Retrieving Current User Using Token

Once a user has obtained an access token, you can use the token to retrieve information about the current user. This is often necessary for displaying user-specific content or enforcing access controls.

Creating a Dependency

To retrieve the current user based on the access token, create a dependency:

Python

from fastapi import Depends, HTTPException
from app.utils import decode_access_token

def get_current_user(request: Request) -> User:
    token = request.headers.get("Authorization").split()[1]
    data = decode_access_token(token)
    user = get_user_by_id(data["sub"])
    return user

Using the Dependency in Endpoints

Python

from fastapi import APIRouter, Depends

router = APIRouter()

@router.get("/me")
async def get_current_user(current_user: User = Depends(get_current_user)):
    return current_user

Additional Factors

• Token Validation: Ensure that the token is valid and not expired before retrieving the user.
• User Data: Consider storing additional user information in the token payload, such as user roles or preferences.
• Security: Protect against token theft and unauthorized access.
• Performance: If performance is a concern, consider caching user information based on the token.

By following these steps, you can effectively retrieve the current user based on their access token in your FastAPI application. This enables you to implement features that require user-specific information, such as personalized content or restricted access to certain resources.