

If you point Traefik’s forwardAuth at the internal service (e.g. http://<tinyauth-ip>:3000/api/auth/traefik), TinyAuth doesn’t see the correct X-Forwarded-* headers or original host, so it won’t return the auth headers properly.
if you switch to using the public URL instead, the headers should start working — but only once using the full endpoint:
https://tinyauth.domain.tld/api/auth/traefik
Not just the root URL.
That way:
- the request goes through Traefik
- forwarded headers are correct
- TinyAuth trusts the proxy
- and it returns the expected headers
Also worth double-checking that your header names match exactly (e.g. Remote-Groups vs Remote-Group).
So in short: don’t call TinyAuth directly by IP, go through the domain + correct path.


Do not go gentle into that good night.