mcpgen: Turn any OpenAPI spec into an MCP server in seconds

A developer created mcpgen, a tool that converts any OpenAPI specification into a ready-to-run MCP server in seconds. The generated server runs over stdio and can be plugged into Claude Desktop or any MCP client. The tool eliminates manual boilerplate for exposing REST endpoints to LLM agents.

I got tired of manually writing MCP tools for every REST endpoint I wanted to expose to an LLM. So I automated it. mcpgen reads an OpenAPI JSON or YAML file and generates a complete, ready‑to‑run MCP server in Python. snake case names mcp and httpx bash pip install mcpgen mcpgen my-api.json -o my-mcp-server python my-mcp-server/server.py The generated server runs over stdio – ready to plug into Claude Desktop or any MCP client. 🧪 Real‑world test Recently a contributor added an OpenAPI 3.1 fixture Xquik API with lookupTweet and getUser endpoints. The tool generated the correct tools, including path parameters and x-api-key auth, on the first try. All 18 tests pass. It works. 🤔 Why you might want it If you’re building LLM agents that need to interact with APIs, mcpgen eliminates the boilerplate. You don’t have to write a single @app.tool decorator by hand. It also makes it dead simple to experiment – change your API spec, regenerate the server, and you’re done. 📦 Links GitHub: JnanaSrota/mcpgen PyPI: pip install mcpgen MIT licensed, open to contributions 🙏 Feedback If you try it with your own API spec and something breaks or works beautifully , I’d love to hear about it. Drop a comment or open an issue. Thanks for reading