Bug Report: Chrome Extension MCP Connection Failing

Summary

The Claude in Chrome browser extension is installed and visible in the sidepanel, but the MCP connection to Claude Code CLI never establishes.

Environment

• OS: Windows (MINGW64_NT-10.0-26200)
• Claude Code Version: Check with claude --version
• Chrome Version: Check in chrome://settings/help
• Extension: Claude in Chrome (from https://claude.ai/chrome)

Steps to Reproduce

1. Install Claude in Chrome extension
2. Open Chrome and verify extension is active (sidepanel opens)
3. Open Claude Code CLI in terminal
4. Attempt to use any mcp__claude-in-chrome__* tool
5. Connection fails with message: "Browser extension is not connected"

Expected Behavior

The MCP connection should establish and allow Claude Code to interact with browser tabs.

Actual Behavior

• Extension shows as installed in Chrome
• Extension sidepanel opens and appears functional
• Claude Code settings show:
• claudeInChromeDefaultEnabled: true
• cachedChromeExtensionInstalled: true
• hasCompletedClaudeInChromeOnboarding: true
• But tabs_context_mcp always returns "Browser extension is not connected"

Troubleshooting Attempted

• [x] Restarted Chrome
• [x] Refreshed/reloaded extension
• [x] Restarted Claude Code CLI
• [x] Verified extension permissions granted
• [x] Extension sidepanel opens successfully

Screenshots

• Extension sidepanel is visible and appears connected
• See attached screenshot showing extension open in Chrome

Additional Context

The MCP tools are available in Claude Code (they appear in the tool list), suggesting the MCP server configuration exists, but the WebSocket/connection between Claude Code and the Chrome extension never establishes.

<img width="442" height="65" alt="Image" src="https://github.com/user-attachments/assets/295c3f29-b168-4ca7-a488-3415bd260b56" />

<img width="212" height="464" alt="Image" src="https://github.com/user-attachments/assets/0542dc30-434b-4cbd-b4ce-ceafb3436032" />