diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 000000000..126c10e94
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,70 @@
+name: CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ '*' ]
+
+env:
+  MIX_ENV: test
+    
+permissions:
+  contents: read
+
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up Elixir
+      uses: erlef/setup-beam@v1
+      with:
+        version-type: strict
+        version-file: .tool-versions
+      env:
+        ImageOS: ubuntu20 
+    - name: Restore dependencies cache
+      uses: actions/cache@v3
+      with:
+        path: deps
+        key: ${{ runner.os }}-mix-${{ hashFiles('**/mix.lock') }}
+        restore-keys: ${{ runner.os }}-mix-
+    - name: Install dependencies
+      run: mix deps.get
+    - name: Retrieve PLT Cache
+      uses: actions/cache@v1
+      id: plt-cache
+      with:
+        path: priv/plts
+        key: ${{ runner.os }}-plts-${{ hashFiles(format('{0}{1}', github.workspace, '/mix.lock')) }}
+    - name: Create PLTs
+      if: steps.plt-cache.outputs.cache-hit != 'true'
+      run: |
+        mkdir -p priv/plts
+        mix dialyzer --plt
+    - name: Run dialyzer
+      run: mix dialyzer --no-check
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up Elixir
+      uses: erlef/setup-beam@v1
+      with:
+        version-type: strict
+        version-file: .tool-versions
+      env:
+        ImageOS: ubuntu20
+    - name: Restore dependencies cache
+      uses: actions/cache@v3
+      with:
+        path: deps
+        key: ${{ runner.os }}-mix-${{ hashFiles('**/mix.lock') }}
+        restore-keys: ${{ runner.os }}-mix-
+    - name: Install dependencies
+      run: mix deps.get 
+    - name: Run tests
+      run: mix test
diff --git a/.gitignore b/.gitignore
index 71f58e1c4..dd2cb66e7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,10 @@
 # If you run "mix test --cover", coverage assets end up here.
 /cover/
 
+# mix dialyzer artifacts
+/priv/plts/*.plt
+/priv/plts/*.plt.hash
+
 # The directory Mix downloads your dependencies sources to.
 /deps/
 
diff --git a/lib/lambda_ethereum_consensus.ex b/lib/lambda_ethereum_consensus.ex
index d36e512fe..36dea310d 100644
--- a/lib/lambda_ethereum_consensus.ex
+++ b/lib/lambda_ethereum_consensus.ex
@@ -12,6 +12,7 @@ defmodule LambdaEthereumConsensus do
       :world
 
   """
+  @spec hello() :: :world
   def hello do
     :world
   end
diff --git a/mix.exs b/mix.exs
index c132a684d..3c1d95b55 100644
--- a/mix.exs
+++ b/mix.exs
@@ -7,7 +7,11 @@ defmodule LambdaEthereumConsensus.MixProject do
       version: "0.1.0",
       elixir: "~> 1.15",
       start_permanent: Mix.env() == :prod,
-      deps: deps()
+      deps: deps(),
+      dialyzer: dialyzer(),
+      preferred_cli_env: [
+        dialyzer: :test
+      ],
     ]
   end
 
@@ -22,8 +26,13 @@ defmodule LambdaEthereumConsensus.MixProject do
   # Run "mix help deps" to learn about dependencies.
   defp deps do
     [
-      # {:dep_from_hexpm, "~> 0.3.0"},
-      # {:dep_from_git, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"}
+      {:dialyxir, "~> 1.1", only: [:dev, :test], runtime: false},
+    ]
+  end
+
+  defp dialyzer() do
+    [
+      plt_file: {:no_warn, "priv/plts/project.plt"}
     ]
   end
 end
diff --git a/mix.lock b/mix.lock
new file mode 100644
index 000000000..1d5ea5427
--- /dev/null
+++ b/mix.lock
@@ -0,0 +1,4 @@
+%{
+  "dialyxir": {:hex, :dialyxir, "1.3.0", "fd1672f0922b7648ff9ce7b1b26fcf0ef56dda964a459892ad15f6b4410b5284", [:mix], [{:erlex, ">= 0.2.6", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "00b2a4bcd6aa8db9dcb0b38c1225b7277dca9bc370b6438715667071a304696f"},
+  "erlex": {:hex, :erlex, "0.2.6", "c7987d15e899c7a2f34f5420d2a2ea0d659682c06ac607572df55a43753aa12e", [:mix], [], "hexpm", "2ed2e25711feb44d52b17d2780eabf998452f6efda104877a3881c2f8c0c0c75"},
+}