## Steps to reproduce 1. Connect Gmail and Google Drive plugins in claude.ai Settings → Integrations 2. Call any Gmail or Google Drive tool (e.g. `search_threads`, `list_recent_files`) 3. Both return: `Incompatible auth server: does not support dynamic client registration` ## Expected Tools authenticate and return results. ## Actual Auth fails on both plugins. Disconnecting/reconnecting in settings + restarting Claude Desktop does not fix it. ## Notes - First-party Google Calendar integra

Gmail and Google Drive plugins fail: "Incompatible auth server: does not support dynamic client registration"

Status Closed — not planned

Maintainer reply None cached

Activity 1 comment · opened Oct 7, 2026 · closed Oct 10, 2026

Connect Gmail and Google Drive plugins in claude.ai Settings → Integrations
Call any Gmail or Google Drive tool (e.g. search_threads, list_recent_files)
Both return: Incompatible auth server: does not support dynamic client registration

Tools authenticate and return results.

Auth fails on both plugins. Disconnecting/reconnecting in settings + restarting Claude Desktop does not fix it.

First-party Google Calendar integration (mcp__claude_ai_Google_Calendar) works fine in the same session with the same Google account
Only the third-party plugin versions of Gmail (mcp__plugin_small-business_gmail) and Drive (mcp__plugin_small-business_google-drive) are affected
Tested on macOS (Darwin 24.6.0), 2026-10-07