When an HTTP MCP server returns invalid_grant (or invalid_token / revoked /
plain 401 from the token endpoint) during OAuth refresh, MCPManager
previously logged "MCP OAuth refresh failed, using existing token" and
re-attached the stale access token as Authorization: Bearer on every
subsequent request. The next tool-load 401'd with invalid_token, future
sessions repeated the loop, and the only recovery was to hand-clear the
credential row in agent.db. Reported with Logfire as the trigger; any
remote HTTP MCP that rotates / revokes refresh tokens is affected.
#resolveAuthConfig now reuses pi-ai's isDefinitiveOAuthFailure classifier
(same one auth-broker and AuthStorage use for first-party providers): on
a definitive failure it calls AuthStorage.remove(credentialId), drops the
Bearer entirely, and the next request surfaces a clean auth error so the
user can /mcp reauth <server> (or /mcp unauth) to recover. Transient
failures (network/fetch failed/ECONNREFUSED) still fall back to the
existing token to ride out blips.
Verified with new mcp-manager-oauth-refresh.test.ts (invalid_grant, 401,
transient fallback, happy-path rotation). The full mcp-* test set
(45 tests across 5 files) still passes.
Fixes#1908
roboomp
95f64b6142