2026-08-17-gemini-cli-mcp-oauth-token-refresh-repaired-for-discovery-configured

MCP OAuth token refresh repaired for discovery-configured servers.

For MCP servers added via OAuth discovery plus dynamic client registration (gemini mcp add --transport http ... with no explicit oauth block), DynamicStoredOAuthProvider passed an empty OAuth config to refreshAccessToken, which threw on the missing clientId before any network call -- and the catch block then deleted the stored credentials, so every reconnect forced a fresh interactive re-auth. getValidToken had the same gap and returned null silently. The fix resolves config.clientId ?? credentials.clientId, passes it into the refresh call, and persists it when saving the refreshed token in both paths. Fixes issue #27745.

Channel: tagged-release. Ancestry: git tag --contains eef19f25c -> v0.55.1 (stable, non-prerelease per gh api .../releases/tags/v0.55.1 prerelease:false). Commit eef19f25c325f35634bdf5fdea5f245414ed4390 merged to main 2026-08-10T19:49Z; first stable tag containing it is v0.55.1, published 2026-08-11T21:15Z.

Operator consequence: Upgrade to v0.55.1 if you run OAuth-backed MCP servers that were registered by discovery. Before this, refresh never worked for that class of server and the failure destroyed recoverable credentials -- meaning any long-running or headless session against such a server would eventually stall waiting for a human to re-authorize. After upgrading, confirm your stored credentials survive a reconnect rather than assuming it.

Receipt

• https://github.com/google-gemini/gemini-cli/pull/28481