If you've published an API on RapidAPI, there's a good chance it has one (or both) of these two holes.
1. Your real backend URL isn't actually secret
RapidAPI's gateway is supposed to be the only way to reach your API. In practice, your real URL leaks constantly — a log line, a Host header, a curious subscriber poking around. Once someone has it, they call your backend directly and skip RapidAPI's billing entirely.
The fix is one dependency:
from fastapi import Header, HTTPException






