diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..5521923
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,29 @@
+name: CI Pipeline
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    name: Lint & Unit Test
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: Install dependencies
+        run: |
+          pip install pytest boto3
+
+      - name: Run unit tests
+        run: |
+          pytest project-d-serverless-api/tests/ -v
\ No newline at end of file
diff --git a/project-d-serverless-api/tests/__init__.py b/project-d-serverless-api/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/project-d-serverless-api/tests/test_lambda.py b/project-d-serverless-api/tests/test_lambda.py
new file mode 100644
index 0000000..d1c0686
--- /dev/null
+++ b/project-d-serverless-api/tests/test_lambda.py
@@ -0,0 +1,31 @@
+import json
+import sys
+import os
+from unittest.mock import patch, MagicMock
+
+os.environ['TABLE_NAME'] = 'test-table'
+os.environ['AWS_DEFAULT_REGION'] = 'ap-northeast-1'
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', 'lambda'))
+
+import index
+
+def test_get_items_returns_200():
+    with patch.object(index, 'table') as mock_table:
+        mock_table.scan.return_value = {'Items': []}
+        event = {"httpMethod": "GET", "pathParameters": None, "body": None}
+        response = index.handler(event, {})  # ← handler に変更
+        assert response["statusCode"] == 200
+
+def test_response_has_cors_header():
+    with patch.object(index, 'table') as mock_table:
+        mock_table.scan.return_value = {'Items': []}
+        event = {"httpMethod": "GET", "pathParameters": None, "body": None}
+        response = index.handler(event, {})  # ← handler に変更
+        assert "Access-Control-Allow-Origin" in response["headers"]
+
+def test_invalid_method_returns_400():
+    with patch.object(index, 'table') as mock_table:
+        event = {"httpMethod": "PATCH", "pathParameters": None, "body": None}
+        response = index.handler(event, {})  # ← handler に変更
+        assert response["statusCode"] == 400
\ No newline at end of file