`MCPServer(token_verifier=...)` no longer needs `auth=AuthSettings(...)`.
On its own a verifier is now a plain bearer gate: requests without a
token it accepts get a 401 whose `WWW-Authenticate` carries no
`resource_metadata`, no protected-resource metadata route is published,
and `get_access_token()` works as before. `AuthSettings` keeps its job of
describing that gate to OAuth clients (required scopes, RFC 9728
metadata, the discovery pointer in the 401), so it is what you add when
a real authorization server issues the tokens.
Previously the constructor refused a verifier without settings, which
forced anyone with a pre-shared token to invent an issuer URL, and the
low-level `Server.streamable_http_app(token_verifier=...)` accepted the
same shape but answered every request 401, valid token included, because
the authentication backend was only installed when settings were given.
Both wiring sites (and `MCPServer.sse_app`) now install the backend
whenever a verifier is present.
The authorization docs gain a "Just a pre-shared token" section with a
runnable example, and the constructor still refuses the two shapes that
cannot work: settings with nothing to gate with, and an embedded
authorization-server provider without settings for its issuer.
Max Isbey