Under the hoodTier: how much it should matter to you
2Useful: my rating, 1 to 5
3Signal: worth watching, 1 to 5
MCPArea: what it touches
Internal ChangesKind: in v2.1.224,
Internal ChangesSection of the release
What
ISSUER_ECHO_DENIED was added to the recognised error codes of both MCP client generations, alongside the existing rejected-auth-header and rejected-bearer codes.
Evidence
ISSUER_ECHO_DENIED
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
