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Example Code

fromfastapiimportRequest,HTTPException,Depends,APIRouterfromjoseimportjwt,JWTErrorSECRET="..."ALGO="HS256"defverify_token(request:Request):ifhasattr(request.state,"user"):returnrequest.state.usertoken=request.cookies.get("access_token")ifnottoken:raiseHTTPException(status_code=401)try:payload=jwt.decode(token,SECRET,algorithms=[ALGO])exceptJWTError:raiseHTTPException(status_code=401)request.state.user=payloadreturnpayloaddefis_admin(request:Request=Depends(verify_token)):user=request.state.userifnotuser.get("is_admin"):raiseHTTPException(status_code=403)returnuserroot_router=APIRouter(prefix="",dependencies=[Depends(verify_token)])admin_router=APIRouter(prefix="/admin",dependencies=[Depends(is_admin)])root_router.include_router(admin_router)

Description

Hi!
Hope you’re doing well.

I’ve got a question regarding how dependencies are executed when using nested APIRouters.

If I attach a dependency like Depends(verify_token) to the root router, I don’t have to repeat token validation in every route — which is great.
However, if I include another router under it (for example /admin) that also defines its own dependency (Depends(is_admin)), both dependencies execute, and the token is validated twice.

This works correctly but feels redundant, since is_admin depends on verify_token anyway.
I’d like to cache the result of the top-level validation so that deeper routers can reuse it instead of triggering another validation pass.

The main step is in

if hasattr(request.state, "user"):          return request.state.user

The caching workaround with request.state may work fine, but I’m wondering if this approach is recommended at all — or if there’s (or planned) a more native way to reuse the dependency results across routers without re-executing them.

Operating System

Windows

Operating System Details

11

FastAPI Version

0.120.4

Pydantic Version

v2.11

Python Version

3.11

Additional Context

No response