fastapi-mcp

FastAPI-MCP

Expose your FastAPI endpoints as Model Context Protocol (MCP) tools, with Auth!

Features

• Authentication built in, using your existing FastAPI dependencies!

• FastAPI-native: Not just another OpenAPI -> MCP converter

• Zero/Minimal configuration required - just point it at your FastAPI app and it works

• Preserving schemas of your request models and response models

• Preserve documentation of all your endpoints, just as it is in Swagger

• Flexible deployment - Mount your MCP server to the same app, or deploy separately

• ASGI transport - Uses FastAPI's ASGI interface directly for efficient communication

Installation

We recommend using uv, a fast Python package installer:

uv add fastapi-mcp

Alternatively, you can install with pip:

pip install fastapi-mcp

Basic Usage

The simplest way to use FastAPI-MCP is to add an MCP server directly to your FastAPI application:

from fastapi import FastAPI
from fastapi_mcp import FastApiMCP

app = FastAPI()

mcp = FastApiMCP(app)

# Mount the MCP server directly to your FastAPI app
mcp.mount()

That's it! Your auto-generated MCP server is now available at https://app.base.url/mcp.

Documentation, Examples and Advanced Usage

FastAPI-MCP provides comprehensive documentation in the docs folder:

• Best Practices - Essential guidelines for converting APIs to MCP tools safely and effectively
• FAQ - Frequently asked questions about usage, development and support
• Tool Naming - Best practices for naming your MCP tools using operation IDs
• Connecting to MCP Server - How to connect various MCP clients like Cursor and Claude Desktop
• Authentication and Authorization - How to authenticate and authorize your MCP tools
• Advanced Usage - Advanced features like custom schemas, endpoint filtering, and separate deployment

Check out the examples directory for code samples demonstrating these features in action.

FastAPI-first Approach

FastAPI-MCP is designed as a native extension of FastAPI, not just a converter that generates MCP tools from your API. This approach offers several key advantages:

• Native dependencies: Secure your MCP endpoints using familiar FastAPI Depends() for authentication and authorization

• ASGI transport: Communicates directly with your FastAPI app using its ASGI interface, eliminating the need for HTTP calls from the MCP to your API

• Unified infrastructure: Your FastAPI app doesn't need to run separately from the MCP server (though separate deployment is also supported)

This design philosophy ensures minimum friction when adding MCP capabilities to your existing FastAPI services.

Development and Contributing

Thank you for considering contributing to FastAPI-MCP! We encourage the community to post Issues and create Pull Requests.

Before you get started, please see our Contribution Guide.

Community

Join MCParty Slack community to connect with other MCP enthusiasts, ask questions, and share your experiences with FastAPI-MCP.

Requirements

• Python 3.10+ (Recommended 3.12)
• uv

License

MIT License. Copyright (c) 2024 Tadata Inc.