[BUG] Gmail Connector keeps disconnecting — "Verbinden" button does nothing

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

The Gmail connector in Claude shows "Du bist noch nicht mit Gmail verbunden" (You are not yet connected to Gmail) every time, even after clicking "Verbinden" (Connect) multiple times (5+ attempts in one session).

Steps to reproduce:

Open Claude (desktop app or web)
Navigate to Gmail connector / plugin
Click "Verbinden" (Connect)
OAuth flow appears to complete (or does not open at all)
Returns to the same "not connected" screen — no connection established
Expected behavior: Gmail connects successfully and stays connected.

Actual behavior: Connection never persists. Button click has no effect.

Environment:

macOS 25.2.0
Claude desktop app
Plugins requiring Gmail: Design, Operations, Marketing
Workaround: None available through the connector UI.

What Should Happen?

The Gmail connector in Claude shows "Du bist noch nicht mit Gmail verbunden" (You are not yet connected to Gmail) every time, even after clicking "Verbinden" (Connect) multiple times (5+ attempts in one session).

Steps to reproduce:

Open Claude (desktop app or web)
Navigate to Gmail connector / plugin
Click "Verbinden" (Connect)
OAuth flow appears to complete (or does not open at all)
Returns to the same "not connected" screen — no connection established
Expected behavior: Gmail connects successfully and stays connected.

Actual behavior: Connection never persists. Button click has no effect.

Environment:

macOS 25.2.0
Claude desktop app
Plugins requiring Gmail: Design, Operations, Marketing
Workaround: None available through the connector UI.

Error Messages/Logs

None

Steps to Reproduce

The Gmail connector in Claude shows "Du bist noch nicht mit Gmail verbunden" (You are not yet connected to Gmail) every time, even after clicking "Verbinden" (Connect) multiple times (5+ attempts in one session).

Steps to reproduce:

Open Claude (desktop app or web)
Navigate to Gmail connector / plugin
Click "Verbinden" (Connect)
OAuth flow appears to complete (or does not open at all)
Returns to the same "not connected" screen — no connection established
Expected behavior: Gmail connects successfully and stays connected.

Actual behavior: Connection never persists. Button click has no effect.

Environment:

macOS 25.2.0
Claude desktop app
Plugins requiring Gmail: Design, Operations, Marketing
Workaround: None available through the connector UI.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

claude cowork connector

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_