Global Dependencies
For some types of applications you might want to add dependencies to the whole application.
Similar to the way you can add dependencies to the path operation decorators, you can add them to the FastAPI application.
In that case, they will be applied to all the path operations in the application:
from typing import Annotated
from fastapi import Depends, FastAPI, Header, HTTPException
async def verify_token(x_token: Annotated[str, Header()]):
if x_token != "fake-super-secret-token":
raise HTTPException(status_code=400, detail="X-Token header invalid")
async def verify_key(x_key: Annotated[str, Header()]):
if x_key != "fake-super-secret-key":
raise HTTPException(status_code=400, detail="X-Key header invalid")
return x_key
app = FastAPI(dependencies=[Depends(verify_token), Depends(verify_key)])
@app.get("/items/")
async def read_items():
return [{"item": "Portal Gun"}, {"item": "Plumbus"}]
@app.get("/users/")
async def read_users():
return [{"username": "Rick"}, {"username": "Morty"}]And all the ideas in the section about adding dependencies to the path operation decorators still apply, but in this case, to all of the path operations in the app.
Dependencies for groups of path operations
Section titled “Dependencies for groups of path operations”Later, when reading about how to structure bigger applications (Bigger Applications - Multiple Files), possibly with multiple files, you will learn how to declare a single dependencies parameter for a group of path operations.