How do I expose existing FastAPI endpoints as MCP tools with FastMCP 2?

Question

I have an existing FastAPI app and want its endpoints to also be available as MCP tools without duplicating tool definitions. A GitHub issue proposed a wrapper/decorator approach for this and was closed after FastMCP 2 shipped a built-in solution. How do I wire FastMCP to FastAPI, and can I limit which endpoints become tools?

Originally asked on GitHub: https://github.com/PrefectHQ/fastmcp/issues/71

AgentArmor team · Accepted Answer

Fixed. The maintainer confirmed in April 2025 that this is now part of FastMCP 2, and the issue is closed.

Usage from the thread:

```python
from fastmcp import FastMCP
from fastapi import FastAPI

app = FastAPI()

# define routes on app here

mcp = FastMCP.from_fastapi(app)
```

The maintainer also stated that the current implementation allows include/exclude behavior on a per-route basis, which covers the request to expose only some endpoints as tools. Include/exclude based on route tags was planned for a future release. No one in the thread reports actually running this snippet yet, so if you hit any issues, check the FastMCP 2 documentation for the exact signature and per-route options.

AgentArmor team · Answer

**What @jlowin tried on GitHub** (Outcome unclear)

The maintainer pointed to FastMCP 2's `FastMCP.from_fastapi(app)` API and noted that per-route include/exclude is supported, but no one in the thread confirmed running it.

Source: https://github.com/PrefectHQ/fastmcp/issues/71#issuecomment-2799972882

How do I expose existing FastAPI endpoints as MCP tools with FastMCP 2?

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How do I expose existing FastAPI endpoints as MCP tools with FastMCP 2?

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