[BUG] Gmail connector OAuth hard-blocked by Google ("This app is blocked") — cannot reconnect in CoWork

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?

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet

Platform: macOS (claude.ai / CoWork)

What's Wrong?

The Gmail connector in Claude CoWork fails to reconnect with a hard Google OAuth block.
Google displays "This app is blocked. This app tried to access sensitive info in your Google Account."
There is no "Advanced" or "Proceed anyway" option — the block is terminal.

Steps to Reproduce

1. Open Claude CoWork → Connectors
2. Attempt to connect/reconnect Gmail
3. Complete Google OAuth flow
4. Google shows "This app is blocked" — no bypass available

Expected Behaviour
Gmail connector authenticates successfully, same as Google Calendar connector.

Actual Behaviour
Hard block from Google. Cannot proceed. Revoke + retry does not help.

Additional Context

• Google Calendar connector connects successfully on the same account
• Prior to the hard block, Gmail showed inconsistent read/write behaviour
• Removed Claude access entirely from Google Account (myaccount.google.com/permissions) and retried from scratch — same result
• This appears related to #46206 (missing gmail.modify scope) and possibly #30166 (OAuth callback issues)
• No workaround available at the user level — this requires Anthropic to resolve the Gmail app's OAuth scope verification with Google

What Should Happen?

Gmail connector authenticates successfully via OAuth, the same way Google Calendar does on the same account. After completing the Google consent screen, Gmail shows as "Connected" in CoWork connectors and its tools become available in chat.

Error Messages/Logs

Google OAuth screen: "This app is blocked. This app tried to access 
sensitive info in your Google Account. To keep your account safe, 
Google blocked this access."

No "Advanced" or "Proceed anyway" option is shown.
No error code provided by Google.

Steps to Reproduce

1. Open Claude CoWork → Connectors
2. Click Connect (or Reconnect) on the Gmail connector
3. Complete the Google account selection and OAuth flow
4. Google displays "This app is blocked" — no way to proceed

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

N/A — issue occurs in Claude CoWork via claude.ai web interface, not Claude Code CLI

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_