Conformance Tests for MCP

A framework for testing MCP (Model Context Protocol) client implementations against the specification.

[!WARNING] This repository is a work in progress and is unstable. Join the conversation in the #conformance-testing-wg in the MCP Contributors discord.

The conformance test framework validates MCP client implementations by:

1. Starting a test server for the specified scenario
2. Running the client implementation with the test server URL
3. Capturing MCP protocol interactions
4. Running conformance checks against the specification
5. Generating detailed test results

• --command - The command to run your MCP client (can include flags)
• --scenario - The test scenario to run (e.g., "initialize")

The framework appends the server URL as the final argument to your command.

Results are saved to results/<scenario>-<timestamp>/:

• checks.json - Array of conformance check results with pass/fail status
• stdout.txt - Client stdout output
• stderr.txt - Client stderr output

• examples/clients/typescript/test1.ts - Valid MCP client (passes all checks)
• examples/clients/typescript/test-broken.ts - Invalid client missing required fields (fails checks)

• initialize - Tests MCP client initialization handshake
  • Validates protocol version
  • Validates clientInfo (name and version)
  • Validates server response handling

See src/runner/DESIGN.md for detailed architecture documentation.

• Runner (src/runner/) - Orchestrates test execution and result generation
• Scenarios (src/scenarios/) - Test scenarios with custom server implementations
• Checks (src/checks.ts) - Conformance validation functions
• Types (src/types.ts) - Shared type definitions

1. Create a new directory in src/scenarios/<scenario-name>/
2. Implement the Scenario interface with start(), stop(), and getChecks()
3. Register the scenario in src/scenarios/index.ts

See src/scenarios/initialize/ for a reference implementation.