The result of router based dependencies is discarded after the dependency is run as it says in the docshere.

FastAPI is designed around dependency injection for the path operations so the idea is to give every request that needs a user the user dependency.

If I have the same dependency in router as well as in the path operation (for getting current user), will the dependency be called twice or will it be cached?

It will be cached.Depends function has ause_cache parameter which is by defaultTrue.

Sorry I have another question on the caching: it works very fine for simple function-based dependencies, but what about parameterized class dependencies? When/admin is visited RoleChecker is run for 3 times

fromtypingimportAnnotatedimportuvicornfromfastapiimportDepends,FastAPI,HTTPException,statusapp=FastAPI()classRoleChecker:def__init__(self,allowed_role:str):self.allowed_role=allowed_roledef__call__(self,role:str="guest"):print(f"called with{role} <=>{self.allowed_role}")ifrolenotinself.allowed_role:raiseHTTPException(status_code=status.HTTP_403_FORBIDDEN,detail=f"User with role '{role}' is not allowed to access this endpoint.",            )returnrole# --- Using the Parameterized Dependencies in Routes ---@app.get("/admin",dependencies=[Depends(RoleChecker("admin"))])asyncdefadmin_dashboard(current_user_role:Annotated[str,Depends(RoleChecker("admin"))],current_user_role2:Annotated[str,Depends(RoleChecker("admin"))],):return {"message":"Welcome to the admin dashboard!","role":current_user_role}@app.get("/")asyncdefindex():"""    A public endpoint that doesn't require any specific role.    """return {"message":"Welcome to the API. Try accessing /admin or /profile with a role parameter."    }if__name__=="__main__":uvicorn.run("poc:app",host="0.0.0.0",port=8001,reload=True)

Hi

It must be ran at least twice for your use case.

The dependency on the@app.get decorator is meant for the route even before the dependencies for the endpoint parameter is injected.

And for the two parameters, e.g.current_user_role and the other one, I suppose you would want to check the role for each 'User' which is then injected into the endpoint function as different 'User' arguments.

From this context, the route dependency is a little redundant hence at the start I mentioned it as 'at least twice'.