feat: adds mcp-spi

Author: Aliaksie

mcp-bom/pom.xml

@@ -26,10 +26,17 @@
 
     <dependencyManagement>
         <dependencies>
-            <!-- Core MCP -->
+            <!-- MCP Spec -->
             <dependency>
                 <groupId>io.modelcontextprotocol.sdk</groupId>
-                <artifactId>mcp</artifactId>
+                <artifactId>mcp-reactor</artifactId>
+                <version>${project.version}</version>
+            </dependency>
+
+            <!-- MCP Reactor -->
+            <dependency>
+                <groupId>io.modelcontextprotocol.sdk</groupId>
+                <artifactId>mcp-reactor</artifactId>
                 <version>${project.version}</version>
             </dependency>
 

mcp/README.md renamed to mcp-reactor/README.md

@@ -8,10 +8,10 @@
 		<artifactId>mcp-parent</artifactId>
 		<version>0.10.0-SNAPSHOT</version>
 	</parent>
-	<artifactId>mcp</artifactId>
+	<artifactId>mcp-reactor</artifactId>
 	<packaging>jar</packaging>
-	<name>Java MCP SDK</name>
-	<description>Java SDK implementation of the Model Context Protocol, enabling seamless integration with language models and AI tools</description>
+	<name>Java MCP Reactor SDK</name>
+	<description>Java Reactor SDK implementation of the Model Context Protocol, enabling seamless integration with language models and AI tools</description>
 	<url>https://github.com/modelcontextprotocol/java-sdk</url>
 
 	<scm>
@@ -65,6 +65,11 @@
 	</build>
 
 	<dependencies>
+		<dependency>
+			<groupId>io.modelcontextprotocol.sdk</groupId>
+			<artifactId>mcp-spi</artifactId>
+			<version>${project.version}</version>
+		</dependency>
 
 		<dependency>
 			<groupId>org.slf4j</groupId>
@@ -83,37 +88,13 @@
 			<artifactId>reactor-core</artifactId>
 		</dependency>
 
-		<dependency>
-			<groupId>org.springframework</groupId>
-			<artifactId>spring-webmvc</artifactId>
-			<version>${springframework.version}</version>
-			<scope>test</scope>
-		</dependency>
-
 
 		<dependency>
 			<groupId>io.projectreactor.netty</groupId>
 			<artifactId>reactor-netty-http</artifactId>
 			<scope>test</scope>
 		</dependency>
 
-		<!-- The Spring Context is required due to the reactor-netty connector being dependent on
-		the Spring Lifecycle, as discussed here:
-		https://github.com/spring-projects/spring-framework/issues/31180 -->
-		<dependency>
-			<groupId>org.springframework</groupId>
-			<artifactId>spring-context</artifactId>
-			<version>${springframework.version}</version>
-			<scope>test</scope>
-		</dependency>
-
-		<dependency>
-			<groupId>org.springframework</groupId>
-			<artifactId>spring-test</artifactId>
-			<version>${springframework.version}</version>
-			<scope>test</scope>
-		</dependency>
-
 		<dependency>
 			<groupId>org.assertj</groupId>
 			<artifactId>assertj-core</artifactId>

mcp/pom.xml renamed to mcp-reactor/pom.xml

@@ -14,9 +14,9 @@
 import java.util.function.Function;
 
 import com.fasterxml.jackson.core.type.TypeReference;
-import io.modelcontextprotocol.spec.McpClientSession;
-import io.modelcontextprotocol.spec.McpClientSession.NotificationHandler;
-import io.modelcontextprotocol.spec.McpClientSession.RequestHandler;
+import io.modelcontextprotocol.session.McpClientSession;
+import io.modelcontextprotocol.session.McpClientSession.NotificationHandler;
+import io.modelcontextprotocol.session.McpClientSession.RequestHandler;
 import io.modelcontextprotocol.spec.McpClientTransport;
 import io.modelcontextprotocol.spec.McpError;
 import io.modelcontextprotocol.spec.McpSchema;
@@ -471,7 +471,8 @@ public Mono<Void> removeRoot(String rootUri) {
 	 */
 	public Mono<Void> rootsListChangedNotification() {
 		return this.withInitializationCheck("sending roots list changed notification",
-				initResult -> this.mcpSession.sendNotification(McpSchema.METHOD_NOTIFICATION_ROOTS_LIST_CHANGED));
+				initResult -> (Mono<Void>) this.mcpSession
+					.sendNotification(McpSchema.METHOD_NOTIFICATION_ROOTS_LIST_CHANGED));
 	}
 
 	private RequestHandler<McpSchema.ListRootsResult> rootsListRequestHandler() {

mcp/src/main/java/io/modelcontextprotocol/client/McpAsyncClient.java renamed to mcp-reactor/src/main/java/io/modelcontextprotocol/client/McpAsyncClient.java

@@ -400,7 +400,7 @@ class AsyncSpec {
 
 		private ClientCapabilities capabilities;
 
-		private Implementation clientInfo = new Implementation("Spring AI MCP Client", "0.3.1");
+		private Implementation clientInfo = new Implementation("Java Reactor AI MCP Client", "0.3.1");
 
 		private final Map<String, Root> roots = new HashMap<>();
 

mcp/src/main/java/io/modelcontextprotocol/client/McpClient.java renamed to mcp-reactor/src/main/java/io/modelcontextprotocol/client/McpClient.java

@@ -22,17 +22,20 @@
 import io.modelcontextprotocol.spec.McpClientTransport;
 import io.modelcontextprotocol.spec.McpError;
 import io.modelcontextprotocol.spec.McpSchema;
+import io.modelcontextprotocol.spec.McpTransport;
 import io.modelcontextprotocol.spec.McpSchema.JSONRPCMessage;
 import io.modelcontextprotocol.util.Assert;
 import io.modelcontextprotocol.util.Utils;
+
+import org.reactivestreams.Publisher;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+
 import reactor.core.publisher.Mono;
 
 /**
- * Server-Sent Events (SSE) implementation of the
- * {@link io.modelcontextprotocol.spec.McpTransport} that follows the MCP HTTP with SSE
- * transport specification, using Java's HttpClient.
+ * Server-Sent Events (SSE) implementation of the {@link McpTransport} that follows the
+ * MCP HTTP with SSE transport specification, using Java's HttpClient.
  *
  * <p>
  * This transport implementation establishes a bidirectional communication channel between
@@ -337,7 +340,7 @@ public HttpClientSseClientTransport build() {
 	 * @return a Mono that completes when the connection is established
 	 */
 	@Override
-	public Mono<Void> connect(Function<Mono<JSONRPCMessage>, Mono<JSONRPCMessage>> handler) {
+	public Mono<Void> connect(Function<Publisher<JSONRPCMessage>, Publisher<JSONRPCMessage>> handler) {
 		CompletableFuture<Void> future = new CompletableFuture<>();
 		connectionFuture.set(future);
 
@@ -358,7 +361,8 @@ public void onEvent(SseEvent event) {
 					}
 					else if (MESSAGE_EVENT_TYPE.equals(event.type())) {
 						JSONRPCMessage message = McpSchema.deserializeJsonRpcMessage(objectMapper, event.data());
-						handler.apply(Mono.just(message)).subscribe();
+						Publisher<McpSchema.JSONRPCMessage> result = handler.apply(Mono.just(message));
+						Mono.from(result).subscribe();
 					}
 					else {
 						logger.error("Received unrecognized SSE event type: {}", event.type());
@@ -435,6 +439,11 @@ public Mono<Void> sendMessage(JSONRPCMessage message) {
 		}
 	}
 
+	@Override
+	public void close() {
+		this.closeGracefully().subscribe();
+	}
+
 	/**
 	 * Gracefully closes the transport connection.
 	 *

mcp/src/main/java/io/modelcontextprotocol/client/McpClientFeatures.java renamed to mcp-reactor/src/main/java/io/modelcontextprotocol/client/McpClientFeatures.java

@@ -21,6 +21,8 @@
 import io.modelcontextprotocol.spec.McpSchema;
 import io.modelcontextprotocol.spec.McpSchema.JSONRPCMessage;
 import io.modelcontextprotocol.util.Assert;
+
+import org.reactivestreams.Publisher;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import reactor.core.publisher.Flux;
@@ -110,7 +112,7 @@ public StdioClientTransport(ServerParameters params, ObjectMapper objectMapper)
 	 * are null
 	 */
 	@Override
-	public Mono<Void> connect(Function<Mono<JSONRPCMessage>, Mono<JSONRPCMessage>> handler) {
+	public Mono<Void> connect(Function<Publisher<JSONRPCMessage>, Publisher<JSONRPCMessage>> handler) {
 		return Mono.<Void>fromRunnable(() -> {
 			handleIncomingMessages(handler);
 			handleIncomingErrors();
@@ -218,7 +220,8 @@ private void startErrorProcessing() {
 		});
 	}
 
-	private void handleIncomingMessages(Function<Mono<JSONRPCMessage>, Mono<JSONRPCMessage>> inboundMessageHandler) {
+	private void handleIncomingMessages(
+			Function<Publisher<JSONRPCMessage>, Publisher<JSONRPCMessage>> inboundMessageHandler) {
 		this.inboundSink.asFlux()
 			.flatMap(message -> Mono.just(message)
 				.transform(inboundMessageHandler)
@@ -333,6 +336,11 @@ protected void handleOutbound(Function<Flux<JSONRPCMessage>, Flux<JSONRPCMessage
 		}).subscribe();
 	}
 
+	@Override
+	public void close() {
+		this.closeGracefully().subscribe();
+	}
+
 	/**
 	 * Gracefully closes the transport by destroying the process and disposing of the
 	 * schedulers. This method sends a TERM signal to the process and waits for it to exit

mcp/src/main/java/io/modelcontextprotocol/client/McpSyncClient.java renamed to mcp-reactor/src/main/java/io/modelcontextprotocol/client/McpSyncClient.java

@@ -16,15 +16,15 @@
 
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import io.modelcontextprotocol.spec.McpClientSession;
+import io.modelcontextprotocol.session.McpClientSession;
 import io.modelcontextprotocol.spec.McpError;
 import io.modelcontextprotocol.spec.McpSchema;
 import io.modelcontextprotocol.spec.McpSchema.CallToolResult;
 import io.modelcontextprotocol.spec.McpSchema.LoggingLevel;
 import io.modelcontextprotocol.spec.McpSchema.LoggingMessageNotification;
 import io.modelcontextprotocol.spec.McpSchema.SetLevelRequest;
 import io.modelcontextprotocol.spec.McpSchema.Tool;
-import io.modelcontextprotocol.spec.McpServerSession;
+import io.modelcontextprotocol.session.McpServerSession;
 import io.modelcontextprotocol.spec.McpServerTransportProvider;
 import io.modelcontextprotocol.util.Utils;
 import org.slf4j.Logger;
@@ -387,7 +387,7 @@ public McpSchema.Implementation getServerInfo() {
 
 		@Override
 		public Mono<Void> closeGracefully() {
-			return this.mcpTransportProvider.closeGracefully();
+			return Mono.from(this.mcpTransportProvider.closeGracefully());
 		}
 
 		@Override
@@ -468,7 +468,8 @@ public Mono<Void> removeTool(String toolName) {
 
 		@Override
 		public Mono<Void> notifyToolsListChanged() {
-			return this.mcpTransportProvider.notifyClients(McpSchema.METHOD_NOTIFICATION_TOOLS_LIST_CHANGED, null);
+			return Mono
+				.from(this.mcpTransportProvider.notifyClients(McpSchema.METHOD_NOTIFICATION_TOOLS_LIST_CHANGED, null));
 		}
 
 		private McpServerSession.RequestHandler<McpSchema.ListToolsResult> toolsListRequestHandler() {
@@ -549,7 +550,8 @@ public Mono<Void> removeResource(String resourceUri) {
 
 		@Override
 		public Mono<Void> notifyResourcesListChanged() {
-			return this.mcpTransportProvider.notifyClients(McpSchema.METHOD_NOTIFICATION_RESOURCES_LIST_CHANGED, null);
+			return Mono.from(this.mcpTransportProvider
+				.notifyClients(McpSchema.METHOD_NOTIFICATION_RESOURCES_LIST_CHANGED, null));
 		}
 
 		private McpServerSession.RequestHandler<McpSchema.ListResourcesResult> resourcesListRequestHandler() {
@@ -642,7 +644,8 @@ public Mono<Void> removePrompt(String promptName) {
 
 		@Override
 		public Mono<Void> notifyPromptsListChanged() {
-			return this.mcpTransportProvider.notifyClients(McpSchema.METHOD_NOTIFICATION_PROMPTS_LIST_CHANGED, null);
+			return Mono.from(
+					this.mcpTransportProvider.notifyClients(McpSchema.METHOD_NOTIFICATION_PROMPTS_LIST_CHANGED, null));
 		}
 
 		private McpServerSession.RequestHandler<McpSchema.ListPromptsResult> promptsListRequestHandler() {
@@ -692,8 +695,8 @@ public Mono<Void> loggingNotification(LoggingMessageNotification loggingMessageN
 				return Mono.empty();
 			}
 
-			return this.mcpTransportProvider.notifyClients(McpSchema.METHOD_NOTIFICATION_MESSAGE,
-					loggingMessageNotification);
+			return Mono.from(this.mcpTransportProvider.notifyClients(McpSchema.METHOD_NOTIFICATION_MESSAGE,
+					loggingMessageNotification));
 		}
 
 		private McpServerSession.RequestHandler<Object> setLoggerRequestHandler() {

mcp/src/main/java/io/modelcontextprotocol/client/transport/FlowSseClient.java renamed to mcp-reactor/src/main/java/io/modelcontextprotocol/client/transport/FlowSseClient.java

@@ -9,7 +9,7 @@
 import io.modelcontextprotocol.spec.McpSchema;
 import io.modelcontextprotocol.spec.McpSchema.LoggingLevel;
 import io.modelcontextprotocol.spec.McpSchema.LoggingMessageNotification;
-import io.modelcontextprotocol.spec.McpServerSession;
+import io.modelcontextprotocol.session.McpServerSession;
 import io.modelcontextprotocol.util.Assert;
 import reactor.core.publisher.Mono;
 

mcp/src/main/java/io/modelcontextprotocol/client/transport/HttpClientSseClientTransport.java renamed to mcp-reactor/src/main/java/io/modelcontextprotocol/client/transport/HttpClientSseClientTransport.java

@@ -276,7 +276,7 @@ static AsyncToolSpecification fromSync(SyncToolSpecification tool) {
 	 * @param readHandler The function that handles resource read requests. The function's
 	 * first argument is an {@link McpAsyncServerExchange} upon which the server can
 	 * interact with the connected client. The second arguments is a
-	 * {@link io.modelcontextprotocol.spec.McpSchema.ReadResourceRequest}.
+	 * {@link McpSchema.ReadResourceRequest}.
 	 */
 	public record AsyncResourceSpecification(McpSchema.Resource resource,
 			BiFunction<McpAsyncServerExchange, McpSchema.ReadResourceRequest, Mono<McpSchema.ReadResourceResult>> readHandler) {
@@ -321,8 +321,7 @@ static AsyncResourceSpecification fromSync(SyncResourceSpecification resource) {
 	 * @param promptHandler The function that processes prompt requests and returns
 	 * formatted templates. The function's first argument is an
 	 * {@link McpAsyncServerExchange} upon which the server can interact with the
-	 * connected client. The second arguments is a
-	 * {@link io.modelcontextprotocol.spec.McpSchema.GetPromptRequest}.
+	 * connected client. The second arguments is a {@link McpSchema.GetPromptRequest}.
 	 */
 	public record AsyncPromptSpecification(McpSchema.Prompt prompt,
 			BiFunction<McpAsyncServerExchange, McpSchema.GetPromptRequest, Mono<McpSchema.GetPromptResult>> promptHandler) {
@@ -353,7 +352,7 @@ static AsyncPromptSpecification fromSync(SyncPromptSpecification prompt) {
 	 * @param completionHandler The asynchronous function that processes completion
 	 * requests and returns results. The first argument is an
 	 * {@link McpAsyncServerExchange} used to interact with the client. The second
-	 * argument is a {@link io.modelcontextprotocol.spec.McpSchema.CompleteRequest}.
+	 * argument is a {@link McpSchema.CompleteRequest}.
 	 */
 	public record AsyncCompletionSpecification(McpSchema.CompleteReference referenceKey,
 			BiFunction<McpAsyncServerExchange, McpSchema.CompleteRequest, Mono<McpSchema.CompleteResult>> completionHandler) {
@@ -442,7 +441,7 @@ public record SyncToolSpecification(McpSchema.Tool tool,
 	 * @param readHandler The function that handles resource read requests. The function's
 	 * first argument is an {@link McpSyncServerExchange} upon which the server can
 	 * interact with the connected client. The second arguments is a
-	 * {@link io.modelcontextprotocol.spec.McpSchema.ReadResourceRequest}.
+	 * {@link McpSchema.ReadResourceRequest}.
 	 */
 	public record SyncResourceSpecification(McpSchema.Resource resource,
 			BiFunction<McpSyncServerExchange, McpSchema.ReadResourceRequest, McpSchema.ReadResourceResult> readHandler) {
@@ -476,8 +475,7 @@ public record SyncResourceSpecification(McpSchema.Resource resource,
 	 * @param promptHandler The function that processes prompt requests and returns
 	 * formatted templates. The function's first argument is an
 	 * {@link McpSyncServerExchange} upon which the server can interact with the connected
-	 * client. The second arguments is a
-	 * {@link io.modelcontextprotocol.spec.McpSchema.GetPromptRequest}.
+	 * client. The second arguments is a {@link McpSchema.GetPromptRequest}.
 	 */
 	public record SyncPromptSpecification(McpSchema.Prompt prompt,
 			BiFunction<McpSyncServerExchange, McpSchema.GetPromptRequest, McpSchema.GetPromptResult> promptHandler) {
@@ -490,7 +488,7 @@ public record SyncPromptSpecification(McpSchema.Prompt prompt,
 	 * @param completionHandler The synchronous function that processes completion
 	 * requests and returns results. The first argument is an
 	 * {@link McpSyncServerExchange} used to interact with the client. The second argument
-	 * is a {@link io.modelcontextprotocol.spec.McpSchema.CompleteRequest}.
+	 * is a {@link McpSchema.CompleteRequest}.
 	 */
 	public record SyncCompletionSpecification(McpSchema.CompleteReference referenceKey,
 			BiFunction<McpSyncServerExchange, McpSchema.CompleteRequest, McpSchema.CompleteResult> completionHandler) {

mcp/src/main/java/io/modelcontextprotocol/client/transport/ServerParameters.java renamed to mcp-reactor/src/main/java/io/modelcontextprotocol/client/transport/ServerParameters.java

@@ -5,7 +5,6 @@
 package io.modelcontextprotocol.server;
 
 import io.modelcontextprotocol.spec.McpSchema;
-import io.modelcontextprotocol.spec.McpSchema.LoggingLevel;
 import io.modelcontextprotocol.spec.McpSchema.LoggingMessageNotification;
 
 /**