{"name":"tengu_mcp_server_connection_failed","slug":"tengu-mcp-server-connection-failed","family":"flag","title":"Feature flags","noun":"feature flag","description":"MCP debug output now shows which protocol version and path a server connection used.","description_source":"entry","described_by":{"version":"2.1.221","anchor":"connection-telemetry-gains-negotiation-and-protocol-fields"},"presence":{"first_seen":null,"removed_in":null,"in_current_build":false,"newest_mined":"2.1.309","builds":0,"mined_builds":150,"first_cited":{"version":"2.1.221","released_at":"2026-08-03 22:16:25","spans":1}},"aliases":[],"entries":[{"version":"2.1.248","anchor":"mcp-connection-failure-telemetry-records-where-the-auth-head","heading":"MCP connection-failure telemetry records where the auth header came from","line":"MCP connection failure reports now note when auth headers came from a credential helper.","released_at":"2026-08-27 20:35:36","reason":"gate cited by this entry, found in this entry's text"},{"version":"2.1.224","anchor":"mcp-events-forwarded-to-datadog-with-identifying-fields-remo","heading":"MCP events forwarded to Datadog, with identifying fields removed and a per-server cap","line":"MCP events are forwarded for logging with identifying fields stripped, and skipped entirely if analytics are off.","released_at":"2026-08-07 01:36:32","reason":"gate cited by this entry, found in this entry's text"},{"version":"2.1.224","anchor":"mcp-oauth-failures-name-the-specific-issuer-mismatch","heading":"MCP OAuth failures name the specific issuer mismatch","line":"MCP OAuth failures now tell you it was an issuer mismatch instead of a generic error.","released_at":"2026-08-07 01:36:32","reason":"gate cited by this entry, found in this entry's text"},{"version":"2.1.222","anchor":"dedicated-error-when-claude-ai-rejects-a-session-bearer-toke","heading":"Dedicated error when claude.ai rejects a session bearer token","line":"If claude.ai rejects your session token, you now get a clear message telling you to run \/login instead of endless retries.","released_at":"2026-08-04 20:37:17","reason":"gate cited by this entry, found in this entry's text"},{"version":"2.1.221","anchor":"connection-telemetry-gains-negotiation-and-protocol-fields","heading":"Connection telemetry gains negotiation and protocol fields","line":"MCP debug output now shows which protocol version and path a server connection used.","released_at":"2026-08-03 22:16:25","reason":"gate cited by this entry, found in this entry's text"},{"version":"2.1.221","anchor":"failure-telemetry-errorcode-is-now-normalized-against-a-fixe","heading":"Failure telemetry errorCode is now normalized against a fixed allowlist","line":"MCP connection failure reporting now uses a fixed set of error codes instead of raw values.","released_at":"2026-08-03 22:16:25","reason":"gate cited by this entry, found in this entry's text"},{"version":"2.1.221","anchor":"mcp-connection-failure-telemetry-records-negotiation-outcome","heading":"MCP connection-failure telemetry records negotiation outcome","line":"Failed MCP connections now record how the handshake was negotiated and whether it fell back.","released_at":"2026-08-03 22:16:25","reason":"gate cited by this entry, found in this entry's text"},{"version":"2.1.221","anchor":"mcp-connection-failure-telemetry-normalizes-the-error-code","heading":"MCP connection-failure telemetry normalizes the error code","line":"MCP failure codes are now cleaned up before reporting, so odd server values don't leak through.","released_at":"2026-08-03 22:16:25","reason":"gate cited by this entry, found in this entry's text"}],"entries_total":8,"docs":[],"docs_total":0,"gates":[],"related":[{"name":"tengu_mcp_server_connection_succeeded","slug":"tengu-mcp-server-connection-succeeded","description":"MCP debug output now shows which protocol version and path a server connection used."}],"url":"https:\/\/changelogs.core-directive.com\/reference\/flag\/tengu-mcp-server-connection-failed","family_url":"https:\/\/changelogs.core-directive.com\/reference\/flag.json"}