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Example Code

from fastapi import APIRouter

router = APIRouter(prefix='/api')

router.include_router(router) # Locks program

Description

Passing a router's own object into the include_router method results in FastAPI locking up, requiring the Python process to be terminated.

This should be resolved by checking if router is self: ... and then raising some error. This is preferred to the current implementation because currently type checkers will not raise any flags and may require some tedious debugging.

Operating System

Windows, macOS

Operating System Details

No response

FastAPI Version

0.115.6

Pydantic Version

2.10.3

Python Version

3.13.3

Additional Context

No response