[BUG] MCP tools fail with "Browser extension is not connected" despite /chrome showing Connected

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?

Environment:

• Claude Code version: (run claude --version)
• Chrome Extension: Claude in Chrome (Beta) v1.0.40
• OS: Windows 11
• Extension ID: fcoeoabgfenejglbffodgkkbkcdhcgfn

Steps to Reproduce:

1. Install Claude in Chrome extension from Chrome Web Store
2. Run claude --chrome
3. Run /chrome command → Shows "Connected" status ✓
4. Run /mcp command → Lists claude-in-chrome as available ✓
5. Attempt any MCP tool (e.g., mcp__claude-in-chrome__tabs_context_mcp)

Expected: Tool executes and returns tab context

Actual: Error: "Browser extension is not connected"

Observations:

• Connection state reports as connected
• MCP server is listed
• Reconnect option says "Already connected"
• But actual tool execution fails
• Suggests connection state isn't propagating to tool execution layer

Workarounds Attempted:

• Complete restart (close Chrome, close Claude Code, reopen in order)
• /chrome → Reconnect extension
• Verified extension is enabled in chrome://extensions/

What Should Happen?

Environment:

• Claude Code version: (run claude --version)
• Chrome Extension: Claude in Chrome (Beta) v1.0.40
• OS: Windows 11
• Extension ID: fcoeoabgfenejglbffodgkkbkcdhcgfn

Steps to Reproduce:

1. Install Claude in Chrome extension from Chrome Web Store
2. Run claude --chrome
3. Run /chrome command → Shows "Connected" status ✓
4. Run /mcp command → Lists claude-in-chrome as available ✓
5. Attempt any MCP tool (e.g., mcp__claude-in-chrome__tabs_context_mcp)

Expected: Tool executes and returns tab context

Actual: Error: "Browser extension is not connected"

Observations:

• Connection state reports as connected
• MCP server is listed
• Reconnect option says "Already connected"
• But actual tool execution fails
• Suggests connection state isn't propagating to tool execution layer

Workarounds Attempted:

• Complete restart (close Chrome, close Claude Code, reopen in order)
• /chrome → Reconnect extension
• Verified extension is enabled in chrome://extensions/

Error Messages/Logs

Environment:
  - Claude Code version: (run claude --version)
  - Chrome Extension: Claude in Chrome (Beta) v1.0.40
  - OS: Windows 11
  - Extension ID: fcoeoabgfenejglbffodgkkbkcdhcgfn

  Steps to Reproduce:
  1. Install Claude in Chrome extension from Chrome Web Store
  2. Run claude --chrome
  3. Run /chrome command → Shows "Connected" status ✓
  4. Run /mcp command → Lists claude-in-chrome as available ✓
  5. Attempt any MCP tool (e.g., mcp__claude-in-chrome__tabs_context_mcp)

  Expected: Tool executes and returns tab context

  Actual: Error: "Browser extension is not connected"

  Observations:
  - Connection state reports as connected
  - MCP server is listed
  - Reconnect option says "Already connected"
  - But actual tool execution fails
  - Suggests connection state isn't propagating to tool execution layer

  Workarounds Attempted:
  - Complete restart (close Chrome, close Claude Code, reopen in order)
  - /chrome → Reconnect extension
  - Verified extension is enabled in chrome://extensions/

Steps to Reproduce

Environment:

• Claude Code version: (run claude --version)
• Chrome Extension: Claude in Chrome (Beta) v1.0.40
• OS: Windows 11
• Extension ID: fcoeoabgfenejglbffodgkkbkcdhcgfn

Steps to Reproduce:

1. Install Claude in Chrome extension from Chrome Web Store
2. Run claude --chrome
3. Run /chrome command → Shows "Connected" status ✓
4. Run /mcp command → Lists claude-in-chrome as available ✓
5. Attempt any MCP tool (e.g., mcp__claude-in-chrome__tabs_context_mcp)

Expected: Tool executes and returns tab context

Actual: Error: "Browser extension is not connected"

Observations:

• Connection state reports as connected
• MCP server is listed
• Reconnect option says "Already connected"
• But actual tool execution fails
• Suggests connection state isn't propagating to tool execution layer

Workarounds Attempted:

• Complete restart (close Chrome, close Claude Code, reopen in order)
• /chrome → Reconnect extension
• Verified extension is enabled in chrome://extensions/

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.19 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_