[BUG] Gmail MCP write permissions blocked by Google ("This app is blocked")

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?

Gmail MCP write permissions blocked by Google ("This app is blocked")

What Should Happen?

I should be able to use

Error Messages/Logs

Steps to Reproduce

1. Go to claude.ai
2. Open Settings → Integrations
3. Connect Gmail integration
4. When prompted by Google OAuth, grant permissions
5. Google shows: "This app is blocked — This app tried to access sensitive info in your Google

Account. To keep your account safe, Google blocked this access."

1. No "Advanced" option is available to bypass the block

Expected behavior: Gmail connects with full read/write permissions

Actual behavior: Google blocks the OAuth app entirely, preventing write access (archive, label,
spam actions all fail with "insufficient authentication scopes")

Account type: Personal Gmail (not Google Workspace)

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.109 (claude code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_