Claude in Chrome MCP: extension installed + /chrome enabled, but tabs_context_mcp persistently returns 'Browser extension is not connected' on macOS

Summary

The claude-in-chrome MCP tools (e.g. mcp__claude-in-chrome__tabs_context_mcp) consistently return Browser extension is not connected despite the Chrome extension being installed, signed in, and the native messaging host registered. /chrome in-session does not flip the connection. A coexisting Claude desktop app on the same machine appears to interfere — but quitting it (and killing its leftover native-host helper) does not free the extension to bind to Claude Code.

Environment

• macOS 26.5 (build 25F5068a)
• Google Chrome 147.0.7727.138
• Claude Code 2.1.117
• Claude desktop app 1.5354.0 (also installed on the same machine)
• Chrome extension Claude in Chrome, ID fcoeoabgfenejglbffodgkkbkcdhcgfn

Native messaging host registration (both present)

~/Library/Application Support/Google/Chrome/NativeMessagingHosts/com.anthropic.claude_browser_extension.json → /Applications/Claude.app/Contents/Helpers/chrome-native-host (consumer Claude desktop)

~/Library/Application Support/Google/Chrome/NativeMessagingHosts/com.anthropic.claude_code_browser_extension.json → ~/.claude/chrome/chrome-native-host (Claude Code CLI; wrapper script execs claude.exe --chrome-native-host)

Both list chrome-extension://fcoeoabgfenejglbffodgkkbkcdhcgfn/ in allowed_origins.

Reproduction steps

1. Install the Claude in Chrome extension, sign in with the same Anthropic account as Claude Code.
2. Open a Claude Code session in a terminal.
3. Run /chrome in the session to enable Chrome MCP tools.
4. Call mcp__claude-in-chrome__tabs_context_mcp (or any other claude-in-chrome tool).

Expected: tab context is returned, or a clear pairing UI appears.

Actual: tool returns Browser extension is not connected. Please ensure the Claude browser extension is installed and running…

What we tried (none flipped the connection)

• Restarted Chrome (full Cmd+Q, not just close window) — multiple times.
• Verified extension shows in chrome://extensions/ and is enabled.
• Verified the user is signed in to the extension (extension options page renders with the correct account).
• Ran /chrome in-session.
• Quit the Claude desktop app entirely.
• Killed the leftover /Applications/Claude.app/Contents/Helpers/chrome-native-host helper process that survived the desktop-app quit.
• Reloaded the extension from chrome://extensions/.
• Polled tabs_context_mcp repeatedly between each step — error is identical every time.

After all the above, no chrome-native-host process is running for either host (ps aux | grep chrome-native-host returns empty), suggesting the extension is not initiating any native-messaging connection at all.

Suspected cause

When both Claude desktop and Claude Code are installed, the extension may default to (or get stuck on) the com.anthropic.claude_browser_extension host name and never attempt com.anthropic.claude_code_browser_extension. There does not appear to be a user-facing toggle in the extension UI (Permissions / Shortcuts / Options tabs) for choosing which Anthropic host to pair with.

Asks

1. Is there a documented way to force the extension to pair with Claude Code specifically when both products are installed?
2. If not, please add a host selector to the extension settings, or have /chrome (or claude --chrome) actively initiate the handshake instead of relying on the extension to discover the host.
3. Better in-product diagnostics for the "not connected" state (extension service-worker logs, last-attempted host name, etc.) would help users self-diagnose.