app/auth.py

from fastapi import Depends, Header

from app.config import Settings, get_settings
from app.errors import OpenAICompatibleError


def require_bearer_auth(
    authorization: str | None = Header(default=None),
    settings: Settings = Depends(get_settings),
) -> None:
    if not settings.require_auth:
        return

    if not authorization or not authorization.startswith("Bearer "):
        raise OpenAICompatibleError(
            status_code=401,
            message="Missing or invalid Authorization header.",
            error_type="invalid_request_error",
            code="invalid_api_key",
        )

    token = authorization.removeprefix("Bearer ").strip()
    if token != settings.api_key:
        raise OpenAICompatibleError(
            status_code=401,
            message="Invalid API key provided.",
            error_type="invalid_request_error",
            code="invalid_api_key",
        )