Example Contact Server

A minimal MCP server demonstrating the mcp-contracts GitHub Action.

What this repo demonstrates

This repo has a simple MCP server (server.js) with a baseline contract snapshot in contracts/baseline.mcpc.json. When a pull request modifies server.js, the GitHub Action automatically:

1. Captures the current MCP tool schemas from the server
2. Diffs them against the baseline snapshot
3. Posts a PR comment with the diff report
4. Fails the check if breaking changes are detected

Try it yourself

1. Fork this repo
2. Create a branch and modify server.js (e.g., add a required parameter to a tool, or remove a tool)
3. Open a pull request
4. Watch the MCP Contract Check workflow run and report changes

Running locally

npm install
npm start

The server communicates over stdio using the MCP protocol.