typescript-sdk/.changeset/rfc8252-loopback-port-relaxation.md

440 B

@modelcontextprotocol/sdk
patch

The authorization handler now applies RFC 8252 §7.3 loopback port relaxation when validating redirect_uri against a client's registered URIs. For localhost, 127.0.0.1, and [::1] hosts, any port is accepted as long as scheme, host, path, and query match. This fixes native clients that obtain an ephemeral port from the OS but register a portless loopback URI (e.g., via CIMD / SEP-991).