Is basically tailored just for traefik's Forward Authentication system. It takes a `GET`, `POST`, `PUT`, `PATCH` or `DELETE` request, reads a Bearer Auth JWT token if available. Alternatively, the token can be supplied in the querystring as `token`. Tokens in the Authorization header override tokens in the querystring. If it is not available or invalid, request fails with 4XX and traefik rejects the request. Otherwise, a success response is returned with a `X-User-Claim` header containing serialised user information. `OPTIONS` requests are allowed to pass through wholesale.