fastapi_oauth2_password_bearer_www_authenticate_401_quickstart.py

1from typing import Annotated
2
3from fastapi import Depends, FastAPI, HTTPException, status
4from fastapi.security import OAuth2PasswordBearer
5
6app = FastAPI()
7
8# This utility will look for an Authorization: Bearer <token> header
9# If not present, it will eventually prompt the user via WWW-Authenticate
10oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")
11
12@app.get("/items/")
13async def read_items(token: Annotated[str, Depends(oauth2_scheme)]):
14    """
15    If the 'token' is missing, FastAPI will automatically return:
16    Status Code: 401 Unauthorized
17    Header: WWW-Authenticate: Bearer
18    """
19    return {"token": token}
20
21if __name__ == "__main__":
22    import uvicorn
23    uvicorn.run(app, host="0.0.0.0", port=8000)