[BUG] Claude in Chrome extension not connecting - MCP shows connected but extension unresponsive

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 Claude browser extension is installed and the MCP server reports as connected, but Claude Code CLI cannot
communicate with the extension. Every attempt returns "Browser extension is not connected" despite MCP showing a
successful connection.

Environment:

• OS: Windows 10 (Build 22631.6199)
• Claude Code version: 2.1.29
• Chrome version: [YOUR CHROME VERSION - check chrome://version]
• Claude extension version: [CHECK IN chrome://extensions]

Steps to reproduce:

1. Install Claude browser extension from https://claude.ai/chrome
2. Open Claude Code CLI
3. MCP server shows as connected
4. Run /chrome command or attempt any browser automation
5. Connection fails with "Browser extension is not connected"

Key observation:
The MCP server indicates it is connected, but the extension does not respond to commands. This suggests a disconnect
between the MCP layer and the actual browser extension communication.

Extensive troubleshooting already attempted:

• Restarted Chrome multiple times
• Restarted Claude Code CLI multiple times
• Toggled extension off/on
• Verified extension permissions
• Confirmed extension is active and clicked the icon
• Completely reinstalled Chrome
• Completely reinstalled Claude Code CLI
• Checked all ports for conflicts
• Ensured only one instance of Chrome is running
• Verified no duplicate Chrome profiles/processes

Expected behavior:
If MCP shows connected, extension commands should work.

Actual behavior:
MCP connected but extension returns "not connected" on all commands.

What Should Happen?

I should be able to connect to the claude chrome extension from claude code cli

Error Messages/Logs

Steps to Reproduce

As above

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

as above

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_