any())
+                if (!_requestDocumentsByType[requestDocumentType].Any())
                 {
-                    _requestDocumentInstancesPerRequestDocumentType.Remove(requestDocumentType);
+                    _requestDocumentsByType.Remove(requestDocumentType);
                 }
             }
         }
@@ -107,52 +109,176 @@ public override bool CanConvert(Type objectType)
         {
             ArgumentGuard.NotNull(objectType);
 
-            return !_isSerializing && _requestDocumentInstancesPerRequestDocumentType.ContainsKey(objectType);
+            if (_serializationScope == null)
+            {
+                return _requestDocumentsByType.ContainsKey(objectType);
+            }
+
+            return _serializationScope.ShouldConvertAsAttributesObject(objectType);
         }
 
         public override object ReadJson(JsonReader reader, Type objectType, object? existingValue, JsonSerializer serializer)
         {
-            throw new Exception("This code should not be reachable.");
+            throw new UnreachableCodeException();
         }
 
         public override void WriteJson(JsonWriter writer, object? value, JsonSerializer serializer)
         {
             ArgumentGuard.NotNull(writer);
+            ArgumentGuard.NotNull(value);
             ArgumentGuard.NotNull(serializer);
 
-            if (value != null)
+            if (_serializationScope == null)
             {
-                if (_alwaysIncludedAttributesPerRequestDocumentInstance.ContainsKey(value))
-                {
-                    AttributeNamesContainer attributeNamesContainer = _alwaysIncludedAttributesPerRequestDocumentInstance[value];
-                    serializer.ContractResolver = new JsonApiDocumentContractResolver(attributeNamesContainer);
-                }
+                AssertObjectIsRequestDocument(value);
 
-                try
-                {
-                    _isSerializing = true;
-                    serializer.Serialize(writer, value);
-                }
-                finally
+                SerializeRequestDocument(writer, value, serializer);
+            }
+            else
+            {
+                AttributeNamesContainer? attributesObjectInfo = _serializationScope.AttributesObjectInScope;
+
+                AssertObjectMatchesSerializationScope(attributesObjectInfo, value);
+
+                SerializeAttributesObject(attributesObjectInfo, writer, value, serializer);
+            }
+        }
+
+        private void AssertObjectIsRequestDocument(object value)
+        {
+            Type objectType = value.GetType();
+
+            if (!_requestDocumentsByType.ContainsKey(objectType))
+            {
+                throw new UnreachableCodeException();
+            }
+        }
+
+        private void SerializeRequestDocument(JsonWriter writer, object value, JsonSerializer serializer)
+        {
+            _serializationScope = new SerializationScope();
+
+            if (_alwaysIncludedAttributesByRequestDocument.TryGetValue(value, out AttributeNamesContainer? attributesObjectInfo))
+            {
+                _serializationScope.AttributesObjectInScope = attributesObjectInfo;
+            }
+
+            try
+            {
+                serializer.Serialize(writer, value);
+            }
+            finally
+            {
+                _serializationScope = null;
+            }
+        }
+
+        private static void AssertObjectMatchesSerializationScope([SysNotNull] AttributeNamesContainer? attributesObjectInfo, object value)
+        {
+            Type objectType = value.GetType();
+
+            if (attributesObjectInfo == null || !attributesObjectInfo.MatchesAttributesObjectType(objectType))
+            {
+                throw new UnreachableCodeException();
+            }
+        }
+
+        private static void SerializeAttributesObject(AttributeNamesContainer alwaysIncludedAttributes, JsonWriter writer, object value,
+            JsonSerializer serializer)
+        {
+            AssertRequiredPropertiesAreNotExcluded(value, alwaysIncludedAttributes, writer);
+
+            serializer.ContractResolver = new JsonApiAttributeContractResolver(alwaysIncludedAttributes);
+            serializer.Serialize(writer, value);
+        }
+
+        private static void AssertRequiredPropertiesAreNotExcluded(object value, AttributeNamesContainer alwaysIncludedAttributes, JsonWriter jsonWriter)
+        {
+            PropertyInfo[] propertyInfos = value.GetType().GetProperties();
+
+            foreach (PropertyInfo attributesPropertyInfo in propertyInfos)
+            {
+                bool isExplicitlyIncluded = alwaysIncludedAttributes.ContainsAttribute(attributesPropertyInfo.Name);
+
+                if (isExplicitlyIncluded)
                 {
-                    _isSerializing = false;
+                    return;
                 }
+
+                AssertRequiredPropertyIsNotIgnored(value, attributesPropertyInfo, jsonWriter.Path);
+            }
+        }
+
+        private static void AssertRequiredPropertyIsNotIgnored(object value, PropertyInfo attribute, string path)
+        {
+            JsonPropertyAttribute jsonPropertyForAttribute = attribute.GetCustomAttributes<JsonPropertyAttribute>().Single();
+
+            if (jsonPropertyForAttribute.Required is not (Required.Always or Required.AllowNull))
+            {
+                return;
+            }
+
+            bool isPropertyIgnored = DefaultValueEqualsCurrentValue(attribute, value);
+
+            if (isPropertyIgnored)
+            {
+                throw new InvalidOperationException($"The following property should not be omitted: {path}.{jsonPropertyForAttribute.PropertyName}.");
+            }
+        }
+
+        private static bool DefaultValueEqualsCurrentValue(PropertyInfo propertyInfo, object instance)
+        {
+            object? currentValue = propertyInfo.GetValue(instance);
+            object? defaultValue = GetDefaultValue(propertyInfo.PropertyType);
+
+            if (defaultValue == null)
+            {
+                return currentValue == null;
+            }
+
+            return defaultValue.Equals(currentValue);
+        }
+
+        private static object? GetDefaultValue(Type type)
+        {
+            return type.IsValueType ? Activator.CreateInstance(type) : null;
+        }
+    }
+
+    private sealed class SerializationScope
+    {
+        private bool _isFirstAttemptToConvertAttributes = true;
+        public AttributeNamesContainer? AttributesObjectInScope { get; set; }
+
+        public bool ShouldConvertAsAttributesObject(Type type)
+        {
+            if (!_isFirstAttemptToConvertAttributes || AttributesObjectInScope == null)
+            {
+                return false;
             }
+
+            if (!AttributesObjectInScope.MatchesAttributesObjectType(type))
+            {
+                return false;
+            }
+
+            _isFirstAttemptToConvertAttributes = false;
+            return true;
         }
     }
 
     private sealed class AttributeNamesContainer
     {
         private readonly ISet<string> _attributeNames;
-        private readonly Type _containerType;
+        private readonly Type _attributesObjectType;
 
-        public AttributeNamesContainer(ISet<string> attributeNames, Type containerType)
+        public AttributeNamesContainer(ISet<string> attributeNames, Type attributesObjectType)
         {
             ArgumentGuard.NotNull(attributeNames);
-            ArgumentGuard.NotNull(containerType);
+            ArgumentGuard.NotNull(attributesObjectType);
 
             _attributeNames = attributeNames;
-            _containerType = containerType;
+            _attributesObjectType = attributesObjectType;
         }
 
         public bool ContainsAttribute(string name)
@@ -160,18 +286,18 @@ public bool ContainsAttribute(string name)
             return _attributeNames.Contains(name);
         }
 
-        public bool ContainerMatchesType(Type type)
+        public bool MatchesAttributesObjectType(Type type)
         {
-            return _containerType == type;
+            return _attributesObjectType == type;
         }
     }
 
-    private sealed class AttributesRegistrationScope : IDisposable
+    private sealed class RequestDocumentRegistrationScope : IDisposable
     {
         private readonly JsonApiJsonConverter _jsonApiJsonConverter;
         private readonly object _requestDocument;
 
-        public AttributesRegistrationScope(JsonApiJsonConverter jsonApiJsonConverter, object requestDocument)
+        public RequestDocumentRegistrationScope(JsonApiJsonConverter jsonApiJsonConverter, object requestDocument)
         {
             ArgumentGuard.NotNull(jsonApiJsonConverter);
             ArgumentGuard.NotNull(requestDocument);
@@ -182,28 +308,30 @@ public AttributesRegistrationScope(JsonApiJsonConverter jsonApiJsonConverter, ob
 
         public void Dispose()
         {
-            _jsonApiJsonConverter.RemoveAttributeRegistration(_requestDocument);
+            _jsonApiJsonConverter.RemoveRegistration(_requestDocument);
         }
     }
 
-    private sealed class JsonApiDocumentContractResolver : DefaultContractResolver
+    private sealed class JsonApiAttributeContractResolver : DefaultContractResolver
     {
-        private readonly AttributeNamesContainer _attributeNamesContainer;
+        private readonly AttributeNamesContainer _alwaysIncludedAttributes;
 
-        public JsonApiDocumentContractResolver(AttributeNamesContainer attributeNamesContainer)
+        public JsonApiAttributeContractResolver(AttributeNamesContainer alwaysIncludedAttributes)
         {
-            ArgumentGuard.NotNull(attributeNamesContainer);
+            ArgumentGuard.NotNull(alwaysIncludedAttributes);
 
-            _attributeNamesContainer = attributeNamesContainer;
+            _alwaysIncludedAttributes = alwaysIncludedAttributes;
         }
 
         protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
         {
             JsonProperty property = base.CreateProperty(member, memberSerialization);
 
-            if (_attributeNamesContainer.ContainerMatchesType(property.DeclaringType!))
+            bool canOmitAttribute = property.Required != Required.Always;
+
+            if (canOmitAttribute && _alwaysIncludedAttributes.MatchesAttributesObjectType(property.DeclaringType!))
             {
-                if (_attributeNamesContainer.ContainsAttribute(property.UnderlyingName!))
+                if (_alwaysIncludedAttributes.ContainsAttribute(property.UnderlyingName!))
                 {
                     property.NullValueHandling = NullValueHandling.Include;
                     property.DefaultValueHandling = DefaultValueHandling.Include;
diff --git a/src/JsonApiDotNetCore.OpenApi.Client/UnreachableCodeException.cs b/src/JsonApiDotNetCore.OpenApi.Client/UnreachableCodeException.cs
new file mode 100644
index 0000000000..f1821329d0
--- /dev/null
+++ b/src/JsonApiDotNetCore.OpenApi.Client/UnreachableCodeException.cs
@@ -0,0 +1,9 @@
+namespace JsonApiDotNetCore.OpenApi.Client;
+
+internal sealed class UnreachableCodeException : Exception
+{
+    public UnreachableCodeException()
+        : base("This code should not be reachable.")
+    {
+    }
+}
diff --git a/src/JsonApiDotNetCore.OpenApi/JsonApiActionDescriptorCollectionProvider.cs b/src/JsonApiDotNetCore.OpenApi/JsonApiActionDescriptorCollectionProvider.cs
index 98ae9938b4..16b173dd17 100644
--- a/src/JsonApiDotNetCore.OpenApi/JsonApiActionDescriptorCollectionProvider.cs
+++ b/src/JsonApiDotNetCore.OpenApi/JsonApiActionDescriptorCollectionProvider.cs
@@ -22,13 +22,14 @@ internal sealed class JsonApiActionDescriptorCollectionProvider : IActionDescrip
 
     public ActionDescriptorCollection ActionDescriptors => GetActionDescriptors();
 
-    public JsonApiActionDescriptorCollectionProvider(IControllerResourceMapping controllerResourceMapping, IActionDescriptorCollectionProvider defaultProvider)
+    public JsonApiActionDescriptorCollectionProvider(IControllerResourceMapping controllerResourceMapping, IActionDescriptorCollectionProvider defaultProvider,
+        ResourceFieldValidationMetadataProvider resourceFieldValidationMetadataProvider)
     {
         ArgumentGuard.NotNull(controllerResourceMapping);
         ArgumentGuard.NotNull(defaultProvider);
 
         _defaultProvider = defaultProvider;
-        _jsonApiEndpointMetadataProvider = new JsonApiEndpointMetadataProvider(controllerResourceMapping);
+        _jsonApiEndpointMetadataProvider = new JsonApiEndpointMetadataProvider(controllerResourceMapping, resourceFieldValidationMetadataProvider);
     }
 
     private ActionDescriptorCollection GetActionDescriptors()
diff --git a/src/JsonApiDotNetCore.OpenApi/JsonApiMetadata/JsonApiEndpointMetadataProvider.cs b/src/JsonApiDotNetCore.OpenApi/JsonApiMetadata/JsonApiEndpointMetadataProvider.cs
index d0fe2f1234..0dcb87cabb 100644
--- a/src/JsonApiDotNetCore.OpenApi/JsonApiMetadata/JsonApiEndpointMetadataProvider.cs
+++ b/src/JsonApiDotNetCore.OpenApi/JsonApiMetadata/JsonApiEndpointMetadataProvider.cs
@@ -15,11 +15,13 @@ internal sealed class JsonApiEndpointMetadataProvider
 {
     private readonly IControllerResourceMapping _controllerResourceMapping;
     private readonly EndpointResolver _endpointResolver = new();
+    private readonly NonPrimaryDocumentTypeFactory _nonPrimaryDocumentTypeFactory;
 
-    public JsonApiEndpointMetadataProvider(IControllerResourceMapping controllerResourceMapping)
+    public JsonApiEndpointMetadataProvider(IControllerResourceMapping controllerResourceMapping,
+        ResourceFieldValidationMetadataProvider resourceFieldValidationMetadataProvider)
     {
         ArgumentGuard.NotNull(controllerResourceMapping);
-
+        _nonPrimaryDocumentTypeFactory = new NonPrimaryDocumentTypeFactory(resourceFieldValidationMetadataProvider);
         _controllerResourceMapping = controllerResourceMapping;
     }
 
@@ -85,12 +87,12 @@ private static PrimaryRequestMetadata GetPatchRequestMetadata(Type resourceClrTy
         return new PrimaryRequestMetadata(documentType);
     }
 
-    private static RelationshipRequestMetadata GetRelationshipRequestMetadata(IEnumerable<RelationshipAttribute> relationships, bool ignoreHasOneRelationships)
+    private RelationshipRequestMetadata GetRelationshipRequestMetadata(IEnumerable<RelationshipAttribute> relationships, bool ignoreHasOneRelationships)
     {
         IEnumerable<RelationshipAttribute> relationshipsOfEndpoint = ignoreHasOneRelationships ? relationships.OfType<HasManyAttribute>() : relationships;
 
         IDictionary<string, Type> requestDocumentTypesByRelationshipName = relationshipsOfEndpoint.ToDictionary(relationship => relationship.PublicName,
-            NonPrimaryDocumentTypeFactory.Instance.GetForRelationshipRequest);
+            _nonPrimaryDocumentTypeFactory.GetForRelationshipRequest);
 
         return new RelationshipRequestMetadata(requestDocumentTypesByRelationshipName);
     }
@@ -129,18 +131,18 @@ private static PrimaryResponseMetadata GetPrimaryResponseMetadata(Type resourceC
         return new PrimaryResponseMetadata(documentType);
     }
 
-    private static SecondaryResponseMetadata GetSecondaryResponseMetadata(IEnumerable<RelationshipAttribute> relationships)
+    private SecondaryResponseMetadata GetSecondaryResponseMetadata(IEnumerable<RelationshipAttribute> relationships)
     {
         IDictionary<string, Type> responseDocumentTypesByRelationshipName = relationships.ToDictionary(relationship => relationship.PublicName,
-            NonPrimaryDocumentTypeFactory.Instance.GetForSecondaryResponse);
+            _nonPrimaryDocumentTypeFactory.GetForSecondaryResponse);
 
         return new SecondaryResponseMetadata(responseDocumentTypesByRelationshipName);
     }
 
-    private static RelationshipResponseMetadata GetRelationshipResponseMetadata(IEnumerable<RelationshipAttribute> relationships)
+    private RelationshipResponseMetadata GetRelationshipResponseMetadata(IEnumerable<RelationshipAttribute> relationships)
     {
         IDictionary<string, Type> responseDocumentTypesByRelationshipName = relationships.ToDictionary(relationship => relationship.PublicName,
-            NonPrimaryDocumentTypeFactory.Instance.GetForRelationshipResponse);
+            _nonPrimaryDocumentTypeFactory.GetForRelationshipResponse);
 
         return new RelationshipResponseMetadata(responseDocumentTypesByRelationshipName);
     }
diff --git a/src/JsonApiDotNetCore.OpenApi/JsonApiObjects/NonPrimaryDocumentTypeFactory.cs b/src/JsonApiDotNetCore.OpenApi/JsonApiObjects/NonPrimaryDocumentTypeFactory.cs
index 95d7e2f6e5..387c181f8b 100644
--- a/src/JsonApiDotNetCore.OpenApi/JsonApiObjects/NonPrimaryDocumentTypeFactory.cs
+++ b/src/JsonApiDotNetCore.OpenApi/JsonApiObjects/NonPrimaryDocumentTypeFactory.cs
@@ -15,10 +15,13 @@ internal sealed class NonPrimaryDocumentTypeFactory
     private static readonly DocumentOpenTypes RelationshipResponseDocumentOpenTypes = new(typeof(ResourceIdentifierCollectionResponseDocument<>),
         typeof(NullableResourceIdentifierResponseDocument<>), typeof(ResourceIdentifierResponseDocument<>));
 
-    public static NonPrimaryDocumentTypeFactory Instance { get; } = new();
+    private readonly ResourceFieldValidationMetadataProvider _resourceFieldValidationMetadataProvider;
 
-    private NonPrimaryDocumentTypeFactory()
+    public NonPrimaryDocumentTypeFactory(ResourceFieldValidationMetadataProvider resourceFieldValidationMetadataProvider)
     {
+        ArgumentGuard.NotNull(resourceFieldValidationMetadataProvider);
+
+        _resourceFieldValidationMetadataProvider = resourceFieldValidationMetadataProvider;
     }
 
     public Type GetForSecondaryResponse(RelationshipAttribute relationship)
@@ -42,13 +45,13 @@ public Type GetForRelationshipResponse(RelationshipAttribute relationship)
         return Get(relationship, RelationshipResponseDocumentOpenTypes);
     }
 
-    private static Type Get(RelationshipAttribute relationship, DocumentOpenTypes types)
+    private Type Get(RelationshipAttribute relationship, DocumentOpenTypes types)
     {
         // @formatter:nested_ternary_style expanded
 
         Type documentOpenType = relationship is HasManyAttribute
             ? types.ManyDataOpenType
-            : relationship.IsNullable()
+            : _resourceFieldValidationMetadataProvider.IsNullable(relationship)
                 ? types.NullableSingleDataOpenType
                 : types.SingleDataOpenType;
 
diff --git a/src/JsonApiDotNetCore.OpenApi/JsonApiObjects/RelationshipTypeFactory.cs b/src/JsonApiDotNetCore.OpenApi/JsonApiObjects/RelationshipTypeFactory.cs
index 7593c9f9f5..06efd7622f 100644
--- a/src/JsonApiDotNetCore.OpenApi/JsonApiObjects/RelationshipTypeFactory.cs
+++ b/src/JsonApiDotNetCore.OpenApi/JsonApiObjects/RelationshipTypeFactory.cs
@@ -5,17 +5,20 @@ namespace JsonApiDotNetCore.OpenApi.JsonApiObjects;
 
 internal sealed class RelationshipTypeFactory
 {
-    public static RelationshipTypeFactory Instance { get; } = new();
+    private readonly ResourceFieldValidationMetadataProvider _resourceFieldValidationMetadataProvider;
+    private readonly NonPrimaryDocumentTypeFactory _nonPrimaryDocumentTypeFactory;
 
-    private RelationshipTypeFactory()
+    public RelationshipTypeFactory(ResourceFieldValidationMetadataProvider resourceFieldValidationMetadataProvider)
     {
+        _nonPrimaryDocumentTypeFactory = new NonPrimaryDocumentTypeFactory(resourceFieldValidationMetadataProvider);
+        _resourceFieldValidationMetadataProvider = resourceFieldValidationMetadataProvider;
     }
 
     public Type GetForRequest(RelationshipAttribute relationship)
     {
         ArgumentGuard.NotNull(relationship);
 
-        return NonPrimaryDocumentTypeFactory.Instance.GetForRelationshipRequest(relationship);
+        return _nonPrimaryDocumentTypeFactory.GetForRelationshipRequest(relationship);
     }
 
     public Type GetForResponse(RelationshipAttribute relationship)
@@ -26,7 +29,7 @@ public Type GetForResponse(RelationshipAttribute relationship)
 
         Type relationshipDataOpenType = relationship is HasManyAttribute
             ? typeof(ToManyRelationshipInResponse<>)
-            : relationship.IsNullable()
+            : _resourceFieldValidationMetadataProvider.IsNullable(relationship)
                 ? typeof(NullableToOneRelationshipInResponse<>)
                 : typeof(ToOneRelationshipInResponse<>);
 
diff --git a/src/JsonApiDotNetCore.OpenApi/MemberInfoExtensions.cs b/src/JsonApiDotNetCore.OpenApi/MemberInfoExtensions.cs
deleted file mode 100644
index f13c91e837..0000000000
--- a/src/JsonApiDotNetCore.OpenApi/MemberInfoExtensions.cs
+++ /dev/null
@@ -1,36 +0,0 @@
-using System.Reflection;
-using Swashbuckle.AspNetCore.SwaggerGen;
-
-namespace JsonApiDotNetCore.OpenApi;
-
-internal static class MemberInfoExtensions
-{
-    public static TypeCategory GetTypeCategory(this MemberInfo source)
-    {
-        ArgumentGuard.NotNull(source);
-
-        Type memberType;
-
-        if (source.MemberType.HasFlag(MemberTypes.Field))
-        {
-            memberType = ((FieldInfo)source).FieldType;
-        }
-        else if (source.MemberType.HasFlag(MemberTypes.Property))
-        {
-            memberType = ((PropertyInfo)source).PropertyType;
-        }
-        else
-        {
-            throw new NotSupportedException($"Member type '{source.MemberType}' must be a property or field.");
-        }
-
-        if (memberType.IsValueType)
-        {
-            return Nullable.GetUnderlyingType(memberType) != null ? TypeCategory.NullableValueType : TypeCategory.ValueType;
-        }
-
-        // Once we switch to .NET 6, we should rely instead on the built-in reflection APIs for nullability information.
-        // See https://devblogs.microsoft.com/dotnet/announcing-net-6-preview-7/#libraries-reflection-apis-for-nullability-information.
-        return source.IsNonNullableReferenceType() ? TypeCategory.NonNullableReferenceType : TypeCategory.NullableReferenceType;
-    }
-}
diff --git a/src/JsonApiDotNetCore.OpenApi/OpenApiSchemaExtensions.cs b/src/JsonApiDotNetCore.OpenApi/OpenApiSchemaExtensions.cs
new file mode 100644
index 0000000000..e86c2c7423
--- /dev/null
+++ b/src/JsonApiDotNetCore.OpenApi/OpenApiSchemaExtensions.cs
@@ -0,0 +1,18 @@
+using Microsoft.OpenApi.Models;
+
+namespace JsonApiDotNetCore.OpenApi;
+
+internal static class OpenApiSchemaExtensions
+{
+    public static OpenApiSchema UnwrapExtendedReferenceSchema(this OpenApiSchema source)
+    {
+        ArgumentGuard.NotNull(source);
+
+        if (source.AllOf.Count != 1)
+        {
+            throw new InvalidOperationException($"Schema '{nameof(source)}' should not contain multiple entries in '{nameof(source.AllOf)}' ");
+        }
+
+        return source.AllOf.Single();
+    }
+}
diff --git a/src/JsonApiDotNetCore.OpenApi/ResourceFieldAttributeExtensions.cs b/src/JsonApiDotNetCore.OpenApi/ResourceFieldAttributeExtensions.cs
deleted file mode 100644
index 32bf9f5187..0000000000
--- a/src/JsonApiDotNetCore.OpenApi/ResourceFieldAttributeExtensions.cs
+++ /dev/null
@@ -1,21 +0,0 @@
-using System.ComponentModel.DataAnnotations;
-using JsonApiDotNetCore.Resources.Annotations;
-using Swashbuckle.AspNetCore.SwaggerGen;
-
-namespace JsonApiDotNetCore.OpenApi;
-
-internal static class ResourceFieldAttributeExtensions
-{
-    public static bool IsNullable(this ResourceFieldAttribute source)
-    {
-        TypeCategory fieldTypeCategory = source.Property.GetTypeCategory();
-        bool hasRequiredAttribute = source.Property.HasAttribute<RequiredAttribute>();
-
-        return fieldTypeCategory switch
-        {
-            TypeCategory.NonNullableReferenceType or TypeCategory.ValueType => false,
-            TypeCategory.NullableReferenceType or TypeCategory.NullableValueType => !hasRequiredAttribute,
-            _ => throw new UnreachableCodeException()
-        };
-    }
-}
diff --git a/src/JsonApiDotNetCore.OpenApi/ResourceFieldValidationMetadataProvider.cs b/src/JsonApiDotNetCore.OpenApi/ResourceFieldValidationMetadataProvider.cs
new file mode 100644
index 0000000000..bfbe32bb31
--- /dev/null
+++ b/src/JsonApiDotNetCore.OpenApi/ResourceFieldValidationMetadataProvider.cs
@@ -0,0 +1,92 @@
+using System.ComponentModel.DataAnnotations;
+using System.Reflection;
+using JsonApiDotNetCore.Configuration;
+using JsonApiDotNetCore.Resources.Annotations;
+using Microsoft.AspNetCore.Mvc.ModelBinding;
+using Swashbuckle.AspNetCore.SwaggerGen;
+
+namespace JsonApiDotNetCore.OpenApi;
+
+internal sealed class ResourceFieldValidationMetadataProvider
+{
+    private readonly bool _validateModelState;
+    private readonly NullabilityInfoContext _nullabilityContext;
+    private readonly IModelMetadataProvider _modelMetadataProvider;
+
+    public ResourceFieldValidationMetadataProvider(IJsonApiOptions options, IModelMetadataProvider modelMetadataProvider)
+    {
+        ArgumentGuard.NotNull(options);
+        ArgumentGuard.NotNull(modelMetadataProvider);
+
+        _validateModelState = options.ValidateModelState;
+        _modelMetadataProvider = modelMetadataProvider;
+        _nullabilityContext = new NullabilityInfoContext();
+    }
+
+    public bool IsNullable(ResourceFieldAttribute field)
+    {
+        ArgumentGuard.NotNull(field);
+
+        if (field is HasManyAttribute)
+        {
+            return false;
+        }
+
+        bool hasRequiredAttribute = field.Property.HasAttribute<RequiredAttribute>();
+        NullabilityInfo nullabilityInfo = _nullabilityContext.Create(field.Property);
+
+        if (field is HasManyAttribute)
+        {
+            return false;
+        }
+
+        if (hasRequiredAttribute && _validateModelState && nullabilityInfo.ReadState != NullabilityState.NotNull)
+        {
+            return false;
+        }
+
+        return nullabilityInfo.ReadState != NullabilityState.NotNull;
+    }
+
+    public bool IsRequired(ResourceFieldAttribute field)
+    {
+        ArgumentGuard.NotNull(field);
+
+        bool hasRequiredAttribute = field.Property.HasAttribute<RequiredAttribute>();
+
+        if (!_validateModelState)
+        {
+            return hasRequiredAttribute;
+        }
+
+        if (field is HasManyAttribute)
+        {
+            return false;
+        }
+
+        bool isNotNull = HasNullabilityStateNotNull(field);
+        bool isRequiredValueType = field.Property.PropertyType.IsValueType && hasRequiredAttribute && isNotNull;
+
+        if (isRequiredValueType)
+        {
+            return false;
+        }
+
+        return IsModelStateValidationRequired(field);
+    }
+
+    private bool IsModelStateValidationRequired(ResourceFieldAttribute field)
+    {
+        ModelMetadata resourceFieldModelMetadata = _modelMetadataProvider.GetMetadataForProperties(field.Type.ClrType)
+            .Single(modelMetadata => modelMetadata.PropertyName! == field.Property.Name);
+
+        return resourceFieldModelMetadata.ValidatorMetadata.Any(validatorMetadata => validatorMetadata is RequiredAttribute);
+    }
+
+    private bool HasNullabilityStateNotNull(ResourceFieldAttribute field)
+    {
+        NullabilityInfo resourceFieldNullabilityInfo = _nullabilityContext.Create(field.Property);
+        bool hasNullabilityStateNotNull = resourceFieldNullabilityInfo is { ReadState: NullabilityState.NotNull, WriteState: NullabilityState.NotNull };
+        return hasNullabilityStateNotNull;
+    }
+}
diff --git a/src/JsonApiDotNetCore.OpenApi/ServiceCollectionExtensions.cs b/src/JsonApiDotNetCore.OpenApi/ServiceCollectionExtensions.cs
index f223c7d994..9a76adb7e5 100644
--- a/src/JsonApiDotNetCore.OpenApi/ServiceCollectionExtensions.cs
+++ b/src/JsonApiDotNetCore.OpenApi/ServiceCollectionExtensions.cs
@@ -34,13 +34,18 @@ public static void AddOpenApi(this IServiceCollection services, IMvcCoreBuilder
 
     private static void AddCustomApiExplorer(IServiceCollection services, IMvcCoreBuilder mvcBuilder)
     {
+        services.AddSingleton<ResourceFieldValidationMetadataProvider>();
+
         services.AddSingleton<IApiDescriptionGroupCollectionProvider>(provider =>
         {
             var controllerResourceMapping = provider.GetRequiredService<IControllerResourceMapping>();
             var actionDescriptorCollectionProvider = provider.GetRequiredService<IActionDescriptorCollectionProvider>();
             var apiDescriptionProviders = provider.GetRequiredService<IEnumerable<IApiDescriptionProvider>>();
+            var resourceFieldValidationMetadataProvider = provider.GetRequiredService<ResourceFieldValidationMetadataProvider>();
+
+            JsonApiActionDescriptorCollectionProvider descriptorCollectionProviderWrapper =
+                new(controllerResourceMapping, actionDescriptorCollectionProvider, resourceFieldValidationMetadataProvider);
 
-            JsonApiActionDescriptorCollectionProvider descriptorCollectionProviderWrapper = new(controllerResourceMapping, actionDescriptorCollectionProvider);
             return new ApiDescriptionGroupCollectionProvider(descriptorCollectionProviderWrapper, apiDescriptionProviders);
         });
 
@@ -64,6 +69,7 @@ private static void AddSwaggerGenerator(IServiceScope scope, IServiceCollection
             SetOperationInfo(swaggerGenOptions, controllerResourceMapping, namingPolicy);
             SetSchemaIdSelector(swaggerGenOptions, resourceGraph, namingPolicy);
             swaggerGenOptions.DocumentFilter<EndpointOrderingFilter>();
+            swaggerGenOptions.UseAllOfToExtendReferenceSchemas();
 
             setupSwaggerGenAction?.Invoke(swaggerGenOptions);
         });
diff --git a/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/JsonApiSchemaGenerator.cs b/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/JsonApiSchemaGenerator.cs
index b4abe196ca..b2bf21db1b 100644
--- a/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/JsonApiSchemaGenerator.cs
+++ b/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/JsonApiSchemaGenerator.cs
@@ -27,20 +27,28 @@ internal sealed class JsonApiSchemaGenerator : ISchemaGenerator
         typeof(NullableToOneRelationshipInRequest<>)
     };
 
+    private static readonly Type[] JsonApiDocumentWithNullableDataOpenTypes =
+    {
+        typeof(NullableSecondaryResourceResponseDocument<>),
+        typeof(NullableResourceIdentifierResponseDocument<>),
+        typeof(NullableToOneRelationshipInRequest<>)
+    };
+
     private readonly ISchemaGenerator _defaultSchemaGenerator;
     private readonly ResourceObjectSchemaGenerator _resourceObjectSchemaGenerator;
-    private readonly NullableReferenceSchemaGenerator _nullableReferenceSchemaGenerator;
     private readonly SchemaRepositoryAccessor _schemaRepositoryAccessor = new();
 
-    public JsonApiSchemaGenerator(SchemaGenerator defaultSchemaGenerator, IResourceGraph resourceGraph, IJsonApiOptions options)
+    public JsonApiSchemaGenerator(SchemaGenerator defaultSchemaGenerator, IResourceGraph resourceGraph, IJsonApiOptions options,
+        ResourceFieldValidationMetadataProvider resourceFieldValidationMetadataProvider)
     {
         ArgumentGuard.NotNull(defaultSchemaGenerator);
         ArgumentGuard.NotNull(resourceGraph);
         ArgumentGuard.NotNull(options);
 
         _defaultSchemaGenerator = defaultSchemaGenerator;
-        _nullableReferenceSchemaGenerator = new NullableReferenceSchemaGenerator(_schemaRepositoryAccessor, options.SerializerOptions.PropertyNamingPolicy);
-        _resourceObjectSchemaGenerator = new ResourceObjectSchemaGenerator(defaultSchemaGenerator, resourceGraph, options, _schemaRepositoryAccessor);
+
+        _resourceObjectSchemaGenerator = new ResourceObjectSchemaGenerator(defaultSchemaGenerator, resourceGraph, options, _schemaRepositoryAccessor,
+            resourceFieldValidationMetadataProvider);
     }
 
     public OpenApiSchema GenerateSchema(Type modelType, SchemaRepository schemaRepository, MemberInfo? memberInfo = null, ParameterInfo? parameterInfo = null,
@@ -53,17 +61,23 @@ public OpenApiSchema GenerateSchema(Type modelType, SchemaRepository schemaRepos
 
         if (schemaRepository.TryLookupByType(modelType, out OpenApiSchema jsonApiDocumentSchema))
         {
-            return jsonApiDocumentSchema;
+            // For unknown reasons, Swashbuckle chooses to wrap root request bodies, but not response bodies. See 
+            // https://github.com/domaindrivendev/Swashbuckle.AspNetCore/issues/861#issuecomment-1373631712
+            return memberInfo != null || parameterInfo != null
+                ? _defaultSchemaGenerator.GenerateSchema(modelType, schemaRepository, memberInfo, parameterInfo)
+                : jsonApiDocumentSchema;
         }
 
         if (IsJsonApiDocument(modelType))
         {
             OpenApiSchema schema = GenerateJsonApiDocumentSchema(modelType);
 
-            if (IsDataPropertyNullable(modelType))
+            if (IsDataPropertyNullableInDocument(modelType))
             {
                 SetDataObjectSchemaToNullable(schema);
             }
+
+            // Schema might depend on other schemas not handled by us, so should not return here.
         }
 
         return _defaultSchemaGenerator.GenerateSchema(modelType, schemaRepository, memberInfo, parameterInfo);
@@ -88,7 +102,7 @@ private OpenApiSchema GenerateJsonApiDocumentSchema(Type documentType)
 
         OpenApiSchema referenceSchemaForDataObject = IsManyDataDocument(documentType)
             ? CreateArrayTypeDataSchema(referenceSchemaForResourceObject)
-            : referenceSchemaForResourceObject;
+            : CreateExtendedReferenceSchema(referenceSchemaForResourceObject);
 
         fullSchemaForDocument.Properties[JsonApiObjectPropertyName.Data] = referenceSchemaForDataObject;
 
@@ -100,25 +114,19 @@ private static bool IsManyDataDocument(Type documentType)
         return documentType.BaseType!.GetGenericTypeDefinition() == typeof(ManyData<>);
     }
 
-    private static bool IsDataPropertyNullable(Type type)
+    private static bool IsDataPropertyNullableInDocument(Type documentType)
     {
-        PropertyInfo? dataProperty = type.GetProperty(nameof(JsonApiObjectPropertyName.Data));
-
-        if (dataProperty == null)
-        {
-            throw new UnreachableCodeException();
-        }
-
-        TypeCategory typeCategory = dataProperty.GetTypeCategory();
+        Type documentOpenType = documentType.GetGenericTypeDefinition();
 
-        return typeCategory == TypeCategory.NullableReferenceType;
+        return JsonApiDocumentWithNullableDataOpenTypes.Contains(documentOpenType);
     }
 
     private void SetDataObjectSchemaToNullable(OpenApiSchema referenceSchemaForDocument)
     {
         OpenApiSchema fullSchemaForDocument = _schemaRepositoryAccessor.Current.Schemas[referenceSchemaForDocument.Reference.Id];
         OpenApiSchema referenceSchemaForData = fullSchemaForDocument.Properties[JsonApiObjectPropertyName.Data];
-        fullSchemaForDocument.Properties[JsonApiObjectPropertyName.Data] = _nullableReferenceSchemaGenerator.GenerateSchema(referenceSchemaForData);
+        referenceSchemaForData.Nullable = true;
+        fullSchemaForDocument.Properties[JsonApiObjectPropertyName.Data] = referenceSchemaForData;
     }
 
     private static OpenApiSchema CreateArrayTypeDataSchema(OpenApiSchema referenceSchemaForResourceObject)
@@ -129,4 +137,15 @@ private static OpenApiSchema CreateArrayTypeDataSchema(OpenApiSchema referenceSc
             Type = "array"
         };
     }
+
+    private static OpenApiSchema CreateExtendedReferenceSchema(OpenApiSchema referenceSchemaForResourceObject)
+    {
+        return new OpenApiSchema
+        {
+            AllOf = new List<OpenApiSchema>
+            {
+                referenceSchemaForResourceObject
+            }
+        };
+    }
 }
diff --git a/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/NullableReferenceSchemaGenerator.cs b/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/NullableReferenceSchemaGenerator.cs
deleted file mode 100644
index 4e09769e87..0000000000
--- a/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/NullableReferenceSchemaGenerator.cs
+++ /dev/null
@@ -1,104 +0,0 @@
-using System.Text.Json;
-using Microsoft.OpenApi.Models;
-
-namespace JsonApiDotNetCore.OpenApi.SwaggerComponents;
-
-internal sealed class NullableReferenceSchemaGenerator
-{
-    private const string PascalCaseNullableSchemaReferenceId = "NullValue";
-
-    private readonly NullableReferenceSchemaStrategy _nullableReferenceStrategy =
-        Enum.Parse<NullableReferenceSchemaStrategy>(NullableReferenceSchemaStrategy.Implicit.ToString());
-
-    private readonly ISchemaRepositoryAccessor _schemaRepositoryAccessor;
-    private readonly string _nullableSchemaReferenceId;
-
-    private OpenApiSchema? _referenceSchemaForExplicitNullValue;
-
-    public NullableReferenceSchemaGenerator(ISchemaRepositoryAccessor schemaRepositoryAccessor, JsonNamingPolicy? namingPolicy)
-    {
-        ArgumentGuard.NotNull(schemaRepositoryAccessor);
-
-        _schemaRepositoryAccessor = schemaRepositoryAccessor;
-
-        _nullableSchemaReferenceId = namingPolicy != null ? namingPolicy.ConvertName(PascalCaseNullableSchemaReferenceId) : PascalCaseNullableSchemaReferenceId;
-    }
-
-    public OpenApiSchema GenerateSchema(OpenApiSchema referenceSchema)
-    {
-        ArgumentGuard.NotNull(referenceSchema);
-
-        return new OpenApiSchema
-        {
-            OneOf = new List<OpenApiSchema>
-            {
-                referenceSchema,
-                _nullableReferenceStrategy == NullableReferenceSchemaStrategy.Explicit ? GetExplicitNullSchema() : GetImplicitNullSchema()
-            }
-        };
-    }
-
-    // This approach is supported in OAS starting from v3.1. See https://github.com/OAI/OpenAPI-Specification/issues/1368#issuecomment-580103688
-    private static OpenApiSchema GetExplicitNullSchema()
-    {
-        return new OpenApiSchema
-        {
-            Type = "null"
-        };
-    }
-
-    // This approach is supported starting from OAS v3.0. See https://github.com/OAI/OpenAPI-Specification/issues/1368#issuecomment-487314681
-    private OpenApiSchema GetImplicitNullSchema()
-    {
-        EnsureFullSchemaForNullValueExists();
-
-        return _referenceSchemaForExplicitNullValue ??= new OpenApiSchema
-        {
-            Reference = new OpenApiReference
-            {
-                Id = _nullableSchemaReferenceId,
-                Type = ReferenceType.Schema
-            }
-        };
-    }
-
-    private void EnsureFullSchemaForNullValueExists()
-    {
-        if (!_schemaRepositoryAccessor.Current.Schemas.ContainsKey(_nullableSchemaReferenceId))
-        {
-            var fullSchemaForNullValue = new OpenApiSchema
-            {
-                Nullable = true,
-                Not = new OpenApiSchema
-                {
-                    AnyOf = new List<OpenApiSchema>
-                    {
-                        new()
-                        {
-                            Type = "string"
-                        },
-                        new()
-                        {
-                            Type = "number"
-                        },
-                        new()
-                        {
-                            Type = "boolean"
-                        },
-                        new()
-                        {
-                            Type = "object"
-                        },
-                        new()
-                        {
-                            Type = "array"
-                        }
-                    },
-                    Items = new OpenApiSchema()
-                }
-            };
-
-            _schemaRepositoryAccessor.Current.AddDefinition(_nullableSchemaReferenceId, fullSchemaForNullValue);
-        }
-    }
-}
diff --git a/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/NullableReferenceSchemaStrategy.cs b/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/NullableReferenceSchemaStrategy.cs
deleted file mode 100644
index 282b4a282b..0000000000
--- a/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/NullableReferenceSchemaStrategy.cs
+++ /dev/null
@@ -1,7 +0,0 @@
-namespace JsonApiDotNetCore.OpenApi.SwaggerComponents;
-
-internal enum NullableReferenceSchemaStrategy
-{
-    Implicit,
-    Explicit
-}
diff --git a/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/ResourceFieldObjectSchemaBuilder.cs b/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/ResourceFieldObjectSchemaBuilder.cs
index 48e65d721c..6959e17284 100644
--- a/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/ResourceFieldObjectSchemaBuilder.cs
+++ b/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/ResourceFieldObjectSchemaBuilder.cs
@@ -1,6 +1,4 @@
-using System.ComponentModel.DataAnnotations;
 using System.Reflection;
-using System.Text.Json;
 using JsonApiDotNetCore.OpenApi.JsonApiObjects;
 using JsonApiDotNetCore.OpenApi.JsonApiObjects.Relationships;
 using JsonApiDotNetCore.OpenApi.JsonApiObjects.ResourceObjects;
@@ -12,35 +10,46 @@ namespace JsonApiDotNetCore.OpenApi.SwaggerComponents;
 
 internal sealed class ResourceFieldObjectSchemaBuilder
 {
-    private static readonly Type[] RelationshipInResponseOpenTypes =
+    private static readonly Type[] RelationshipSchemaInResponseOpenTypes =
     {
         typeof(ToOneRelationshipInResponse<>),
         typeof(ToManyRelationshipInResponse<>),
         typeof(NullableToOneRelationshipInResponse<>)
     };
 
+    private static readonly Type[] NullableRelationshipSchemaOpenTypes =
+    {
+        typeof(NullableToOneRelationshipInRequest<>),
+        typeof(NullableToOneRelationshipInResponse<>)
+    };
+
     private readonly ResourceTypeInfo _resourceTypeInfo;
     private readonly ISchemaRepositoryAccessor _schemaRepositoryAccessor;
     private readonly SchemaGenerator _defaultSchemaGenerator;
     private readonly ResourceTypeSchemaGenerator _resourceTypeSchemaGenerator;
     private readonly SchemaRepository _resourceSchemaRepository = new();
-    private readonly NullableReferenceSchemaGenerator _nullableReferenceSchemaGenerator;
     private readonly IDictionary<string, OpenApiSchema> _schemasForResourceFields;
+    private readonly ResourceFieldValidationMetadataProvider _resourceFieldValidationMetadataProvider;
+    private readonly RelationshipTypeFactory _relationshipTypeFactory;
+    private readonly NullabilityInfoContext _nullabilityInfoContext = new();
 
     public ResourceFieldObjectSchemaBuilder(ResourceTypeInfo resourceTypeInfo, ISchemaRepositoryAccessor schemaRepositoryAccessor,
-        SchemaGenerator defaultSchemaGenerator, ResourceTypeSchemaGenerator resourceTypeSchemaGenerator, JsonNamingPolicy? namingPolicy)
+        SchemaGenerator defaultSchemaGenerator, ResourceTypeSchemaGenerator resourceTypeSchemaGenerator,
+        ResourceFieldValidationMetadataProvider resourceFieldValidationMetadataProvider)
     {
         ArgumentGuard.NotNull(resourceTypeInfo);
         ArgumentGuard.NotNull(schemaRepositoryAccessor);
         ArgumentGuard.NotNull(defaultSchemaGenerator);
         ArgumentGuard.NotNull(resourceTypeSchemaGenerator);
+        ArgumentGuard.NotNull(resourceFieldValidationMetadataProvider);
 
         _resourceTypeInfo = resourceTypeInfo;
         _schemaRepositoryAccessor = schemaRepositoryAccessor;
         _defaultSchemaGenerator = defaultSchemaGenerator;
         _resourceTypeSchemaGenerator = resourceTypeSchemaGenerator;
+        _resourceFieldValidationMetadataProvider = resourceFieldValidationMetadataProvider;
 
-        _nullableReferenceSchemaGenerator = new NullableReferenceSchemaGenerator(schemaRepositoryAccessor, namingPolicy);
+        _relationshipTypeFactory = new RelationshipTypeFactory(resourceFieldValidationMetadataProvider);
         _schemasForResourceFields = GetFieldSchemas();
     }
 
@@ -65,9 +74,17 @@ public void SetMembersOfAttributesObject(OpenApiSchema fullSchemaForAttributesOb
 
             if (matchingAttribute != null && matchingAttribute.Capabilities.HasFlag(requiredCapability))
             {
-                AddAttributeSchemaToResourceObject(matchingAttribute, fullSchemaForAttributesObject, resourceFieldSchema);
+                bool isPrimitiveOpenApiType = resourceFieldSchema.AllOf.IsNullOrEmpty();
+
+                // Types like enum and and complex attributes are not primitive and handles as reference schemas. 
+                if (!isPrimitiveOpenApiType)
+                {
+                    EnsureAttributeSchemaIsExposed(resourceFieldSchema, matchingAttribute);
+                }
 
-                resourceFieldSchema.Nullable = matchingAttribute.IsNullable();
+                fullSchemaForAttributesObject.Properties[matchingAttribute.PublicName] = resourceFieldSchema;
+
+                resourceFieldSchema.Nullable = _resourceFieldValidationMetadataProvider.IsNullable(matchingAttribute);
 
                 if (IsFieldRequired(matchingAttribute))
                 {
@@ -84,40 +101,40 @@ private static AttrCapabilities GetRequiredCapabilityForAttributes(Type resource
             resourceObjectOpenType == typeof(ResourceObjectInPatchRequest<>) ? AttrCapabilities.AllowChange : throw new UnreachableCodeException();
     }
 
-    private void AddAttributeSchemaToResourceObject(AttrAttribute attribute, OpenApiSchema attributesObjectSchema, OpenApiSchema resourceAttributeSchema)
+    private void EnsureAttributeSchemaIsExposed(OpenApiSchema attributeReferenceSchema, AttrAttribute attribute)
     {
-        if (resourceAttributeSchema.Reference != null && !_schemaRepositoryAccessor.Current.TryLookupByType(attribute.Property.PropertyType, out _))
+        Type nonNullableTypeInPropertyType = GetRepresentedTypeForAttributeSchema(attribute);
+
+        if (_schemaRepositoryAccessor.Current.TryLookupByType(nonNullableTypeInPropertyType, out _))
         {
-            ExposeSchema(resourceAttributeSchema.Reference, attribute.Property.PropertyType);
+            return;
         }
 
-        attributesObjectSchema.Properties.Add(attribute.PublicName, resourceAttributeSchema);
+        string schemaId = attributeReferenceSchema.UnwrapExtendedReferenceSchema().Reference.Id;
+
+        OpenApiSchema fullSchema = _resourceSchemaRepository.Schemas[schemaId];
+        _schemaRepositoryAccessor.Current.AddDefinition(schemaId, fullSchema);
+        _schemaRepositoryAccessor.Current.RegisterType(nonNullableTypeInPropertyType, schemaId);
     }
 
-    private void ExposeSchema(OpenApiReference openApiReference, Type typeRepresentedBySchema)
+    private Type GetRepresentedTypeForAttributeSchema(AttrAttribute attribute)
     {
-        OpenApiSchema fullSchema = _resourceSchemaRepository.Schemas[openApiReference.Id];
-        _schemaRepositoryAccessor.Current.AddDefinition(openApiReference.Id, fullSchema);
-        _schemaRepositoryAccessor.Current.RegisterType(typeRepresentedBySchema, openApiReference.Id);
+        NullabilityInfo attributeNullabilityInfo = _nullabilityInfoContext.Create(attribute.Property);
+
+        bool isNullable = attributeNullabilityInfo is { ReadState: NullabilityState.Nullable, WriteState: NullabilityState.Nullable };
+
+        Type nonNullableTypeInPropertyType = isNullable
+            ? Nullable.GetUnderlyingType(attribute.Property.PropertyType) ?? attribute.Property.PropertyType
+            : attribute.Property.PropertyType;
+
+        return nonNullableTypeInPropertyType;
     }
 
     private bool IsFieldRequired(ResourceFieldAttribute field)
     {
-        if (field is HasManyAttribute || _resourceTypeInfo.ResourceObjectOpenType != typeof(ResourceObjectInPostRequest<>))
-        {
-            return false;
-        }
-
-        TypeCategory fieldTypeCategory = field.Property.GetTypeCategory();
-        bool hasRequiredAttribute = field.Property.HasAttribute<RequiredAttribute>();
+        bool isSchemaForUpdateResourceEndpoint = _resourceTypeInfo.ResourceObjectOpenType == typeof(ResourceObjectInPatchRequest<>);
 
-        return fieldTypeCategory switch
-        {
-            TypeCategory.NonNullableReferenceType => true,
-            TypeCategory.ValueType => hasRequiredAttribute,
-            TypeCategory.NullableReferenceType or TypeCategory.NullableValueType => hasRequiredAttribute,
-            _ => throw new UnreachableCodeException()
-        };
+        return !isSchemaForUpdateResourceEndpoint && _resourceFieldValidationMetadataProvider.IsRequired(field);
     }
 
     public void SetMembersOfRelationshipsObject(OpenApiSchema fullSchemaForRelationshipsObject)
@@ -165,9 +182,18 @@ private void AddRelationshipSchemaToResourceObject(RelationshipAttribute relatio
     {
         Type relationshipSchemaType = GetRelationshipSchemaType(relationship, _resourceTypeInfo.ResourceObjectOpenType);
 
-        OpenApiSchema relationshipSchema = GetReferenceSchemaForRelationship(relationshipSchemaType) ?? CreateRelationshipSchema(relationshipSchemaType);
+        OpenApiSchema referenceSchemaForRelationship =
+            GetReferenceSchemaForRelationship(relationshipSchemaType) ?? CreateRelationshipReferenceSchema(relationshipSchemaType);
+
+        var extendedReferenceSchemaForRelationship = new OpenApiSchema
+        {
+            AllOf = new List<OpenApiSchema>
+            {
+                referenceSchemaForRelationship
+            }
+        };
 
-        fullSchemaForRelationshipsObject.Properties.Add(relationship.PublicName, relationshipSchema);
+        fullSchemaForRelationshipsObject.Properties.Add(relationship.PublicName, extendedReferenceSchemaForRelationship);
 
         if (IsFieldRequired(relationship))
         {
@@ -175,11 +201,11 @@ private void AddRelationshipSchemaToResourceObject(RelationshipAttribute relatio
         }
     }
 
-    private static Type GetRelationshipSchemaType(RelationshipAttribute relationship, Type resourceObjectType)
+    private Type GetRelationshipSchemaType(RelationshipAttribute relationship, Type resourceObjectType)
     {
         return resourceObjectType.GetGenericTypeDefinition().IsAssignableTo(typeof(ResourceObjectInResponse<>))
-            ? RelationshipTypeFactory.Instance.GetForResponse(relationship)
-            : RelationshipTypeFactory.Instance.GetForRequest(relationship);
+            ? _relationshipTypeFactory.GetForResponse(relationship)
+            : _relationshipTypeFactory.GetForRequest(relationship);
     }
 
     private OpenApiSchema? GetReferenceSchemaForRelationship(Type relationshipSchemaType)
@@ -188,16 +214,15 @@ private static Type GetRelationshipSchemaType(RelationshipAttribute relationship
         return referenceSchema;
     }
 
-    private OpenApiSchema CreateRelationshipSchema(Type relationshipSchemaType)
+    private OpenApiSchema CreateRelationshipReferenceSchema(Type relationshipSchemaType)
     {
         OpenApiSchema referenceSchema = _defaultSchemaGenerator.GenerateSchema(relationshipSchemaType, _schemaRepositoryAccessor.Current);
 
         OpenApiSchema fullSchema = _schemaRepositoryAccessor.Current.Schemas[referenceSchema.Reference.Id];
 
-        if (IsDataPropertyNullable(relationshipSchemaType))
+        if (IsDataPropertyNullableInRelationshipSchemaType(relationshipSchemaType))
         {
-            fullSchema.Properties[JsonApiObjectPropertyName.Data] =
-                _nullableReferenceSchemaGenerator.GenerateSchema(fullSchema.Properties[JsonApiObjectPropertyName.Data]);
+            fullSchema.Properties[JsonApiObjectPropertyName.Data].Nullable = true;
         }
 
         if (IsRelationshipInResponseType(relationshipSchemaType))
@@ -212,18 +237,12 @@ private static bool IsRelationshipInResponseType(Type relationshipSchemaType)
     {
         Type relationshipSchemaOpenType = relationshipSchemaType.GetGenericTypeDefinition();
 
-        return RelationshipInResponseOpenTypes.Contains(relationshipSchemaOpenType);
+        return RelationshipSchemaInResponseOpenTypes.Contains(relationshipSchemaOpenType);
     }
 
-    private static bool IsDataPropertyNullable(Type type)
+    private static bool IsDataPropertyNullableInRelationshipSchemaType(Type relationshipSchemaType)
     {
-        PropertyInfo? dataProperty = type.GetProperty(nameof(JsonApiObjectPropertyName.Data));
-
-        if (dataProperty == null)
-        {
-            throw new UnreachableCodeException();
-        }
-
-        return dataProperty.GetTypeCategory() == TypeCategory.NullableReferenceType;
+        Type relationshipSchemaOpenType = relationshipSchemaType.GetGenericTypeDefinition();
+        return NullableRelationshipSchemaOpenTypes.Contains(relationshipSchemaOpenType);
     }
 }
diff --git a/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/ResourceObjectSchemaGenerator.cs b/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/ResourceObjectSchemaGenerator.cs
index 090fcea2dd..ca6cfafdab 100644
--- a/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/ResourceObjectSchemaGenerator.cs
+++ b/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/ResourceObjectSchemaGenerator.cs
@@ -15,7 +15,7 @@ internal sealed class ResourceObjectSchemaGenerator
     private readonly Func<ResourceTypeInfo, ResourceFieldObjectSchemaBuilder> _resourceFieldObjectSchemaBuilderFactory;
 
     public ResourceObjectSchemaGenerator(SchemaGenerator defaultSchemaGenerator, IResourceGraph resourceGraph, IJsonApiOptions options,
-        ISchemaRepositoryAccessor schemaRepositoryAccessor)
+        ISchemaRepositoryAccessor schemaRepositoryAccessor, ResourceFieldValidationMetadataProvider resourceFieldValidationMetadataProvider)
     {
         ArgumentGuard.NotNull(defaultSchemaGenerator);
         ArgumentGuard.NotNull(resourceGraph);
@@ -31,7 +31,7 @@ public ResourceObjectSchemaGenerator(SchemaGenerator defaultSchemaGenerator, IRe
         _allowClientGeneratedIds = options.AllowClientGeneratedIds;
 
         _resourceFieldObjectSchemaBuilderFactory = resourceTypeInfo => new ResourceFieldObjectSchemaBuilder(resourceTypeInfo, schemaRepositoryAccessor,
-            defaultSchemaGenerator, _resourceTypeSchemaGenerator, options.SerializerOptions.PropertyNamingPolicy);
+            defaultSchemaGenerator, _resourceTypeSchemaGenerator, resourceFieldValidationMetadataProvider);
     }
 
     public OpenApiSchema GenerateSchema(Type resourceObjectType)
@@ -92,7 +92,9 @@ private void SetResourceType(OpenApiSchema fullSchemaForResourceObject, Type res
 
     private void SetResourceAttributes(OpenApiSchema fullSchemaForResourceObject, ResourceFieldObjectSchemaBuilder builder)
     {
-        OpenApiSchema referenceSchemaForAttributesObject = fullSchemaForResourceObject.Properties[JsonApiObjectPropertyName.AttributesObject];
+        OpenApiSchema referenceSchemaForAttributesObject =
+            fullSchemaForResourceObject.Properties[JsonApiObjectPropertyName.AttributesObject].UnwrapExtendedReferenceSchema();
+
         OpenApiSchema fullSchemaForAttributesObject = _schemaRepositoryAccessor.Current.Schemas[referenceSchemaForAttributesObject.Reference.Id];
 
         builder.SetMembersOfAttributesObject(fullSchemaForAttributesObject);
@@ -110,7 +112,9 @@ private void SetResourceAttributes(OpenApiSchema fullSchemaForResourceObject, Re
 
     private void SetResourceRelationships(OpenApiSchema fullSchemaForResourceObject, ResourceFieldObjectSchemaBuilder builder)
     {
-        OpenApiSchema referenceSchemaForRelationshipsObject = fullSchemaForResourceObject.Properties[JsonApiObjectPropertyName.RelationshipsObject];
+        OpenApiSchema referenceSchemaForRelationshipsObject =
+            fullSchemaForResourceObject.Properties[JsonApiObjectPropertyName.RelationshipsObject].UnwrapExtendedReferenceSchema();
+
         OpenApiSchema fullSchemaForRelationshipsObject = _schemaRepositoryAccessor.Current.Schemas[referenceSchemaForRelationshipsObject.Reference.Id];
 
         builder.SetMembersOfRelationshipsObject(fullSchemaForRelationshipsObject);
diff --git a/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/ResourceTypeSchemaGenerator.cs b/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/ResourceTypeSchemaGenerator.cs
index 592a8ed860..6db24901b2 100644
--- a/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/ResourceTypeSchemaGenerator.cs
+++ b/src/JsonApiDotNetCore.OpenApi/SwaggerComponents/ResourceTypeSchemaGenerator.cs
@@ -28,9 +28,9 @@ public OpenApiSchema Get(Type resourceClrType)
     {
         ArgumentGuard.NotNull(resourceClrType);
 
-        if (_resourceClrTypeSchemaCache.TryGetValue(resourceClrType, out OpenApiSchema? referenceSchema))
+        if (_resourceClrTypeSchemaCache.TryGetValue(resourceClrType, out OpenApiSchema? extendedReferenceSchema))
         {
-            return referenceSchema;
+            return extendedReferenceSchema;
         }
 
         ResourceType resourceType = _resourceGraph.GetResourceType(resourceClrType);
@@ -46,7 +46,7 @@ public OpenApiSchema Get(Type resourceClrType)
 
         string schemaId = GetSchemaId(resourceType);
 
-        referenceSchema = new OpenApiSchema
+        var referenceSchema = new OpenApiSchema
         {
             Reference = new OpenApiReference
             {
@@ -55,10 +55,18 @@ public OpenApiSchema Get(Type resourceClrType)
             }
         };
 
-        _schemaRepositoryAccessor.Current.AddDefinition(referenceSchema.Reference.Id, fullSchema);
-        _resourceClrTypeSchemaCache.Add(resourceType.ClrType, referenceSchema);
+        extendedReferenceSchema = new OpenApiSchema
+        {
+            AllOf = new List<OpenApiSchema>
+            {
+                referenceSchema
+            }
+        };
+
+        _schemaRepositoryAccessor.Current.AddDefinition(schemaId, fullSchema);
+        _resourceClrTypeSchemaCache.Add(resourceType.ClrType, extendedReferenceSchema);
 
-        return referenceSchema;
+        return extendedReferenceSchema;
     }
 
     private string GetSchemaId(ResourceType resourceType)
diff --git a/src/JsonApiDotNetCore.OpenApi/TypeCategory.cs b/src/JsonApiDotNetCore.OpenApi/TypeCategory.cs
deleted file mode 100644
index 1641e31775..0000000000
--- a/src/JsonApiDotNetCore.OpenApi/TypeCategory.cs
+++ /dev/null
@@ -1,9 +0,0 @@
-namespace JsonApiDotNetCore.OpenApi;
-
-internal enum TypeCategory
-{
-    NonNullableReferenceType,
-    NullableReferenceType,
-    ValueType,
-    NullableValueType
-}
diff --git a/test/OpenApiClientTests/LegacyClient/ApiResponse.cs b/test/OpenApiClientTests/ApiResponse.cs
similarity index 94%
rename from test/OpenApiClientTests/LegacyClient/ApiResponse.cs
rename to test/OpenApiClientTests/ApiResponse.cs
index e62353d17a..7ea398c73a 100644
--- a/test/OpenApiClientTests/LegacyClient/ApiResponse.cs
+++ b/test/OpenApiClientTests/ApiResponse.cs
@@ -3,7 +3,7 @@
 
 #pragma warning disable AV1008 // Class should not be static
 
-namespace OpenApiClientTests.LegacyClient;
+namespace OpenApiClientTests;
 
 internal static class ApiResponse
 {
diff --git a/test/OpenApiClientTests/LegacyClient/FakeHttpClientWrapper.cs b/test/OpenApiClientTests/FakeHttpClientWrapper.cs
similarity index 90%
rename from test/OpenApiClientTests/LegacyClient/FakeHttpClientWrapper.cs
rename to test/OpenApiClientTests/FakeHttpClientWrapper.cs
index 8a5501354f..8226a4e496 100644
--- a/test/OpenApiClientTests/LegacyClient/FakeHttpClientWrapper.cs
+++ b/test/OpenApiClientTests/FakeHttpClientWrapper.cs
@@ -1,9 +1,10 @@
 using System.Net;
 using System.Net.Http.Headers;
 using System.Text;
+using System.Text.Json;
 using JsonApiDotNetCore.OpenApi.Client;
 
-namespace OpenApiClientTests.LegacyClient;
+namespace OpenApiClientTests;
 
 /// <summary>
 /// Enables to inject an outgoing response body and inspect the incoming request.
@@ -22,6 +23,17 @@ private FakeHttpClientWrapper(HttpClient httpClient, FakeHttpMessageHandler hand
         _handler = handler;
     }
 
+    public JsonElement ParseRequestBody()
+    {
+        if (RequestBody == null)
+        {
+            throw new InvalidOperationException();
+        }
+
+        using JsonDocument jsonDocument = JsonDocument.Parse(RequestBody);
+        return jsonDocument.RootElement.Clone();
+    }
+
     public static FakeHttpClientWrapper Create(HttpStatusCode statusCode, string? responseBody)
     {
         HttpResponseMessage response = CreateResponse(statusCode, responseBody);
diff --git a/test/OpenApiClientTests/FakerFactory.cs b/test/OpenApiClientTests/FakerFactory.cs
new file mode 100644
index 0000000000..c28adbaa60
--- /dev/null
+++ b/test/OpenApiClientTests/FakerFactory.cs
@@ -0,0 +1,41 @@
+using System.Reflection;
+using AutoBogus;
+
+namespace OpenApiClientTests;
+
+internal sealed class FakerFactory
+{
+    public static FakerFactory Instance { get; } = new();
+
+    private FakerFactory()
+    {
+    }
+
+    public AutoFaker<TTarget> Create<TTarget>()
+        where TTarget : class
+    {
+        return new AutoFaker<TTarget>();
+    }
+
+    public AutoFaker<TTarget> CreateForObjectWithResourceId<TTarget, TId>()
+        where TTarget : class
+    {
+        return new AutoFaker<TTarget>().Configure(builder => builder.WithOverride(new ResourceStringIdOverride<TId>()));
+    }
+
+    private sealed class ResourceStringIdOverride<TId> : AutoGeneratorOverride
+    {
+        private readonly IAutoFaker _idFaker = AutoFaker.Create();
+
+        public override bool CanOverride(AutoGenerateContext context)
+        {
+            PropertyInfo? resourceIdPropertyInfo = context.GenerateType.GetProperty("Id");
+            return resourceIdPropertyInfo != null && resourceIdPropertyInfo.PropertyType == typeof(string);
+        }
+
+        public override void Generate(AutoGenerateOverrideContext context)
+        {
+            ((dynamic)context.Instance).Id = _idFaker.Generate<TId>()!.ToString()!;
+        }
+    }
+}
diff --git a/test/OpenApiClientTests/LegacyClient/ClientAttributeRegistrationLifeTimeTests.cs b/test/OpenApiClientTests/LegacyClient/RequestDocumentRegistrationLifetimeTests.cs
similarity index 79%
rename from test/OpenApiClientTests/LegacyClient/ClientAttributeRegistrationLifeTimeTests.cs
rename to test/OpenApiClientTests/LegacyClient/RequestDocumentRegistrationLifetimeTests.cs
index 4582f9578d..b6855c06d2 100644
--- a/test/OpenApiClientTests/LegacyClient/ClientAttributeRegistrationLifeTimeTests.cs
+++ b/test/OpenApiClientTests/LegacyClient/RequestDocumentRegistrationLifetimeTests.cs
@@ -6,10 +6,10 @@
 
 namespace OpenApiClientTests.LegacyClient;
 
-public sealed class ClientAttributeRegistrationLifetimeTests
+public sealed class RequestDocumentRegistrationLifetimeTests
 {
     [Fact]
-    public async Task Disposed_attribute_registration_for_document_does_not_affect_request()
+    public async Task Disposed_request_document_registration_does_not_affect_request()
     {
         // Arrange
         using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
@@ -27,7 +27,7 @@ public async Task Disposed_attribute_registration_for_document_does_not_affect_r
             }
         };
 
-        using (apiClient.RegisterAttributesForRequestDocument<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument,
+        using (apiClient.WithPartialAttributeSerialization<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument,
             airplane => airplane.AirtimeInHours))
         {
             _ = await ApiResponse.TranslateAsync(async () => await apiClient.PatchAirplaneAsync(airplaneId, requestDocument));
@@ -51,7 +51,7 @@ public async Task Disposed_attribute_registration_for_document_does_not_affect_r
     }
 
     [Fact]
-    public async Task Attribute_registration_can_be_used_for_multiple_requests()
+    public async Task Request_document_registration_can_be_used_for_multiple_requests()
     {
         // Arrange
         using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
@@ -72,7 +72,7 @@ public async Task Attribute_registration_can_be_used_for_multiple_requests()
             }
         };
 
-        using (apiClient.RegisterAttributesForRequestDocument<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument,
+        using (apiClient.WithPartialAttributeSerialization<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument,
             airplane => airplane.AirtimeInHours))
         {
             _ = await ApiResponse.TranslateAsync(async () => await apiClient.PatchAirplaneAsync(airplaneId, requestDocument));
@@ -98,7 +98,7 @@ public async Task Attribute_registration_can_be_used_for_multiple_requests()
     }
 
     [Fact]
-    public async Task Request_is_unaffected_by_attribute_registration_for_different_document_of_same_type()
+    public async Task Request_is_unaffected_by_request_document_registration_of_different_request_document_of_same_type()
     {
         // Arrange
         using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
@@ -128,10 +128,10 @@ public async Task Request_is_unaffected_by_attribute_registration_for_different_
             }
         };
 
-        using (apiClient.RegisterAttributesForRequestDocument<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument1,
+        using (apiClient.WithPartialAttributeSerialization<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument1,
             airplane => airplane.AirtimeInHours))
         {
-            using (apiClient.RegisterAttributesForRequestDocument<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument2,
+            using (apiClient.WithPartialAttributeSerialization<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument2,
                 airplane => airplane.SerialNumber))
             {
             }
@@ -153,7 +153,7 @@ public async Task Request_is_unaffected_by_attribute_registration_for_different_
     }
 
     [Fact]
-    public async Task Attribute_values_can_be_changed_after_attribute_registration()
+    public async Task Attribute_values_can_be_changed_after_request_document_registration()
     {
         // Arrange
         using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
@@ -174,7 +174,7 @@ public async Task Attribute_values_can_be_changed_after_attribute_registration()
             }
         };
 
-        using (apiClient.RegisterAttributesForRequestDocument<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument,
+        using (apiClient.WithPartialAttributeSerialization<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument,
             airplane => airplane.IsInMaintenance))
         {
             requestDocument.Data.Attributes.IsInMaintenance = false;
@@ -196,7 +196,7 @@ public async Task Attribute_values_can_be_changed_after_attribute_registration()
     }
 
     [Fact]
-    public async Task Attribute_registration_is_unaffected_by_successive_attribute_registration_for_document_of_different_type()
+    public async Task Request_document_registration_is_unaffected_by_successive_registration_of_request_document_of_different_type()
     {
         // Arrange
         using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
@@ -223,10 +223,10 @@ public async Task Attribute_registration_is_unaffected_by_successive_attribute_r
             }
         };
 
-        using (apiClient.RegisterAttributesForRequestDocument<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument1,
+        using (apiClient.WithPartialAttributeSerialization<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument1,
             airplane => airplane.IsInMaintenance))
         {
-            using (apiClient.RegisterAttributesForRequestDocument<AirplanePostRequestDocument, AirplaneAttributesInPostRequest>(requestDocument2,
+            using (apiClient.WithPartialAttributeSerialization<AirplanePostRequestDocument, AirplaneAttributesInPostRequest>(requestDocument2,
                 airplane => airplane.AirtimeInHours))
             {
                 // Act
@@ -247,7 +247,7 @@ public async Task Attribute_registration_is_unaffected_by_successive_attribute_r
     }
 
     [Fact]
-    public async Task Attribute_registration_is_unaffected_by_preceding_disposed_attribute_registration_for_different_document_of_same_type()
+    public async Task Request_document_registration_is_unaffected_by_preceding_disposed_registration_of_different_request_document_of_same_type()
     {
         // Arrange
         using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
@@ -265,7 +265,7 @@ public async Task Attribute_registration_is_unaffected_by_preceding_disposed_att
             }
         };
 
-        using (apiClient.RegisterAttributesForRequestDocument<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument1,
+        using (apiClient.WithPartialAttributeSerialization<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument1,
             airplane => airplane.AirtimeInHours))
         {
             _ = await ApiResponse.TranslateAsync(async () => await apiClient.PatchAirplaneAsync(airplaneId1, requestDocument1));
@@ -288,7 +288,7 @@ public async Task Attribute_registration_is_unaffected_by_preceding_disposed_att
 
         wrapper.ChangeResponse(HttpStatusCode.NoContent, null);
 
-        using (apiClient.RegisterAttributesForRequestDocument<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument2,
+        using (apiClient.WithPartialAttributeSerialization<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument2,
             airplane => airplane.SerialNumber))
         {
             // Act
@@ -309,7 +309,7 @@ public async Task Attribute_registration_is_unaffected_by_preceding_disposed_att
     }
 
     [Fact]
-    public async Task Attribute_registration_is_unaffected_by_preceding_disposed_attribute_registration_for_document_of_different_type()
+    public async Task Request_document_registration_is_unaffected_by_preceding_disposed_registration_of_request_document_of_different_type()
     {
         // Arrange
         using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
@@ -320,11 +320,14 @@ public async Task Attribute_registration_is_unaffected_by_preceding_disposed_att
             Data = new AirplaneDataInPostRequest
             {
                 Type = AirplaneResourceType.Airplanes,
-                Attributes = new AirplaneAttributesInPostRequest()
+                Attributes = new AirplaneAttributesInPostRequest
+                {
+                    Name = "Jay Jay the Jet Plane"
+                }
             }
         };
 
-        using (apiClient.RegisterAttributesForRequestDocument<AirplanePostRequestDocument, AirplaneAttributesInPostRequest>(requestDocument1,
+        using (apiClient.WithPartialAttributeSerialization<AirplanePostRequestDocument, AirplaneAttributesInPostRequest>(requestDocument1,
             airplane => airplane.AirtimeInHours))
         {
             _ = await ApiResponse.TranslateAsync(async () => await apiClient.PostAirplaneAsync(requestDocument1));
@@ -347,7 +350,7 @@ public async Task Attribute_registration_is_unaffected_by_preceding_disposed_att
 
         wrapper.ChangeResponse(HttpStatusCode.NoContent, null);
 
-        using (apiClient.RegisterAttributesForRequestDocument<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument2,
+        using (apiClient.WithPartialAttributeSerialization<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument2,
             airplane => airplane.SerialNumber))
         {
             // Act
@@ -368,7 +371,7 @@ public async Task Attribute_registration_is_unaffected_by_preceding_disposed_att
     }
 
     [Fact]
-    public async Task Attribute_registration_is_unaffected_by_preceding_attribute_registration_for_different_document_of_same_type()
+    public async Task Request_document_registration_is_unaffected_by_preceding_registration_of_different_request_document_of_same_type()
     {
         // Arrange
         using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
@@ -398,10 +401,10 @@ public async Task Attribute_registration_is_unaffected_by_preceding_attribute_re
             }
         };
 
-        using (apiClient.RegisterAttributesForRequestDocument<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument1,
+        using (apiClient.WithPartialAttributeSerialization<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument1,
             airplane => airplane.SerialNumber))
         {
-            using (apiClient.RegisterAttributesForRequestDocument<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument2,
+            using (apiClient.WithPartialAttributeSerialization<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument2,
                 airplane => airplane.IsInMaintenance, airplane => airplane.AirtimeInHours))
             {
                 // Act
diff --git a/test/OpenApiClientTests/LegacyClient/RequestTests.cs b/test/OpenApiClientTests/LegacyClient/RequestTests.cs
index e03e8f1015..ab58b101e6 100644
--- a/test/OpenApiClientTests/LegacyClient/RequestTests.cs
+++ b/test/OpenApiClientTests/LegacyClient/RequestTests.cs
@@ -152,7 +152,7 @@ public async Task Partial_posting_resource_produces_expected_request()
             }
         };
 
-        using (apiClient.RegisterAttributesForRequestDocument<AirplanePostRequestDocument, AirplaneAttributesInPostRequest>(requestDocument,
+        using (apiClient.WithPartialAttributeSerialization<AirplanePostRequestDocument, AirplaneAttributesInPostRequest>(requestDocument,
             airplane => airplane.SerialNumber))
         {
             // Act
@@ -203,7 +203,7 @@ public async Task Partial_patching_resource_produces_expected_request()
             }
         };
 
-        using (apiClient.RegisterAttributesForRequestDocument<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument,
+        using (apiClient.WithPartialAttributeSerialization<AirplanePatchRequestDocument, AirplaneAttributesInPatchRequest>(requestDocument,
             airplane => airplane.SerialNumber, airplane => airplane.LastServicedAt, airplane => airplane.IsInMaintenance, airplane => airplane.AirtimeInHours))
         {
             // Act
diff --git a/test/OpenApiClientTests/LegacyClient/ResponseTests.cs b/test/OpenApiClientTests/LegacyClient/ResponseTests.cs
index 10f86adca5..b112a23d05 100644
--- a/test/OpenApiClientTests/LegacyClient/ResponseTests.cs
+++ b/test/OpenApiClientTests/LegacyClient/ResponseTests.cs
@@ -149,7 +149,9 @@ public async Task Getting_resource_translates_response()
         // Arrange
         const string flightId = "ZvuH1";
         const string departsAtInZuluTime = "2021-06-08T12:53:30.554Z";
+        const string flightDestination = "Amsterdam";
         const string arrivesAtWithUtcOffset = "2019-02-20T11:56:33.0721266+01:00";
+        const string flightServiceOnBoard = "Movies";
 
         const string responseBody = @"{
   ""links"": {
@@ -160,7 +162,9 @@ public async Task Getting_resource_translates_response()
       ""id"": """ + flightId + @""",
       ""attributes"": {
         ""departs-at"": """ + departsAtInZuluTime + @""",
-        ""arrives-at"": """ + arrivesAtWithUtcOffset + @"""
+        ""arrives-at"": """ + arrivesAtWithUtcOffset + @""",
+        ""final-destination"": """ + flightDestination + @""",
+        ""services-on-board"": [""" + flightServiceOnBoard + @"""]
       },
       ""links"": {
         ""self"": """ + HostPrefix + @"flights/" + flightId + @"""
@@ -181,8 +185,8 @@ public async Task Getting_resource_translates_response()
         document.Data.Relationships.Should().BeNull();
         document.Data.Attributes.DepartsAt.Should().Be(DateTimeOffset.Parse(departsAtInZuluTime));
         document.Data.Attributes.ArrivesAt.Should().Be(DateTimeOffset.Parse(arrivesAtWithUtcOffset));
-        document.Data.Attributes.ServicesOnBoard.Should().BeNull();
-        document.Data.Attributes.FinalDestination.Should().BeNull();
+        document.Data.Attributes.ServicesOnBoard.Should().Contain(flightServiceOnBoard);
+        document.Data.Attributes.FinalDestination.Should().Be(flightDestination);
         document.Data.Attributes.StopOverDestination.Should().BeNull();
         document.Data.Attributes.OperatedBy.Should().Be(default);
     }
diff --git a/test/OpenApiClientTests/LegacyClient/swagger.g.json b/test/OpenApiClientTests/LegacyClient/swagger.g.json
index f95214e8d4..f2c0237d1d 100644
--- a/test/OpenApiClientTests/LegacyClient/swagger.g.json
+++ b/test/OpenApiClientTests/LegacyClient/swagger.g.json
@@ -51,7 +51,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/airplane-post-request-document"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/airplane-post-request-document"
+                  }
+                ]
               }
             }
           }
@@ -149,7 +153,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/airplane-patch-request-document"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/airplane-patch-request-document"
+                  }
+                ]
               }
             }
           }
@@ -326,7 +334,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -356,7 +368,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -386,7 +402,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -444,7 +464,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/flight-attendant-post-request-document"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/flight-attendant-post-request-document"
+                  }
+                ]
               }
             }
           }
@@ -542,7 +566,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/flight-attendant-patch-request-document"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/flight-attendant-patch-request-document"
+                  }
+                ]
               }
             }
           }
@@ -719,7 +747,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -749,7 +781,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -779,7 +815,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -925,7 +965,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -955,7 +999,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -985,7 +1033,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1043,7 +1095,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/flight-post-request-document"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/flight-post-request-document"
+                  }
+                ]
               }
             }
           }
@@ -1141,7 +1197,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/flight-patch-request-document"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/flight-patch-request-document"
+                  }
+                ]
               }
             }
           }
@@ -1318,7 +1378,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/nullable-to-one-flight-attendant-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/nullable-to-one-flight-attendant-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1464,7 +1528,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1494,7 +1562,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1524,7 +1596,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1670,7 +1746,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-passenger-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-passenger-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1700,7 +1780,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-passenger-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-passenger-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1730,7 +1814,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-passenger-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-passenger-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1876,7 +1964,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-one-flight-attendant-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-one-flight-attendant-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1970,6 +2062,9 @@
         "additionalProperties": false
       },
       "airplane-attributes-in-response": {
+        "required": [
+          "name"
+        ],
         "type": "object",
         "properties": {
           "name": {
@@ -2004,7 +2099,11 @@
             "nullable": true
           },
           "kind": {
-            "$ref": "#/components/schemas/aircraft-kind"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/aircraft-kind"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2024,13 +2123,21 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-collection-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-collection-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2043,17 +2150,29 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/airplane-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/airplane-attributes-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-attributes-in-patch-request"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/airplane-relationships-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-relationships-in-patch-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2065,13 +2184,25 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/airplane-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-resource-type"
+              }
+            ]
           },
           "attributes": {
-            "$ref": "#/components/schemas/airplane-attributes-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-attributes-in-post-request"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/airplane-relationships-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-relationships-in-post-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2085,24 +2216,40 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/airplane-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/airplane-attributes-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-attributes-in-response"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/airplane-relationships-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-relationships-in-response"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -2114,7 +2261,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/airplane-data-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-data-in-patch-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2126,7 +2277,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/airplane-data-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-data-in-post-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2139,17 +2294,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/airplane-data-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-data-in-response"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2158,7 +2325,11 @@
         "type": "object",
         "properties": {
           "flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2167,7 +2338,11 @@
         "type": "object",
         "properties": {
           "flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2176,7 +2351,11 @@
         "type": "object",
         "properties": {
           "flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-response"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2238,6 +2417,10 @@
         "additionalProperties": false
       },
       "flight-attendant-attributes-in-response": {
+        "required": [
+          "email-address",
+          "profile-image-url"
+        ],
         "type": "object",
         "properties": {
           "email-address": {
@@ -2277,13 +2460,21 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-collection-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-collection-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2296,17 +2487,29 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/flight-attendant-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/flight-attendant-attributes-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-attributes-in-patch-request"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/flight-attendant-relationships-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-relationships-in-patch-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2318,13 +2521,25 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/flight-attendant-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-resource-type"
+              }
+            ]
           },
           "attributes": {
-            "$ref": "#/components/schemas/flight-attendant-attributes-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-attributes-in-post-request"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/flight-attendant-relationships-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-relationships-in-post-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2338,24 +2553,40 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/flight-attendant-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/flight-attendant-attributes-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-attributes-in-response"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/flight-attendant-relationships-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-relationships-in-response"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -2368,7 +2599,11 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/flight-attendant-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
@@ -2392,13 +2627,21 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-identifier-collection-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-identifier-collection-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2411,17 +2654,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-attendant-identifier"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-identifier"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-identifier-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-identifier-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2433,7 +2688,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-attendant-data-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-data-in-patch-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2445,7 +2704,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-attendant-data-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-data-in-post-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2458,17 +2721,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-attendant-data-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-data-in-response"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2477,10 +2752,18 @@
         "type": "object",
         "properties": {
           "scheduled-for-flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-request"
+              }
+            ]
           },
           "purser-on-flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2489,10 +2772,18 @@
         "type": "object",
         "properties": {
           "scheduled-for-flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-request"
+              }
+            ]
           },
           "purser-on-flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2501,10 +2792,18 @@
         "type": "object",
         "properties": {
           "scheduled-for-flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-response"
+              }
+            ]
           },
           "purser-on-flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-response"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2523,17 +2822,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-attendant-data-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-data-in-response"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2551,12 +2862,20 @@
             "nullable": true
           },
           "operated-by": {
-            "$ref": "#/components/schemas/airline"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airline"
+              }
+            ]
           }
         },
         "additionalProperties": false
       },
       "flight-attributes-in-response": {
+        "required": [
+          "final-destination",
+          "services-on-board"
+        ],
         "type": "object",
         "properties": {
           "final-destination": {
@@ -2569,7 +2888,11 @@
             "nullable": true
           },
           "operated-by": {
-            "$ref": "#/components/schemas/airline"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airline"
+              }
+            ]
           },
           "departs-at": {
             "type": "string",
@@ -2605,13 +2928,21 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-collection-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-collection-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2624,17 +2955,29 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/flight-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/flight-attributes-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attributes-in-patch-request"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/flight-relationships-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-relationships-in-patch-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2646,10 +2989,18 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/flight-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-resource-type"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/flight-relationships-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-relationships-in-post-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2663,24 +3014,40 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/flight-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/flight-attributes-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attributes-in-response"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/flight-relationships-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-relationships-in-response"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -2693,7 +3060,11 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/flight-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
@@ -2717,13 +3088,21 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-identifier-collection-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-identifier-collection-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2735,7 +3114,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-data-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-data-in-patch-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2747,7 +3130,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-data-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-data-in-post-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2760,17 +3147,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-data-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-data-in-response"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2779,16 +3178,32 @@
         "type": "object",
         "properties": {
           "cabin-crew-members": {
-            "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+              }
+            ]
           },
           "purser": {
-            "$ref": "#/components/schemas/to-one-flight-attendant-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-one-flight-attendant-in-request"
+              }
+            ]
           },
           "backup-purser": {
-            "$ref": "#/components/schemas/nullable-to-one-flight-attendant-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullable-to-one-flight-attendant-in-request"
+              }
+            ]
           },
           "passengers": {
-            "$ref": "#/components/schemas/to-many-passenger-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-passenger-in-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2800,34 +3215,69 @@
         "type": "object",
         "properties": {
           "cabin-crew-members": {
-            "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+              }
+            ]
           },
           "purser": {
-            "$ref": "#/components/schemas/to-one-flight-attendant-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-one-flight-attendant-in-request"
+              }
+            ]
           },
           "backup-purser": {
-            "$ref": "#/components/schemas/nullable-to-one-flight-attendant-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullable-to-one-flight-attendant-in-request"
+              }
+            ]
           },
           "passengers": {
-            "$ref": "#/components/schemas/to-many-passenger-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-passenger-in-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
       },
       "flight-relationships-in-response": {
+        "required": [
+          "purser"
+        ],
         "type": "object",
         "properties": {
           "cabin-crew-members": {
-            "$ref": "#/components/schemas/to-many-flight-attendant-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-attendant-in-response"
+              }
+            ]
           },
           "purser": {
-            "$ref": "#/components/schemas/to-one-flight-attendant-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-one-flight-attendant-in-response"
+              }
+            ]
           },
           "backup-purser": {
-            "$ref": "#/components/schemas/nullable-to-one-flight-attendant-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullable-to-one-flight-attendant-in-response"
+              }
+            ]
           },
           "passengers": {
-            "$ref": "#/components/schemas/to-many-passenger-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-passenger-in-response"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2858,7 +3308,7 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -2996,29 +3446,6 @@
         },
         "additionalProperties": false
       },
-      "null-value": {
-        "not": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "type": "number"
-            },
-            {
-              "type": "boolean"
-            },
-            {
-              "type": "object"
-            },
-            {
-              "type": "array"
-            }
-          ],
-          "items": { }
-        },
-        "nullable": true
-      },
       "nullable-flight-attendant-identifier-response-document": {
         "required": [
           "data",
@@ -3027,24 +3454,30 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/flight-attendant-identifier"
-              },
-              {
-                "$ref": "#/components/schemas/null-value"
               }
-            ]
+            ],
+            "nullable": true
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-identifier-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-identifier-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -3057,24 +3490,30 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/flight-attendant-data-in-response"
-              },
-              {
-                "$ref": "#/components/schemas/null-value"
               }
-            ]
+            ],
+            "nullable": true
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -3086,14 +3525,12 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/flight-attendant-identifier"
-              },
-              {
-                "$ref": "#/components/schemas/null-value"
               }
-            ]
+            ],
+            "nullable": true
           }
         },
         "additionalProperties": false
@@ -3105,21 +3542,23 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/flight-attendant-identifier"
-              },
-              {
-                "$ref": "#/components/schemas/null-value"
               }
-            ]
+            ],
+            "nullable": true
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-relationship-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-relationship-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -3132,7 +3571,11 @@
             "nullable": true
           },
           "cabin-area": {
-            "$ref": "#/components/schemas/cabin-area"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/cabin-area"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -3152,13 +3595,21 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-collection-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-collection-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -3172,21 +3623,33 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/passenger-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/passenger-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/passenger-attributes-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/passenger-attributes-in-response"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -3199,7 +3662,11 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/passenger-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/passenger-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
@@ -3223,13 +3690,21 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-identifier-collection-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-identifier-collection-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -3268,11 +3743,15 @@
             }
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-relationship-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-relationship-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -3305,11 +3784,15 @@
             }
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-relationship-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-relationship-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -3342,11 +3825,15 @@
             }
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-relationship-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-relationship-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -3358,7 +3845,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-attendant-identifier"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-identifier"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -3370,18 +3861,26 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-attendant-identifier"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-identifier"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-relationship-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-relationship-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
       }
     }
   }
-}
\ No newline at end of file
+}
diff --git a/test/OpenApiClientTests/NamingConventions/CamelCase/swagger.g.json b/test/OpenApiClientTests/NamingConventions/CamelCase/swagger.g.json
index d2850c032d..b356959a8d 100644
--- a/test/OpenApiClientTests/NamingConventions/CamelCase/swagger.g.json
+++ b/test/OpenApiClientTests/NamingConventions/CamelCase/swagger.g.json
@@ -51,7 +51,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/supermarketPostRequestDocument"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/supermarketPostRequestDocument"
+                  }
+                ]
               }
             }
           }
@@ -152,7 +156,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/supermarketPatchRequestDocument"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/supermarketPatchRequestDocument"
+                  }
+                ]
               }
             }
           }
@@ -335,7 +343,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/nullableToOneStaffMemberInRequest"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/nullableToOneStaffMemberInRequest"
+                  }
+                ]
               }
             }
           }
@@ -486,7 +498,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/toManyStaffMemberInRequest"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyStaffMemberInRequest"
+                  }
+                ]
               }
             }
           }
@@ -517,7 +533,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/toManyStaffMemberInRequest"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyStaffMemberInRequest"
+                  }
+                ]
               }
             }
           }
@@ -548,7 +568,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/toManyStaffMemberInRequest"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyStaffMemberInRequest"
+                  }
+                ]
               }
             }
           }
@@ -699,7 +723,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/toOneStaffMemberInRequest"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toOneStaffMemberInRequest"
+                  }
+                ]
               }
             }
           }
@@ -734,7 +762,7 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -872,29 +900,6 @@
         },
         "additionalProperties": false
       },
-      "nullValue": {
-        "not": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "type": "number"
-            },
-            {
-              "type": "boolean"
-            },
-            {
-              "type": "object"
-            },
-            {
-              "type": "array"
-            }
-          ],
-          "items": { }
-        },
-        "nullable": true
-      },
       "nullableStaffMemberIdentifierResponseDocument": {
         "required": [
           "data",
@@ -903,24 +908,30 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/staffMemberIdentifier"
-              },
-              {
-                "$ref": "#/components/schemas/nullValue"
               }
-            ]
+            ],
+            "nullable": true
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapiObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/linksInResourceIdentifierDocument"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceIdentifierDocument"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -933,24 +944,30 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/staffMemberDataInResponse"
-              },
-              {
-                "$ref": "#/components/schemas/nullValue"
               }
-            ]
+            ],
+            "nullable": true
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapiObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/linksInResourceDocument"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceDocument"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -962,14 +979,12 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/staffMemberIdentifier"
-              },
-              {
-                "$ref": "#/components/schemas/nullValue"
               }
-            ]
+            ],
+            "nullable": true
           }
         },
         "additionalProperties": false
@@ -981,26 +996,31 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/staffMemberIdentifier"
-              },
-              {
-                "$ref": "#/components/schemas/nullValue"
               }
-            ]
+            ],
+            "nullable": true
           },
           "links": {
-            "$ref": "#/components/schemas/linksInRelationshipObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInRelationshipObject"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
       },
       "staffMemberAttributesInResponse": {
+        "required": [
+          "name"
+        ],
         "type": "object",
         "properties": {
           "name": {
@@ -1028,13 +1048,21 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapiObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/linksInResourceCollectionDocument"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceCollectionDocument"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1048,21 +1076,33 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/staffMemberResourceType"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/staffMemberResourceType"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/staffMemberAttributesInResponse"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/staffMemberAttributesInResponse"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/linksInResourceObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceObject"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -1075,7 +1115,11 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/staffMemberResourceType"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/staffMemberResourceType"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
@@ -1099,13 +1143,21 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapiObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/linksInResourceIdentifierCollectionDocument"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceIdentifierCollectionDocument"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1118,17 +1170,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/staffMemberIdentifier"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/staffMemberIdentifier"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapiObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/linksInResourceIdentifierDocument"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceIdentifierDocument"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1147,17 +1211,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/staffMemberDataInResponse"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/staffMemberDataInResponse"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapiObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/linksInResourceDocument"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceDocument"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1169,7 +1245,11 @@
             "type": "string"
           },
           "kind": {
-            "$ref": "#/components/schemas/supermarketType"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarketType"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1184,19 +1264,30 @@
             "type": "string"
           },
           "kind": {
-            "$ref": "#/components/schemas/supermarketType"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarketType"
+              }
+            ]
           }
         },
         "additionalProperties": false
       },
       "supermarketAttributesInResponse": {
+        "required": [
+          "nameOfCity"
+        ],
         "type": "object",
         "properties": {
           "nameOfCity": {
             "type": "string"
           },
           "kind": {
-            "$ref": "#/components/schemas/supermarketType"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarketType"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1216,13 +1307,21 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapiObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/linksInResourceCollectionDocument"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceCollectionDocument"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1235,17 +1334,29 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/supermarketResourceType"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarketResourceType"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/supermarketAttributesInPatchRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarketAttributesInPatchRequest"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/supermarketRelationshipsInPatchRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarketRelationshipsInPatchRequest"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1257,13 +1368,25 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/supermarketResourceType"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarketResourceType"
+              }
+            ]
           },
           "attributes": {
-            "$ref": "#/components/schemas/supermarketAttributesInPostRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarketAttributesInPostRequest"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/supermarketRelationshipsInPostRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarketRelationshipsInPostRequest"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1277,24 +1400,40 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/supermarketResourceType"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarketResourceType"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/supermarketAttributesInResponse"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarketAttributesInResponse"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/supermarketRelationshipsInResponse"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarketRelationshipsInResponse"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/linksInResourceObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceObject"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -1306,7 +1445,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/supermarketDataInPatchRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarketDataInPatchRequest"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1318,7 +1461,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/supermarketDataInPostRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarketDataInPostRequest"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1331,17 +1478,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/supermarketDataInResponse"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarketDataInResponse"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapiObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/linksInResourceDocument"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceDocument"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1350,13 +1509,25 @@
         "type": "object",
         "properties": {
           "storeManager": {
-            "$ref": "#/components/schemas/toOneStaffMemberInRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneStaffMemberInRequest"
+              }
+            ]
           },
           "backupStoreManager": {
-            "$ref": "#/components/schemas/nullableToOneStaffMemberInRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneStaffMemberInRequest"
+              }
+            ]
           },
           "cashiers": {
-            "$ref": "#/components/schemas/toManyStaffMemberInRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyStaffMemberInRequest"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1368,28 +1539,55 @@
         "type": "object",
         "properties": {
           "storeManager": {
-            "$ref": "#/components/schemas/toOneStaffMemberInRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneStaffMemberInRequest"
+              }
+            ]
           },
           "backupStoreManager": {
-            "$ref": "#/components/schemas/nullableToOneStaffMemberInRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneStaffMemberInRequest"
+              }
+            ]
           },
           "cashiers": {
-            "$ref": "#/components/schemas/toManyStaffMemberInRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyStaffMemberInRequest"
+              }
+            ]
           }
         },
         "additionalProperties": false
       },
       "supermarketRelationshipsInResponse": {
+        "required": [
+          "storeManager"
+        ],
         "type": "object",
         "properties": {
           "storeManager": {
-            "$ref": "#/components/schemas/toOneStaffMemberInResponse"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneStaffMemberInResponse"
+              }
+            ]
           },
           "backupStoreManager": {
-            "$ref": "#/components/schemas/nullableToOneStaffMemberInResponse"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneStaffMemberInResponse"
+              }
+            ]
           },
           "cashiers": {
-            "$ref": "#/components/schemas/toManyStaffMemberInResponse"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyStaffMemberInResponse"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1436,11 +1634,15 @@
             }
           },
           "links": {
-            "$ref": "#/components/schemas/linksInRelationshipObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInRelationshipObject"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -1452,7 +1654,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/staffMemberIdentifier"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/staffMemberIdentifier"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1464,18 +1670,26 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/staffMemberIdentifier"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/staffMemberIdentifier"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/linksInRelationshipObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInRelationshipObject"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
       }
     }
   }
-}
\ No newline at end of file
+}
diff --git a/test/OpenApiClientTests/NamingConventions/KebabCase/swagger.g.json b/test/OpenApiClientTests/NamingConventions/KebabCase/swagger.g.json
index 1d7feb51f0..1e257a710f 100644
--- a/test/OpenApiClientTests/NamingConventions/KebabCase/swagger.g.json
+++ b/test/OpenApiClientTests/NamingConventions/KebabCase/swagger.g.json
@@ -51,7 +51,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/supermarket-post-request-document"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/supermarket-post-request-document"
+                  }
+                ]
               }
             }
           }
@@ -152,7 +156,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/supermarket-patch-request-document"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/supermarket-patch-request-document"
+                  }
+                ]
               }
             }
           }
@@ -335,7 +343,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/nullable-to-one-staff-member-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/nullable-to-one-staff-member-in-request"
+                  }
+                ]
               }
             }
           }
@@ -486,7 +498,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-staff-member-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-staff-member-in-request"
+                  }
+                ]
               }
             }
           }
@@ -517,7 +533,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-staff-member-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-staff-member-in-request"
+                  }
+                ]
               }
             }
           }
@@ -548,7 +568,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-staff-member-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-staff-member-in-request"
+                  }
+                ]
               }
             }
           }
@@ -699,7 +723,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-one-staff-member-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-one-staff-member-in-request"
+                  }
+                ]
               }
             }
           }
@@ -734,7 +762,7 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -872,29 +900,6 @@
         },
         "additionalProperties": false
       },
-      "null-value": {
-        "not": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "type": "number"
-            },
-            {
-              "type": "boolean"
-            },
-            {
-              "type": "object"
-            },
-            {
-              "type": "array"
-            }
-          ],
-          "items": { }
-        },
-        "nullable": true
-      },
       "nullable-staff-member-identifier-response-document": {
         "required": [
           "data",
@@ -903,24 +908,30 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/staff-member-identifier"
-              },
-              {
-                "$ref": "#/components/schemas/null-value"
               }
-            ]
+            ],
+            "nullable": true
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-identifier-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-identifier-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -933,24 +944,30 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/staff-member-data-in-response"
-              },
-              {
-                "$ref": "#/components/schemas/null-value"
               }
-            ]
+            ],
+            "nullable": true
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -962,14 +979,12 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/staff-member-identifier"
-              },
-              {
-                "$ref": "#/components/schemas/null-value"
               }
-            ]
+            ],
+            "nullable": true
           }
         },
         "additionalProperties": false
@@ -981,26 +996,31 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/staff-member-identifier"
-              },
-              {
-                "$ref": "#/components/schemas/null-value"
               }
-            ]
+            ],
+            "nullable": true
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-relationship-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-relationship-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
       },
       "staff-member-attributes-in-response": {
+        "required": [
+          "name"
+        ],
         "type": "object",
         "properties": {
           "name": {
@@ -1028,13 +1048,21 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-collection-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-collection-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1048,21 +1076,33 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/staff-member-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/staff-member-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/staff-member-attributes-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/staff-member-attributes-in-response"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -1075,7 +1115,11 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/staff-member-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/staff-member-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
@@ -1099,13 +1143,21 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-identifier-collection-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-identifier-collection-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1118,17 +1170,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/staff-member-identifier"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/staff-member-identifier"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-identifier-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-identifier-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1147,17 +1211,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/staff-member-data-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/staff-member-data-in-response"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1169,7 +1245,11 @@
             "type": "string"
           },
           "kind": {
-            "$ref": "#/components/schemas/supermarket-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarket-type"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1184,19 +1264,30 @@
             "type": "string"
           },
           "kind": {
-            "$ref": "#/components/schemas/supermarket-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarket-type"
+              }
+            ]
           }
         },
         "additionalProperties": false
       },
       "supermarket-attributes-in-response": {
+        "required": [
+          "name-of-city"
+        ],
         "type": "object",
         "properties": {
           "name-of-city": {
             "type": "string"
           },
           "kind": {
-            "$ref": "#/components/schemas/supermarket-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarket-type"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1216,13 +1307,21 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-collection-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-collection-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1235,17 +1334,29 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/supermarket-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarket-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/supermarket-attributes-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarket-attributes-in-patch-request"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/supermarket-relationships-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarket-relationships-in-patch-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1257,13 +1368,25 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/supermarket-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarket-resource-type"
+              }
+            ]
           },
           "attributes": {
-            "$ref": "#/components/schemas/supermarket-attributes-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarket-attributes-in-post-request"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/supermarket-relationships-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarket-relationships-in-post-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1277,24 +1400,40 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/supermarket-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarket-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/supermarket-attributes-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarket-attributes-in-response"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/supermarket-relationships-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarket-relationships-in-response"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -1306,7 +1445,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/supermarket-data-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarket-data-in-patch-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1318,7 +1461,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/supermarket-data-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarket-data-in-post-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1331,17 +1478,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/supermarket-data-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/supermarket-data-in-response"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1350,13 +1509,25 @@
         "type": "object",
         "properties": {
           "store-manager": {
-            "$ref": "#/components/schemas/to-one-staff-member-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-one-staff-member-in-request"
+              }
+            ]
           },
           "backup-store-manager": {
-            "$ref": "#/components/schemas/nullable-to-one-staff-member-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullable-to-one-staff-member-in-request"
+              }
+            ]
           },
           "cashiers": {
-            "$ref": "#/components/schemas/to-many-staff-member-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-staff-member-in-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1368,28 +1539,55 @@
         "type": "object",
         "properties": {
           "store-manager": {
-            "$ref": "#/components/schemas/to-one-staff-member-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-one-staff-member-in-request"
+              }
+            ]
           },
           "backup-store-manager": {
-            "$ref": "#/components/schemas/nullable-to-one-staff-member-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullable-to-one-staff-member-in-request"
+              }
+            ]
           },
           "cashiers": {
-            "$ref": "#/components/schemas/to-many-staff-member-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-staff-member-in-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
       },
       "supermarket-relationships-in-response": {
+        "required": [
+          "store-manager"
+        ],
         "type": "object",
         "properties": {
           "store-manager": {
-            "$ref": "#/components/schemas/to-one-staff-member-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-one-staff-member-in-response"
+              }
+            ]
           },
           "backup-store-manager": {
-            "$ref": "#/components/schemas/nullable-to-one-staff-member-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullable-to-one-staff-member-in-response"
+              }
+            ]
           },
           "cashiers": {
-            "$ref": "#/components/schemas/to-many-staff-member-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-staff-member-in-response"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1436,11 +1634,15 @@
             }
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-relationship-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-relationship-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -1452,7 +1654,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/staff-member-identifier"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/staff-member-identifier"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1464,18 +1670,26 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/staff-member-identifier"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/staff-member-identifier"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-relationship-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-relationship-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
       }
     }
   }
-}
\ No newline at end of file
+}
diff --git a/test/OpenApiClientTests/NamingConventions/PascalCase/swagger.g.json b/test/OpenApiClientTests/NamingConventions/PascalCase/swagger.g.json
index fa5041afad..f6de5bef79 100644
--- a/test/OpenApiClientTests/NamingConventions/PascalCase/swagger.g.json
+++ b/test/OpenApiClientTests/NamingConventions/PascalCase/swagger.g.json
@@ -51,7 +51,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/SupermarketPostRequestDocument"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/SupermarketPostRequestDocument"
+                  }
+                ]
               }
             }
           }
@@ -152,7 +156,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/SupermarketPatchRequestDocument"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/SupermarketPatchRequestDocument"
+                  }
+                ]
               }
             }
           }
@@ -335,7 +343,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/NullableToOneStaffMemberInRequest"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/NullableToOneStaffMemberInRequest"
+                  }
+                ]
               }
             }
           }
@@ -486,7 +498,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/ToManyStaffMemberInRequest"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/ToManyStaffMemberInRequest"
+                  }
+                ]
               }
             }
           }
@@ -517,7 +533,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/ToManyStaffMemberInRequest"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/ToManyStaffMemberInRequest"
+                  }
+                ]
               }
             }
           }
@@ -548,7 +568,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/ToManyStaffMemberInRequest"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/ToManyStaffMemberInRequest"
+                  }
+                ]
               }
             }
           }
@@ -699,7 +723,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/ToOneStaffMemberInRequest"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/ToOneStaffMemberInRequest"
+                  }
+                ]
               }
             }
           }
@@ -734,7 +762,7 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -872,29 +900,6 @@
         },
         "additionalProperties": false
       },
-      "NullValue": {
-        "not": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "type": "number"
-            },
-            {
-              "type": "boolean"
-            },
-            {
-              "type": "object"
-            },
-            {
-              "type": "array"
-            }
-          ],
-          "items": { }
-        },
-        "nullable": true
-      },
       "NullableStaffMemberIdentifierResponseDocument": {
         "required": [
           "data",
@@ -903,24 +908,30 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/StaffMemberIdentifier"
-              },
-              {
-                "$ref": "#/components/schemas/NullValue"
               }
-            ]
+            ],
+            "nullable": true
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/JsonapiObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/JsonapiObject"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/LinksInResourceIdentifierDocument"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/LinksInResourceIdentifierDocument"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -933,24 +944,30 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/StaffMemberDataInResponse"
-              },
-              {
-                "$ref": "#/components/schemas/NullValue"
               }
-            ]
+            ],
+            "nullable": true
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/JsonapiObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/JsonapiObject"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/LinksInResourceDocument"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/LinksInResourceDocument"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -962,14 +979,12 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/StaffMemberIdentifier"
-              },
-              {
-                "$ref": "#/components/schemas/NullValue"
               }
-            ]
+            ],
+            "nullable": true
           }
         },
         "additionalProperties": false
@@ -981,26 +996,31 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/StaffMemberIdentifier"
-              },
-              {
-                "$ref": "#/components/schemas/NullValue"
               }
-            ]
+            ],
+            "nullable": true
           },
           "links": {
-            "$ref": "#/components/schemas/LinksInRelationshipObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/LinksInRelationshipObject"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
       },
       "StaffMemberAttributesInResponse": {
+        "required": [
+          "Name"
+        ],
         "type": "object",
         "properties": {
           "Name": {
@@ -1028,13 +1048,21 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/JsonapiObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/JsonapiObject"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/LinksInResourceCollectionDocument"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/LinksInResourceCollectionDocument"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1048,21 +1076,33 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/StaffMemberResourceType"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/StaffMemberResourceType"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/StaffMemberAttributesInResponse"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/StaffMemberAttributesInResponse"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/LinksInResourceObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/LinksInResourceObject"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -1075,7 +1115,11 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/StaffMemberResourceType"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/StaffMemberResourceType"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
@@ -1099,13 +1143,21 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/JsonapiObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/JsonapiObject"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/LinksInResourceIdentifierCollectionDocument"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/LinksInResourceIdentifierCollectionDocument"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1118,17 +1170,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/StaffMemberIdentifier"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/StaffMemberIdentifier"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/JsonapiObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/JsonapiObject"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/LinksInResourceIdentifierDocument"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/LinksInResourceIdentifierDocument"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1147,17 +1211,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/StaffMemberDataInResponse"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/StaffMemberDataInResponse"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/JsonapiObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/JsonapiObject"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/LinksInResourceDocument"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/LinksInResourceDocument"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1169,7 +1245,11 @@
             "type": "string"
           },
           "Kind": {
-            "$ref": "#/components/schemas/SupermarketType"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/SupermarketType"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1184,19 +1264,30 @@
             "type": "string"
           },
           "Kind": {
-            "$ref": "#/components/schemas/SupermarketType"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/SupermarketType"
+              }
+            ]
           }
         },
         "additionalProperties": false
       },
       "SupermarketAttributesInResponse": {
+        "required": [
+          "NameOfCity"
+        ],
         "type": "object",
         "properties": {
           "NameOfCity": {
             "type": "string"
           },
           "Kind": {
-            "$ref": "#/components/schemas/SupermarketType"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/SupermarketType"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1216,13 +1307,21 @@
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/JsonapiObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/JsonapiObject"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/LinksInResourceCollectionDocument"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/LinksInResourceCollectionDocument"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1235,17 +1334,29 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/SupermarketResourceType"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/SupermarketResourceType"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/SupermarketAttributesInPatchRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/SupermarketAttributesInPatchRequest"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/SupermarketRelationshipsInPatchRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/SupermarketRelationshipsInPatchRequest"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1257,13 +1368,25 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/SupermarketResourceType"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/SupermarketResourceType"
+              }
+            ]
           },
           "attributes": {
-            "$ref": "#/components/schemas/SupermarketAttributesInPostRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/SupermarketAttributesInPostRequest"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/SupermarketRelationshipsInPostRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/SupermarketRelationshipsInPostRequest"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1277,24 +1400,40 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/SupermarketResourceType"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/SupermarketResourceType"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/SupermarketAttributesInResponse"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/SupermarketAttributesInResponse"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/SupermarketRelationshipsInResponse"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/SupermarketRelationshipsInResponse"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/LinksInResourceObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/LinksInResourceObject"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -1306,7 +1445,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/SupermarketDataInPatchRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/SupermarketDataInPatchRequest"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1318,7 +1461,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/SupermarketDataInPostRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/SupermarketDataInPostRequest"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1331,17 +1478,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/SupermarketDataInResponse"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/SupermarketDataInResponse"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/JsonapiObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/JsonapiObject"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/LinksInResourceDocument"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/LinksInResourceDocument"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1350,13 +1509,25 @@
         "type": "object",
         "properties": {
           "StoreManager": {
-            "$ref": "#/components/schemas/ToOneStaffMemberInRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/ToOneStaffMemberInRequest"
+              }
+            ]
           },
           "BackupStoreManager": {
-            "$ref": "#/components/schemas/NullableToOneStaffMemberInRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/NullableToOneStaffMemberInRequest"
+              }
+            ]
           },
           "Cashiers": {
-            "$ref": "#/components/schemas/ToManyStaffMemberInRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/ToManyStaffMemberInRequest"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1368,28 +1539,55 @@
         "type": "object",
         "properties": {
           "StoreManager": {
-            "$ref": "#/components/schemas/ToOneStaffMemberInRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/ToOneStaffMemberInRequest"
+              }
+            ]
           },
           "BackupStoreManager": {
-            "$ref": "#/components/schemas/NullableToOneStaffMemberInRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/NullableToOneStaffMemberInRequest"
+              }
+            ]
           },
           "Cashiers": {
-            "$ref": "#/components/schemas/ToManyStaffMemberInRequest"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/ToManyStaffMemberInRequest"
+              }
+            ]
           }
         },
         "additionalProperties": false
       },
       "SupermarketRelationshipsInResponse": {
+        "required": [
+          "StoreManager"
+        ],
         "type": "object",
         "properties": {
           "StoreManager": {
-            "$ref": "#/components/schemas/ToOneStaffMemberInResponse"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/ToOneStaffMemberInResponse"
+              }
+            ]
           },
           "BackupStoreManager": {
-            "$ref": "#/components/schemas/NullableToOneStaffMemberInResponse"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/NullableToOneStaffMemberInResponse"
+              }
+            ]
           },
           "Cashiers": {
-            "$ref": "#/components/schemas/ToManyStaffMemberInResponse"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/ToManyStaffMemberInResponse"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1436,11 +1634,15 @@
             }
           },
           "links": {
-            "$ref": "#/components/schemas/LinksInRelationshipObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/LinksInRelationshipObject"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
@@ -1452,7 +1654,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/StaffMemberIdentifier"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/StaffMemberIdentifier"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -1464,18 +1670,26 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/StaffMemberIdentifier"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/StaffMemberIdentifier"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/LinksInRelationshipObject"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/LinksInRelationshipObject"
+              }
+            ]
           },
           "meta": {
             "type": "object",
-            "additionalProperties": { }
+            "additionalProperties": {}
           }
         },
         "additionalProperties": false
       }
     }
   }
-}
\ No newline at end of file
+}
diff --git a/test/OpenApiClientTests/ObjectExtensions.cs b/test/OpenApiClientTests/ObjectExtensions.cs
new file mode 100644
index 0000000000..9bf15b6ac7
--- /dev/null
+++ b/test/OpenApiClientTests/ObjectExtensions.cs
@@ -0,0 +1,37 @@
+using System.Reflection;
+using JsonApiDotNetCore.OpenApi.Client;
+
+namespace OpenApiClientTests;
+
+internal static class ObjectExtensions
+{
+    public static object? GetPropertyValue(this object source, string propertyName)
+    {
+        ArgumentGuard.NotNull(source);
+        ArgumentGuard.NotNull(propertyName);
+
+        PropertyInfo propertyInfo = source.GetType().GetProperties().Single(property => property.Name == propertyName);
+
+        return propertyInfo.GetValue(source);
+    }
+
+    public static void SetPropertyValue(this object source, string propertyName, object? value)
+    {
+        ArgumentGuard.NotNull(source);
+        ArgumentGuard.NotNull(propertyName);
+
+        PropertyInfo propertyInfo = source.GetType().GetProperties().Single(property => property.Name == propertyName);
+
+        propertyInfo.SetValue(source, value);
+    }
+
+    public static object? GetDefaultValueForProperty(this object source, string propertyName)
+    {
+        ArgumentGuard.NotNull(source);
+        ArgumentGuard.NotNull(propertyName);
+
+        PropertyInfo propertyInfo = source.GetType().GetProperties().Single(property => property.Name == propertyName);
+
+        return Activator.CreateInstance(propertyInfo.PropertyType);
+    }
+}
diff --git a/test/OpenApiClientTests/OpenApiClientTests.cs b/test/OpenApiClientTests/OpenApiClientTests.cs
new file mode 100644
index 0000000000..bb0b5d61a1
--- /dev/null
+++ b/test/OpenApiClientTests/OpenApiClientTests.cs
@@ -0,0 +1,20 @@
+using System.Linq.Expressions;
+
+namespace OpenApiClientTests;
+
+public class OpenApiClientTests
+{
+    private const string AttributesObjectParameterName = "attributesObject";
+
+    protected static Expression<Func<TAttributesObject, object?>> CreateIncludedAttributeSelector<TAttributesObject>(string propertyName)
+        where TAttributesObject : class
+    {
+        Type attributesObjectType = typeof(TAttributesObject);
+
+        ParameterExpression parameter = Expression.Parameter(attributesObjectType, AttributesObjectParameterName);
+        MemberExpression property = Expression.Property(parameter, propertyName);
+        UnaryExpression toObjectConversion = Expression.Convert(property, typeof(object));
+
+        return Expression.Lambda<Func<TAttributesObject, object?>>(toObjectConversion, parameter);
+    }
+}
diff --git a/test/OpenApiClientTests/OpenApiClientTests.csproj b/test/OpenApiClientTests/OpenApiClientTests.csproj
index 4d7bf979ec..c5e7f0acdd 100644
--- a/test/OpenApiClientTests/OpenApiClientTests.csproj
+++ b/test/OpenApiClientTests/OpenApiClientTests.csproj
@@ -9,6 +9,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="AutoBogus" Version="2.13.1" />
     <PackageReference Include="coverlet.collector" Version="$(CoverletVersion)" PrivateAssets="All" />
     <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="$(AspNetVersion)" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="$(TestSdkVersion)" />
@@ -52,5 +53,34 @@
       <CodeGenerator>NSwagCSharp</CodeGenerator>
       <Options>/UseBaseUrl:false /ClientClassAccessModifier:internal /GenerateExceptionClasses:false /AdditionalNamespaceUsages:JsonApiDotNetCore.OpenApi.Client.Exceptions</Options>
     </OpenApiReference>
+    <OpenApiReference Include="ResourceFieldValidation\NullableReferenceTypesDisabled\ModelStateValidationDisabled\swagger.g.json">
+      <ClassName>NrtOffMsvOffClient</ClassName>
+      <OutputPath>NrtOffMsvOffClient.cs</OutputPath>
+      <CodeGenerator>NSwagCSharp</CodeGenerator>
+      <Namespace>OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationDisabled.GeneratedCode</Namespace>
+      <Options>/UseBaseUrl:false /ClientClassAccessModifier:internal /GenerateExceptionClasses:false /AdditionalNamespaceUsages:JsonApiDotNetCore.OpenApi.Client.Exceptions /GenerateNullableReferenceTypes:false</Options>
+    </OpenApiReference>
+    <OpenApiReference Include="ResourceFieldValidation\NullableReferenceTypesDisabled\ModelStateValidationEnabled\swagger.g.json">
+      <ClassName>NrtOffMsvOnClient</ClassName>
+      <OutputPath>NrtOffMsvOnClient.cs</OutputPath>
+      <CodeGenerator>NSwagCSharp</CodeGenerator>
+      <Namespace>OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationEnabled.GeneratedCode</Namespace>
+      <Options>/UseBaseUrl:false /ClientClassAccessModifier:internal /GenerateExceptionClasses:false /AdditionalNamespaceUsages:JsonApiDotNetCore.OpenApi.Client.Exceptions /GenerateNullableReferenceTypes:false</Options>
+    </OpenApiReference>
+    <OpenApiReference Include="ResourceFieldValidation\NullableReferenceTypesEnabled\ModelStateValidationDisabled\swagger.g.json">
+      <ClassName>NrtOnMsvOffClient</ClassName>
+      <OutputPath>NrtOnMsvOffClient.cs</OutputPath>
+      <CodeGenerator>NSwagCSharp</CodeGenerator>
+      <Namespace>OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationDisabled.GeneratedCode</Namespace>
+      <Options>/UseBaseUrl:false /ClientClassAccessModifier:internal /GenerateExceptionClasses:false /AdditionalNamespaceUsages:JsonApiDotNetCore.OpenApi.Client.Exceptions /GenerateNullableReferenceTypes:true</Options>
+    </OpenApiReference>
+    <OpenApiReference Include="ResourceFieldValidation\NullableReferenceTypesEnabled\ModelStateValidationEnabled\swagger.g.json">
+      <ClassName>NrtOnMsvOnClient</ClassName>
+      <OutputPath>NrtOnMsvOnClient.cs</OutputPath>
+      <CodeGenerator>NSwagCSharp</CodeGenerator>
+      <Namespace>OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationEnabled.GeneratedCode</Namespace>
+      <Options>/UseBaseUrl:false /ClientClassAccessModifier:internal /GenerateExceptionClasses:false /AdditionalNamespaceUsages:JsonApiDotNetCore.OpenApi.Client.Exceptions /GenerateNullableReferenceTypes:true</Options>
+    </OpenApiReference>
   </ItemGroup>
-</Project>
\ No newline at end of file
+
+</Project>
diff --git a/test/OpenApiClientTests/PropertyInfoAssertionsExtension.cs b/test/OpenApiClientTests/PropertyInfoAssertionsExtension.cs
new file mode 100644
index 0000000000..e49bef1a0d
--- /dev/null
+++ b/test/OpenApiClientTests/PropertyInfoAssertionsExtension.cs
@@ -0,0 +1,20 @@
+using System.Reflection;
+using FluentAssertions;
+using FluentAssertions.Types;
+
+namespace OpenApiClientTests;
+
+internal static class PropertyInfoAssertionsExtensions
+{
+    [CustomAssertion]
+    public static void HaveNullabilityState(this PropertyInfoAssertions source, NullabilityState expected, string because = "", params object[] becauseArgs)
+    {
+        PropertyInfo propertyInfo = source.Subject;
+
+        NullabilityInfoContext nullabilityContext = new();
+        NullabilityInfo nullabilityInfo = nullabilityContext.Create(propertyInfo);
+
+        nullabilityInfo.ReadState.Should().Be(expected, because, becauseArgs);
+        nullabilityInfo.WriteState.Should().Be(expected, because, becauseArgs);
+    }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/CreateResourceTests.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/CreateResourceTests.cs
new file mode 100644
index 0000000000..5dfa347b05
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/CreateResourceTests.cs
@@ -0,0 +1,445 @@
+using System.Linq.Expressions;
+using System.Net;
+using System.Text.Json;
+using FluentAssertions;
+using FluentAssertions.Specialized;
+using Newtonsoft.Json;
+using OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationDisabled.GeneratedCode;
+using TestBuildingBlocks;
+using Xunit;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationDisabled;
+
+public sealed class CreateResourceTests : OpenApiClientTests
+{
+    private readonly ResourceFieldValidationFakers _fakers = new();
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ReferenceType), "referenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredReferenceType), "requiredReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableValueType), "nullableValueType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableValueType), "requiredNullableValueType")]
+    public async Task Can_clear_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOffClient(wrapper.HttpClient);
+
+        Expression<Func<ResourceAttributesInPostRequest, object?>> includeAttributeSelector =
+            CreateIncludedAttributeSelector<ResourceAttributesInPostRequest>(attributePropertyName);
+
+        using (apiClient.WithPartialAttributeSerialization(requestDocument, includeAttributeSelector))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.attributes").With(attributesObject =>
+        {
+            attributesObject.ShouldContainPath(jsonPropertyName).With(attribute => attribute.ValueKind.Should().Be(JsonValueKind.Null));
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ValueType), "valueType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredValueType), "requiredValueType")]
+    public async Task Can_set_default_value_to_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? defaultValue = requestDocument.Data.Attributes.GetDefaultValueForProperty(attributePropertyName);
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, defaultValue);
+
+        Expression<Func<ResourceAttributesInPostRequest, object?>> includeAttributeSelector =
+            CreateIncludedAttributeSelector<ResourceAttributesInPostRequest>(attributePropertyName);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOffClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization(requestDocument, includeAttributeSelector))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.attributes").With(attributesObject =>
+        {
+            attributesObject.ShouldContainPath(jsonPropertyName).With(attribute => attribute.ShouldBeInteger(0));
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ReferenceType), "referenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ValueType), "valueType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableValueType), "nullableValueType")]
+    public async Task Can_exclude_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceAttributesInPostRequest emptyAttributesObject = new();
+        object? defaultValue = emptyAttributesObject.GetPropertyValue(attributePropertyName);
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOffClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.attributes").With(attributesObject =>
+        {
+            attributesObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredReferenceType), "requiredReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredValueType), "requiredValueType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableValueType), "requiredNullableValueType")]
+    public async Task Cannot_exclude_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceAttributesInPostRequest emptyAttributesObject = new();
+        object? defaultValue = emptyAttributesObject.GetPropertyValue(attributePropertyName);
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOffClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+                await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+            // Assert
+            ExceptionAssertions<InvalidOperationException> assertion = await action.Should().ThrowExactlyAsync<InvalidOperationException>();
+            InvalidOperationException exception = assertion.Subject.Single();
+            exception.Message.Should().Be($"The following property should not be omitted: data.attributes.{jsonPropertyName}.");
+        }
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToOne), nameof(ResourceRelationshipsInPostRequest.ToOne.Data), "toOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToOne), nameof(ResourceRelationshipsInPostRequest.RequiredToOne.Data), "requiredToOne")]
+    public async Task Can_clear_relationship_with_partial_attribute_serialization(string relationshipPropertyName, string dataPropertyName,
+        string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? relationshipObject = requestDocument.Data.Relationships.GetPropertyValue(relationshipPropertyName);
+        relationshipObject!.SetPropertyValue(dataPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOffClient(wrapper.HttpClient);
+
+        // Act
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath($"data.relationships.{jsonPropertyName}.data").With(relationshipDataObject =>
+        {
+            relationshipDataObject.ValueKind.Should().Be(JsonValueKind.Null);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToOne), nameof(ResourceRelationshipsInPostRequest.ToOne.Data), "toOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToOne), nameof(ResourceRelationshipsInPostRequest.RequiredToOne.Data), "requiredToOne")]
+    public async Task Can_clear_relationship_without_partial_attribute_serialization(string relationshipPropertyName, string dataPropertyName,
+        string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? relationshipObject = requestDocument.Data.Relationships.GetPropertyValue(relationshipPropertyName);
+        relationshipObject!.SetPropertyValue(dataPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOffClient(wrapper.HttpClient);
+
+        // Act
+        await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath($"data.relationships.{jsonPropertyName}.data").With(relationshipDataObject =>
+        {
+            relationshipDataObject.ValueKind.Should().Be(JsonValueKind.Null);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToMany), nameof(ResourceRelationshipsInPostRequest.ToMany.Data), "toMany")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToMany), nameof(ResourceRelationshipsInPostRequest.RequiredToMany.Data), "requiredToMany")]
+    public async Task Cannot_clear_relationship_with_partial_attribute_serialization(string relationshipPropertyName, string dataPropertyName,
+        string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? relationshipObject = requestDocument.Data.Relationships.GetPropertyValue(relationshipPropertyName);
+        relationshipObject!.SetPropertyValue(dataPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOffClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+                await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+            // Assert
+            ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+            JsonSerializationException exception = assertion.Subject.Single();
+
+            exception.Message.Should()
+                .Be($"Cannot write a null value for property 'data'. Property requires a value. Path 'data.relationships.{jsonPropertyName}'.");
+        }
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToMany), nameof(ResourceRelationshipsInPostRequest.ToMany.Data), "toMany")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToMany), nameof(ResourceRelationshipsInPostRequest.RequiredToMany.Data), "requiredToMany")]
+    public async Task Cannot_clear_relationship_without_partial_attribute_serialization(string relationshipPropertyName, string dataPropertyName,
+        string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? relationshipObject = requestDocument.Data.Relationships.GetPropertyValue(relationshipPropertyName);
+        relationshipObject!.SetPropertyValue(dataPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOffClient(wrapper.HttpClient);
+
+        // Act
+        Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+        // Assert
+        ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+        JsonSerializationException exception = assertion.Subject.Single();
+
+        exception.Message.Should()
+            .Be($"Cannot write a null value for property 'data'. Property requires a value. Path 'data.relationships.{jsonPropertyName}'.");
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToOne), "toOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToMany), "toMany")]
+    public async Task Can_exclude_relationship_with_partial_attribute_serialization(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPostRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOffClient(wrapper.HttpClient);
+
+        // Act
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.relationships").With(relationshipsObject =>
+        {
+            relationshipsObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToOne), "toOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToMany), "toMany")]
+    public async Task Can_exclude_relationship_without_partial_attribute_serialization(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPostRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOffClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.relationships").With(relationshipsObject =>
+        {
+            relationshipsObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/GeneratedCode/NrtOffMsvOffClient.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/GeneratedCode/NrtOffMsvOffClient.cs
new file mode 100644
index 0000000000..4bea9db090
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/GeneratedCode/NrtOffMsvOffClient.cs
@@ -0,0 +1,14 @@
+using JsonApiDotNetCore.OpenApi.Client;
+using Newtonsoft.Json;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationDisabled.GeneratedCode;
+
+internal partial class NrtOffMsvOffClient : JsonApiClient
+{
+    partial void UpdateJsonSerializerSettings(JsonSerializerSettings settings)
+    {
+        SetSerializerSettingsForJsonApi(settings);
+
+        settings.Formatting = Formatting.Indented;
+    }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/NullabilityTests.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/NullabilityTests.cs
new file mode 100644
index 0000000000..8079c4896c
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/NullabilityTests.cs
@@ -0,0 +1,23 @@
+using System.Reflection;
+using FluentAssertions;
+using OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationDisabled.GeneratedCode;
+using Xunit;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationDisabled;
+
+public sealed class NullabilityTests
+{
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ReferenceType), NullabilityState.Unknown)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredReferenceType), NullabilityState.Unknown)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ValueType), NullabilityState.NotNull)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredValueType), NullabilityState.NotNull)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableValueType), NullabilityState.Nullable)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableValueType), NullabilityState.Nullable)]
+    public void Nullability_of_generated_property_is_as_expected(string propertyName, NullabilityState expectedState)
+    {
+        PropertyInfo[] properties = typeof(ResourceAttributesInPostRequest).GetProperties();
+        PropertyInfo property = properties.Single(property => property.Name == propertyName);
+        property.Should().HaveNullabilityState(expectedState);
+    }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/ResourceFieldValidationFakers.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/ResourceFieldValidationFakers.cs
new file mode 100644
index 0000000000..817344c11c
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/ResourceFieldValidationFakers.cs
@@ -0,0 +1,24 @@
+using Bogus;
+using OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationDisabled.GeneratedCode;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationDisabled;
+
+internal sealed class ResourceFieldValidationFakers
+{
+    private readonly Lazy<Faker<ResourceAttributesInPostRequest>> _lazyPostAttributesFaker = new(() =>
+        FakerFactory.Instance.Create<ResourceAttributesInPostRequest>());
+
+    private readonly Lazy<Faker<ResourceAttributesInPatchRequest>> _lazyPatchAttributesFaker = new(() =>
+        FakerFactory.Instance.Create<ResourceAttributesInPatchRequest>());
+
+    private readonly Lazy<Faker<NullableToOneEmptyResourceInRequest>> _lazyNullableToOneFaker = new(() =>
+        FakerFactory.Instance.CreateForObjectWithResourceId<NullableToOneEmptyResourceInRequest, int>());
+
+    private readonly Lazy<Faker<ToManyEmptyResourceInRequest>> _lazyToManyFaker = new(() =>
+        FakerFactory.Instance.CreateForObjectWithResourceId<ToManyEmptyResourceInRequest, int>());
+
+    public Faker<ResourceAttributesInPostRequest> PostAttributes => _lazyPostAttributesFaker.Value;
+    public Faker<ResourceAttributesInPatchRequest> PatchAttributes => _lazyPatchAttributesFaker.Value;
+    public Faker<NullableToOneEmptyResourceInRequest> NullableToOne => _lazyNullableToOneFaker.Value;
+    public Faker<ToManyEmptyResourceInRequest> ToMany => _lazyToManyFaker.Value;
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/UpdateResourceTests.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/UpdateResourceTests.cs
new file mode 100644
index 0000000000..68e71e97b9
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/UpdateResourceTests.cs
@@ -0,0 +1,146 @@
+using System.Net;
+using System.Text.Json;
+using FluentAssertions;
+using FluentAssertions.Specialized;
+using Newtonsoft.Json;
+using OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationDisabled.GeneratedCode;
+using TestBuildingBlocks;
+using Xunit;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationDisabled;
+
+public sealed class UpdateResourceTests
+{
+    private readonly ResourceFieldValidationFakers _fakers = new();
+
+    [Fact]
+    public async Task Cannot_exclude_id()
+    {
+        // Arrange
+        var requestDocument = new ResourcePatchRequestDocument
+        {
+            Data = new ResourceDataInPatchRequest
+            {
+                Id = "1",
+                Attributes = _fakers.PatchAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPatchRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceDataInPatchRequest emptyDataObject = new();
+        requestDocument.Data.Id = emptyDataObject.Id;
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOffClient(wrapper.HttpClient);
+
+        // Act
+        Func<Task> action = async () => await ApiResponse.TranslateAsync(async () => await apiClient.PatchResourceAsync(999, requestDocument));
+
+        // Assert
+        await action.Should().ThrowAsync<JsonSerializationException>();
+        ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+        JsonSerializationException exception = assertion.Subject.Single();
+
+        exception.Message.Should().Be("Cannot write a null value for property 'id'. Property requires a value. Path 'data'.");
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.ReferenceType), "referenceType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.RequiredReferenceType), "requiredReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.ValueType), "valueType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.RequiredValueType), "requiredValueType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.NullableValueType), "nullableValueType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.RequiredNullableValueType), "requiredNullableValueType")]
+    public async Task Can_exclude_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePatchRequestDocument
+        {
+            Data = new ResourceDataInPatchRequest
+            {
+                Id = "1",
+                Attributes = _fakers.PatchAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPatchRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceAttributesInPatchRequest emptyAttributesObject = new();
+        object? defaultValue = emptyAttributesObject.GetPropertyValue(attributePropertyName);
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOffClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePatchRequestDocument, ResourceAttributesInPatchRequest>(requestDocument))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PatchResourceAsync(int.Parse(requestDocument.Data.Id), requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.attributes").With(attributesObject =>
+        {
+            attributesObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.ToOne), "toOne")]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.RequiredToOne), "requiredToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.ToMany), "toMany")]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.RequiredToMany), "requiredToMany")]
+    public async Task Can_exclude_relationship(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePatchRequestDocument
+        {
+            Data = new ResourceDataInPatchRequest
+            {
+                Id = "1",
+                Attributes = _fakers.PatchAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPatchRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPatchRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOffClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePatchRequestDocument, ResourceAttributesInPatchRequest>(requestDocument))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PatchResourceAsync(int.Parse(requestDocument.Data.Id), requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.relationships").With(relationshipsObject =>
+        {
+            relationshipsObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/swagger.g.json b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/swagger.g.json
new file mode 100644
index 0000000000..27d5a781d9
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/swagger.g.json
@@ -0,0 +1,1854 @@
+{
+  "openapi": "3.0.1",
+  "info": {
+    "title": "OpenApiTests",
+    "version": "1.0"
+  },
+  "paths": {
+    "/Resource": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceCollection",
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceCollection",
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "post": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "postResource",
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/resourcePostRequestDocument"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "201": {
+            "description": "Created",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourcePrimaryResponseDocument"
+                }
+              }
+            }
+          },
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResource",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourcePrimaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResource",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourcePrimaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResource",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/resourcePatchRequestDocument"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourcePrimaryResponseDocument"
+                }
+              }
+            }
+          },
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "delete": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "deleteResource",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/requiredToMany": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredToMany",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredToMany",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/requiredToMany": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "post": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "postResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "delete": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "deleteResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/requiredToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/requiredToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceRequiredToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/toMany": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceToMany",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceToMany",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/toMany": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "post": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "postResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "delete": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "deleteResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/toOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/toOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    }
+  },
+  "components": {
+    "schemas": {
+      "emptyResourceCollectionResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/emptyResourceDataInResponse"
+            }
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceCollectionDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceDataInResponse": {
+        "required": [
+          "id",
+          "links",
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceResourceType"
+              }
+            ]
+          },
+          "id": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceIdentifier": {
+        "required": [
+          "id",
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceResourceType"
+              }
+            ]
+          },
+          "id": {
+            "minLength": 1,
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceIdentifierCollectionResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/emptyResourceIdentifier"
+            }
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceIdentifierCollectionDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceResourceType": {
+        "enum": [
+          "emptyResources"
+        ],
+        "type": "string"
+      },
+      "jsonapiObject": {
+        "type": "object",
+        "properties": {
+          "version": {
+            "type": "string"
+          },
+          "ext": {
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
+          },
+          "profile": {
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInRelationshipObject": {
+        "required": [
+          "related",
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "related": {
+            "minLength": 1,
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceCollectionDocument": {
+        "required": [
+          "first",
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "describedby": {
+            "type": "string"
+          },
+          "first": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "last": {
+            "type": "string"
+          },
+          "prev": {
+            "type": "string"
+          },
+          "next": {
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceDocument": {
+        "required": [
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "describedby": {
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceIdentifierCollectionDocument": {
+        "required": [
+          "first",
+          "related",
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "describedby": {
+            "type": "string"
+          },
+          "related": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "first": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "last": {
+            "type": "string"
+          },
+          "prev": {
+            "type": "string"
+          },
+          "next": {
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceIdentifierDocument": {
+        "required": [
+          "related",
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "describedby": {
+            "type": "string"
+          },
+          "related": {
+            "minLength": 1,
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceObject": {
+        "required": [
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "nullableEmptyResourceIdentifierResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ],
+            "nullable": true
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceIdentifierDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "nullableEmptyResourceSecondaryResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceDataInResponse"
+              }
+            ],
+            "nullable": true
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "nullableToOneEmptyResourceInRequest": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ],
+            "nullable": true
+          }
+        },
+        "additionalProperties": false
+      },
+      "nullableToOneEmptyResourceInResponse": {
+        "required": [
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ],
+            "nullable": true
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInRelationshipObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceAttributesInPatchRequest": {
+        "type": "object",
+        "properties": {
+          "referenceType": {
+            "type": "string",
+            "nullable": true
+          },
+          "requiredReferenceType": {
+            "minLength": 1,
+            "type": "string",
+            "nullable": true
+          },
+          "valueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "requiredValueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "nullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          },
+          "requiredNullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceAttributesInPostRequest": {
+        "required": [
+          "requiredNullableValueType",
+          "requiredReferenceType",
+          "requiredValueType"
+        ],
+        "type": "object",
+        "properties": {
+          "referenceType": {
+            "type": "string",
+            "nullable": true
+          },
+          "requiredReferenceType": {
+            "minLength": 1,
+            "type": "string",
+            "nullable": true
+          },
+          "valueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "requiredValueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "nullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          },
+          "requiredNullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceAttributesInResponse": {
+        "required": [
+          "requiredNullableValueType",
+          "requiredReferenceType",
+          "requiredValueType"
+        ],
+        "type": "object",
+        "properties": {
+          "referenceType": {
+            "type": "string",
+            "nullable": true
+          },
+          "requiredReferenceType": {
+            "minLength": 1,
+            "type": "string",
+            "nullable": true
+          },
+          "valueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "requiredValueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "nullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          },
+          "requiredNullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceCollectionResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/resourceDataInResponse"
+            }
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceCollectionDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceDataInPatchRequest": {
+        "required": [
+          "id",
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceResourceType"
+              }
+            ]
+          },
+          "id": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "attributes": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceAttributesInPatchRequest"
+              }
+            ]
+          },
+          "relationships": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceRelationshipsInPatchRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceDataInPostRequest": {
+        "required": [
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceResourceType"
+              }
+            ]
+          },
+          "attributes": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceAttributesInPostRequest"
+              }
+            ]
+          },
+          "relationships": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceRelationshipsInPostRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceDataInResponse": {
+        "required": [
+          "id",
+          "links",
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceResourceType"
+              }
+            ]
+          },
+          "id": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "attributes": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceAttributesInResponse"
+              }
+            ]
+          },
+          "relationships": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceRelationshipsInResponse"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourcePatchRequestDocument": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceDataInPatchRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourcePostRequestDocument": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceDataInPostRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourcePrimaryResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceDataInResponse"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceRelationshipsInPatchRequest": {
+        "type": "object",
+        "properties": {
+          "toOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "toMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredToMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceRelationshipsInPostRequest": {
+        "required": [
+          "requiredToMany",
+          "requiredToOne"
+        ],
+        "type": "object",
+        "properties": {
+          "toOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "toMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredToMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceRelationshipsInResponse": {
+        "required": [
+          "requiredToMany",
+          "requiredToOne"
+        ],
+        "type": "object",
+        "properties": {
+          "toOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInResponse"
+              }
+            ]
+          },
+          "requiredToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInResponse"
+              }
+            ]
+          },
+          "toMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInResponse"
+              }
+            ]
+          },
+          "requiredToMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInResponse"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceResourceType": {
+        "enum": [
+          "Resource"
+        ],
+        "type": "string"
+      },
+      "toManyEmptyResourceInRequest": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/emptyResourceIdentifier"
+            }
+          }
+        },
+        "additionalProperties": false
+      },
+      "toManyEmptyResourceInResponse": {
+        "required": [
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/emptyResourceIdentifier"
+            }
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInRelationshipObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      }
+    }
+  }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/CreateResourceTests.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/CreateResourceTests.cs
new file mode 100644
index 0000000000..f3a5130486
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/CreateResourceTests.cs
@@ -0,0 +1,569 @@
+using System.Linq.Expressions;
+using System.Net;
+using System.Text.Json;
+using FluentAssertions;
+using FluentAssertions.Specialized;
+using Newtonsoft.Json;
+using OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationEnabled.GeneratedCode;
+using TestBuildingBlocks;
+using Xunit;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationEnabled;
+
+public sealed class CreateResourceTests : OpenApiClientTests
+{
+    private readonly ResourceFieldValidationFakers _fakers = new();
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ReferenceType), "referenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableValueType), "nullableValueType")]
+    public async Task Can_clear_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOnClient(wrapper.HttpClient);
+
+        Expression<Func<ResourceAttributesInPostRequest, object?>> includeAttributeSelector =
+            CreateIncludedAttributeSelector<ResourceAttributesInPostRequest>(attributePropertyName);
+
+        using (apiClient.WithPartialAttributeSerialization(requestDocument, includeAttributeSelector))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.attributes").With(attributesObject =>
+        {
+            attributesObject.ShouldContainPath(jsonPropertyName).With(attribute => attribute.ValueKind.Should().Be(JsonValueKind.Null));
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ValueType), "valueType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredValueType), "requiredValueType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableValueType), "requiredNullableValueType")]
+    public async Task Can_set_default_value_to_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? defaultValue = requestDocument.Data.Attributes.GetDefaultValueForProperty(attributePropertyName);
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, defaultValue);
+
+        Expression<Func<ResourceAttributesInPostRequest, object?>> includeAttributeSelector =
+            CreateIncludedAttributeSelector<ResourceAttributesInPostRequest>(attributePropertyName);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOnClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization(requestDocument, includeAttributeSelector))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.attributes").With(attributesObject =>
+        {
+            attributesObject.ShouldContainPath(jsonPropertyName).With(attribute => attribute.ShouldBeInteger(0));
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredReferenceType), "requiredReferenceType")]
+    public async Task Cannot_clear_attribute(string clrPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        requestDocument.Data.Attributes.SetPropertyValue(clrPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOnClient(wrapper.HttpClient);
+
+        Expression<Func<ResourceAttributesInPostRequest, object?>> includeAttributeSelector =
+            CreateIncludedAttributeSelector<ResourceAttributesInPostRequest>(clrPropertyName);
+
+        using (apiClient.WithPartialAttributeSerialization(requestDocument, includeAttributeSelector))
+        {
+            // Act
+            Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+                await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+            // Assert
+            ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+            JsonSerializationException exception = assertion.Subject.Single();
+
+            exception.Message.Should().Contain($"Cannot write a null value for property '{jsonPropertyName}'.");
+        }
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ReferenceType), "referenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ValueType), "valueType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredValueType), "requiredValueType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableValueType), "nullableValueType")]
+    public async Task Can_exclude_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceAttributesInPostRequest emptyAttributesObject = new();
+        object? defaultValue = emptyAttributesObject.GetPropertyValue(attributePropertyName);
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOnClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.attributes").With(attributesObject =>
+        {
+            attributesObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredReferenceType), "requiredReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableValueType), "requiredNullableValueType")]
+    public async Task Cannot_exclude_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceAttributesInPostRequest emptyAttributesObject = new();
+        object? defaultValue = emptyAttributesObject.GetPropertyValue(attributePropertyName);
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOnClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+                await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+            // Assert
+            ExceptionAssertions<InvalidOperationException> assertion = await action.Should().ThrowExactlyAsync<InvalidOperationException>();
+            InvalidOperationException exception = assertion.Subject.Single();
+            exception.Message.Should().Be($"The following property should not be omitted: data.attributes.{jsonPropertyName}.");
+        }
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToOne), nameof(ResourceRelationshipsInPostRequest.ToOne.Data), "toOne")]
+    public async Task Can_clear_relationship_with_partial_attribute_serialization(string relationshipPropertyName, string dataPropertyName,
+        string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? relationshipObject = requestDocument.Data.Relationships.GetPropertyValue(relationshipPropertyName);
+        relationshipObject!.SetPropertyValue(dataPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOnClient(wrapper.HttpClient);
+
+        // Act
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath($"data.relationships.{jsonPropertyName}.data").With(relationshipDataObject =>
+        {
+            relationshipDataObject.ValueKind.Should().Be(JsonValueKind.Null);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToOne), nameof(ResourceRelationshipsInPostRequest.ToOne.Data), "toOne")]
+    public async Task Can_clear_relationship_without_partial_attribute_serialization(string relationshipPropertyName, string dataPropertyName,
+        string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? relationshipObject = requestDocument.Data.Relationships.GetPropertyValue(relationshipPropertyName);
+        relationshipObject!.SetPropertyValue(dataPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOnClient(wrapper.HttpClient);
+
+        // Act
+        await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath($"data.relationships.{jsonPropertyName}.data").With(relationshipDataObject =>
+        {
+            relationshipDataObject.ValueKind.Should().Be(JsonValueKind.Null);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToOne), nameof(ResourceRelationshipsInPostRequest.RequiredToOne.Data), "requiredToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToMany), nameof(ResourceRelationshipsInPostRequest.ToMany.Data), "toMany")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToMany), nameof(ResourceRelationshipsInPostRequest.RequiredToMany.Data), "requiredToMany")]
+    public async Task Cannot_clear_relationship_with_partial_attribute_serialization(string relationshipPropertyName, string dataPropertyName,
+        string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? relationshipObject = requestDocument.Data.Relationships.GetPropertyValue(relationshipPropertyName);
+        relationshipObject!.SetPropertyValue(dataPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOnClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+                await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+            // Assert
+            ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+            JsonSerializationException exception = assertion.Subject.Single();
+
+            exception.Message.Should()
+                .Be($"Cannot write a null value for property 'data'. Property requires a value. Path 'data.relationships.{jsonPropertyName}'.");
+        }
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToOne), nameof(ResourceRelationshipsInPostRequest.RequiredToOne.Data), "requiredToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToMany), nameof(ResourceRelationshipsInPostRequest.ToMany.Data), "toMany")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToMany), nameof(ResourceRelationshipsInPostRequest.RequiredToMany.Data), "requiredToMany")]
+    public async Task Cannot_clear_relationship_without_partial_attribute_serialization(string relationshipPropertyName, string dataPropertyName,
+        string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? relationshipObject = requestDocument.Data.Relationships.GetPropertyValue(relationshipPropertyName);
+        relationshipObject!.SetPropertyValue(dataPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOnClient(wrapper.HttpClient);
+
+        // Act
+        Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+        // Assert
+        ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+        JsonSerializationException exception = assertion.Subject.Single();
+
+        exception.Message.Should()
+            .Be($"Cannot write a null value for property 'data'. Property requires a value. Path 'data.relationships.{jsonPropertyName}'.");
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToOne), "toOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToMany), "toMany")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToMany), "requiredToMany")]
+    public async Task Can_exclude_relationship_with_partial_attribute_serialization(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPostRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOnClient(wrapper.HttpClient);
+
+        // Act
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.relationships").With(relationshipsObject =>
+        {
+            relationshipsObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToOne), "toOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToMany), "toMany")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToMany), "requiredToMany")]
+    public async Task Can_exclude_relationship_without_partial_attribute_serialization(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPostRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOnClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.relationships").With(relationshipsObject =>
+        {
+            relationshipsObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToOne), "requiredToOne")]
+    public async Task Cannot_exclude_relationship_with_partial_attribute_serialization(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPostRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOnClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+                await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+            // Assert
+            ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+            JsonSerializationException exception = assertion.Subject.Single();
+
+            exception.Message.Should()
+                .Be($"Cannot write a null value for property 'id'. Property requires a value. Path 'data.relationships.{jsonPropertyName}.data'.");
+        }
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToOne), "requiredToOne")]
+    public async Task Cannot_exclude_relationship_without_partial_attribute_serialization(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPostRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOnClient(wrapper.HttpClient);
+
+        // Act
+        Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+        // Assert
+        ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+        JsonSerializationException exception = assertion.Subject.Single();
+
+        exception.Message.Should()
+            .Be($"Cannot write a null value for property 'id'. Property requires a value. Path 'data.relationships.{jsonPropertyName}.data'.");
+    }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/GeneratedCode/NrtOffMsvOnClient.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/GeneratedCode/NrtOffMsvOnClient.cs
new file mode 100644
index 0000000000..94bb5efc37
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/GeneratedCode/NrtOffMsvOnClient.cs
@@ -0,0 +1,14 @@
+using JsonApiDotNetCore.OpenApi.Client;
+using Newtonsoft.Json;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationEnabled.GeneratedCode;
+
+internal partial class NrtOffMsvOnClient : JsonApiClient
+{
+    partial void UpdateJsonSerializerSettings(JsonSerializerSettings settings)
+    {
+        SetSerializerSettingsForJsonApi(settings);
+
+        settings.Formatting = Formatting.Indented;
+    }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/NullabilityTests.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/NullabilityTests.cs
new file mode 100644
index 0000000000..53252ee439
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/NullabilityTests.cs
@@ -0,0 +1,23 @@
+using System.Reflection;
+using FluentAssertions;
+using OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationEnabled.GeneratedCode;
+using Xunit;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationEnabled;
+
+public sealed class NullabilityTests
+{
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ReferenceType), NullabilityState.Unknown)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredReferenceType), NullabilityState.Unknown)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ValueType), NullabilityState.NotNull)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredValueType), NullabilityState.NotNull)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableValueType), NullabilityState.Nullable)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableValueType), NullabilityState.NotNull)]
+    public void Nullability_of_generated_property_is_as_expected(string propertyName, NullabilityState expectedState)
+    {
+        PropertyInfo[] properties = typeof(ResourceAttributesInPostRequest).GetProperties();
+        PropertyInfo property = properties.Single(property => property.Name == propertyName);
+        property.Should().HaveNullabilityState(expectedState);
+    }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/ResourceFieldValidationFakers.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/ResourceFieldValidationFakers.cs
new file mode 100644
index 0000000000..e3dbbd0d36
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/ResourceFieldValidationFakers.cs
@@ -0,0 +1,28 @@
+using Bogus;
+using OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationEnabled.GeneratedCode;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationEnabled;
+
+internal sealed class ResourceFieldValidationFakers
+{
+    private readonly Lazy<Faker<ResourceAttributesInPostRequest>> _lazyPostAttributesFaker = new(() =>
+        FakerFactory.Instance.Create<ResourceAttributesInPostRequest>());
+
+    private readonly Lazy<Faker<ResourceAttributesInPatchRequest>> _lazyPatchAttributesFaker = new(() =>
+        FakerFactory.Instance.Create<ResourceAttributesInPatchRequest>());
+
+    private readonly Lazy<Faker<ToOneEmptyResourceInRequest>> _lazyToOneFaker = new(() =>
+        FakerFactory.Instance.CreateForObjectWithResourceId<ToOneEmptyResourceInRequest, int>());
+
+    private readonly Lazy<Faker<NullableToOneEmptyResourceInRequest>> _lazyNullableToOneFaker = new(() =>
+        FakerFactory.Instance.CreateForObjectWithResourceId<NullableToOneEmptyResourceInRequest, int>());
+
+    private readonly Lazy<Faker<ToManyEmptyResourceInRequest>> _lazyToManyFaker = new(() =>
+        FakerFactory.Instance.CreateForObjectWithResourceId<ToManyEmptyResourceInRequest, int>());
+
+    public Faker<ResourceAttributesInPostRequest> PostAttributes => _lazyPostAttributesFaker.Value;
+    public Faker<ResourceAttributesInPatchRequest> PatchAttributes => _lazyPatchAttributesFaker.Value;
+    public Faker<ToOneEmptyResourceInRequest> ToOne => _lazyToOneFaker.Value;
+    public Faker<NullableToOneEmptyResourceInRequest> NullableToOne => _lazyNullableToOneFaker.Value;
+    public Faker<ToManyEmptyResourceInRequest> ToMany => _lazyToManyFaker.Value;
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/UpdateResourceTests.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/UpdateResourceTests.cs
new file mode 100644
index 0000000000..81f54f6dd0
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/UpdateResourceTests.cs
@@ -0,0 +1,146 @@
+using System.Net;
+using System.Text.Json;
+using FluentAssertions;
+using FluentAssertions.Specialized;
+using Newtonsoft.Json;
+using OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationEnabled.GeneratedCode;
+using TestBuildingBlocks;
+using Xunit;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationEnabled;
+
+public sealed class UpdateResourceTests
+{
+    private readonly ResourceFieldValidationFakers _fakers = new();
+
+    [Fact]
+    public async Task Cannot_exclude_id()
+    {
+        // Arrange
+        var requestDocument = new ResourcePatchRequestDocument
+        {
+            Data = new ResourceDataInPatchRequest
+            {
+                Id = "1",
+                Attributes = _fakers.PatchAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPatchRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceDataInPatchRequest emptyDataObject = new();
+        requestDocument.Data.Id = emptyDataObject.Id;
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOnClient(wrapper.HttpClient);
+
+        // Act
+        Func<Task> action = async () => await ApiResponse.TranslateAsync(async () => await apiClient.PatchResourceAsync(999, requestDocument));
+
+        // Assert
+        await action.Should().ThrowAsync<JsonSerializationException>();
+        ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+        JsonSerializationException exception = assertion.Subject.Single();
+
+        exception.Message.Should().Be("Cannot write a null value for property 'id'. Property requires a value. Path 'data'.");
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.ReferenceType), "referenceType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.RequiredReferenceType), "requiredReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.ValueType), "valueType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.RequiredValueType), "requiredValueType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.NullableValueType), "nullableValueType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.RequiredNullableValueType), "requiredNullableValueType")]
+    public async Task Can_exclude_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePatchRequestDocument
+        {
+            Data = new ResourceDataInPatchRequest
+            {
+                Id = "1",
+                Attributes = _fakers.PatchAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPatchRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceAttributesInPatchRequest emptyAttributesObject = new();
+        object? defaultValue = emptyAttributesObject.GetPropertyValue(attributePropertyName);
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOnClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePatchRequestDocument, ResourceAttributesInPatchRequest>(requestDocument))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PatchResourceAsync(int.Parse(requestDocument.Data.Id), requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.attributes").With(attributesObject =>
+        {
+            attributesObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.ToOne), "toOne")]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.RequiredToOne), "requiredToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.ToMany), "toMany")]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.RequiredToMany), "requiredToMany")]
+    public async Task Can_exclude_relationship(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePatchRequestDocument
+        {
+            Data = new ResourceDataInPatchRequest
+            {
+                Id = "1",
+                Attributes = _fakers.PatchAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPatchRequest
+                {
+                    ToOne = _fakers.NullableToOne.Generate(),
+                    RequiredToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPatchRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOffMsvOnClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePatchRequestDocument, ResourceAttributesInPatchRequest>(requestDocument))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PatchResourceAsync(int.Parse(requestDocument.Data.Id), requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.relationships").With(relationshipsObject =>
+        {
+            relationshipsObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/swagger.g.json b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/swagger.g.json
new file mode 100644
index 0000000000..56e047eaee
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/swagger.g.json
@@ -0,0 +1,1957 @@
+{
+  "openapi": "3.0.1",
+  "info": {
+    "title": "OpenApiTests",
+    "version": "1.0"
+  },
+  "paths": {
+    "/Resource": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceCollection",
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceCollection",
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "post": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "postResource",
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/resourcePostRequestDocument"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "201": {
+            "description": "Created",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourcePrimaryResponseDocument"
+                }
+              }
+            }
+          },
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResource",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourcePrimaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResource",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourcePrimaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResource",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/resourcePatchRequestDocument"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourcePrimaryResponseDocument"
+                }
+              }
+            }
+          },
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "delete": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "deleteResource",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/requiredToMany": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredToMany",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredToMany",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/requiredToMany": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "post": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "postResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "delete": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "deleteResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/requiredToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/requiredToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceRequiredToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/toMany": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceToMany",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceToMany",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/toMany": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "post": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "postResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "delete": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "deleteResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/toOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/toOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    }
+  },
+  "components": {
+    "schemas": {
+      "emptyResourceCollectionResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/emptyResourceDataInResponse"
+            }
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceCollectionDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceDataInResponse": {
+        "required": [
+          "id",
+          "links",
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceResourceType"
+              }
+            ]
+          },
+          "id": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceIdentifier": {
+        "required": [
+          "id",
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceResourceType"
+              }
+            ]
+          },
+          "id": {
+            "minLength": 1,
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceIdentifierCollectionResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/emptyResourceIdentifier"
+            }
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceIdentifierCollectionDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceIdentifierResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceIdentifierDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceResourceType": {
+        "enum": [
+          "emptyResources"
+        ],
+        "type": "string"
+      },
+      "emptyResourceSecondaryResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceDataInResponse"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "jsonapiObject": {
+        "type": "object",
+        "properties": {
+          "version": {
+            "type": "string"
+          },
+          "ext": {
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
+          },
+          "profile": {
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInRelationshipObject": {
+        "required": [
+          "related",
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "related": {
+            "minLength": 1,
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceCollectionDocument": {
+        "required": [
+          "first",
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "describedby": {
+            "type": "string"
+          },
+          "first": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "last": {
+            "type": "string"
+          },
+          "prev": {
+            "type": "string"
+          },
+          "next": {
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceDocument": {
+        "required": [
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "describedby": {
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceIdentifierCollectionDocument": {
+        "required": [
+          "first",
+          "related",
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "describedby": {
+            "type": "string"
+          },
+          "related": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "first": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "last": {
+            "type": "string"
+          },
+          "prev": {
+            "type": "string"
+          },
+          "next": {
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceIdentifierDocument": {
+        "required": [
+          "related",
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "describedby": {
+            "type": "string"
+          },
+          "related": {
+            "minLength": 1,
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceObject": {
+        "required": [
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "nullableEmptyResourceIdentifierResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ],
+            "nullable": true
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceIdentifierDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "nullableEmptyResourceSecondaryResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceDataInResponse"
+              }
+            ],
+            "nullable": true
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "nullableToOneEmptyResourceInRequest": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ],
+            "nullable": true
+          }
+        },
+        "additionalProperties": false
+      },
+      "nullableToOneEmptyResourceInResponse": {
+        "required": [
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ],
+            "nullable": true
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInRelationshipObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceAttributesInPatchRequest": {
+        "type": "object",
+        "properties": {
+          "referenceType": {
+            "type": "string",
+            "nullable": true
+          },
+          "requiredReferenceType": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "valueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "requiredValueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "nullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          },
+          "requiredNullableValueType": {
+            "type": "integer",
+            "format": "int32"
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceAttributesInPostRequest": {
+        "required": [
+          "requiredNullableValueType",
+          "requiredReferenceType"
+        ],
+        "type": "object",
+        "properties": {
+          "referenceType": {
+            "type": "string",
+            "nullable": true
+          },
+          "requiredReferenceType": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "valueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "requiredValueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "nullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          },
+          "requiredNullableValueType": {
+            "type": "integer",
+            "format": "int32"
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceAttributesInResponse": {
+        "required": [
+          "requiredNullableValueType",
+          "requiredReferenceType"
+        ],
+        "type": "object",
+        "properties": {
+          "referenceType": {
+            "type": "string",
+            "nullable": true
+          },
+          "requiredReferenceType": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "valueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "requiredValueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "nullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          },
+          "requiredNullableValueType": {
+            "type": "integer",
+            "format": "int32"
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceCollectionResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/resourceDataInResponse"
+            }
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceCollectionDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceDataInPatchRequest": {
+        "required": [
+          "id",
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceResourceType"
+              }
+            ]
+          },
+          "id": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "attributes": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceAttributesInPatchRequest"
+              }
+            ]
+          },
+          "relationships": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceRelationshipsInPatchRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceDataInPostRequest": {
+        "required": [
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceResourceType"
+              }
+            ]
+          },
+          "attributes": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceAttributesInPostRequest"
+              }
+            ]
+          },
+          "relationships": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceRelationshipsInPostRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceDataInResponse": {
+        "required": [
+          "id",
+          "links",
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceResourceType"
+              }
+            ]
+          },
+          "id": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "attributes": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceAttributesInResponse"
+              }
+            ]
+          },
+          "relationships": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceRelationshipsInResponse"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourcePatchRequestDocument": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceDataInPatchRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourcePostRequestDocument": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceDataInPostRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourcePrimaryResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceDataInResponse"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceRelationshipsInPatchRequest": {
+        "type": "object",
+        "properties": {
+          "toOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "toMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredToMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceRelationshipsInPostRequest": {
+        "required": [
+          "requiredToOne"
+        ],
+        "type": "object",
+        "properties": {
+          "toOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "toMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredToMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceRelationshipsInResponse": {
+        "required": [
+          "requiredToOne"
+        ],
+        "type": "object",
+        "properties": {
+          "toOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInResponse"
+              }
+            ]
+          },
+          "requiredToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInResponse"
+              }
+            ]
+          },
+          "toMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInResponse"
+              }
+            ]
+          },
+          "requiredToMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInResponse"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceResourceType": {
+        "enum": [
+          "Resource"
+        ],
+        "type": "string"
+      },
+      "toManyEmptyResourceInRequest": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/emptyResourceIdentifier"
+            }
+          }
+        },
+        "additionalProperties": false
+      },
+      "toManyEmptyResourceInResponse": {
+        "required": [
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/emptyResourceIdentifier"
+            }
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInRelationshipObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "toOneEmptyResourceInRequest": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "toOneEmptyResourceInResponse": {
+        "required": [
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInRelationshipObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      }
+    }
+  }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/CreateResourceTests.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/CreateResourceTests.cs
new file mode 100644
index 0000000000..0ca3a6fb82
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/CreateResourceTests.cs
@@ -0,0 +1,609 @@
+using System.Linq.Expressions;
+using System.Net;
+using System.Text.Json;
+using FluentAssertions;
+using FluentAssertions.Specialized;
+using Newtonsoft.Json;
+using OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationDisabled.GeneratedCode;
+using TestBuildingBlocks;
+using Xunit;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationDisabled;
+
+public sealed class CreateResourceTests : OpenApiClientTests
+{
+    private readonly ResourceFieldValidationFakers _fakers = new();
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableReferenceType), "nullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableReferenceType), "requiredNullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableValueType), "nullableValueType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableValueType), "requiredNullableValueType")]
+    public async Task Can_clear_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOffClient(wrapper.HttpClient);
+
+        Expression<Func<ResourceAttributesInPostRequest, object?>> includeAttributeSelector =
+            CreateIncludedAttributeSelector<ResourceAttributesInPostRequest>(attributePropertyName);
+
+        using (apiClient.WithPartialAttributeSerialization(requestDocument, includeAttributeSelector))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.attributes").With(attributesObject =>
+        {
+            attributesObject.ShouldContainPath(jsonPropertyName).With(attribute => attribute.ValueKind.Should().Be(JsonValueKind.Null));
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ValueType), "valueType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredValueType), "requiredValueType")]
+    public async Task Can_set_default_value_to_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? defaultValue = requestDocument.Data.Attributes.GetDefaultValueForProperty(attributePropertyName);
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, defaultValue);
+
+        Expression<Func<ResourceAttributesInPostRequest, object?>> includeAttributeSelector =
+            CreateIncludedAttributeSelector<ResourceAttributesInPostRequest>(attributePropertyName);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOffClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization(requestDocument, includeAttributeSelector))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.attributes").With(attributesObject =>
+        {
+            attributesObject.ShouldContainPath(jsonPropertyName).With(attribute => attribute.ShouldBeInteger(0));
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NonNullableReferenceType), "nonNullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNonNullableReferenceType), "requiredNonNullableReferenceType")]
+    public async Task Cannot_clear_attribute(string clrPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        requestDocument.Data.Attributes.SetPropertyValue(clrPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOffClient(wrapper.HttpClient);
+
+        Expression<Func<ResourceAttributesInPostRequest, object?>> includeAttributeSelector =
+            CreateIncludedAttributeSelector<ResourceAttributesInPostRequest>(clrPropertyName);
+
+        using (apiClient.WithPartialAttributeSerialization(requestDocument, includeAttributeSelector))
+        {
+            // Act
+            Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+                await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+            // Assert
+            ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+            JsonSerializationException exception = assertion.Subject.Single();
+
+            exception.Message.Should().Contain($"Cannot write a null value for property '{jsonPropertyName}'.");
+        }
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NonNullableReferenceType), "nonNullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableReferenceType), "nullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ValueType), "valueType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableValueType), "nullableValueType")]
+    public async Task Can_exclude_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceAttributesInPostRequest emptyAttributesObject = new();
+        object? defaultValue = emptyAttributesObject.GetPropertyValue(attributePropertyName);
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOffClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.attributes").With(attributesObject =>
+        {
+            attributesObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNonNullableReferenceType), "requiredNonNullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableReferenceType), "requiredNullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredValueType), "requiredValueType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableValueType), "requiredNullableValueType")]
+    public async Task Cannot_exclude_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceAttributesInPostRequest emptyAttributesObject = new();
+        object? defaultValue = emptyAttributesObject.GetPropertyValue(attributePropertyName);
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOffClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+                await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+            // Assert
+            ExceptionAssertions<InvalidOperationException> assertion = await action.Should().ThrowExactlyAsync<InvalidOperationException>();
+            InvalidOperationException exception = assertion.Subject.Single();
+            exception.Message.Should().Be($"The following property should not be omitted: data.attributes.{jsonPropertyName}.");
+        }
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.NullableToOne), nameof(ResourceRelationshipsInPostRequest.NullableToOne.Data), "nullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredNullableToOne), nameof(ResourceRelationshipsInPostRequest.RequiredNullableToOne.Data),
+        "requiredNullableToOne")]
+    public async Task Can_clear_relationship_with_partial_attribute_serialization(string relationshipPropertyName, string dataPropertyName,
+        string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? relationshipObject = requestDocument.Data.Relationships.GetPropertyValue(relationshipPropertyName);
+        relationshipObject!.SetPropertyValue(dataPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOffClient(wrapper.HttpClient);
+
+        // Act
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath($"data.relationships.{jsonPropertyName}.data").With(relationshipDataObject =>
+        {
+            relationshipDataObject.ValueKind.Should().Be(JsonValueKind.Null);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.NullableToOne), nameof(ResourceRelationshipsInPostRequest.NullableToOne.Data), "nullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredNullableToOne), nameof(ResourceRelationshipsInPostRequest.RequiredNullableToOne.Data),
+        "requiredNullableToOne")]
+    public async Task Can_clear_relationship_without_partial_attribute_serialization(string relationshipPropertyName, string dataPropertyName,
+        string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? relationshipObject = requestDocument.Data.Relationships.GetPropertyValue(relationshipPropertyName);
+        relationshipObject!.SetPropertyValue(dataPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOffClient(wrapper.HttpClient);
+
+        // Act
+        await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath($"data.relationships.{jsonPropertyName}.data").With(relationshipDataObject =>
+        {
+            relationshipDataObject.ValueKind.Should().Be(JsonValueKind.Null);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.NonNullableToOne), nameof(ResourceRelationshipsInPostRequest.NonNullableToOne.Data),
+        "nonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredNonNullableToOne), nameof(ResourceRelationshipsInPostRequest.RequiredNonNullableToOne.Data),
+        "requiredNonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToMany), nameof(ResourceRelationshipsInPostRequest.ToMany.Data), "toMany")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToMany), nameof(ResourceRelationshipsInPostRequest.RequiredToMany.Data), "requiredToMany")]
+    public async Task Cannot_clear_relationship_with_partial_attribute_serialization(string relationshipPropertyName, string dataPropertyName,
+        string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? relationshipObject = requestDocument.Data.Relationships.GetPropertyValue(relationshipPropertyName);
+        relationshipObject!.SetPropertyValue(dataPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOffClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+                await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+            // Assert
+            ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+            JsonSerializationException exception = assertion.Subject.Single();
+
+            exception.Message.Should()
+                .Be($"Cannot write a null value for property 'data'. Property requires a value. Path 'data.relationships.{jsonPropertyName}'.");
+        }
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.NonNullableToOne), nameof(ResourceRelationshipsInPostRequest.NonNullableToOne.Data),
+        "nonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredNonNullableToOne), nameof(ResourceRelationshipsInPostRequest.RequiredNonNullableToOne.Data),
+        "requiredNonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToMany), nameof(ResourceRelationshipsInPostRequest.ToMany.Data), "toMany")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToMany), nameof(ResourceRelationshipsInPostRequest.RequiredToMany.Data), "requiredToMany")]
+    public async Task Cannot_clear_relationship_without_partial_attribute_serialization(string relationshipPropertyName, string dataPropertyName,
+        string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? relationshipObject = requestDocument.Data.Relationships.GetPropertyValue(relationshipPropertyName);
+        relationshipObject!.SetPropertyValue(dataPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOffClient(wrapper.HttpClient);
+
+        // Act
+        Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+        // Assert
+        ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+        JsonSerializationException exception = assertion.Subject.Single();
+
+        exception.Message.Should()
+            .Be($"Cannot write a null value for property 'data'. Property requires a value. Path 'data.relationships.{jsonPropertyName}'.");
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.NonNullableToOne), "nonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.NullableToOne), "nullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToMany), "toMany")]
+    public async Task Can_exclude_relationship_with_partial_attribute_serialization(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPostRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOffClient(wrapper.HttpClient);
+
+        // Act
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.relationships").With(relationshipsObject =>
+        {
+            relationshipsObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.NonNullableToOne), "nonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.NullableToOne), "nullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToMany), "toMany")]
+    public async Task Can_exclude_relationship_without_partial_attribute_serialization(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPostRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOffClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.relationships").With(relationshipsObject =>
+        {
+            relationshipsObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredNonNullableToOne), "requiredNonNullableToOne")]
+    public async Task Cannot_exclude_relationship_with_partial_attribute_serialization(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPostRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOffClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+                await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+            // Assert
+            ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+            JsonSerializationException exception = assertion.Subject.Single();
+
+            exception.Message.Should()
+                .Be($"Cannot write a null value for property 'id'. Property requires a value. Path 'data.relationships.{jsonPropertyName}.data'.");
+        }
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredNonNullableToOne), "requiredNonNullableToOne")]
+    public async Task Cannot_exclude_relationship_without_partial_attribute_serialization(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPostRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOffClient(wrapper.HttpClient);
+
+        // Act
+        Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+        // Assert
+        ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+        JsonSerializationException exception = assertion.Subject.Single();
+
+        exception.Message.Should()
+            .Be($"Cannot write a null value for property 'id'. Property requires a value. Path 'data.relationships.{jsonPropertyName}.data'.");
+    }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/GeneratedCode/NrtOnMsvOffClient.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/GeneratedCode/NrtOnMsvOffClient.cs
new file mode 100644
index 0000000000..c44cdbe3d7
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/GeneratedCode/NrtOnMsvOffClient.cs
@@ -0,0 +1,14 @@
+using JsonApiDotNetCore.OpenApi.Client;
+using Newtonsoft.Json;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationDisabled.GeneratedCode;
+
+internal partial class NrtOnMsvOffClient : JsonApiClient
+{
+    partial void UpdateJsonSerializerSettings(JsonSerializerSettings settings)
+    {
+        SetSerializerSettingsForJsonApi(settings);
+
+        settings.Formatting = Formatting.Indented;
+    }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/NullabilityTests.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/NullabilityTests.cs
new file mode 100644
index 0000000000..dc2bc84ccd
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/NullabilityTests.cs
@@ -0,0 +1,25 @@
+using System.Reflection;
+using FluentAssertions;
+using OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationDisabled.GeneratedCode;
+using Xunit;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationDisabled;
+
+public sealed class NullabilityTests
+{
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NonNullableReferenceType), NullabilityState.NotNull)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNonNullableReferenceType), NullabilityState.NotNull)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableReferenceType), NullabilityState.Nullable)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableReferenceType), NullabilityState.Nullable)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ValueType), NullabilityState.NotNull)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredValueType), NullabilityState.NotNull)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableValueType), NullabilityState.Nullable)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableValueType), NullabilityState.Nullable)]
+    public void Nullability_of_generated_property_is_as_expected(string propertyName, NullabilityState expectedState)
+    {
+        PropertyInfo[] properties = typeof(ResourceAttributesInPostRequest).GetProperties();
+        PropertyInfo property = properties.Single(property => property.Name == propertyName);
+        property.Should().HaveNullabilityState(expectedState);
+    }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/ResourceFieldValidationFakers.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/ResourceFieldValidationFakers.cs
new file mode 100644
index 0000000000..b0c9c260c7
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/ResourceFieldValidationFakers.cs
@@ -0,0 +1,28 @@
+using Bogus;
+using OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationDisabled.GeneratedCode;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationDisabled;
+
+internal sealed class ResourceFieldValidationFakers
+{
+    private readonly Lazy<Faker<ResourceAttributesInPostRequest>> _lazyPostAttributesFaker = new(() =>
+        FakerFactory.Instance.Create<ResourceAttributesInPostRequest>());
+
+    private readonly Lazy<Faker<ResourceAttributesInPatchRequest>> _lazyPatchAttributesFaker = new(() =>
+        FakerFactory.Instance.Create<ResourceAttributesInPatchRequest>());
+
+    private readonly Lazy<Faker<ToOneEmptyResourceInRequest>> _lazyToOneFaker = new(() =>
+        FakerFactory.Instance.CreateForObjectWithResourceId<ToOneEmptyResourceInRequest, int>());
+
+    private readonly Lazy<Faker<NullableToOneEmptyResourceInRequest>> _lazyNullableToOneFaker = new(() =>
+        FakerFactory.Instance.CreateForObjectWithResourceId<NullableToOneEmptyResourceInRequest, int>());
+
+    private readonly Lazy<Faker<ToManyEmptyResourceInRequest>> _lazyToManyFaker = new(() =>
+        FakerFactory.Instance.CreateForObjectWithResourceId<ToManyEmptyResourceInRequest, int>());
+
+    public Faker<ResourceAttributesInPostRequest> PostAttributes => _lazyPostAttributesFaker.Value;
+    public Faker<ResourceAttributesInPatchRequest> PatchAttributes => _lazyPatchAttributesFaker.Value;
+    public Faker<ToOneEmptyResourceInRequest> ToOne => _lazyToOneFaker.Value;
+    public Faker<NullableToOneEmptyResourceInRequest> NullableToOne => _lazyNullableToOneFaker.Value;
+    public Faker<ToManyEmptyResourceInRequest> ToMany => _lazyToManyFaker.Value;
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/UpdateResourceTests.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/UpdateResourceTests.cs
new file mode 100644
index 0000000000..5596c17962
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/UpdateResourceTests.cs
@@ -0,0 +1,156 @@
+using System.Net;
+using System.Text.Json;
+using FluentAssertions;
+using FluentAssertions.Specialized;
+using Newtonsoft.Json;
+using OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationDisabled.GeneratedCode;
+using TestBuildingBlocks;
+using Xunit;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationDisabled;
+
+public sealed class UpdateResourceTests
+{
+    private readonly ResourceFieldValidationFakers _fakers = new();
+
+    [Fact]
+    public async Task Cannot_exclude_id()
+    {
+        // Arrange
+        var requestDocument = new ResourcePatchRequestDocument
+        {
+            Data = new ResourceDataInPatchRequest
+            {
+                Id = "1",
+                Attributes = _fakers.PatchAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPatchRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceDataInPatchRequest emptyDataObject = new();
+        requestDocument.Data.Id = emptyDataObject.Id;
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOffClient(wrapper.HttpClient);
+
+        // Act
+        Func<Task> action = async () => await ApiResponse.TranslateAsync(async () => await apiClient.PatchResourceAsync(999, requestDocument));
+
+        // Assert
+        await action.Should().ThrowAsync<JsonSerializationException>();
+        ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+        JsonSerializationException exception = assertion.Subject.Single();
+
+        exception.Message.Should().Be("Cannot write a null value for property 'id'. Property requires a value. Path 'data'.");
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.NonNullableReferenceType), "nonNullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.RequiredNonNullableReferenceType), "requiredNonNullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.NullableReferenceType), "nullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.RequiredNullableReferenceType), "requiredNullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.ValueType), "valueType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.RequiredValueType), "requiredValueType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.NullableValueType), "nullableValueType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.RequiredNullableValueType), "requiredNullableValueType")]
+    public async Task Can_exclude_attribute_that_is_required_in_create_resource(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePatchRequestDocument
+        {
+            Data = new ResourceDataInPatchRequest
+            {
+                Id = "1",
+                Attributes = _fakers.PatchAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPatchRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceAttributesInPatchRequest emptyAttributesObject = new();
+        object? defaultValue = emptyAttributesObject.GetPropertyValue(attributePropertyName);
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOffClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePatchRequestDocument, ResourceAttributesInPatchRequest>(requestDocument))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PatchResourceAsync(int.Parse(requestDocument.Data.Id), requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.attributes").With(attributesObject =>
+        {
+            attributesObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.NonNullableToOne), "nonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.RequiredNonNullableToOne), "requiredNonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.NullableToOne), "nullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.RequiredNullableToOne), "requiredNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.ToMany), "toMany")]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.RequiredToMany), "requiredToMany")]
+    public async Task Can_exclude_relationship_that_is_required_in_create_resource(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePatchRequestDocument
+        {
+            Data = new ResourceDataInPatchRequest
+            {
+                Id = "1",
+                Attributes = _fakers.PatchAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPatchRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.NullableToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPatchRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOffClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePatchRequestDocument, ResourceAttributesInPatchRequest>(requestDocument))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PatchResourceAsync(int.Parse(requestDocument.Data.Id), requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.relationships").With(relationshipsObject =>
+        {
+            relationshipsObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/swagger.g.json b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/swagger.g.json
new file mode 100644
index 0000000000..71ebea9da7
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/swagger.g.json
@@ -0,0 +1,2344 @@
+{
+  "openapi": "3.0.1",
+  "info": {
+    "title": "OpenApiTests",
+    "version": "1.0"
+  },
+  "paths": {
+    "/Resource": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceCollection",
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceCollection",
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "post": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "postResource",
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/resourcePostRequestDocument"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "201": {
+            "description": "Created",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourcePrimaryResponseDocument"
+                }
+              }
+            }
+          },
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResource",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourcePrimaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResource",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourcePrimaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResource",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/resourcePatchRequestDocument"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourcePrimaryResponseDocument"
+                }
+              }
+            }
+          },
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "delete": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "deleteResource",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/nonNullableToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceNonNullableToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceNonNullableToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/nonNullableToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceNonNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceNonNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceNonNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/nullableToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceNullableToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceNullableToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/nullableToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/requiredNonNullableToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredNonNullableToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredNonNullableToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/requiredNonNullableToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredNonNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredNonNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceRequiredNonNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/requiredNullableToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredNullableToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredNullableToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/requiredNullableToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceRequiredNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/requiredToMany": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredToMany",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredToMany",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/requiredToMany": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "post": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "postResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "delete": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "deleteResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/toMany": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceToMany",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceToMany",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/toMany": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "post": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "postResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "delete": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "deleteResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    }
+  },
+  "components": {
+    "schemas": {
+      "emptyResourceCollectionResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/emptyResourceDataInResponse"
+            }
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceCollectionDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceDataInResponse": {
+        "required": [
+          "id",
+          "links",
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceResourceType"
+              }
+            ]
+          },
+          "id": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceIdentifier": {
+        "required": [
+          "id",
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceResourceType"
+              }
+            ]
+          },
+          "id": {
+            "minLength": 1,
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceIdentifierCollectionResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/emptyResourceIdentifier"
+            }
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceIdentifierCollectionDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceIdentifierResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceIdentifierDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceResourceType": {
+        "enum": [
+          "emptyResources"
+        ],
+        "type": "string"
+      },
+      "emptyResourceSecondaryResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceDataInResponse"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "jsonapiObject": {
+        "type": "object",
+        "properties": {
+          "version": {
+            "type": "string"
+          },
+          "ext": {
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
+          },
+          "profile": {
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInRelationshipObject": {
+        "required": [
+          "related",
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "related": {
+            "minLength": 1,
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceCollectionDocument": {
+        "required": [
+          "first",
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "describedby": {
+            "type": "string"
+          },
+          "first": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "last": {
+            "type": "string"
+          },
+          "prev": {
+            "type": "string"
+          },
+          "next": {
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceDocument": {
+        "required": [
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "describedby": {
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceIdentifierCollectionDocument": {
+        "required": [
+          "first",
+          "related",
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "describedby": {
+            "type": "string"
+          },
+          "related": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "first": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "last": {
+            "type": "string"
+          },
+          "prev": {
+            "type": "string"
+          },
+          "next": {
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceIdentifierDocument": {
+        "required": [
+          "related",
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "describedby": {
+            "type": "string"
+          },
+          "related": {
+            "minLength": 1,
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceObject": {
+        "required": [
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "nullableEmptyResourceIdentifierResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ],
+            "nullable": true
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceIdentifierDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "nullableEmptyResourceSecondaryResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceDataInResponse"
+              }
+            ],
+            "nullable": true
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "nullableToOneEmptyResourceInRequest": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ],
+            "nullable": true
+          }
+        },
+        "additionalProperties": false
+      },
+      "nullableToOneEmptyResourceInResponse": {
+        "required": [
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ],
+            "nullable": true
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInRelationshipObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceAttributesInPatchRequest": {
+        "type": "object",
+        "properties": {
+          "nonNullableReferenceType": {
+            "type": "string"
+          },
+          "requiredNonNullableReferenceType": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "nullableReferenceType": {
+            "type": "string",
+            "nullable": true
+          },
+          "requiredNullableReferenceType": {
+            "minLength": 1,
+            "type": "string",
+            "nullable": true
+          },
+          "valueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "requiredValueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "nullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          },
+          "requiredNullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceAttributesInPostRequest": {
+        "required": [
+          "requiredNonNullableReferenceType",
+          "requiredNullableReferenceType",
+          "requiredNullableValueType",
+          "requiredValueType"
+        ],
+        "type": "object",
+        "properties": {
+          "nonNullableReferenceType": {
+            "type": "string"
+          },
+          "requiredNonNullableReferenceType": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "nullableReferenceType": {
+            "type": "string",
+            "nullable": true
+          },
+          "requiredNullableReferenceType": {
+            "minLength": 1,
+            "type": "string",
+            "nullable": true
+          },
+          "valueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "requiredValueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "nullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          },
+          "requiredNullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceAttributesInResponse": {
+        "required": [
+          "requiredNonNullableReferenceType",
+          "requiredNullableReferenceType",
+          "requiredNullableValueType",
+          "requiredValueType"
+        ],
+        "type": "object",
+        "properties": {
+          "nonNullableReferenceType": {
+            "type": "string"
+          },
+          "requiredNonNullableReferenceType": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "nullableReferenceType": {
+            "type": "string",
+            "nullable": true
+          },
+          "requiredNullableReferenceType": {
+            "minLength": 1,
+            "type": "string",
+            "nullable": true
+          },
+          "valueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "requiredValueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "nullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          },
+          "requiredNullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceCollectionResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/resourceDataInResponse"
+            }
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceCollectionDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceDataInPatchRequest": {
+        "required": [
+          "id",
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceResourceType"
+              }
+            ]
+          },
+          "id": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "attributes": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceAttributesInPatchRequest"
+              }
+            ]
+          },
+          "relationships": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceRelationshipsInPatchRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceDataInPostRequest": {
+        "required": [
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceResourceType"
+              }
+            ]
+          },
+          "attributes": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceAttributesInPostRequest"
+              }
+            ]
+          },
+          "relationships": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceRelationshipsInPostRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceDataInResponse": {
+        "required": [
+          "id",
+          "links",
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceResourceType"
+              }
+            ]
+          },
+          "id": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "attributes": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceAttributesInResponse"
+              }
+            ]
+          },
+          "relationships": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceRelationshipsInResponse"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourcePatchRequestDocument": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceDataInPatchRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourcePostRequestDocument": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceDataInPostRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourcePrimaryResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceDataInResponse"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceRelationshipsInPatchRequest": {
+        "type": "object",
+        "properties": {
+          "nonNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredNonNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "nullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "toMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredToMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceRelationshipsInPostRequest": {
+        "required": [
+          "requiredNonNullableToOne",
+          "requiredNullableToOne",
+          "requiredToMany"
+        ],
+        "type": "object",
+        "properties": {
+          "nonNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredNonNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "nullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "toMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredToMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceRelationshipsInResponse": {
+        "required": [
+          "requiredNonNullableToOne",
+          "requiredNullableToOne",
+          "requiredToMany"
+        ],
+        "type": "object",
+        "properties": {
+          "nonNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInResponse"
+              }
+            ]
+          },
+          "requiredNonNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInResponse"
+              }
+            ]
+          },
+          "nullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInResponse"
+              }
+            ]
+          },
+          "requiredNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInResponse"
+              }
+            ]
+          },
+          "toMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInResponse"
+              }
+            ]
+          },
+          "requiredToMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInResponse"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceResourceType": {
+        "enum": [
+          "Resource"
+        ],
+        "type": "string"
+      },
+      "toManyEmptyResourceInRequest": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/emptyResourceIdentifier"
+            }
+          }
+        },
+        "additionalProperties": false
+      },
+      "toManyEmptyResourceInResponse": {
+        "required": [
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/emptyResourceIdentifier"
+            }
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInRelationshipObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "toOneEmptyResourceInRequest": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "toOneEmptyResourceInResponse": {
+        "required": [
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInRelationshipObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      }
+    }
+  }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/CreateResourceTests.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/CreateResourceTests.cs
new file mode 100644
index 0000000000..44aa5da920
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/CreateResourceTests.cs
@@ -0,0 +1,613 @@
+using System.Linq.Expressions;
+using System.Net;
+using System.Text.Json;
+using FluentAssertions;
+using FluentAssertions.Specialized;
+using Newtonsoft.Json;
+using OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationEnabled.GeneratedCode;
+using TestBuildingBlocks;
+using Xunit;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationEnabled;
+
+public sealed class CreateResourceTests : OpenApiClientTests
+{
+    private readonly ResourceFieldValidationFakers _fakers = new();
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableReferenceType), "nullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableValueType), "nullableValueType")]
+    public async Task Can_clear_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOnClient(wrapper.HttpClient);
+
+        Expression<Func<ResourceAttributesInPostRequest, object?>> includeAttributeSelector =
+            CreateIncludedAttributeSelector<ResourceAttributesInPostRequest>(attributePropertyName);
+
+        using (apiClient.WithPartialAttributeSerialization(requestDocument, includeAttributeSelector))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.attributes").With(attributesObject =>
+        {
+            attributesObject.ShouldContainPath(jsonPropertyName).With(attribute => attribute.ValueKind.Should().Be(JsonValueKind.Null));
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ValueType), "valueType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredValueType), "requiredValueType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableValueType), "requiredNullableValueType")]
+    public async Task Can_set_default_value_to_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? defaultValue = requestDocument.Data.Attributes.GetDefaultValueForProperty(attributePropertyName);
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, defaultValue);
+
+        Expression<Func<ResourceAttributesInPostRequest, object?>> includeAttributeSelector =
+            CreateIncludedAttributeSelector<ResourceAttributesInPostRequest>(attributePropertyName);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOnClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization(requestDocument, includeAttributeSelector))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.attributes").With(attributesObject =>
+        {
+            attributesObject.ShouldContainPath(jsonPropertyName).With(attribute => attribute.ShouldBeInteger(0));
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NonNullableReferenceType), "nonNullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNonNullableReferenceType), "requiredNonNullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableReferenceType), "requiredNullableReferenceType")]
+    public async Task Cannot_clear_attribute(string clrPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        requestDocument.Data.Attributes.SetPropertyValue(clrPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOnClient(wrapper.HttpClient);
+
+        Expression<Func<ResourceAttributesInPostRequest, object?>> includeAttributeSelector =
+            CreateIncludedAttributeSelector<ResourceAttributesInPostRequest>(clrPropertyName);
+
+        using (apiClient.WithPartialAttributeSerialization(requestDocument, includeAttributeSelector))
+        {
+            // Act
+            Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+                await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+            // Assert
+            ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+            JsonSerializationException exception = assertion.Subject.Single();
+
+            exception.Message.Should().Contain($"Cannot write a null value for property '{jsonPropertyName}'.");
+        }
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableReferenceType), "nullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ValueType), "valueType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredValueType), "requiredValueType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableValueType), "nullableValueType")]
+    public async Task Can_exclude_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceAttributesInPostRequest emptyAttributesObject = new();
+        object? defaultValue = emptyAttributesObject.GetPropertyValue(attributePropertyName);
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOnClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.attributes").With(attributesObject =>
+        {
+            attributesObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NonNullableReferenceType), "nonNullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNonNullableReferenceType), "requiredNonNullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableReferenceType), "requiredNullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableValueType), "requiredNullableValueType")]
+    public async Task Cannot_exclude_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceAttributesInPostRequest emptyAttributesObject = new();
+        object? defaultValue = emptyAttributesObject.GetPropertyValue(attributePropertyName);
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOnClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+                await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+            // Assert
+            ExceptionAssertions<InvalidOperationException> assertion = await action.Should().ThrowExactlyAsync<InvalidOperationException>();
+            InvalidOperationException exception = assertion.Subject.Single();
+            exception.Message.Should().Be($"The following property should not be omitted: data.attributes.{jsonPropertyName}.");
+        }
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.NullableToOne), nameof(ResourceRelationshipsInPostRequest.NullableToOne.Data), "nullableToOne")]
+    public async Task Can_clear_relationship_with_partial_attribute_serialization(string relationshipPropertyName, string dataPropertyName,
+        string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? relationshipObject = requestDocument.Data.Relationships.GetPropertyValue(relationshipPropertyName);
+        relationshipObject!.SetPropertyValue(dataPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOnClient(wrapper.HttpClient);
+
+        // Act
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath($"data.relationships.{jsonPropertyName}.data").With(relationshipDataObject =>
+        {
+            relationshipDataObject.ValueKind.Should().Be(JsonValueKind.Null);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.NullableToOne), nameof(ResourceRelationshipsInPostRequest.NullableToOne.Data), "nullableToOne")]
+    public async Task Can_clear_relationship_without_partial_attribute_serialization(string relationshipPropertyName, string dataPropertyName,
+        string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? relationshipObject = requestDocument.Data.Relationships.GetPropertyValue(relationshipPropertyName);
+        relationshipObject!.SetPropertyValue(dataPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOnClient(wrapper.HttpClient);
+
+        // Act
+        await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath($"data.relationships.{jsonPropertyName}.data").With(relationshipDataObject =>
+        {
+            relationshipDataObject.ValueKind.Should().Be(JsonValueKind.Null);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.NonNullableToOne), nameof(ResourceRelationshipsInPostRequest.NonNullableToOne.Data),
+        "nonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredNonNullableToOne), nameof(ResourceRelationshipsInPostRequest.RequiredNonNullableToOne.Data),
+        "requiredNonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredNullableToOne), nameof(ResourceRelationshipsInPostRequest.RequiredNullableToOne.Data),
+        "requiredNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToMany), nameof(ResourceRelationshipsInPostRequest.ToMany.Data), "toMany")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToMany), nameof(ResourceRelationshipsInPostRequest.RequiredToMany.Data), "requiredToMany")]
+    public async Task Cannot_clear_relationship_with_partial_attribute_serialization(string relationshipPropertyName, string dataPropertyName,
+        string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? relationshipObject = requestDocument.Data.Relationships.GetPropertyValue(relationshipPropertyName);
+        relationshipObject!.SetPropertyValue(dataPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOnClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+                await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+            // Assert
+            ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+            JsonSerializationException exception = assertion.Subject.Single();
+
+            exception.Message.Should()
+                .Be($"Cannot write a null value for property 'data'. Property requires a value. Path 'data.relationships.{jsonPropertyName}'.");
+        }
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.NonNullableToOne), nameof(ResourceRelationshipsInPostRequest.NonNullableToOne.Data),
+        "nonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredNonNullableToOne), nameof(ResourceRelationshipsInPostRequest.RequiredNonNullableToOne.Data),
+        "requiredNonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredNullableToOne), nameof(ResourceRelationshipsInPostRequest.RequiredNullableToOne.Data),
+        "requiredNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToMany), nameof(ResourceRelationshipsInPostRequest.ToMany.Data), "toMany")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToMany), nameof(ResourceRelationshipsInPostRequest.RequiredToMany.Data), "requiredToMany")]
+    public async Task Cannot_clear_relationship_without_partial_attribute_serialization(string relationshipPropertyName, string dataPropertyName,
+        string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        object? relationshipObject = requestDocument.Data.Relationships.GetPropertyValue(relationshipPropertyName);
+        relationshipObject!.SetPropertyValue(dataPropertyName, null);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOnClient(wrapper.HttpClient);
+
+        // Act
+        Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+        // Assert
+        ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+        JsonSerializationException exception = assertion.Subject.Single();
+
+        exception.Message.Should()
+            .Be($"Cannot write a null value for property 'data'. Property requires a value. Path 'data.relationships.{jsonPropertyName}'.");
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.NullableToOne), "nullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToMany), "toMany")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToMany), "requiredToMany")]
+    public async Task Can_exclude_relationship_with_partial_attribute_serialization(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPostRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOnClient(wrapper.HttpClient);
+
+        // Act
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.relationships").With(relationshipsObject =>
+        {
+            relationshipsObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.NullableToOne), "nullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.ToMany), "toMany")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredToMany), "requiredToMany")]
+    public async Task Can_exclude_relationship_without_partial_attribute_serialization(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPostRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOnClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.relationships").With(relationshipsObject =>
+        {
+            relationshipsObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.NonNullableToOne), "nonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredNonNullableToOne), "requiredNonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredNullableToOne), "requiredNullableToOne")]
+    public async Task Cannot_exclude_relationship_with_partial_attribute_serialization(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPostRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOnClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePostRequestDocument, ResourceAttributesInPostRequest>(requestDocument))
+        {
+            // Act
+            Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+                await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+            // Assert
+            ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+            JsonSerializationException exception = assertion.Subject.Single();
+
+            exception.Message.Should()
+                .Be($"Cannot write a null value for property 'id'. Property requires a value. Path 'data.relationships.{jsonPropertyName}.data'.");
+        }
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.NonNullableToOne), "nonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredNonNullableToOne), "requiredNonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPostRequest.RequiredNullableToOne), "requiredNullableToOne")]
+    public async Task Cannot_exclude_relationship_without_partial_attribute_serialization(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePostRequestDocument
+        {
+            Data = new ResourceDataInPostRequest
+            {
+                Attributes = _fakers.PostAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPostRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPostRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOnClient(wrapper.HttpClient);
+
+        // Act
+        Func<Task<ResourcePrimaryResponseDocument?>> action = async () =>
+            await ApiResponse.TranslateAsync(async () => await apiClient.PostResourceAsync(requestDocument));
+
+        // Assert
+        ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+        JsonSerializationException exception = assertion.Subject.Single();
+
+        exception.Message.Should()
+            .Be($"Cannot write a null value for property 'id'. Property requires a value. Path 'data.relationships.{jsonPropertyName}.data'.");
+    }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/GeneratedCode/NrtOnMsvOnClient.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/GeneratedCode/NrtOnMsvOnClient.cs
new file mode 100644
index 0000000000..1eed829acb
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/GeneratedCode/NrtOnMsvOnClient.cs
@@ -0,0 +1,14 @@
+using JsonApiDotNetCore.OpenApi.Client;
+using Newtonsoft.Json;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationEnabled.GeneratedCode;
+
+internal partial class NrtOnMsvOnClient : JsonApiClient
+{
+    partial void UpdateJsonSerializerSettings(JsonSerializerSettings settings)
+    {
+        SetSerializerSettingsForJsonApi(settings);
+
+        settings.Formatting = Formatting.Indented;
+    }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/NullabilityTests.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/NullabilityTests.cs
new file mode 100644
index 0000000000..e3c1a5ce31
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/NullabilityTests.cs
@@ -0,0 +1,25 @@
+using System.Reflection;
+using FluentAssertions;
+using OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationEnabled.GeneratedCode;
+using Xunit;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationEnabled;
+
+public sealed class NullabilityTests
+{
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NonNullableReferenceType), NullabilityState.NotNull)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNonNullableReferenceType), NullabilityState.NotNull)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableReferenceType), NullabilityState.Nullable)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableReferenceType), NullabilityState.NotNull)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.ValueType), NullabilityState.NotNull)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredValueType), NullabilityState.NotNull)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.NullableValueType), NullabilityState.Nullable)]
+    [InlineData(nameof(ResourceAttributesInPostRequest.RequiredNullableValueType), NullabilityState.NotNull)]
+    public void Nullability_of_generated_property_is_as_expected(string propertyName, NullabilityState expectedState)
+    {
+        PropertyInfo[] properties = typeof(ResourceAttributesInPostRequest).GetProperties();
+        PropertyInfo property = properties.Single(property => property.Name == propertyName);
+        property.Should().HaveNullabilityState(expectedState);
+    }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/ResourceFieldValidationFakers.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/ResourceFieldValidationFakers.cs
new file mode 100644
index 0000000000..c032f0c073
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/ResourceFieldValidationFakers.cs
@@ -0,0 +1,28 @@
+using Bogus;
+using OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationEnabled.GeneratedCode;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationEnabled;
+
+internal sealed class ResourceFieldValidationFakers
+{
+    private readonly Lazy<Faker<ResourceAttributesInPostRequest>> _lazyPostAttributesFaker = new(() =>
+        FakerFactory.Instance.Create<ResourceAttributesInPostRequest>());
+
+    private readonly Lazy<Faker<ResourceAttributesInPatchRequest>> _lazyPatchAttributesFaker = new(() =>
+        FakerFactory.Instance.Create<ResourceAttributesInPatchRequest>());
+
+    private readonly Lazy<Faker<ToOneEmptyResourceInRequest>> _lazyToOneFaker = new(() =>
+        FakerFactory.Instance.CreateForObjectWithResourceId<ToOneEmptyResourceInRequest, int>());
+
+    private readonly Lazy<Faker<NullableToOneEmptyResourceInRequest>> _lazyNullableToOneFaker = new(() =>
+        FakerFactory.Instance.CreateForObjectWithResourceId<NullableToOneEmptyResourceInRequest, int>());
+
+    private readonly Lazy<Faker<ToManyEmptyResourceInRequest>> _lazyToManyFaker = new(() =>
+        FakerFactory.Instance.CreateForObjectWithResourceId<ToManyEmptyResourceInRequest, int>());
+
+    public Faker<ResourceAttributesInPostRequest> PostAttributes => _lazyPostAttributesFaker.Value;
+    public Faker<ResourceAttributesInPatchRequest> PatchAttributes => _lazyPatchAttributesFaker.Value;
+    public Faker<ToOneEmptyResourceInRequest> ToOne => _lazyToOneFaker.Value;
+    public Faker<NullableToOneEmptyResourceInRequest> NullableToOne => _lazyNullableToOneFaker.Value;
+    public Faker<ToManyEmptyResourceInRequest> ToMany => _lazyToManyFaker.Value;
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/UpdateResourceTests.cs b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/UpdateResourceTests.cs
new file mode 100644
index 0000000000..d0695d6cf7
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/UpdateResourceTests.cs
@@ -0,0 +1,156 @@
+using System.Net;
+using System.Text.Json;
+using FluentAssertions;
+using FluentAssertions.Specialized;
+using Newtonsoft.Json;
+using OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationEnabled.GeneratedCode;
+using TestBuildingBlocks;
+using Xunit;
+
+namespace OpenApiClientTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationEnabled;
+
+public sealed class UpdateResourceTests
+{
+    private readonly ResourceFieldValidationFakers _fakers = new();
+
+    [Fact]
+    public async Task Cannot_exclude_id()
+    {
+        // Arrange
+        var requestDocument = new ResourcePatchRequestDocument
+        {
+            Data = new ResourceDataInPatchRequest
+            {
+                Id = "1",
+                Attributes = _fakers.PatchAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPatchRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceDataInPatchRequest emptyDataObject = new();
+        requestDocument.Data.Id = emptyDataObject.Id;
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOnClient(wrapper.HttpClient);
+
+        // Act
+        Func<Task> action = async () => await ApiResponse.TranslateAsync(async () => await apiClient.PatchResourceAsync(999, requestDocument));
+
+        // Assert
+        await action.Should().ThrowAsync<JsonSerializationException>();
+        ExceptionAssertions<JsonSerializationException> assertion = await action.Should().ThrowExactlyAsync<JsonSerializationException>();
+        JsonSerializationException exception = assertion.Subject.Single();
+
+        exception.Message.Should().Be("Cannot write a null value for property 'id'. Property requires a value. Path 'data'.");
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.NonNullableReferenceType), "nonNullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.RequiredNonNullableReferenceType), "requiredNonNullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.NullableReferenceType), "nullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.RequiredNullableReferenceType), "requiredNullableReferenceType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.ValueType), "valueType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.RequiredValueType), "requiredValueType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.NullableValueType), "nullableValueType")]
+    [InlineData(nameof(ResourceAttributesInPatchRequest.RequiredNullableValueType), "requiredNullableValueType")]
+    public async Task Can_exclude_attribute(string attributePropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePatchRequestDocument
+        {
+            Data = new ResourceDataInPatchRequest
+            {
+                Id = "1",
+                Attributes = _fakers.PatchAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPatchRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceAttributesInPatchRequest emptyAttributesObject = new();
+        object? defaultValue = emptyAttributesObject.GetPropertyValue(attributePropertyName);
+        requestDocument.Data.Attributes.SetPropertyValue(attributePropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOnClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePatchRequestDocument, ResourceAttributesInPatchRequest>(requestDocument))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PatchResourceAsync(int.Parse(requestDocument.Data.Id), requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.attributes").With(attributesObject =>
+        {
+            attributesObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+
+    [Theory]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.NonNullableToOne), "nonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.RequiredNonNullableToOne), "requiredNonNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.NullableToOne), "nullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.RequiredNullableToOne), "requiredNullableToOne")]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.ToMany), "toMany")]
+    [InlineData(nameof(ResourceRelationshipsInPatchRequest.RequiredToMany), "requiredToMany")]
+    public async Task Can_exclude_relationship(string relationshipPropertyName, string jsonPropertyName)
+    {
+        // Arrange
+        var requestDocument = new ResourcePatchRequestDocument
+        {
+            Data = new ResourceDataInPatchRequest
+            {
+                Id = "1",
+                Attributes = _fakers.PatchAttributes.Generate(),
+                Relationships = new ResourceRelationshipsInPatchRequest
+                {
+                    NonNullableToOne = _fakers.ToOne.Generate(),
+                    RequiredNonNullableToOne = _fakers.ToOne.Generate(),
+                    NullableToOne = _fakers.NullableToOne.Generate(),
+                    RequiredNullableToOne = _fakers.ToOne.Generate(),
+                    ToMany = _fakers.ToMany.Generate(),
+                    RequiredToMany = _fakers.ToMany.Generate()
+                }
+            }
+        };
+
+        ResourceRelationshipsInPatchRequest emptyRelationshipsObject = new();
+        object? defaultValue = emptyRelationshipsObject.GetPropertyValue(relationshipPropertyName);
+        requestDocument.Data.Relationships.SetPropertyValue(relationshipPropertyName, defaultValue);
+
+        using var wrapper = FakeHttpClientWrapper.Create(HttpStatusCode.NoContent, null);
+        var apiClient = new NrtOnMsvOnClient(wrapper.HttpClient);
+
+        using (apiClient.WithPartialAttributeSerialization<ResourcePatchRequestDocument, ResourceAttributesInPatchRequest>(requestDocument))
+        {
+            // Act
+            await ApiResponse.TranslateAsync(async () => await apiClient.PatchResourceAsync(int.Parse(requestDocument.Data.Id), requestDocument));
+        }
+
+        // Assert
+        JsonElement document = wrapper.ParseRequestBody();
+
+        document.ShouldContainPath("data.relationships").With(relationshipsObject =>
+        {
+            relationshipsObject.ShouldNotContainPath(jsonPropertyName);
+        });
+    }
+}
diff --git a/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/swagger.g.json b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/swagger.g.json
new file mode 100644
index 0000000000..b9565e70db
--- /dev/null
+++ b/test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/swagger.g.json
@@ -0,0 +1,2338 @@
+{
+  "openapi": "3.0.1",
+  "info": {
+    "title": "OpenApiTests",
+    "version": "1.0"
+  },
+  "paths": {
+    "/Resource": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceCollection",
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceCollection",
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "post": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "postResource",
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/resourcePostRequestDocument"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "201": {
+            "description": "Created",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourcePrimaryResponseDocument"
+                }
+              }
+            }
+          },
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResource",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourcePrimaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResource",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourcePrimaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResource",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/resourcePatchRequestDocument"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/resourcePrimaryResponseDocument"
+                }
+              }
+            }
+          },
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "delete": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "deleteResource",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/nonNullableToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceNonNullableToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceNonNullableToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/nonNullableToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceNonNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceNonNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceNonNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/nullableToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceNullableToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceNullableToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/nullableToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/nullableEmptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/requiredNonNullableToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredNonNullableToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredNonNullableToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/requiredNonNullableToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredNonNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredNonNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceRequiredNonNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/requiredNullableToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredNullableToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredNullableToOne",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceSecondaryResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/requiredNullableToOne": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceRequiredNullableToOneRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/requiredToMany": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredToMany",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredToMany",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/requiredToMany": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "post": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "postResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "delete": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "deleteResourceRequiredToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    },
+    "/Resource/{id}/toMany": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceToMany",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceToMany",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/Resource/{id}/relationships/toMany": {
+      "get": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "getResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "head": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "headResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/vnd.api+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/emptyResourceIdentifierCollectionResponseDocument"
+                }
+              }
+            }
+          }
+        }
+      },
+      "post": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "postResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "patch": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "patchResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      },
+      "delete": {
+        "tags": [
+          "Resource"
+        ],
+        "operationId": "deleteResourceToManyRelationship",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "integer",
+              "format": "int32"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/vnd.api+json": {
+              "schema": {
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        }
+      }
+    }
+  },
+  "components": {
+    "schemas": {
+      "emptyResourceCollectionResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/emptyResourceDataInResponse"
+            }
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceCollectionDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceDataInResponse": {
+        "required": [
+          "id",
+          "links",
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceResourceType"
+              }
+            ]
+          },
+          "id": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceIdentifier": {
+        "required": [
+          "id",
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceResourceType"
+              }
+            ]
+          },
+          "id": {
+            "minLength": 1,
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceIdentifierCollectionResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/emptyResourceIdentifier"
+            }
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceIdentifierCollectionDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceIdentifierResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceIdentifierDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "emptyResourceResourceType": {
+        "enum": [
+          "emptyResources"
+        ],
+        "type": "string"
+      },
+      "emptyResourceSecondaryResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceDataInResponse"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "jsonapiObject": {
+        "type": "object",
+        "properties": {
+          "version": {
+            "type": "string"
+          },
+          "ext": {
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
+          },
+          "profile": {
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInRelationshipObject": {
+        "required": [
+          "related",
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "related": {
+            "minLength": 1,
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceCollectionDocument": {
+        "required": [
+          "first",
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "describedby": {
+            "type": "string"
+          },
+          "first": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "last": {
+            "type": "string"
+          },
+          "prev": {
+            "type": "string"
+          },
+          "next": {
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceDocument": {
+        "required": [
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "describedby": {
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceIdentifierCollectionDocument": {
+        "required": [
+          "first",
+          "related",
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "describedby": {
+            "type": "string"
+          },
+          "related": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "first": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "last": {
+            "type": "string"
+          },
+          "prev": {
+            "type": "string"
+          },
+          "next": {
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceIdentifierDocument": {
+        "required": [
+          "related",
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "describedby": {
+            "type": "string"
+          },
+          "related": {
+            "minLength": 1,
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "linksInResourceObject": {
+        "required": [
+          "self"
+        ],
+        "type": "object",
+        "properties": {
+          "self": {
+            "minLength": 1,
+            "type": "string"
+          }
+        },
+        "additionalProperties": false
+      },
+      "nullableEmptyResourceIdentifierResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ],
+            "nullable": true
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceIdentifierDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "nullableEmptyResourceSecondaryResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceDataInResponse"
+              }
+            ],
+            "nullable": true
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "nullableToOneEmptyResourceInRequest": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ],
+            "nullable": true
+          }
+        },
+        "additionalProperties": false
+      },
+      "nullableToOneEmptyResourceInResponse": {
+        "required": [
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ],
+            "nullable": true
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInRelationshipObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceAttributesInPatchRequest": {
+        "type": "object",
+        "properties": {
+          "nonNullableReferenceType": {
+            "type": "string"
+          },
+          "requiredNonNullableReferenceType": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "nullableReferenceType": {
+            "type": "string",
+            "nullable": true
+          },
+          "requiredNullableReferenceType": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "valueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "requiredValueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "nullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          },
+          "requiredNullableValueType": {
+            "type": "integer",
+            "format": "int32"
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceAttributesInPostRequest": {
+        "required": [
+          "nonNullableReferenceType",
+          "requiredNonNullableReferenceType",
+          "requiredNullableReferenceType",
+          "requiredNullableValueType"
+        ],
+        "type": "object",
+        "properties": {
+          "nonNullableReferenceType": {
+            "type": "string"
+          },
+          "requiredNonNullableReferenceType": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "nullableReferenceType": {
+            "type": "string",
+            "nullable": true
+          },
+          "requiredNullableReferenceType": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "valueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "requiredValueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "nullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          },
+          "requiredNullableValueType": {
+            "type": "integer",
+            "format": "int32"
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceAttributesInResponse": {
+        "required": [
+          "nonNullableReferenceType",
+          "requiredNonNullableReferenceType",
+          "requiredNullableReferenceType",
+          "requiredNullableValueType"
+        ],
+        "type": "object",
+        "properties": {
+          "nonNullableReferenceType": {
+            "type": "string"
+          },
+          "requiredNonNullableReferenceType": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "nullableReferenceType": {
+            "type": "string",
+            "nullable": true
+          },
+          "requiredNullableReferenceType": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "valueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "requiredValueType": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "nullableValueType": {
+            "type": "integer",
+            "format": "int32",
+            "nullable": true
+          },
+          "requiredNullableValueType": {
+            "type": "integer",
+            "format": "int32"
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceCollectionResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/resourceDataInResponse"
+            }
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceCollectionDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceDataInPatchRequest": {
+        "required": [
+          "id",
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceResourceType"
+              }
+            ]
+          },
+          "id": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "attributes": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceAttributesInPatchRequest"
+              }
+            ]
+          },
+          "relationships": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceRelationshipsInPatchRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceDataInPostRequest": {
+        "required": [
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceResourceType"
+              }
+            ]
+          },
+          "attributes": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceAttributesInPostRequest"
+              }
+            ]
+          },
+          "relationships": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceRelationshipsInPostRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceDataInResponse": {
+        "required": [
+          "id",
+          "links",
+          "type"
+        ],
+        "type": "object",
+        "properties": {
+          "type": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceResourceType"
+              }
+            ]
+          },
+          "id": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "attributes": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceAttributesInResponse"
+              }
+            ]
+          },
+          "relationships": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceRelationshipsInResponse"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourcePatchRequestDocument": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceDataInPatchRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourcePostRequestDocument": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceDataInPostRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourcePrimaryResponseDocument": {
+        "required": [
+          "data",
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/resourceDataInResponse"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          },
+          "jsonapi": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapiObject"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInResourceDocument"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceRelationshipsInPatchRequest": {
+        "type": "object",
+        "properties": {
+          "nonNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredNonNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "nullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "toMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredToMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceRelationshipsInPostRequest": {
+        "required": [
+          "nonNullableToOne",
+          "requiredNonNullableToOne",
+          "requiredNullableToOne"
+        ],
+        "type": "object",
+        "properties": {
+          "nonNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredNonNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "nullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInRequest"
+              }
+            ]
+          },
+          "toMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+              }
+            ]
+          },
+          "requiredToMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInRequest"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceRelationshipsInResponse": {
+        "required": [
+          "nonNullableToOne",
+          "requiredNonNullableToOne",
+          "requiredNullableToOne"
+        ],
+        "type": "object",
+        "properties": {
+          "nonNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInResponse"
+              }
+            ]
+          },
+          "requiredNonNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInResponse"
+              }
+            ]
+          },
+          "nullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullableToOneEmptyResourceInResponse"
+              }
+            ]
+          },
+          "requiredNullableToOne": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toOneEmptyResourceInResponse"
+              }
+            ]
+          },
+          "toMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInResponse"
+              }
+            ]
+          },
+          "requiredToMany": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/toManyEmptyResourceInResponse"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "resourceResourceType": {
+        "enum": [
+          "Resource"
+        ],
+        "type": "string"
+      },
+      "toManyEmptyResourceInRequest": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/emptyResourceIdentifier"
+            }
+          }
+        },
+        "additionalProperties": false
+      },
+      "toManyEmptyResourceInResponse": {
+        "required": [
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/emptyResourceIdentifier"
+            }
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInRelationshipObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      },
+      "toOneEmptyResourceInRequest": {
+        "required": [
+          "data"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ]
+          }
+        },
+        "additionalProperties": false
+      },
+      "toOneEmptyResourceInResponse": {
+        "required": [
+          "links"
+        ],
+        "type": "object",
+        "properties": {
+          "data": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/emptyResourceIdentifier"
+              }
+            ]
+          },
+          "links": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/linksInRelationshipObject"
+              }
+            ]
+          },
+          "meta": {
+            "type": "object",
+            "additionalProperties": {}
+          }
+        },
+        "additionalProperties": false
+      }
+    }
+  }
+}
diff --git a/test/OpenApiTests/LegacyOpenApiIntegration/swagger.json b/test/OpenApiTests/LegacyOpenApiIntegration/swagger.json
index 4b6c140fc4..f2c0237d1d 100644
--- a/test/OpenApiTests/LegacyOpenApiIntegration/swagger.json
+++ b/test/OpenApiTests/LegacyOpenApiIntegration/swagger.json
@@ -51,7 +51,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/airplane-post-request-document"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/airplane-post-request-document"
+                  }
+                ]
               }
             }
           }
@@ -149,7 +153,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/airplane-patch-request-document"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/airplane-patch-request-document"
+                  }
+                ]
               }
             }
           }
@@ -326,7 +334,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -356,7 +368,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -386,7 +402,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -444,7 +464,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/flight-attendant-post-request-document"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/flight-attendant-post-request-document"
+                  }
+                ]
               }
             }
           }
@@ -542,7 +566,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/flight-attendant-patch-request-document"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/flight-attendant-patch-request-document"
+                  }
+                ]
               }
             }
           }
@@ -719,7 +747,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -749,7 +781,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -779,7 +815,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -925,7 +965,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -955,7 +999,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -985,7 +1033,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1043,7 +1095,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/flight-post-request-document"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/flight-post-request-document"
+                  }
+                ]
               }
             }
           }
@@ -1141,7 +1197,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/flight-patch-request-document"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/flight-patch-request-document"
+                  }
+                ]
               }
             }
           }
@@ -1318,7 +1378,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/nullable-to-one-flight-attendant-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/nullable-to-one-flight-attendant-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1464,7 +1528,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1494,7 +1562,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1524,7 +1596,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1670,7 +1746,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-passenger-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-passenger-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1700,7 +1780,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-passenger-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-passenger-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1730,7 +1814,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-many-passenger-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-many-passenger-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1876,7 +1964,11 @@
           "content": {
             "application/vnd.api+json": {
               "schema": {
-                "$ref": "#/components/schemas/to-one-flight-attendant-in-request"
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/to-one-flight-attendant-in-request"
+                  }
+                ]
               }
             }
           }
@@ -1970,6 +2062,9 @@
         "additionalProperties": false
       },
       "airplane-attributes-in-response": {
+        "required": [
+          "name"
+        ],
         "type": "object",
         "properties": {
           "name": {
@@ -2004,7 +2099,11 @@
             "nullable": true
           },
           "kind": {
-            "$ref": "#/components/schemas/aircraft-kind"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/aircraft-kind"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2027,10 +2126,18 @@
             "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-collection-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-collection-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2043,17 +2150,29 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/airplane-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/airplane-attributes-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-attributes-in-patch-request"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/airplane-relationships-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-relationships-in-patch-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2065,13 +2184,25 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/airplane-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-resource-type"
+              }
+            ]
           },
           "attributes": {
-            "$ref": "#/components/schemas/airplane-attributes-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-attributes-in-post-request"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/airplane-relationships-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-relationships-in-post-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2085,20 +2216,36 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/airplane-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/airplane-attributes-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-attributes-in-response"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/airplane-relationships-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-relationships-in-response"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
@@ -2114,7 +2261,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/airplane-data-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-data-in-patch-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2126,7 +2277,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/airplane-data-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-data-in-post-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2139,17 +2294,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/airplane-data-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airplane-data-in-response"
+              }
+            ]
           },
           "meta": {
             "type": "object",
             "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2158,7 +2325,11 @@
         "type": "object",
         "properties": {
           "flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2167,7 +2338,11 @@
         "type": "object",
         "properties": {
           "flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2176,7 +2351,11 @@
         "type": "object",
         "properties": {
           "flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-response"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2238,6 +2417,10 @@
         "additionalProperties": false
       },
       "flight-attendant-attributes-in-response": {
+        "required": [
+          "email-address",
+          "profile-image-url"
+        ],
         "type": "object",
         "properties": {
           "email-address": {
@@ -2280,10 +2463,18 @@
             "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-collection-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-collection-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2296,17 +2487,29 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/flight-attendant-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/flight-attendant-attributes-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-attributes-in-patch-request"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/flight-attendant-relationships-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-relationships-in-patch-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2318,13 +2521,25 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/flight-attendant-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-resource-type"
+              }
+            ]
           },
           "attributes": {
-            "$ref": "#/components/schemas/flight-attendant-attributes-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-attributes-in-post-request"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/flight-attendant-relationships-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-relationships-in-post-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2338,20 +2553,36 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/flight-attendant-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/flight-attendant-attributes-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-attributes-in-response"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/flight-attendant-relationships-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-relationships-in-response"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
@@ -2368,7 +2599,11 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/flight-attendant-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
@@ -2395,10 +2630,18 @@
             "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-identifier-collection-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-identifier-collection-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2411,17 +2654,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-attendant-identifier"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-identifier"
+              }
+            ]
           },
           "meta": {
             "type": "object",
             "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-identifier-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-identifier-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2433,7 +2688,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-attendant-data-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-data-in-patch-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2445,7 +2704,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-attendant-data-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-data-in-post-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2458,17 +2721,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-attendant-data-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-data-in-response"
+              }
+            ]
           },
           "meta": {
             "type": "object",
             "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2477,10 +2752,18 @@
         "type": "object",
         "properties": {
           "scheduled-for-flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-request"
+              }
+            ]
           },
           "purser-on-flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2489,10 +2772,18 @@
         "type": "object",
         "properties": {
           "scheduled-for-flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-request"
+              }
+            ]
           },
           "purser-on-flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2501,10 +2792,18 @@
         "type": "object",
         "properties": {
           "scheduled-for-flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-response"
+              }
+            ]
           },
           "purser-on-flights": {
-            "$ref": "#/components/schemas/to-many-flight-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-in-response"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2523,17 +2822,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-attendant-data-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-data-in-response"
+              }
+            ]
           },
           "meta": {
             "type": "object",
             "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2551,12 +2862,20 @@
             "nullable": true
           },
           "operated-by": {
-            "$ref": "#/components/schemas/airline"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airline"
+              }
+            ]
           }
         },
         "additionalProperties": false
       },
       "flight-attributes-in-response": {
+        "required": [
+          "final-destination",
+          "services-on-board"
+        ],
         "type": "object",
         "properties": {
           "final-destination": {
@@ -2569,7 +2888,11 @@
             "nullable": true
           },
           "operated-by": {
-            "$ref": "#/components/schemas/airline"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/airline"
+              }
+            ]
           },
           "departs-at": {
             "type": "string",
@@ -2608,10 +2931,18 @@
             "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-collection-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-collection-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2624,17 +2955,29 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/flight-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/flight-attributes-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attributes-in-patch-request"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/flight-relationships-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-relationships-in-patch-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2646,10 +2989,18 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/flight-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-resource-type"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/flight-relationships-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-relationships-in-post-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2663,20 +3014,36 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/flight-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/flight-attributes-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attributes-in-response"
+              }
+            ]
           },
           "relationships": {
-            "$ref": "#/components/schemas/flight-relationships-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-relationships-in-response"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
@@ -2693,7 +3060,11 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/flight-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
@@ -2720,10 +3091,18 @@
             "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-identifier-collection-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-identifier-collection-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2735,7 +3114,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-data-in-patch-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-data-in-patch-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2747,7 +3130,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-data-in-post-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-data-in-post-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2760,17 +3147,29 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-data-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-data-in-response"
+              }
+            ]
           },
           "meta": {
             "type": "object",
             "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2779,16 +3178,32 @@
         "type": "object",
         "properties": {
           "cabin-crew-members": {
-            "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+              }
+            ]
           },
           "purser": {
-            "$ref": "#/components/schemas/to-one-flight-attendant-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-one-flight-attendant-in-request"
+              }
+            ]
           },
           "backup-purser": {
-            "$ref": "#/components/schemas/nullable-to-one-flight-attendant-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullable-to-one-flight-attendant-in-request"
+              }
+            ]
           },
           "passengers": {
-            "$ref": "#/components/schemas/to-many-passenger-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-passenger-in-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2800,34 +3215,69 @@
         "type": "object",
         "properties": {
           "cabin-crew-members": {
-            "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-attendant-in-request"
+              }
+            ]
           },
           "purser": {
-            "$ref": "#/components/schemas/to-one-flight-attendant-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-one-flight-attendant-in-request"
+              }
+            ]
           },
           "backup-purser": {
-            "$ref": "#/components/schemas/nullable-to-one-flight-attendant-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullable-to-one-flight-attendant-in-request"
+              }
+            ]
           },
           "passengers": {
-            "$ref": "#/components/schemas/to-many-passenger-in-request"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-passenger-in-request"
+              }
+            ]
           }
         },
         "additionalProperties": false
       },
       "flight-relationships-in-response": {
+        "required": [
+          "purser"
+        ],
         "type": "object",
         "properties": {
           "cabin-crew-members": {
-            "$ref": "#/components/schemas/to-many-flight-attendant-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-flight-attendant-in-response"
+              }
+            ]
           },
           "purser": {
-            "$ref": "#/components/schemas/to-one-flight-attendant-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-one-flight-attendant-in-response"
+              }
+            ]
           },
           "backup-purser": {
-            "$ref": "#/components/schemas/nullable-to-one-flight-attendant-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/nullable-to-one-flight-attendant-in-response"
+              }
+            ]
           },
           "passengers": {
-            "$ref": "#/components/schemas/to-many-passenger-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/to-many-passenger-in-response"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -2996,29 +3446,6 @@
         },
         "additionalProperties": false
       },
-      "null-value": {
-        "not": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "type": "number"
-            },
-            {
-              "type": "boolean"
-            },
-            {
-              "type": "object"
-            },
-            {
-              "type": "array"
-            }
-          ],
-          "items": {}
-        },
-        "nullable": true
-      },
       "nullable-flight-attendant-identifier-response-document": {
         "required": [
           "data",
@@ -3027,24 +3454,30 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/flight-attendant-identifier"
-              },
-              {
-                "$ref": "#/components/schemas/null-value"
               }
-            ]
+            ],
+            "nullable": true
           },
           "meta": {
             "type": "object",
             "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-identifier-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-identifier-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -3057,24 +3490,30 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/flight-attendant-data-in-response"
-              },
-              {
-                "$ref": "#/components/schemas/null-value"
               }
-            ]
+            ],
+            "nullable": true
           },
           "meta": {
             "type": "object",
             "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -3086,14 +3525,12 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/flight-attendant-identifier"
-              },
-              {
-                "$ref": "#/components/schemas/null-value"
               }
-            ]
+            ],
+            "nullable": true
           }
         },
         "additionalProperties": false
@@ -3105,17 +3542,19 @@
         "type": "object",
         "properties": {
           "data": {
-            "oneOf": [
+            "allOf": [
               {
                 "$ref": "#/components/schemas/flight-attendant-identifier"
-              },
-              {
-                "$ref": "#/components/schemas/null-value"
               }
-            ]
+            ],
+            "nullable": true
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-relationship-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-relationship-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
@@ -3132,7 +3571,11 @@
             "nullable": true
           },
           "cabin-area": {
-            "$ref": "#/components/schemas/cabin-area"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/cabin-area"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -3155,10 +3598,18 @@
             "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-collection-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-collection-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -3172,17 +3623,29 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/passenger-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/passenger-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
             "type": "string"
           },
           "attributes": {
-            "$ref": "#/components/schemas/passenger-attributes-in-response"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/passenger-attributes-in-response"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
@@ -3199,7 +3662,11 @@
         "type": "object",
         "properties": {
           "type": {
-            "$ref": "#/components/schemas/passenger-resource-type"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/passenger-resource-type"
+              }
+            ]
           },
           "id": {
             "minLength": 1,
@@ -3226,10 +3693,18 @@
             "additionalProperties": {}
           },
           "jsonapi": {
-            "$ref": "#/components/schemas/jsonapi-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/jsonapi-object"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-resource-identifier-collection-document"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-resource-identifier-collection-document"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -3268,7 +3743,11 @@
             }
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-relationship-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-relationship-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
@@ -3305,7 +3784,11 @@
             }
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-relationship-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-relationship-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
@@ -3342,7 +3825,11 @@
             }
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-relationship-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-relationship-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
@@ -3358,7 +3845,11 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-attendant-identifier"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-identifier"
+              }
+            ]
           }
         },
         "additionalProperties": false
@@ -3370,10 +3861,18 @@
         "type": "object",
         "properties": {
           "data": {
-            "$ref": "#/components/schemas/flight-attendant-identifier"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/flight-attendant-identifier"
+              }
+            ]
           },
           "links": {
-            "$ref": "#/components/schemas/links-in-relationship-object"
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/links-in-relationship-object"
+              }
+            ]
           },
           "meta": {
             "type": "object",
diff --git a/test/OpenApiTests/NamingConventions/CamelCase/CamelCaseTests.cs b/test/OpenApiTests/NamingConventions/CamelCase/CamelCaseTests.cs
index e0bbd5bad3..33372b10d9 100644
--- a/test/OpenApiTests/NamingConventions/CamelCase/CamelCaseTests.cs
+++ b/test/OpenApiTests/NamingConventions/CamelCase/CamelCaseTests.cs
@@ -43,9 +43,9 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                propertiesElement.ShouldContainPath("jsonapi.$ref").ShouldBeSchemaReferenceId("jsonapiObject");
+                propertiesElement.ShouldContainPath("jsonapi.allOf[0].$ref").ShouldBeSchemaReferenceId("jsonapiObject");
 
-                linksInResourceCollectionDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.$ref")
+                linksInResourceCollectionDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("linksInResourceCollectionDocument").SchemaReferenceId;
 
                 resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.items.$ref").ShouldBeSchemaReferenceId("supermarketDataInResponse")
@@ -69,16 +69,16 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
 
             schemasElement.ShouldContainPath($"{resourceDataSchemaRefId}.properties").With(propertiesElement =>
             {
-                linksInResourceObjectSchemaRefId = propertiesElement.ShouldContainPath("links.$ref").ShouldBeSchemaReferenceId("linksInResourceObject")
+                linksInResourceObjectSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref").ShouldBeSchemaReferenceId("linksInResourceObject")
                     .SchemaReferenceId;
 
-                primaryResourceTypeSchemaRefId = propertiesElement.ShouldContainPath("type.$ref").ShouldBeSchemaReferenceId("supermarketResourceType")
+                primaryResourceTypeSchemaRefId = propertiesElement.ShouldContainPath("type.allOf[0].$ref").ShouldBeSchemaReferenceId("supermarketResourceType")
                     .SchemaReferenceId;
 
-                resourceAttributesInResponseSchemaRefId = propertiesElement.ShouldContainPath("attributes.$ref")
+                resourceAttributesInResponseSchemaRefId = propertiesElement.ShouldContainPath("attributes.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("supermarketAttributesInResponse").SchemaReferenceId;
 
-                resourceRelationshipInResponseSchemaRefId = propertiesElement.ShouldContainPath("relationships.$ref")
+                resourceRelationshipInResponseSchemaRefId = propertiesElement.ShouldContainPath("relationships.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("supermarketRelationshipsInResponse").SchemaReferenceId;
             });
 
@@ -96,7 +96,7 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
             {
                 propertiesElement.Should().ContainProperty("nameOfCity");
                 propertiesElement.Should().ContainProperty("kind");
-                propertiesElement.ShouldContainPath("kind.$ref").ShouldBeSchemaReferenceId("supermarketType");
+                propertiesElement.ShouldContainPath("kind.allOf[0].$ref").ShouldBeSchemaReferenceId("supermarketType");
             });
 
             string? nullableToOneResourceResponseDataSchemaRefId = null;
@@ -105,13 +105,13 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
             {
                 propertiesElement.Should().ContainProperty("storeManager");
 
-                propertiesElement.ShouldContainPath("storeManager.$ref").ShouldBeSchemaReferenceId("toOneStaffMemberInResponse");
+                propertiesElement.ShouldContainPath("storeManager.allOf[0].$ref").ShouldBeSchemaReferenceId("toOneStaffMemberInResponse");
 
-                nullableToOneResourceResponseDataSchemaRefId = propertiesElement.ShouldContainPath("backupStoreManager.$ref")
+                nullableToOneResourceResponseDataSchemaRefId = propertiesElement.ShouldContainPath("backupStoreManager.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("nullableToOneStaffMemberInResponse").SchemaReferenceId;
 
                 propertiesElement.Should().ContainProperty("cashiers");
-                propertiesElement.ShouldContainPath("cashiers.$ref").ShouldBeSchemaReferenceId("toManyStaffMemberInResponse");
+                propertiesElement.ShouldContainPath("cashiers.allOf[0].$ref").ShouldBeSchemaReferenceId("toManyStaffMemberInResponse");
             });
 
             string? linksInRelationshipObjectSchemaRefId = null;
@@ -119,13 +119,11 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
 
             schemasElement.ShouldContainPath($"{nullableToOneResourceResponseDataSchemaRefId}.properties").With(propertiesElement =>
             {
-                linksInRelationshipObjectSchemaRefId = propertiesElement.ShouldContainPath("links.$ref").ShouldBeSchemaReferenceId("linksInRelationshipObject")
-                    .SchemaReferenceId;
+                linksInRelationshipObjectSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref")
+                    .ShouldBeSchemaReferenceId("linksInRelationshipObject").SchemaReferenceId;
 
-                relatedResourceIdentifierSchemaRefId = propertiesElement.ShouldContainPath("data.oneOf[0].$ref")
+                relatedResourceIdentifierSchemaRefId = propertiesElement.ShouldContainPath("data.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("staffMemberIdentifier").SchemaReferenceId;
-
-                propertiesElement.ShouldContainPath("data.oneOf[1].$ref").ShouldBeSchemaReferenceId("nullValue");
             });
 
             schemasElement.ShouldContainPath($"{linksInRelationshipObjectSchemaRefId}.properties").With(propertiesElement =>
@@ -138,7 +136,7 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
 
             schemasElement.ShouldContainPath($"{relatedResourceIdentifierSchemaRefId}.properties").With(propertiesElement =>
             {
-                relatedResourceTypeSchemaRefId = propertiesElement.ShouldContainPath("type.$ref").ShouldBeSchemaReferenceId("staffMemberResourceType")
+                relatedResourceTypeSchemaRefId = propertiesElement.ShouldContainPath("type.allOf[0].$ref").ShouldBeSchemaReferenceId("staffMemberResourceType")
                     .SchemaReferenceId;
             });
 
@@ -172,8 +170,8 @@ public async Task Casing_convention_is_applied_to_GetSingle_endpoint()
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                linksInResourceDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.$ref").ShouldBeSchemaReferenceId("linksInResourceDocument")
-                    .SchemaReferenceId;
+                linksInResourceDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref")
+                    .ShouldBeSchemaReferenceId("linksInResourceDocument").SchemaReferenceId;
             });
 
             schemasElement.ShouldContainPath($"{linksInResourceDocumentSchemaRefId}.properties").With(propertiesElement =>
@@ -210,13 +208,13 @@ public async Task Casing_convention_is_applied_to_GetSecondary_endpoint_with_sin
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.$ref").ShouldBeSchemaReferenceId("staffMemberDataInResponse")
+                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.allOf[0].$ref").ShouldBeSchemaReferenceId("staffMemberDataInResponse")
                     .SchemaReferenceId;
             });
 
             schemasElement.ShouldContainPath($"{resourceDataSchemaRefId}.properties").With(propertiesElement =>
             {
-                propertiesElement.ShouldContainPath("attributes.$ref").ShouldBeSchemaReferenceId("staffMemberAttributesInResponse");
+                propertiesElement.ShouldContainPath("attributes.allOf[0].$ref").ShouldBeSchemaReferenceId("staffMemberAttributesInResponse");
             });
         });
     }
@@ -285,7 +283,7 @@ public async Task Casing_convention_is_applied_to_GetRelationship_endpoint_with_
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                linksInResourceIdentifierDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.$ref")
+                linksInResourceIdentifierDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("linksInResourceIdentifierDocument").SchemaReferenceId;
             });
 
@@ -343,7 +341,7 @@ public async Task Casing_convention_is_applied_to_GetRelationship_endpoint_with_
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                linksInResourceIdentifierCollectionDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.$ref")
+                linksInResourceIdentifierCollectionDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("linksInResourceIdentifierCollectionDocument").SchemaReferenceId;
             });
 
@@ -376,7 +374,7 @@ public async Task Casing_convention_is_applied_to_Post_endpoint()
                 operationElement.ShouldBeString("postSupermarket");
             });
 
-            documentSchemaRefId = getElement.ShouldContainPath("requestBody.content['application/vnd.api+json'].schema.$ref")
+            documentSchemaRefId = getElement.ShouldContainPath("requestBody.content['application/vnd.api+json'].schema.allOf[0].$ref")
                 .ShouldBeSchemaReferenceId("supermarketPostRequestDocument").SchemaReferenceId;
         });
 
@@ -386,7 +384,7 @@ public async Task Casing_convention_is_applied_to_Post_endpoint()
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.$ref").ShouldBeSchemaReferenceId("supermarketDataInPostRequest")
+                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.allOf[0].$ref").ShouldBeSchemaReferenceId("supermarketDataInPostRequest")
                     .SchemaReferenceId;
             });
 
@@ -394,22 +392,22 @@ public async Task Casing_convention_is_applied_to_Post_endpoint()
 
             schemasElement.ShouldContainPath($"{resourceDataSchemaRefId}.properties").With(propertiesElement =>
             {
-                propertiesElement.ShouldContainPath("attributes.$ref").ShouldBeSchemaReferenceId("supermarketAttributesInPostRequest");
+                propertiesElement.ShouldContainPath("attributes.allOf[0].$ref").ShouldBeSchemaReferenceId("supermarketAttributesInPostRequest");
 
-                resourceRelationshipInPostRequestSchemaRefId = propertiesElement.ShouldContainPath("relationships.$ref")
+                resourceRelationshipInPostRequestSchemaRefId = propertiesElement.ShouldContainPath("relationships.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("supermarketRelationshipsInPostRequest").SchemaReferenceId;
             });
 
             schemasElement.ShouldContainPath($"{resourceRelationshipInPostRequestSchemaRefId}.properties").With(propertiesElement =>
             {
                 propertiesElement.Should().ContainProperty("storeManager");
-                propertiesElement.ShouldContainPath("storeManager.$ref").ShouldBeSchemaReferenceId("toOneStaffMemberInRequest");
+                propertiesElement.ShouldContainPath("storeManager.allOf[0].$ref").ShouldBeSchemaReferenceId("toOneStaffMemberInRequest");
 
                 propertiesElement.Should().ContainProperty("backupStoreManager");
-                propertiesElement.ShouldContainPath("backupStoreManager.$ref").ShouldBeSchemaReferenceId("nullableToOneStaffMemberInRequest");
+                propertiesElement.ShouldContainPath("backupStoreManager.allOf[0].$ref").ShouldBeSchemaReferenceId("nullableToOneStaffMemberInRequest");
 
                 propertiesElement.Should().ContainProperty("cashiers");
-                propertiesElement.ShouldContainPath("cashiers.$ref").ShouldBeSchemaReferenceId("toManyStaffMemberInRequest");
+                propertiesElement.ShouldContainPath("cashiers.allOf[0].$ref").ShouldBeSchemaReferenceId("toManyStaffMemberInRequest");
             });
         });
     }
@@ -446,7 +444,7 @@ public async Task Casing_convention_is_applied_to_Patch_endpoint()
                 operationElement.ShouldBeString("patchSupermarket");
             });
 
-            documentSchemaRefId = getElement.ShouldContainPath("requestBody.content['application/vnd.api+json'].schema.$ref")
+            documentSchemaRefId = getElement.ShouldContainPath("requestBody.content['application/vnd.api+json'].schema.allOf[0].$ref")
                 .ShouldBeSchemaReferenceId("supermarketPatchRequestDocument").SchemaReferenceId;
         });
 
@@ -456,14 +454,14 @@ public async Task Casing_convention_is_applied_to_Patch_endpoint()
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.$ref").ShouldBeSchemaReferenceId("supermarketDataInPatchRequest")
+                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.allOf[0].$ref").ShouldBeSchemaReferenceId("supermarketDataInPatchRequest")
                     .SchemaReferenceId;
             });
 
             schemasElement.ShouldContainPath($"{resourceDataSchemaRefId}.properties").With(propertiesElement =>
             {
-                propertiesElement.ShouldContainPath("attributes.$ref").ShouldBeSchemaReferenceId("supermarketAttributesInPatchRequest");
-                propertiesElement.ShouldContainPath("relationships.$ref").ShouldBeSchemaReferenceId("supermarketRelationshipsInPatchRequest");
+                propertiesElement.ShouldContainPath("attributes.allOf[0].$ref").ShouldBeSchemaReferenceId("supermarketAttributesInPatchRequest");
+                propertiesElement.ShouldContainPath("relationships.allOf[0].$ref").ShouldBeSchemaReferenceId("supermarketRelationshipsInPatchRequest");
             });
         });
     }
diff --git a/test/OpenApiTests/NamingConventions/KebabCase/KebabCaseTests.cs b/test/OpenApiTests/NamingConventions/KebabCase/KebabCaseTests.cs
index 0a532a6e3f..47af397845 100644
--- a/test/OpenApiTests/NamingConventions/KebabCase/KebabCaseTests.cs
+++ b/test/OpenApiTests/NamingConventions/KebabCase/KebabCaseTests.cs
@@ -43,9 +43,9 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                propertiesElement.ShouldContainPath("jsonapi.$ref").ShouldBeSchemaReferenceId("jsonapi-object");
+                propertiesElement.ShouldContainPath("jsonapi.allOf[0].$ref").ShouldBeSchemaReferenceId("jsonapi-object");
 
-                linksInResourceCollectionDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.$ref")
+                linksInResourceCollectionDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("links-in-resource-collection-document").SchemaReferenceId;
 
                 resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.items.$ref").ShouldBeSchemaReferenceId("supermarket-data-in-response")
@@ -69,16 +69,16 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
 
             schemasElement.ShouldContainPath($"{resourceDataSchemaRefId}.properties").With(propertiesElement =>
             {
-                linksInResourceObjectSchemaRefId = propertiesElement.ShouldContainPath("links.$ref").ShouldBeSchemaReferenceId("links-in-resource-object")
-                    .SchemaReferenceId;
+                linksInResourceObjectSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref")
+                    .ShouldBeSchemaReferenceId("links-in-resource-object").SchemaReferenceId;
 
-                primaryResourceTypeSchemaRefId = propertiesElement.ShouldContainPath("type.$ref").ShouldBeSchemaReferenceId("supermarket-resource-type")
-                    .SchemaReferenceId;
+                primaryResourceTypeSchemaRefId = propertiesElement.ShouldContainPath("type.allOf[0].$ref")
+                    .ShouldBeSchemaReferenceId("supermarket-resource-type").SchemaReferenceId;
 
-                resourceAttributesInResponseSchemaRefId = propertiesElement.ShouldContainPath("attributes.$ref")
+                resourceAttributesInResponseSchemaRefId = propertiesElement.ShouldContainPath("attributes.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("supermarket-attributes-in-response").SchemaReferenceId;
 
-                resourceRelationshipInResponseSchemaRefId = propertiesElement.ShouldContainPath("relationships.$ref")
+                resourceRelationshipInResponseSchemaRefId = propertiesElement.ShouldContainPath("relationships.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("supermarket-relationships-in-response").SchemaReferenceId;
             });
 
@@ -96,7 +96,7 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
             {
                 propertiesElement.Should().ContainProperty("name-of-city");
                 propertiesElement.Should().ContainProperty("kind");
-                propertiesElement.ShouldContainPath("kind.$ref").ShouldBeSchemaReferenceId("supermarket-type");
+                propertiesElement.ShouldContainPath("kind.allOf[0].$ref").ShouldBeSchemaReferenceId("supermarket-type");
             });
 
             string? nullableToOneResourceResponseDataSchemaRefId = null;
@@ -105,13 +105,13 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
             {
                 propertiesElement.Should().ContainProperty("store-manager");
 
-                propertiesElement.ShouldContainPath("store-manager.$ref").ShouldBeSchemaReferenceId("to-one-staff-member-in-response");
+                propertiesElement.ShouldContainPath("store-manager.allOf[0].$ref").ShouldBeSchemaReferenceId("to-one-staff-member-in-response");
 
-                nullableToOneResourceResponseDataSchemaRefId = propertiesElement.ShouldContainPath("backup-store-manager.$ref")
+                nullableToOneResourceResponseDataSchemaRefId = propertiesElement.ShouldContainPath("backup-store-manager.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("nullable-to-one-staff-member-in-response").SchemaReferenceId;
 
                 propertiesElement.Should().ContainProperty("cashiers");
-                propertiesElement.ShouldContainPath("cashiers.$ref").ShouldBeSchemaReferenceId("to-many-staff-member-in-response");
+                propertiesElement.ShouldContainPath("cashiers.allOf[0].$ref").ShouldBeSchemaReferenceId("to-many-staff-member-in-response");
             });
 
             string? linksInRelationshipObjectSchemaRefId = null;
@@ -119,13 +119,11 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
 
             schemasElement.ShouldContainPath($"{nullableToOneResourceResponseDataSchemaRefId}.properties").With(propertiesElement =>
             {
-                linksInRelationshipObjectSchemaRefId = propertiesElement.ShouldContainPath("links.$ref")
+                linksInRelationshipObjectSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("links-in-relationship-object").SchemaReferenceId;
 
-                relatedResourceIdentifierSchemaRefId = propertiesElement.ShouldContainPath("data.oneOf[0].$ref")
+                relatedResourceIdentifierSchemaRefId = propertiesElement.ShouldContainPath("data.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("staff-member-identifier").SchemaReferenceId;
-
-                propertiesElement.ShouldContainPath("data.oneOf[1].$ref").ShouldBeSchemaReferenceId("null-value");
             });
 
             schemasElement.ShouldContainPath($"{linksInRelationshipObjectSchemaRefId}.properties").With(propertiesElement =>
@@ -138,8 +136,8 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
 
             schemasElement.ShouldContainPath($"{relatedResourceIdentifierSchemaRefId}.properties").With(propertiesElement =>
             {
-                relatedResourceTypeSchemaRefId = propertiesElement.ShouldContainPath("type.$ref").ShouldBeSchemaReferenceId("staff-member-resource-type")
-                    .SchemaReferenceId;
+                relatedResourceTypeSchemaRefId = propertiesElement.ShouldContainPath("type.allOf[0].$ref")
+                    .ShouldBeSchemaReferenceId("staff-member-resource-type").SchemaReferenceId;
             });
 
             schemasElement.ShouldContainPath($"{relatedResourceTypeSchemaRefId}.enum[0]").ShouldBeSchemaReferenceId("staff-members");
@@ -172,8 +170,8 @@ public async Task Casing_convention_is_applied_to_GetSingle_endpoint()
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                linksInResourceDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.$ref").ShouldBeSchemaReferenceId("links-in-resource-document")
-                    .SchemaReferenceId;
+                linksInResourceDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref")
+                    .ShouldBeSchemaReferenceId("links-in-resource-document").SchemaReferenceId;
             });
 
             schemasElement.ShouldContainPath($"{linksInResourceDocumentSchemaRefId}.properties").With(propertiesElement =>
@@ -210,13 +208,13 @@ public async Task Casing_convention_is_applied_to_GetSecondary_endpoint_with_sin
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.$ref").ShouldBeSchemaReferenceId("staff-member-data-in-response")
+                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.allOf[0].$ref").ShouldBeSchemaReferenceId("staff-member-data-in-response")
                     .SchemaReferenceId;
             });
 
             schemasElement.ShouldContainPath($"{resourceDataSchemaRefId}.properties").With(propertiesElement =>
             {
-                propertiesElement.ShouldContainPath("attributes.$ref").ShouldBeSchemaReferenceId("staff-member-attributes-in-response");
+                propertiesElement.ShouldContainPath("attributes.allOf[0].$ref").ShouldBeSchemaReferenceId("staff-member-attributes-in-response");
             });
         });
     }
@@ -285,7 +283,7 @@ public async Task Casing_convention_is_applied_to_GetRelationship_endpoint_with_
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                linksInResourceIdentifierDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.$ref")
+                linksInResourceIdentifierDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("links-in-resource-identifier-document").SchemaReferenceId;
             });
 
@@ -343,7 +341,7 @@ public async Task Casing_convention_is_applied_to_GetRelationship_endpoint_with_
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                linksInResourceIdentifierCollectionDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.$ref")
+                linksInResourceIdentifierCollectionDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("links-in-resource-identifier-collection-document").SchemaReferenceId;
             });
 
@@ -376,7 +374,7 @@ public async Task Casing_convention_is_applied_to_Post_endpoint()
                 operationElement.ShouldBeString("post-supermarket");
             });
 
-            documentSchemaRefId = getElement.ShouldContainPath("requestBody.content['application/vnd.api+json'].schema.$ref")
+            documentSchemaRefId = getElement.ShouldContainPath("requestBody.content['application/vnd.api+json'].schema.allOf[0].$ref")
                 .ShouldBeSchemaReferenceId("supermarket-post-request-document").SchemaReferenceId;
         });
 
@@ -386,30 +384,30 @@ public async Task Casing_convention_is_applied_to_Post_endpoint()
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.$ref").ShouldBeSchemaReferenceId("supermarket-data-in-post-request")
-                    .SchemaReferenceId;
+                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.allOf[0].$ref")
+                    .ShouldBeSchemaReferenceId("supermarket-data-in-post-request").SchemaReferenceId;
             });
 
             string? resourceRelationshipInPostRequestSchemaRefId = null;
 
             schemasElement.ShouldContainPath($"{resourceDataSchemaRefId}.properties").With(propertiesElement =>
             {
-                propertiesElement.ShouldContainPath("attributes.$ref").ShouldBeSchemaReferenceId("supermarket-attributes-in-post-request");
+                propertiesElement.ShouldContainPath("attributes.allOf[0].$ref").ShouldBeSchemaReferenceId("supermarket-attributes-in-post-request");
 
-                resourceRelationshipInPostRequestSchemaRefId = propertiesElement.ShouldContainPath("relationships.$ref")
+                resourceRelationshipInPostRequestSchemaRefId = propertiesElement.ShouldContainPath("relationships.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("supermarket-relationships-in-post-request").SchemaReferenceId;
             });
 
             schemasElement.ShouldContainPath($"{resourceRelationshipInPostRequestSchemaRefId}.properties").With(propertiesElement =>
             {
                 propertiesElement.Should().ContainProperty("store-manager");
-                propertiesElement.ShouldContainPath("store-manager.$ref").ShouldBeSchemaReferenceId("to-one-staff-member-in-request");
+                propertiesElement.ShouldContainPath("store-manager.allOf[0].$ref").ShouldBeSchemaReferenceId("to-one-staff-member-in-request");
 
                 propertiesElement.Should().ContainProperty("backup-store-manager");
-                propertiesElement.ShouldContainPath("backup-store-manager.$ref").ShouldBeSchemaReferenceId("nullable-to-one-staff-member-in-request");
+                propertiesElement.ShouldContainPath("backup-store-manager.allOf[0].$ref").ShouldBeSchemaReferenceId("nullable-to-one-staff-member-in-request");
 
                 propertiesElement.Should().ContainProperty("cashiers");
-                propertiesElement.ShouldContainPath("cashiers.$ref").ShouldBeSchemaReferenceId("to-many-staff-member-in-request");
+                propertiesElement.ShouldContainPath("cashiers.allOf[0].$ref").ShouldBeSchemaReferenceId("to-many-staff-member-in-request");
             });
         });
     }
@@ -446,7 +444,7 @@ public async Task Casing_convention_is_applied_to_Patch_endpoint()
                 operationElement.ShouldBeString("patch-supermarket");
             });
 
-            documentSchemaRefId = getElement.ShouldContainPath("requestBody.content['application/vnd.api+json'].schema.$ref")
+            documentSchemaRefId = getElement.ShouldContainPath("requestBody.content['application/vnd.api+json'].schema.allOf[0].$ref")
                 .ShouldBeSchemaReferenceId("supermarket-patch-request-document").SchemaReferenceId;
         });
 
@@ -456,14 +454,14 @@ public async Task Casing_convention_is_applied_to_Patch_endpoint()
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.$ref").ShouldBeSchemaReferenceId("supermarket-data-in-patch-request")
-                    .SchemaReferenceId;
+                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.allOf[0].$ref")
+                    .ShouldBeSchemaReferenceId("supermarket-data-in-patch-request").SchemaReferenceId;
             });
 
             schemasElement.ShouldContainPath($"{resourceDataSchemaRefId}.properties").With(propertiesElement =>
             {
-                propertiesElement.ShouldContainPath("attributes.$ref").ShouldBeSchemaReferenceId("supermarket-attributes-in-patch-request");
-                propertiesElement.ShouldContainPath("relationships.$ref").ShouldBeSchemaReferenceId("supermarket-relationships-in-patch-request");
+                propertiesElement.ShouldContainPath("attributes.allOf[0].$ref").ShouldBeSchemaReferenceId("supermarket-attributes-in-patch-request");
+                propertiesElement.ShouldContainPath("relationships.allOf[0].$ref").ShouldBeSchemaReferenceId("supermarket-relationships-in-patch-request");
             });
         });
     }
diff --git a/test/OpenApiTests/NamingConventions/PascalCase/PascalCaseTests.cs b/test/OpenApiTests/NamingConventions/PascalCase/PascalCaseTests.cs
index 73868dcdad..c8cee4411b 100644
--- a/test/OpenApiTests/NamingConventions/PascalCase/PascalCaseTests.cs
+++ b/test/OpenApiTests/NamingConventions/PascalCase/PascalCaseTests.cs
@@ -44,9 +44,9 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                propertiesElement.ShouldContainPath("jsonapi.$ref").ShouldBeSchemaReferenceId("JsonapiObject");
+                propertiesElement.ShouldContainPath("jsonapi.allOf[0].$ref").ShouldBeSchemaReferenceId("JsonapiObject");
 
-                linksInResourceCollectionDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.$ref")
+                linksInResourceCollectionDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("LinksInResourceCollectionDocument").SchemaReferenceId;
 
                 resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.items.$ref").ShouldBeSchemaReferenceId("SupermarketDataInResponse")
@@ -70,16 +70,16 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
 
             schemasElement.ShouldContainPath($"{resourceDataSchemaRefId}.properties").With(propertiesElement =>
             {
-                linksInResourceObjectSchemaRefId = propertiesElement.ShouldContainPath("links.$ref").ShouldBeSchemaReferenceId("LinksInResourceObject")
+                linksInResourceObjectSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref").ShouldBeSchemaReferenceId("LinksInResourceObject")
                     .SchemaReferenceId;
 
-                primaryResourceTypeSchemaRefId = propertiesElement.ShouldContainPath("type.$ref").ShouldBeSchemaReferenceId("SupermarketResourceType")
+                primaryResourceTypeSchemaRefId = propertiesElement.ShouldContainPath("type.allOf[0].$ref").ShouldBeSchemaReferenceId("SupermarketResourceType")
                     .SchemaReferenceId;
 
-                resourceAttributesInResponseSchemaRefId = propertiesElement.ShouldContainPath("attributes.$ref")
+                resourceAttributesInResponseSchemaRefId = propertiesElement.ShouldContainPath("attributes.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("SupermarketAttributesInResponse").SchemaReferenceId;
 
-                resourceRelationshipInResponseSchemaRefId = propertiesElement.ShouldContainPath("relationships.$ref")
+                resourceRelationshipInResponseSchemaRefId = propertiesElement.ShouldContainPath("relationships.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("SupermarketRelationshipsInResponse").SchemaReferenceId;
             });
 
@@ -97,7 +97,7 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
             {
                 propertiesElement.Should().ContainProperty("NameOfCity");
                 propertiesElement.Should().ContainProperty("Kind");
-                propertiesElement.ShouldContainPath("Kind.$ref").ShouldBeSchemaReferenceId("SupermarketType");
+                propertiesElement.ShouldContainPath("Kind.allOf[0].$ref").ShouldBeSchemaReferenceId("SupermarketType");
             });
 
             string? nullableToOneResourceResponseDataSchemaRefId = null;
@@ -106,13 +106,13 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
             {
                 propertiesElement.Should().ContainProperty("StoreManager");
 
-                propertiesElement.ShouldContainPath("StoreManager.$ref").ShouldBeSchemaReferenceId("ToOneStaffMemberInResponse");
+                propertiesElement.ShouldContainPath("StoreManager.allOf[0].$ref").ShouldBeSchemaReferenceId("ToOneStaffMemberInResponse");
 
-                nullableToOneResourceResponseDataSchemaRefId = propertiesElement.ShouldContainPath("BackupStoreManager.$ref")
+                nullableToOneResourceResponseDataSchemaRefId = propertiesElement.ShouldContainPath("BackupStoreManager.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("NullableToOneStaffMemberInResponse").SchemaReferenceId;
 
                 propertiesElement.Should().ContainProperty("Cashiers");
-                propertiesElement.ShouldContainPath("Cashiers.$ref").ShouldBeSchemaReferenceId("ToManyStaffMemberInResponse");
+                propertiesElement.ShouldContainPath("Cashiers.allOf[0].$ref").ShouldBeSchemaReferenceId("ToManyStaffMemberInResponse");
             });
 
             string? linksInRelationshipObjectSchemaRefId = null;
@@ -120,13 +120,11 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
 
             schemasElement.ShouldContainPath($"{nullableToOneResourceResponseDataSchemaRefId}.properties").With(propertiesElement =>
             {
-                linksInRelationshipObjectSchemaRefId = propertiesElement.ShouldContainPath("links.$ref").ShouldBeSchemaReferenceId("LinksInRelationshipObject")
-                    .SchemaReferenceId;
+                linksInRelationshipObjectSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref")
+                    .ShouldBeSchemaReferenceId("LinksInRelationshipObject").SchemaReferenceId;
 
-                relatedResourceIdentifierSchemaRefId = propertiesElement.ShouldContainPath("data.oneOf[0].$ref")
+                relatedResourceIdentifierSchemaRefId = propertiesElement.ShouldContainPath("data.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("StaffMemberIdentifier").SchemaReferenceId;
-
-                propertiesElement.ShouldContainPath("data.oneOf[1].$ref").ShouldBeSchemaReferenceId("NullValue");
             });
 
             schemasElement.ShouldContainPath($"{linksInRelationshipObjectSchemaRefId}.properties").With(propertiesElement =>
@@ -139,7 +137,7 @@ public async Task Casing_convention_is_applied_to_GetCollection_endpoint()
 
             schemasElement.ShouldContainPath($"{relatedResourceIdentifierSchemaRefId}.properties").With(propertiesElement =>
             {
-                relatedResourceTypeSchemaRefId = propertiesElement.ShouldContainPath("type.$ref").ShouldBeSchemaReferenceId("StaffMemberResourceType")
+                relatedResourceTypeSchemaRefId = propertiesElement.ShouldContainPath("type.allOf[0].$ref").ShouldBeSchemaReferenceId("StaffMemberResourceType")
                     .SchemaReferenceId;
             });
 
@@ -173,8 +171,8 @@ public async Task Casing_convention_is_applied_to_GetSingle_endpoint()
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                linksInResourceDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.$ref").ShouldBeSchemaReferenceId("LinksInResourceDocument")
-                    .SchemaReferenceId;
+                linksInResourceDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref")
+                    .ShouldBeSchemaReferenceId("LinksInResourceDocument").SchemaReferenceId;
             });
 
             schemasElement.ShouldContainPath($"{linksInResourceDocumentSchemaRefId}.properties").With(propertiesElement =>
@@ -211,13 +209,13 @@ public async Task Casing_convention_is_applied_to_GetSecondary_endpoint_with_sin
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.$ref").ShouldBeSchemaReferenceId("StaffMemberDataInResponse")
+                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.allOf[0].$ref").ShouldBeSchemaReferenceId("StaffMemberDataInResponse")
                     .SchemaReferenceId;
             });
 
             schemasElement.ShouldContainPath($"{resourceDataSchemaRefId}.properties").With(propertiesElement =>
             {
-                propertiesElement.ShouldContainPath("attributes.$ref").ShouldBeSchemaReferenceId("StaffMemberAttributesInResponse");
+                propertiesElement.ShouldContainPath("attributes.allOf[0].$ref").ShouldBeSchemaReferenceId("StaffMemberAttributesInResponse");
             });
         });
     }
@@ -286,7 +284,7 @@ public async Task Casing_convention_is_applied_to_GetRelationship_endpoint_with_
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                linksInResourceIdentifierDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.$ref")
+                linksInResourceIdentifierDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("LinksInResourceIdentifierDocument").SchemaReferenceId;
             });
 
@@ -344,7 +342,7 @@ public async Task Casing_convention_is_applied_to_GetRelationship_endpoint_with_
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                linksInResourceIdentifierCollectionDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.$ref")
+                linksInResourceIdentifierCollectionDocumentSchemaRefId = propertiesElement.ShouldContainPath("links.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("LinksInResourceIdentifierCollectionDocument").SchemaReferenceId;
             });
 
@@ -377,7 +375,7 @@ public async Task Casing_convention_is_applied_to_Post_endpoint()
                 operationElement.ShouldBeString("PostSupermarket");
             });
 
-            documentSchemaRefId = getElement.ShouldContainPath("requestBody.content['application/vnd.api+json'].schema.$ref")
+            documentSchemaRefId = getElement.ShouldContainPath("requestBody.content['application/vnd.api+json'].schema.allOf[0].$ref")
                 .ShouldBeSchemaReferenceId("SupermarketPostRequestDocument").SchemaReferenceId;
         });
 
@@ -387,7 +385,7 @@ public async Task Casing_convention_is_applied_to_Post_endpoint()
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.$ref").ShouldBeSchemaReferenceId("SupermarketDataInPostRequest")
+                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.allOf[0].$ref").ShouldBeSchemaReferenceId("SupermarketDataInPostRequest")
                     .SchemaReferenceId;
             });
 
@@ -395,22 +393,22 @@ public async Task Casing_convention_is_applied_to_Post_endpoint()
 
             schemasElement.ShouldContainPath($"{resourceDataSchemaRefId}.properties").With(propertiesElement =>
             {
-                propertiesElement.ShouldContainPath("attributes.$ref").ShouldBeSchemaReferenceId("SupermarketAttributesInPostRequest");
+                propertiesElement.ShouldContainPath("attributes.allOf[0].$ref").ShouldBeSchemaReferenceId("SupermarketAttributesInPostRequest");
 
-                resourceRelationshipInPostRequestSchemaRefId = propertiesElement.ShouldContainPath("relationships.$ref")
+                resourceRelationshipInPostRequestSchemaRefId = propertiesElement.ShouldContainPath("relationships.allOf[0].$ref")
                     .ShouldBeSchemaReferenceId("SupermarketRelationshipsInPostRequest").SchemaReferenceId;
             });
 
             schemasElement.ShouldContainPath($"{resourceRelationshipInPostRequestSchemaRefId}.properties").With(propertiesElement =>
             {
                 propertiesElement.Should().ContainProperty("StoreManager");
-                propertiesElement.ShouldContainPath("StoreManager.$ref").ShouldBeSchemaReferenceId("ToOneStaffMemberInRequest");
+                propertiesElement.ShouldContainPath("StoreManager.allOf[0].$ref").ShouldBeSchemaReferenceId("ToOneStaffMemberInRequest");
 
                 propertiesElement.Should().ContainProperty("BackupStoreManager");
-                propertiesElement.ShouldContainPath("BackupStoreManager.$ref").ShouldBeSchemaReferenceId("NullableToOneStaffMemberInRequest");
+                propertiesElement.ShouldContainPath("BackupStoreManager.allOf[0].$ref").ShouldBeSchemaReferenceId("NullableToOneStaffMemberInRequest");
 
                 propertiesElement.Should().ContainProperty("Cashiers");
-                propertiesElement.ShouldContainPath("Cashiers.$ref").ShouldBeSchemaReferenceId("ToManyStaffMemberInRequest");
+                propertiesElement.ShouldContainPath("Cashiers.allOf[0].$ref").ShouldBeSchemaReferenceId("ToManyStaffMemberInRequest");
             });
         });
     }
@@ -447,7 +445,7 @@ public async Task Casing_convention_is_applied_to_Patch_endpoint()
                 operationElement.ShouldBeString("PatchSupermarket");
             });
 
-            documentSchemaRefId = getElement.ShouldContainPath("requestBody.content['application/vnd.api+json'].schema.$ref")
+            documentSchemaRefId = getElement.ShouldContainPath("requestBody.content['application/vnd.api+json'].schema.allOf[0].$ref")
                 .ShouldBeSchemaReferenceId("SupermarketPatchRequestDocument").SchemaReferenceId;
         });
 
@@ -457,14 +455,14 @@ public async Task Casing_convention_is_applied_to_Patch_endpoint()
 
             schemasElement.ShouldContainPath($"{documentSchemaRefId}.properties").With(propertiesElement =>
             {
-                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.$ref").ShouldBeSchemaReferenceId("SupermarketDataInPatchRequest")
+                resourceDataSchemaRefId = propertiesElement.ShouldContainPath("data.allOf[0].$ref").ShouldBeSchemaReferenceId("SupermarketDataInPatchRequest")
                     .SchemaReferenceId;
             });
 
             schemasElement.ShouldContainPath($"{resourceDataSchemaRefId}.properties").With(propertiesElement =>
             {
-                propertiesElement.ShouldContainPath("attributes.$ref").ShouldBeSchemaReferenceId("SupermarketAttributesInPatchRequest");
-                propertiesElement.ShouldContainPath("relationships.$ref").ShouldBeSchemaReferenceId("SupermarketRelationshipsInPatchRequest");
+                propertiesElement.ShouldContainPath("attributes.allOf[0].$ref").ShouldBeSchemaReferenceId("SupermarketAttributesInPatchRequest");
+                propertiesElement.ShouldContainPath("relationships.allOf[0].$ref").ShouldBeSchemaReferenceId("SupermarketRelationshipsInPatchRequest");
             });
         });
     }
diff --git a/test/OpenApiTests/OpenApiStartup.cs b/test/OpenApiTests/OpenApiStartup.cs
index 46978e7f67..e34ed1894c 100644
--- a/test/OpenApiTests/OpenApiStartup.cs
+++ b/test/OpenApiTests/OpenApiStartup.cs
@@ -6,7 +6,7 @@
 
 namespace OpenApiTests;
 
-public abstract class OpenApiStartup<TDbContext> : TestableStartup<TDbContext>
+public class OpenApiStartup<TDbContext> : TestableStartup<TDbContext>
     where TDbContext : TestableDbContext
 {
     public override void ConfigureServices(IServiceCollection services)
diff --git a/test/OpenApiTests/OpenApiTestContext.cs b/test/OpenApiTests/OpenApiTestContext.cs
index f720df7d26..e54d09a269 100644
--- a/test/OpenApiTests/OpenApiTestContext.cs
+++ b/test/OpenApiTests/OpenApiTestContext.cs
@@ -2,7 +2,6 @@
 using System.Text.Json;
 using JetBrains.Annotations;
 using TestBuildingBlocks;
-using SysNotNull = System.Diagnostics.CodeAnalysis.NotNullAttribute;
 
 namespace OpenApiTests;
 
@@ -27,34 +26,27 @@ internal async Task<JsonElement> GetSwaggerDocumentAsync()
 
     private async Task<JsonElement> CreateSwaggerDocumentAsync()
     {
-        string absoluteOutputPath = GetSwaggerDocumentAbsoluteOutputPath(SwaggerDocumentOutputPath);
-
         string content = await GetAsync("swagger/v1/swagger.json");
 
         JsonElement rootElement = ParseSwaggerDocument(content);
-        await WriteToDiskAsync(absoluteOutputPath, rootElement);
+
+        if (SwaggerDocumentOutputPath != null)
+        {
+            string absoluteOutputPath = GetSwaggerDocumentAbsoluteOutputPath(SwaggerDocumentOutputPath);
+            await WriteToDiskAsync(absoluteOutputPath, rootElement);
+        }
 
         return rootElement;
     }
 
-    private static string GetSwaggerDocumentAbsoluteOutputPath(string? relativePath)
+    private static string GetSwaggerDocumentAbsoluteOutputPath(string relativePath)
     {
-        AssertHasSwaggerDocumentOutputPath(relativePath);
-
         string solutionRoot = Path.Combine(Assembly.GetExecutingAssembly().Location, "../../../../../../");
         string outputPath = Path.Combine(solutionRoot, relativePath, "swagger.g.json");
 
         return Path.GetFullPath(outputPath);
     }
 
-    private static void AssertHasSwaggerDocumentOutputPath([SysNotNull] string? relativePath)
-    {
-        if (relativePath is null)
-        {
-            throw new Exception($"Property '{nameof(OpenApiTestContext<object, TestableDbContext>)}.{nameof(SwaggerDocumentOutputPath)}' must be set.");
-        }
-    }
-
     private async Task<string> GetAsync(string requestUrl)
     {
         using var request = new HttpRequestMessage(HttpMethod.Get, requestUrl);
diff --git a/test/OpenApiTests/OpenApiTests.csproj b/test/OpenApiTests/OpenApiTests.csproj
index d6cb1d3002..bbd9209a7b 100644
--- a/test/OpenApiTests/OpenApiTests.csproj
+++ b/test/OpenApiTests/OpenApiTests.csproj
@@ -6,7 +6,7 @@
   <ItemGroup>
     <EmbeddedResource Include="LegacyOpenApiIntegration\swagger.json" />
   </ItemGroup>
-  
+
   <ItemGroup>
     <ProjectReference Include="..\..\src\JsonApiDotNetCore.SourceGenerators\JsonApiDotNetCore.SourceGenerators.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
     <ProjectReference Include="..\..\src\JsonApiDotNetCore.OpenApi\JsonApiDotNetCore.OpenApi.csproj" />
@@ -17,6 +17,5 @@
     <PackageReference Include="coverlet.collector" Version="$(CoverletVersion)" PrivateAssets="All" />
     <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="$(AspNetVersion)" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="$(TestSdkVersion)" />
-    <PackageReference Include="BlushingPenguin.JsonPath" Version="1.0.6" />
   </ItemGroup>
 </Project>
diff --git a/test/OpenApiTests/ResourceFieldValidation/EmptyResource.cs b/test/OpenApiTests/ResourceFieldValidation/EmptyResource.cs
new file mode 100644
index 0000000000..0d7ddf5f1c
--- /dev/null
+++ b/test/OpenApiTests/ResourceFieldValidation/EmptyResource.cs
@@ -0,0 +1,9 @@
+using JetBrains.Annotations;
+using JsonApiDotNetCore.Resources;
+
+namespace OpenApiTests.ResourceFieldValidation;
+
+[UsedImplicitly(ImplicitUseKindFlags.InstantiatedNoFixedConstructorSignature)]
+public class EmptyResource : Identifiable<int>
+{
+}
diff --git a/test/OpenApiTests/ResourceFieldValidation/ModelStateValidationDisabledStartup.cs b/test/OpenApiTests/ResourceFieldValidation/ModelStateValidationDisabledStartup.cs
new file mode 100644
index 0000000000..0bea8b4d58
--- /dev/null
+++ b/test/OpenApiTests/ResourceFieldValidation/ModelStateValidationDisabledStartup.cs
@@ -0,0 +1,17 @@
+using JetBrains.Annotations;
+using JsonApiDotNetCore.Configuration;
+using TestBuildingBlocks;
+
+namespace OpenApiTests.ResourceFieldValidation;
+
+[UsedImplicitly(ImplicitUseKindFlags.InstantiatedNoFixedConstructorSignature)]
+public sealed class ModelStateValidationDisabledStartup<TDbContext> : OpenApiStartup<TDbContext>
+    where TDbContext : TestableDbContext
+{
+    protected override void SetJsonApiOptions(JsonApiOptions options)
+    {
+        base.SetJsonApiOptions(options);
+
+        options.ValidateModelState = false;
+    }
+}
diff --git a/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/NullabilityTests.cs b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/NullabilityTests.cs
new file mode 100644
index 0000000000..d0d51fb350
--- /dev/null
+++ b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/NullabilityTests.cs
@@ -0,0 +1,102 @@
+using System.Text.Json;
+using FluentAssertions;
+using TestBuildingBlocks;
+using Xunit;
+
+namespace OpenApiTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationDisabled;
+
+public sealed class NullabilityTests
+    : IClassFixture<OpenApiTestContext<ModelStateValidationDisabledStartup<NullableReferenceTypesDisabledDbContext>, NullableReferenceTypesDisabledDbContext>>
+{
+    private readonly OpenApiTestContext<ModelStateValidationDisabledStartup<NullableReferenceTypesDisabledDbContext>, NullableReferenceTypesDisabledDbContext>
+        _testContext;
+
+    public NullabilityTests(
+        OpenApiTestContext<ModelStateValidationDisabledStartup<NullableReferenceTypesDisabledDbContext>, NullableReferenceTypesDisabledDbContext> testContext)
+    {
+        _testContext = testContext;
+
+        testContext.UseController<NrtDisabledResourcesController>();
+        testContext.SwaggerDocumentOutputPath = "test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled";
+    }
+
+    [Theory]
+    [InlineData("referenceType")]
+    [InlineData("requiredReferenceType")]
+    [InlineData("nullableValueType")]
+    [InlineData("requiredNullableValueType")]
+    public async Task Schema_property_for_attribute_is_nullable(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceAttributesInResponse.properties").With(schemaProperties =>
+        {
+            schemaProperties.ShouldContainPath(jsonPropertyName).With(schemaProperty =>
+            {
+                schemaProperty.ShouldContainPath("nullable").With(nullableProperty => nullableProperty.ValueKind.Should().Be(JsonValueKind.True));
+            });
+        });
+    }
+
+    [Theory]
+    [InlineData("valueType")]
+    [InlineData("requiredValueType")]
+    public async Task Schema_property_for_attribute_is_not_nullable(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceAttributesInResponse.properties").With(schemaProperties =>
+        {
+            schemaProperties.ShouldContainPath(jsonPropertyName).With(schemaProperty =>
+            {
+                schemaProperty.ShouldNotContainPath("nullable");
+            });
+        });
+    }
+
+    [Theory]
+    [InlineData("toOne")]
+    [InlineData("requiredToOne")]
+    public async Task Schema_property_for_relationship_is_nullable(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceRelationshipsInPostRequest.properties").With(schemaProperties =>
+        {
+            schemaProperties.ShouldContainPath($"{jsonPropertyName}.allOf[0].$ref").WithSchemaReferenceId(schemaReferenceId =>
+            {
+                document.ShouldContainPath($"components.schemas.{schemaReferenceId}.properties.data").With(relationshipDataSchema =>
+                {
+                    relationshipDataSchema.ShouldContainPath("nullable").With(nullableProperty => nullableProperty.ValueKind.Should().Be(JsonValueKind.True));
+                });
+            });
+        });
+    }
+
+    [Theory]
+    [InlineData("toMany")]
+    [InlineData("requiredToMany")]
+    public async Task Schema_property_for_relationship_is_not_nullable(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceRelationshipsInPostRequest.properties").With(schemaProperties =>
+        {
+            schemaProperties.ShouldContainPath($"{jsonPropertyName}.allOf[0].$ref").WithSchemaReferenceId(schemaReferenceId =>
+            {
+                document.ShouldContainPath($"components.schemas.{schemaReferenceId}.properties.data").With(relationshipDataSchema =>
+                {
+                    relationshipDataSchema.ShouldNotContainPath("nullable");
+                });
+            });
+        });
+    }
+}
diff --git a/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/RequiredTests.cs b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/RequiredTests.cs
new file mode 100644
index 0000000000..5688462fb9
--- /dev/null
+++ b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationDisabled/RequiredTests.cs
@@ -0,0 +1,106 @@
+using System.Text.Json;
+using TestBuildingBlocks;
+using Xunit;
+
+namespace OpenApiTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationDisabled;
+
+public sealed class RequiredTests
+    : IClassFixture<OpenApiTestContext<ModelStateValidationDisabledStartup<NullableReferenceTypesDisabledDbContext>, NullableReferenceTypesDisabledDbContext>>
+{
+    private readonly OpenApiTestContext<ModelStateValidationDisabledStartup<NullableReferenceTypesDisabledDbContext>, NullableReferenceTypesDisabledDbContext>
+        _testContext;
+
+    public RequiredTests(
+        OpenApiTestContext<ModelStateValidationDisabledStartup<NullableReferenceTypesDisabledDbContext>, NullableReferenceTypesDisabledDbContext> testContext)
+    {
+        _testContext = testContext;
+
+        testContext.UseController<NrtDisabledResourcesController>();
+    }
+
+    [Theory]
+    [InlineData("requiredReferenceType")]
+    [InlineData("requiredValueType")]
+    [InlineData("requiredNullableValueType")]
+    public async Task Schema_property_for_attribute_is_required_for_creating_resource(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceAttributesInPostRequest").With(attributesObjectSchema =>
+        {
+            attributesObjectSchema.ShouldContainPath($"properties.{jsonPropertyName}");
+            attributesObjectSchema.ShouldContainPath("required").With(propertySet => propertySet.ShouldBeArrayWithElement(jsonPropertyName));
+        });
+    }
+
+    [Theory]
+    [InlineData("referenceType")]
+    [InlineData("valueType")]
+    [InlineData("nullableValueType")]
+    public async Task Schema_property_for_attribute_is_not_required_for_creating_resource(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceAttributesInPostRequest").With(attributesObjectSchema =>
+        {
+            attributesObjectSchema.ShouldContainPath($"properties.{jsonPropertyName}");
+            attributesObjectSchema.ShouldContainPath("required").With(propertySet => propertySet.ShouldBeArrayWithoutElement(jsonPropertyName));
+        });
+    }
+
+    [Theory]
+    [InlineData("requiredToOne")]
+    [InlineData("requiredToMany")]
+    public async Task Schema_property_for_relationship_is_required_for_creating_resource(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceRelationshipsInPostRequest").With(relationshipsObjectSchema =>
+        {
+            relationshipsObjectSchema.ShouldContainPath($"properties.{jsonPropertyName}");
+            relationshipsObjectSchema.ShouldContainPath("required").With(propertySet => propertySet.ShouldBeArrayWithElement(jsonPropertyName));
+        });
+    }
+
+    [Theory]
+    [InlineData("toOne")]
+    [InlineData("toMany")]
+    public async Task Schema_property_for_relationship_is_not_required_for_creating_resource(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceRelationshipsInPostRequest").With(relationshipsObjectSchema =>
+        {
+            relationshipsObjectSchema.ShouldContainPath($"properties.{jsonPropertyName}");
+            relationshipsObjectSchema.ShouldContainPath("required").With(propertySet => propertySet.ShouldBeArrayWithoutElement(jsonPropertyName));
+        });
+    }
+
+    [Fact]
+    public async Task No_attribute_schema_properties_are_required_when_updating_resource()
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldNotContainPath("components.schemas.resourceAttributesInPatchRequest.required");
+    }
+
+    [Fact]
+    public async Task No_relationship_schema_properties_are_required_when_updating_resource()
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldNotContainPath("components.schemas.resourceRelationshipsInPatchRequest.required");
+    }
+}
diff --git a/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/NullabilityTests.cs b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/NullabilityTests.cs
new file mode 100644
index 0000000000..534a7ed8b9
--- /dev/null
+++ b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/NullabilityTests.cs
@@ -0,0 +1,100 @@
+using System.Text.Json;
+using FluentAssertions;
+using TestBuildingBlocks;
+using Xunit;
+
+namespace OpenApiTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationEnabled;
+
+public sealed class NullabilityTests
+    : IClassFixture<OpenApiTestContext<OpenApiStartup<NullableReferenceTypesDisabledDbContext>, NullableReferenceTypesDisabledDbContext>>
+{
+    private readonly OpenApiTestContext<OpenApiStartup<NullableReferenceTypesDisabledDbContext>, NullableReferenceTypesDisabledDbContext> _testContext;
+
+    public NullabilityTests(OpenApiTestContext<OpenApiStartup<NullableReferenceTypesDisabledDbContext>, NullableReferenceTypesDisabledDbContext> testContext)
+    {
+        _testContext = testContext;
+
+        testContext.UseController<NrtDisabledResourcesController>();
+        testContext.SwaggerDocumentOutputPath = "test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled";
+    }
+
+    [Theory]
+    [InlineData("referenceType")]
+    [InlineData("nullableValueType")]
+    public async Task Schema_property_for_attribute_is_nullable(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceAttributesInResponse.properties").With(schemaProperties =>
+        {
+            schemaProperties.ShouldContainPath(jsonPropertyName).With(schemaProperty =>
+            {
+                schemaProperty.ShouldContainPath("nullable").With(nullableProperty => nullableProperty.ValueKind.Should().Be(JsonValueKind.True));
+            });
+        });
+    }
+
+    [Theory]
+    [InlineData("requiredReferenceType")]
+    [InlineData("valueType")]
+    [InlineData("requiredValueType")]
+    [InlineData("requiredNullableValueType")]
+    public async Task Schema_property_for_attribute_is_not_nullable(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceAttributesInResponse.properties").With(schemaProperties =>
+        {
+            schemaProperties.ShouldContainPath(jsonPropertyName).With(schemaProperty =>
+            {
+                schemaProperty.ShouldNotContainPath("nullable");
+            });
+        });
+    }
+
+    [Theory]
+    [InlineData("toOne")]
+    public async Task Schema_property_for_relationship_is_nullable(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceRelationshipsInPostRequest.properties").With(schemaProperties =>
+        {
+            schemaProperties.ShouldContainPath($"{jsonPropertyName}.allOf[0].$ref").WithSchemaReferenceId(schemaReferenceId =>
+            {
+                document.ShouldContainPath($"components.schemas.{schemaReferenceId}.properties.data").With(relationshipDataSchema =>
+                {
+                    relationshipDataSchema.ShouldContainPath("nullable").With(nullableProperty => nullableProperty.ValueKind.Should().Be(JsonValueKind.True));
+                });
+            });
+        });
+    }
+
+    [Theory]
+    [InlineData("requiredToOne")]
+    [InlineData("toMany")]
+    [InlineData("requiredToMany")]
+    public async Task Schema_property_for_relationship_is_not_nullable(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceRelationshipsInPostRequest.properties").With(schemaProperties =>
+        {
+            schemaProperties.ShouldContainPath($"{jsonPropertyName}.allOf[0].$ref").WithSchemaReferenceId(schemaReferenceId =>
+            {
+                document.ShouldContainPath($"components.schemas.{schemaReferenceId}.properties.data").With(relationshipDataSchema =>
+                {
+                    relationshipDataSchema.ShouldNotContainPath("nullable");
+                });
+            });
+        });
+    }
+}
diff --git a/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/RequiredTests.cs b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/RequiredTests.cs
new file mode 100644
index 0000000000..cba6e2035b
--- /dev/null
+++ b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/ModelStateValidationEnabled/RequiredTests.cs
@@ -0,0 +1,104 @@
+using System.Text.Json;
+using TestBuildingBlocks;
+using Xunit;
+
+namespace OpenApiTests.ResourceFieldValidation.NullableReferenceTypesDisabled.ModelStateValidationEnabled;
+
+public sealed class RequiredTests
+    : IClassFixture<OpenApiTestContext<OpenApiStartup<NullableReferenceTypesDisabledDbContext>, NullableReferenceTypesDisabledDbContext>>
+{
+    private readonly OpenApiTestContext<OpenApiStartup<NullableReferenceTypesDisabledDbContext>, NullableReferenceTypesDisabledDbContext> _testContext;
+
+    public RequiredTests(OpenApiTestContext<OpenApiStartup<NullableReferenceTypesDisabledDbContext>, NullableReferenceTypesDisabledDbContext> testContext)
+    {
+        _testContext = testContext;
+
+        testContext.UseController<NrtDisabledResourcesController>();
+    }
+
+    [Theory]
+    [InlineData("requiredReferenceType")]
+    [InlineData("requiredNullableValueType")]
+    public async Task Schema_property_for_attribute_is_required_for_creating_resource(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceAttributesInPostRequest").With(attributesObjectSchema =>
+        {
+            attributesObjectSchema.ShouldContainPath($"properties.{jsonPropertyName}");
+            attributesObjectSchema.ShouldContainPath("required").With(propertySet => propertySet.ShouldBeArrayWithElement(jsonPropertyName));
+        });
+    }
+
+    [Theory]
+    [InlineData("referenceType")]
+    [InlineData("valueType")]
+    [InlineData("requiredValueType")]
+    [InlineData("nullableValueType")]
+    public async Task Schema_property_for_attribute_is_not_required_for_creating_resource(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceAttributesInPostRequest").With(attributesObjectSchema =>
+        {
+            attributesObjectSchema.ShouldContainPath($"properties.{jsonPropertyName}");
+            attributesObjectSchema.ShouldContainPath("required").With(propertySet => propertySet.ShouldBeArrayWithoutElement(jsonPropertyName));
+        });
+    }
+
+    [Theory]
+    [InlineData("requiredToOne")]
+    public async Task Schema_property_for_relationship_is_required_for_creating_resource(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceRelationshipsInPostRequest").With(relationshipsObjectSchema =>
+        {
+            relationshipsObjectSchema.ShouldContainPath($"properties.{jsonPropertyName}");
+            relationshipsObjectSchema.ShouldContainPath("required").With(propertySet => propertySet.ShouldBeArrayWithElement(jsonPropertyName));
+        });
+    }
+
+    [Theory]
+    [InlineData("toOne")]
+    [InlineData("toMany")]
+    [InlineData("requiredToMany")]
+    public async Task Schema_property_for_relationship_is_not_required_for_creating_resource(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceRelationshipsInPostRequest").With(relationshipsObjectSchema =>
+        {
+            relationshipsObjectSchema.ShouldContainPath($"properties.{jsonPropertyName}");
+            relationshipsObjectSchema.ShouldContainPath("required").With(propertySet => propertySet.ShouldBeArrayWithoutElement(jsonPropertyName));
+        });
+    }
+
+    [Fact]
+    public async Task No_attribute_schema_properties_are_required_when_updating_resource()
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldNotContainPath("components.schemas.resourceAttributesInPatchRequest.required");
+    }
+
+    [Fact]
+    public async Task No_relationship_schema_properties_are_required_when_updating_resource()
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldNotContainPath("components.schemas.resourceRelationshipsInPatchRequest.required");
+    }
+}
diff --git a/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/NrtDisabledResource.cs b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/NrtDisabledResource.cs
new file mode 100644
index 0000000000..4a297cf3e9
--- /dev/null
+++ b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/NrtDisabledResource.cs
@@ -0,0 +1,48 @@
+#nullable disable
+
+using System.ComponentModel.DataAnnotations;
+using JetBrains.Annotations;
+using JsonApiDotNetCore.Resources;
+using JsonApiDotNetCore.Resources.Annotations;
+
+namespace OpenApiTests.ResourceFieldValidation.NullableReferenceTypesDisabled;
+
+[UsedImplicitly(ImplicitUseTargetFlags.Members)]
+[Resource(PublicName = "Resource", ControllerNamespace = "OpenApiTests.ResourceFieldValidation")]
+public sealed class NrtDisabledResource : Identifiable<int>
+{
+    [Attr]
+    public string ReferenceType { get; set; }
+
+    [Attr]
+    [Required]
+    public string RequiredReferenceType { get; set; }
+
+    [Attr]
+    public int ValueType { get; set; }
+
+    [Attr]
+    [Required]
+    public int RequiredValueType { get; set; }
+
+    [Attr]
+    public int? NullableValueType { get; set; }
+
+    [Attr]
+    [Required]
+    public int? RequiredNullableValueType { get; set; }
+
+    [HasOne]
+    public EmptyResource ToOne { get; set; }
+
+    [Required]
+    [HasOne]
+    public EmptyResource RequiredToOne { get; set; }
+
+    [HasMany]
+    public ICollection<EmptyResource> ToMany { get; set; } = new HashSet<EmptyResource>();
+
+    [Required]
+    [HasMany]
+    public ICollection<EmptyResource> RequiredToMany { get; set; } = new HashSet<EmptyResource>();
+}
diff --git a/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/NullableReferenceTypesDisabledDbContext.cs b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/NullableReferenceTypesDisabledDbContext.cs
new file mode 100644
index 0000000000..1e8691d9de
--- /dev/null
+++ b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesDisabled/NullableReferenceTypesDisabledDbContext.cs
@@ -0,0 +1,35 @@
+using JetBrains.Annotations;
+using Microsoft.EntityFrameworkCore;
+using TestBuildingBlocks;
+
+namespace OpenApiTests.ResourceFieldValidation.NullableReferenceTypesDisabled;
+
+// @formatter:wrap_chained_method_calls chop_always
+
+[UsedImplicitly(ImplicitUseTargetFlags.Members)]
+public sealed class NullableReferenceTypesDisabledDbContext : TestableDbContext
+{
+    public DbSet<NrtDisabledResource> NrtDisabledResources => Set<NrtDisabledResource>();
+
+    public NullableReferenceTypesDisabledDbContext(DbContextOptions<NullableReferenceTypesDisabledDbContext> options)
+        : base(options)
+    {
+    }
+
+    protected override void OnModelCreating(ModelBuilder builder)
+    {
+        builder.Entity<NrtDisabledResource>()
+            .HasOne(resource => resource.ToOne);
+
+        builder.Entity<NrtDisabledResource>()
+            .HasOne(resource => resource.RequiredToOne);
+
+        builder.Entity<NrtDisabledResource>()
+            .HasMany(resource => resource.ToMany);
+
+        builder.Entity<NrtDisabledResource>()
+            .HasMany(resource => resource.RequiredToMany);
+
+        base.OnModelCreating(builder);
+    }
+}
diff --git a/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/NullabilityTests.cs b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/NullabilityTests.cs
new file mode 100644
index 0000000000..23e58e54bd
--- /dev/null
+++ b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/NullabilityTests.cs
@@ -0,0 +1,106 @@
+using System.Text.Json;
+using FluentAssertions;
+using TestBuildingBlocks;
+using Xunit;
+
+namespace OpenApiTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationDisabled;
+
+public sealed class NullabilityTests
+    : IClassFixture<OpenApiTestContext<ModelStateValidationDisabledStartup<NullableReferenceTypesEnabledDbContext>, NullableReferenceTypesEnabledDbContext>>
+{
+    private readonly OpenApiTestContext<ModelStateValidationDisabledStartup<NullableReferenceTypesEnabledDbContext>, NullableReferenceTypesEnabledDbContext>
+        _testContext;
+
+    public NullabilityTests(
+        OpenApiTestContext<ModelStateValidationDisabledStartup<NullableReferenceTypesEnabledDbContext>, NullableReferenceTypesEnabledDbContext> testContext)
+    {
+        _testContext = testContext;
+
+        testContext.UseController<NrtEnabledResourcesController>();
+        testContext.SwaggerDocumentOutputPath = "test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled";
+    }
+
+    [Theory]
+    [InlineData("nullableReferenceType")]
+    [InlineData("requiredNullableReferenceType")]
+    [InlineData("nullableValueType")]
+    [InlineData("requiredNullableValueType")]
+    public async Task Schema_property_for_attribute_is_nullable(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceAttributesInResponse.properties").With(schemaProperties =>
+        {
+            schemaProperties.ShouldContainPath(jsonPropertyName).With(schemaProperty =>
+            {
+                schemaProperty.ShouldContainPath("nullable").With(nullableProperty => nullableProperty.ValueKind.Should().Be(JsonValueKind.True));
+            });
+        });
+    }
+
+    [Theory]
+    [InlineData("nonNullableReferenceType")]
+    [InlineData("requiredNonNullableReferenceType")]
+    [InlineData("valueType")]
+    [InlineData("requiredValueType")]
+    public async Task Schema_property_for_attribute_is_not_nullable(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceAttributesInResponse.properties").With(schemaProperties =>
+        {
+            schemaProperties.ShouldContainPath(jsonPropertyName).With(schemaProperty =>
+            {
+                schemaProperty.ShouldNotContainPath("nullable");
+            });
+        });
+    }
+
+    [Theory]
+    [InlineData("nullableToOne")]
+    [InlineData("requiredNullableToOne")]
+    public async Task Schema_property_for_relationship_is_nullable(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceRelationshipsInPostRequest.properties").With(schemaProperties =>
+        {
+            schemaProperties.ShouldContainPath($"{jsonPropertyName}.allOf[0].$ref").WithSchemaReferenceId(schemaReferenceId =>
+            {
+                document.ShouldContainPath($"components.schemas.{schemaReferenceId}.properties.data").With(relationshipDataSchema =>
+                {
+                    relationshipDataSchema.ShouldContainPath("nullable").With(nullableProperty => nullableProperty.ValueKind.Should().Be(JsonValueKind.True));
+                });
+            });
+        });
+    }
+
+    [Theory]
+    [InlineData("nonNullableToOne")]
+    [InlineData("requiredNonNullableToOne")]
+    [InlineData("toMany")]
+    [InlineData("requiredToMany")]
+    public async Task Schema_property_for_relationship_is_not_nullable(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceRelationshipsInPostRequest.properties").With(schemaProperties =>
+        {
+            schemaProperties.ShouldContainPath($"{jsonPropertyName}.allOf[0].$ref").WithSchemaReferenceId(schemaReferenceId =>
+            {
+                document.ShouldContainPath($"components.schemas.{schemaReferenceId}.properties.data").With(relationshipDataSchema =>
+                {
+                    relationshipDataSchema.ShouldNotContainPath("nullable");
+                });
+            });
+        });
+    }
+}
diff --git a/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/RequiredTests.cs b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/RequiredTests.cs
new file mode 100644
index 0000000000..0cca901d44
--- /dev/null
+++ b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationDisabled/RequiredTests.cs
@@ -0,0 +1,110 @@
+using System.Text.Json;
+using TestBuildingBlocks;
+using Xunit;
+
+namespace OpenApiTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationDisabled;
+
+public sealed class RequiredTests
+    : IClassFixture<OpenApiTestContext<ModelStateValidationDisabledStartup<NullableReferenceTypesEnabledDbContext>, NullableReferenceTypesEnabledDbContext>>
+{
+    private readonly OpenApiTestContext<ModelStateValidationDisabledStartup<NullableReferenceTypesEnabledDbContext>, NullableReferenceTypesEnabledDbContext>
+        _testContext;
+
+    public RequiredTests(
+        OpenApiTestContext<ModelStateValidationDisabledStartup<NullableReferenceTypesEnabledDbContext>, NullableReferenceTypesEnabledDbContext> testContext)
+    {
+        _testContext = testContext;
+
+        testContext.UseController<NrtEnabledResourcesController>();
+    }
+
+    [Theory]
+    [InlineData("requiredNonNullableReferenceType")]
+    [InlineData("requiredNullableReferenceType")]
+    [InlineData("requiredValueType")]
+    [InlineData("requiredNullableValueType")]
+    public async Task Schema_property_for_attribute_is_required_for_creating_resource(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceAttributesInPostRequest").With(attributesObjectSchema =>
+        {
+            attributesObjectSchema.ShouldContainPath($"properties.{jsonPropertyName}");
+            attributesObjectSchema.ShouldContainPath("required").With(propertySet => propertySet.ShouldBeArrayWithElement(jsonPropertyName));
+        });
+    }
+
+    [Theory]
+    [InlineData("nonNullableReferenceType")]
+    [InlineData("nullableReferenceType")]
+    [InlineData("valueType")]
+    [InlineData("nullableValueType")]
+    public async Task Schema_property_for_attribute_is_not_required_for_creating_resource(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceAttributesInPostRequest").With(attributesObjectSchema =>
+        {
+            attributesObjectSchema.ShouldContainPath($"properties.{jsonPropertyName}");
+            attributesObjectSchema.ShouldContainPath("required").With(propertySet => propertySet.ShouldBeArrayWithoutElement(jsonPropertyName));
+        });
+    }
+
+    [Theory]
+    [InlineData("requiredNonNullableToOne")]
+    [InlineData("requiredNullableToOne")]
+    [InlineData("requiredToMany")]
+    public async Task Schema_property_for_relationship_is_required_for_creating_resource(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceRelationshipsInPostRequest").With(relationshipsObjectSchema =>
+        {
+            relationshipsObjectSchema.ShouldContainPath($"properties.{jsonPropertyName}");
+            relationshipsObjectSchema.ShouldContainPath("required").With(propertySet => propertySet.ShouldBeArrayWithElement(jsonPropertyName));
+        });
+    }
+
+    [Theory]
+    [InlineData("nonNullableToOne")]
+    [InlineData("nullableToOne")]
+    [InlineData("toMany")]
+    public async Task Schema_property_for_relationship_is_not_required_for_creating_resource(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceRelationshipsInPostRequest").With(relationshipsObjectSchema =>
+        {
+            relationshipsObjectSchema.ShouldContainPath($"properties.{jsonPropertyName}");
+            relationshipsObjectSchema.ShouldContainPath("required").With(propertySet => propertySet.ShouldBeArrayWithoutElement(jsonPropertyName));
+        });
+    }
+
+    [Fact]
+    public async Task No_attribute_schema_properties_are_required_when_updating_resource()
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldNotContainPath("components.schemas.resourceAttributesInPatchRequest.required");
+    }
+
+    [Fact]
+    public async Task No_relationship_schema_properties_are_required_when_updating_resource()
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldNotContainPath("components.schemas.resourceRelationshipsInPatchRequest.required");
+    }
+}
diff --git a/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/NullabilityTests.cs b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/NullabilityTests.cs
new file mode 100644
index 0000000000..a2fb76c38f
--- /dev/null
+++ b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/NullabilityTests.cs
@@ -0,0 +1,104 @@
+using System.Text.Json;
+using FluentAssertions;
+using TestBuildingBlocks;
+using Xunit;
+
+namespace OpenApiTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationEnabled;
+
+public sealed class NullabilityTests
+    : IClassFixture<OpenApiTestContext<OpenApiStartup<NullableReferenceTypesEnabledDbContext>, NullableReferenceTypesEnabledDbContext>>
+{
+    private readonly OpenApiTestContext<OpenApiStartup<NullableReferenceTypesEnabledDbContext>, NullableReferenceTypesEnabledDbContext> _testContext;
+
+    public NullabilityTests(OpenApiTestContext<OpenApiStartup<NullableReferenceTypesEnabledDbContext>, NullableReferenceTypesEnabledDbContext> testContext)
+    {
+        _testContext = testContext;
+
+        testContext.UseController<NrtEnabledResourcesController>();
+        testContext.SwaggerDocumentOutputPath = "test/OpenApiClientTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled";
+    }
+
+    [Theory]
+    [InlineData("nullableReferenceType")]
+    [InlineData("nullableValueType")]
+    public async Task Schema_property_for_attribute_is_nullable(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceAttributesInResponse.properties").With(schemaProperties =>
+        {
+            schemaProperties.ShouldContainPath(jsonPropertyName).With(schemaProperty =>
+            {
+                schemaProperty.ShouldContainPath("nullable").With(nullableProperty => nullableProperty.ValueKind.Should().Be(JsonValueKind.True));
+            });
+        });
+    }
+
+    [Theory]
+    [InlineData("nonNullableReferenceType")]
+    [InlineData("requiredNonNullableReferenceType")]
+    [InlineData("requiredNullableReferenceType")]
+    [InlineData("valueType")]
+    [InlineData("requiredValueType")]
+    [InlineData("requiredNullableValueType")]
+    public async Task Schema_property_for_attribute_is_not_nullable(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceAttributesInResponse.properties").With(schemaProperties =>
+        {
+            schemaProperties.ShouldContainPath(jsonPropertyName).With(schemaProperty =>
+            {
+                schemaProperty.ShouldNotContainPath("nullable");
+            });
+        });
+    }
+
+    [Theory]
+    [InlineData("nullableToOne")]
+    public async Task Schema_property_for_relationship_is_nullable(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceRelationshipsInPostRequest.properties").With(schemaProperties =>
+        {
+            schemaProperties.ShouldContainPath($"{jsonPropertyName}.allOf[0].$ref").WithSchemaReferenceId(schemaReferenceId =>
+            {
+                document.ShouldContainPath($"components.schemas.{schemaReferenceId}.properties.data").With(relationshipDataSchema =>
+                {
+                    relationshipDataSchema.ShouldContainPath("nullable").With(nullableProperty => nullableProperty.ValueKind.Should().Be(JsonValueKind.True));
+                });
+            });
+        });
+    }
+
+    [Theory]
+    [InlineData("nonNullableToOne")]
+    [InlineData("requiredNonNullableToOne")]
+    [InlineData("requiredNullableToOne")]
+    [InlineData("toMany")]
+    [InlineData("requiredToMany")]
+    public async Task Schema_property_for_relationship_is_not_nullable(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceRelationshipsInPostRequest.properties").With(schemaProperties =>
+        {
+            schemaProperties.ShouldContainPath($"{jsonPropertyName}.allOf[0].$ref").WithSchemaReferenceId(schemaReferenceId =>
+            {
+                document.ShouldContainPath($"components.schemas.{schemaReferenceId}.properties.data").With(relationshipDataSchema =>
+                {
+                    relationshipDataSchema.ShouldNotContainPath("nullable");
+                });
+            });
+        });
+    }
+}
diff --git a/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/RequiredTests.cs b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/RequiredTests.cs
new file mode 100644
index 0000000000..f0fbc13272
--- /dev/null
+++ b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/ModelStateValidationEnabled/RequiredTests.cs
@@ -0,0 +1,108 @@
+using System.Text.Json;
+using TestBuildingBlocks;
+using Xunit;
+
+namespace OpenApiTests.ResourceFieldValidation.NullableReferenceTypesEnabled.ModelStateValidationEnabled;
+
+public sealed class RequiredTests
+    : IClassFixture<OpenApiTestContext<OpenApiStartup<NullableReferenceTypesEnabledDbContext>, NullableReferenceTypesEnabledDbContext>>
+{
+    private readonly OpenApiTestContext<OpenApiStartup<NullableReferenceTypesEnabledDbContext>, NullableReferenceTypesEnabledDbContext> _testContext;
+
+    public RequiredTests(OpenApiTestContext<OpenApiStartup<NullableReferenceTypesEnabledDbContext>, NullableReferenceTypesEnabledDbContext> testContext)
+    {
+        _testContext = testContext;
+
+        testContext.UseController<NrtEnabledResourcesController>();
+    }
+
+    [Theory]
+    [InlineData("nonNullableReferenceType")]
+    [InlineData("requiredNonNullableReferenceType")]
+    [InlineData("requiredNullableReferenceType")]
+    [InlineData("requiredNullableValueType")]
+    public async Task Schema_property_for_attribute_is_required_for_creating_resource(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceAttributesInPostRequest").With(attributesObjectSchema =>
+        {
+            attributesObjectSchema.ShouldContainPath($"properties.{jsonPropertyName}");
+            attributesObjectSchema.ShouldContainPath("required").With(propertySet => propertySet.ShouldBeArrayWithElement(jsonPropertyName));
+        });
+    }
+
+    [Theory]
+    [InlineData("nullableReferenceType")]
+    [InlineData("valueType")]
+    [InlineData("requiredValueType")]
+    [InlineData("nullableValueType")]
+    public async Task Schema_property_for_attribute_is_not_required_for_creating_resource(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceAttributesInPostRequest").With(attributesObjectSchema =>
+        {
+            attributesObjectSchema.ShouldContainPath($"properties.{jsonPropertyName}");
+            attributesObjectSchema.ShouldContainPath("required").With(propertySet => propertySet.ShouldBeArrayWithoutElement(jsonPropertyName));
+        });
+    }
+
+    [Theory]
+    [InlineData("nonNullableToOne")]
+    [InlineData("requiredNonNullableToOne")]
+    [InlineData("requiredNullableToOne")]
+    public async Task Schema_property_for_relationship_is_required_for_creating_resource(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceRelationshipsInPostRequest").With(relationshipsObjectSchema =>
+        {
+            relationshipsObjectSchema.ShouldContainPath($"properties.{jsonPropertyName}");
+            relationshipsObjectSchema.ShouldContainPath("required").With(propertySet => propertySet.ShouldBeArrayWithElement(jsonPropertyName));
+        });
+    }
+
+    [Theory]
+    [InlineData("nullableToOne")]
+    [InlineData("toMany")]
+    [InlineData("requiredToMany")]
+    public async Task Schema_property_for_relationship_is_not_required_for_creating_resource(string jsonPropertyName)
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldContainPath("components.schemas.resourceRelationshipsInPostRequest").With(relationshipsObjectSchema =>
+        {
+            relationshipsObjectSchema.ShouldContainPath($"properties.{jsonPropertyName}");
+            relationshipsObjectSchema.ShouldContainPath("required").With(propertySet => propertySet.ShouldBeArrayWithoutElement(jsonPropertyName));
+        });
+    }
+
+    [Fact]
+    public async Task No_attribute_schema_properties_are_required_when_updating_resource()
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldNotContainPath("components.schemas.resourceAttributesInPatchRequest.required");
+    }
+
+    [Fact]
+    public async Task No_relationship_schema_properties_are_required_when_updating_resource()
+    {
+        // Act
+        JsonElement document = await _testContext.GetSwaggerDocumentAsync();
+
+        // Assert
+        document.ShouldNotContainPath("components.schemas.resourceRelationshipsInPatchRequest.required");
+    }
+}
diff --git a/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/NrtEnabledResource.cs b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/NrtEnabledResource.cs
new file mode 100644
index 0000000000..8908f2a50f
--- /dev/null
+++ b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/NrtEnabledResource.cs
@@ -0,0 +1,60 @@
+using System.ComponentModel.DataAnnotations;
+using JetBrains.Annotations;
+using JsonApiDotNetCore.Resources;
+using JsonApiDotNetCore.Resources.Annotations;
+
+namespace OpenApiTests.ResourceFieldValidation.NullableReferenceTypesEnabled;
+
+[UsedImplicitly(ImplicitUseTargetFlags.Members)]
+[Resource(PublicName = "Resource", ControllerNamespace = "OpenApiTests.ResourceFieldValidation")]
+public sealed class NrtEnabledResource : Identifiable<int>
+{
+    [Attr]
+    public string NonNullableReferenceType { get; set; } = null!;
+
+    [Attr]
+    [Required]
+    public string RequiredNonNullableReferenceType { get; set; } = null!;
+
+    [Attr]
+    public string? NullableReferenceType { get; set; }
+
+    [Attr]
+    [Required]
+    public string? RequiredNullableReferenceType { get; set; }
+
+    [Attr]
+    public int ValueType { get; set; }
+
+    [Attr]
+    [Required]
+    public int RequiredValueType { get; set; }
+
+    [Attr]
+    public int? NullableValueType { get; set; }
+
+    [Attr]
+    [Required]
+    public int? RequiredNullableValueType { get; set; }
+
+    [HasOne]
+    public EmptyResource NonNullableToOne { get; set; } = null!;
+
+    [Required]
+    [HasOne]
+    public EmptyResource RequiredNonNullableToOne { get; set; } = null!;
+
+    [HasOne]
+    public EmptyResource? NullableToOne { get; set; }
+
+    [Required]
+    [HasOne]
+    public EmptyResource? RequiredNullableToOne { get; set; }
+
+    [HasMany]
+    public ICollection<EmptyResource> ToMany { get; set; } = new HashSet<EmptyResource>();
+
+    [Required]
+    [HasMany]
+    public ICollection<EmptyResource> RequiredToMany { get; set; } = new HashSet<EmptyResource>();
+}
diff --git a/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/NullableReferenceTypesEnabledDbContext.cs b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/NullableReferenceTypesEnabledDbContext.cs
new file mode 100644
index 0000000000..54f1620db5
--- /dev/null
+++ b/test/OpenApiTests/ResourceFieldValidation/NullableReferenceTypesEnabled/NullableReferenceTypesEnabledDbContext.cs
@@ -0,0 +1,41 @@
+using JetBrains.Annotations;
+using Microsoft.EntityFrameworkCore;
+using TestBuildingBlocks;
+
+namespace OpenApiTests.ResourceFieldValidation.NullableReferenceTypesEnabled;
+
+// @formatter:wrap_chained_method_calls chop_always
+
+[UsedImplicitly(ImplicitUseTargetFlags.Members)]
+public sealed class NullableReferenceTypesEnabledDbContext : TestableDbContext
+{
+    public DbSet<NrtEnabledResource> NullableReferenceTypesEnabledResources => Set<NrtEnabledResource>();
+
+    public NullableReferenceTypesEnabledDbContext(DbContextOptions<NullableReferenceTypesEnabledDbContext> options)
+        : base(options)
+    {
+    }
+
+    protected override void OnModelCreating(ModelBuilder builder)
+    {
+        builder.Entity<NrtEnabledResource>()
+            .HasOne(resource => resource.NonNullableToOne);
+
+        builder.Entity<NrtEnabledResource>()
+            .HasOne(resource => resource.RequiredNonNullableToOne);
+
+        builder.Entity<NrtEnabledResource>()
+            .HasOne(resource => resource.NullableToOne);
+
+        builder.Entity<NrtEnabledResource>()
+            .HasOne(resource => resource.RequiredNullableToOne);
+
+        builder.Entity<NrtEnabledResource>()
+            .HasMany(resource => resource.ToMany);
+
+        builder.Entity<NrtEnabledResource>()
+            .HasMany(resource => resource.RequiredToMany);
+
+        base.OnModelCreating(builder);
+    }
+}
diff --git a/test/OpenApiTests/JsonElementExtensions.cs b/test/TestBuildingBlocks/JsonElementExtensions.cs
similarity index 56%
rename from test/OpenApiTests/JsonElementExtensions.cs
rename to test/TestBuildingBlocks/JsonElementExtensions.cs
index d8dc7d4e20..6eafecc4ca 100644
--- a/test/OpenApiTests/JsonElementExtensions.cs
+++ b/test/TestBuildingBlocks/JsonElementExtensions.cs
@@ -2,11 +2,11 @@
 using BlushingPenguin.JsonPath;
 using FluentAssertions;
 using FluentAssertions.Execution;
-using TestBuildingBlocks;
+using JetBrains.Annotations;
 
-namespace OpenApiTests;
+namespace TestBuildingBlocks;
 
-internal static class JsonElementExtensions
+public static class JsonElementExtensions
 {
     public static JsonElementAssertions Should(this JsonElement source)
     {
@@ -19,13 +19,50 @@ public static JsonElement ShouldContainPath(this JsonElement source, string path
         return elementSelector.Should().NotThrow().Subject;
     }
 
+    public static void ShouldNotContainPath(this JsonElement source, string path)
+    {
+        JsonElement? pathToken = source.SelectToken(path);
+
+        pathToken.Should().BeNull();
+    }
+
     public static void ShouldBeString(this JsonElement source, string value)
     {
         source.ValueKind.Should().Be(JsonValueKind.String);
         source.GetString().Should().Be(value);
     }
 
+    public static void ShouldBeArrayWithElement(this JsonElement source, string value)
+    {
+        source.ValueKind.Should().Be(JsonValueKind.Array);
+
+        var deserializedCollection = JsonSerializer.Deserialize<List<string>>(source.GetRawText());
+        deserializedCollection.Should().Contain(value);
+    }
+
+    public static void ShouldBeArrayWithoutElement(this JsonElement source, string value)
+    {
+        source.ValueKind.Should().Be(JsonValueKind.Array);
+
+        var deserializedCollection = JsonSerializer.Deserialize<List<string>>(source.GetRawText());
+        deserializedCollection.Should().NotContain(value);
+    }
+
+    public static void ShouldBeInteger(this JsonElement source, int value)
+    {
+        source.ValueKind.Should().Be(JsonValueKind.Number);
+        source.GetInt32().Should().Be(value);
+    }
+
     public static SchemaReferenceIdContainer ShouldBeSchemaReferenceId(this JsonElement source, string value)
+    {
+        string schemaReferenceId = GetSchemaReferenceId(source);
+        schemaReferenceId.Should().Be(value);
+
+        return new SchemaReferenceIdContainer(value);
+    }
+
+    private static string GetSchemaReferenceId(this JsonElement source)
     {
         source.ValueKind.Should().Be(JsonValueKind.String);
 
@@ -33,16 +70,21 @@ public static SchemaReferenceIdContainer ShouldBeSchemaReferenceId(this JsonElem
         jsonElementValue.ShouldNotBeNull();
 
         string schemaReferenceId = jsonElementValue.Split('/').Last();
-        schemaReferenceId.Should().Be(value);
+        return schemaReferenceId;
+    }
 
-        return new SchemaReferenceIdContainer(value);
+    public static void WithSchemaReferenceId(this JsonElement subject, [InstantHandle] Action<string> continuation)
+    {
+        string schemaReferenceId = GetSchemaReferenceId(subject);
+
+        continuation(schemaReferenceId);
     }
 
     public sealed class SchemaReferenceIdContainer
     {
         public string SchemaReferenceId { get; }
 
-        public SchemaReferenceIdContainer(string schemaReferenceId)
+        internal SchemaReferenceIdContainer(string schemaReferenceId)
         {
             SchemaReferenceId = schemaReferenceId;
         }
@@ -50,7 +92,7 @@ public SchemaReferenceIdContainer(string schemaReferenceId)
 
     public sealed class JsonElementAssertions : JsonElementAssertions<JsonElementAssertions>
     {
-        public JsonElementAssertions(JsonElement subject)
+        internal JsonElementAssertions(JsonElement subject)
             : base(subject)
         {
         }
diff --git a/test/TestBuildingBlocks/TestBuildingBlocks.csproj b/test/TestBuildingBlocks/TestBuildingBlocks.csproj
index ce8c54ef3b..55e2830bb9 100644
--- a/test/TestBuildingBlocks/TestBuildingBlocks.csproj
+++ b/test/TestBuildingBlocks/TestBuildingBlocks.csproj
@@ -8,6 +8,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="BlushingPenguin.JsonPath" Version="1.0.6" />
     <PackageReference Include="Bogus" Version="34.0.2" />
     <PackageReference Include="coverlet.collector" Version="$(CoverletVersion)" PrivateAssets="All" />
     <PackageReference Include="FluentAssertions" Version="6.8.0" />