[BUG] Gmail Connector – "This app is blocked" when creating labels (OAuth scope issue)

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?

Bug Report: Gmail Connector – "This app is blocked" when creating labels (OAuth scope issue)
Environment: Claude.ai web interface, private Gmail account (not Google Workspace)
What I tried to do: Create a Gmail label via the Claude Gmail connector.
Steps taken & results:

Gmail connector (MCP) – first attempt: Called create_label → got Google OAuth warning page ("Diese App ist blockiert" / "This app is blocked"). No "Advanced" link visible to bypass the block.
Reconnected the Gmail connector in Claude.ai Settings → Connectors, then retried create_label → same authentication failure.
Tried Claude in Chrome extension as an alternative workaround → blocked by organization policy, not available.
Retried Gmail connector directly after tools were reloaded → error: Authentication failed.

Error message from Google OAuth: "Diese App ist blockiert" (This app is blocked) – the OAuth warning page shows no way to proceed, no "Advanced" or "Continue anyway" option.
Root cause (based on existing GitHub issues #46206 and #50754): The Gmail connector does not request the gmail.modify or gmail.labels OAuth scope during authorization. Without this scope, Google hard-blocks write operations like label creation. This appears to be a server-side issue in the connector implementation.
Expected behavior: After connecting the Gmail connector and granting permissions, create_label should work.
Actual behavior: Google blocks the OAuth flow entirely with no workaround available to the user.
Related issues:

https://github.com/anthropics/claude-code/issues/46206
https://github.com/anthropics/claude-code/issues/50754

What Should Happen?

Expected behavior: After connecting the Gmail connector and granting permissions, create_label should work.
Actual behavior: Google blocks the OAuth flow entirely with no workaround available to the user.

Error Messages/Logs

Error message from Google OAuth: "Diese App ist blockiert" (This app is blocked) – the OAuth warning page shows no way to proceed, no "Advanced" or "Continue anyway" option.

Steps to Reproduce

Gmail connector (MCP) – first attempt: Called create_label → got Google OAuth warning page ("Diese App ist blockiert" / "This app is blocked"). No "Advanced" link visible to bypass the block.
Reconnected the Gmail connector in Claude.ai Settings → Connectors, then retried create_label → same authentication failure.
Tried Claude in Chrome extension as an alternative workaround → blocked by organization policy, not available.
Retried Gmail connector directly after tools were reloaded → error: Authentication failed.

Claude Model

Sonnet (default)

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

latest

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_