The RFC 8414 Authorization Server Metadata the proxy publishes. It advertises
the proxy's own /authorize, /token, and /register endpoints (NOT the
upstream's), mandates PKCE S256, and lists the supported scopes. Because a
registration_endpoint is present, MCP clients select Dynamic Client
Registration and obtain the fixed upstream credentials transparently.
The RFC 8414 Authorization Server Metadata the proxy publishes. It advertises the proxy's own /authorize, /token, and /register endpoints (NOT the upstream's), mandates PKCE S256, and lists the supported scopes. Because a registration_endpoint is present, MCP clients select Dynamic Client Registration and obtain the fixed upstream credentials transparently.