Authentication

Tutorials

• Authentication and Authorization with FastAPI: A Complete Guide | Better Stack Community

Basic Authentication

auth.py

import secrets
from fastapi import Depends, FastAPI, HTTPException, status
from fastapi.security import HTTPBasic, HTTPBasicCredentials

security = HTTPBasic()

def authenticate_user(credentials: HTTPBasicCredentials = Depends(security)):
    # In a real application, you'd verify against a database
    correct_username = secrets.compare_digest(credentials.username, "admin")
    correct_password = secrets.compare_digest(credentials.password, "secret")

    if not (correct_username and correct_password):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid credentials",
            headers={"WWW-Authenticate": "Basic"},
        )

    return credentials.username

main.py

from fastapi import FastAPI, Depends
from auth import authenticate_user

app = FastAPI(title="Authentication Demo", version="1.0.0")

@app.get("/")
async def root():
    return {"message": "Welcome to FastAPI Authentication Demo"}

@app.get("/protected")
async def protected_route(current_user: str = Depends(authenticate_user)):
    return {"message": f"Hello {current_user}, this is a protected route!"}