[BUG] Chrome MCP shows "connected" but tool calls fail with "not currently 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?

The Chrome MCP works correctly when accessed from the Claude Mac app (claude.ai desktop), but fails when accessed from Claude Code CLI.

What works:

• Claude Mac app can successfully connect to and use the Chrome extension MCP
• - Tool calls like Claude in Chrome[tabs_context] work perfectly from the Mac app
• - - The extension is clearly functional

What doesn't work:

• Claude Code CLI with claude --chrome flag
• - /mcp command shows claude-in-chrome ✓ connected (green checkmark)
• - - But when Claude actually tries to use Chrome tools, it fails with "The Chrome extension is not currently connected"

This suggests the MCP server registration works, but the actual communication channel between Claude Code CLI and the extension isn't being established - even though it works fine from the Claude Mac app.

Steps to reproduce:

1. Install Claude Chrome extension v1.0.40
2. 2. Confirm it works: Use Claude Mac app to connect to Chrome MCP (this succeeds)
3. 3. Run claude --chrome in terminal
4. 4. Run /mcp - shows claude-in-chrome ✓ connected
5. 5. Ask Claude to test the Chrome connection
6. 6. Tool call fails with "not currently connected"

Environment:

• Claude Code: 2.1.19
• - Claude Chrome Extension: 1.0.40 (Beta)
• - - Chrome: 144.0.7559.97 (Official Build) (arm64)
• - - - macOS: Tahoe 26.3 (Build 25D5101c)
• - - - - Hardware: MacBook Pro 14" M4 Max, 64GB RAM

Troubleshooting attempted:

• Restarted Chrome completely
• - Disabled/re-enabled extension
• - - Used /chrome command and clicked reconnect
• - - - Checked chrome://extensions - no errors in service worker
• - - - - Reinstalled extension
• - - - - - Verified extension works via Claude Mac app

What Should Happen?

When /mcp shows claude-in-chrome as "connected", the Chrome tools should actually work. Tool calls like Claude in Chrome[tabs_context] should successfully communicate with the browser extension and return tab information.

Either:

1. The connection should work when it reports "connected", OR
2. 2. The /mcp status should accurately reflect the actual connection state (show "disconnected" or "error" if the communication channel isn't functional)

Error Messages/Logs

Steps to Reproduce

1. Install Claude Chrome extension v1.0.40 from chrome://extensions
2. 2. Open Claude Mac app (claude.ai desktop) and verify Chrome MCP works (it does)
3. 3. Open terminal and run claude --chrome
4. 4. Run /mcp command - observe claude-in-chrome ✓ connected with green checkmark
5. 5. Ask Claude to test the Chrome connection (e.g., "take a screenshot of this tab")
6. 6. Observe tool call fails with "The Chrome extension is not currently connected"

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.19 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_