Under the hoodTier: how much it should matter to you
1Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
MCPArea: what it touches
ImprovementsKind: in v2.1.224,
ImprovementsSection of the release
What
OAuth failures against an MCP server now classify issuer-echo problems separately from generic auth errors, so logs and telemetry can tell them apart from cases like a redirect URI mismatch or a Microsoft Entra specific failure.
Details
The token refresh path can now fail with the distinct reason mcp_oauth_refresh_issuer_echo_denied.
Evidence
issuer_echo_mismatch
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
