FastAPI MCP turns an existing FastAPI application into a Model Context Protocol server in about three lines of code, exposing your endpoints as tools that AI agents can call — with your existing authentication intact. It has earned about 12,000 stars on GitHub since its 2025 release.
MCP has become the standard way agents talk to applications, but wiring it up usually means writing and maintaining a separate server that mirrors your API. FastAPI MCP takes the opposite approach: point it at your FastAPI app and it generates the MCP server directly from the application itself — not from a static OpenAPI file — preserving your request and response schemas and your endpoint documentation exactly as written. Crucially, it reuses your FastAPI dependency-based authentication and authorization, so the tools agents call enforce the same permissions as the API itself. It communicates through FastAPI’s ASGI interface for efficient in-process calls, needs zero configuration to start, and can be mounted on the same application or deployed as a separate service. For teams whose internal tools and data already sit behind FastAPI services, it is the shortest path from ‘we have an API’ to ‘our agents can use it’ — in Claude, Cursor, Windsurf or any other MCP client.
FastAPI MCP is free and open source under the MIT license. Its maker, Tadata, also offers a managed hosted solution for teams that prefer not to run their own MCP infrastructure, which makes the overall offering freemium.
FastAPI MCP is for Python backend teams that already run FastAPI services and want AI agents to call those services as tools — quickly, and with the API’s real authentication and schemas rather than a hand-maintained copy.