MCP Testing Frameworks

Testing MCP servers requires verifying both the logic and the protocol adherence.

Testing Layers

1. Unit Tests: Testing the underlying Python functions independently of MCP.
2. Integration Tests: Mocking the MCP Client to verify that tools respond correctly over the protocol.
3. E2E Tests: Running the server in a real environment (e.g., Claude Desktop) and verifying behavior.

Tools

• pytest: The standard for Python testing.
• MCP Python SDK Test Utilities: Helper classes for simulating client interactions.

Best Practices

• Schema Validation: Verify that the generated JSON Schema matches expectations.
• Edge Cases: Test tools with empty, invalid, and large inputs.