[BUG] claude --chrome on macOS: native host launches and socket exists, but terminal claude never connects to bridge socket

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?

mcp__claude-in-chrome__tabs_context_mcp (and all other mcp__claude-in-chrome__* tools) always return "Browser extension is not connected. Please ensure the Claude browser extension is installed and running..." — even though every layer of the integration is verifiably alive.

Decisive evidence: lsof -p <terminal-claude-pid> shows no open socket and no connection attempt to the bridge socket, even with the --chrome flag and a healthy native host running. So the terminal claude --chrome process never even tries to attach to the bridge socket created by the native host.

This appears to be the same root cause as #41879 (stalled ~5 weeks with no engineer engagement). Filing fresh on the latest version with cleaner diagnostic data.

What Should Happen?

claude --chrome should connect to the running chrome-native-host bridge socket on startup, and mcp__claude-in-chrome__* tools should return real data (tab context, navigate, etc.) against the running Chrome instance.

Error Messages/Logs

$ # Native host is running and socket exists
$ pgrep -fl chrome-native-host
10544 .../claude.exe --chrome-native-host

$ ls /tmp/claude-mcp-browser-bridge-<user>/
10544.sock

$ lsof -p 10544 | grep sock
claude.ex 10544 <user> 4u unix ... /tmp/claude-mcp-browser-bridge-<user>/10544.sock

$ # But terminal claude (PID 9597, started with --chrome) never opens it
$ lsof -p 9597 | grep -E "sock |browser-bridge"
(no output)

$ # MCP tool result
mcp__claude-in-chrome__tabs_context_mcp
→ "Browser extension is not connected. Please ensure the Claude browser extension is installed and running (https://claude.ai/chrome), and that you are logged into claude.ai with the same account as Claude Code..."

$ # /chrome slash command produces no visible output
/chrome → (no content)

Steps to Reproduce

1. Install Claude in Chrome extension (ID fcoeoabgfenejglbffodgkkbkcdhcgfn); sign into claude.ai with the same account as Claude Code.
2. Verify native messaging host config at ~/Library/Application Support/Google/Chrome/NativeMessagingHosts/com.anthropic.claude_code_browser_extension.json points to ~/.claude/chrome/chrome-native-host and allowed_origins contains the extension ID.
3. Start claude --chrome from terminal (also tested claude --continue --chrome; same result).
4. Click the extension icon in Chrome → pgrep -fl chrome-native-host shows the spawned process; /tmp/claude-mcp-browser-bridge-<user>/<pid>.sock exists; lsof confirms the native host has it open.
5. In the claude session, call any mcp__claude-in-chrome__* tool → always returns "not connected".
6. lsof -p <terminal-claude-pid> confirms terminal claude has not opened the socket.

Things tried that did not fix it:

• Reinstalling the Chrome extension
• Removing ~/.claude/chrome/ and letting claude regenerate the host binary
• Full Chrome quit + restart, multiple cycles
• claude --chrome without --continue
• Disabling the orphan Claude Desktop host file com.anthropic.claude_browser_extension.json (Claude Desktop is not installed on this machine)

Claude Model

Not sure / Multiple models

Is this a regression?

Not sure

Last Working Version

_No response_

Claude Code Version

2.1.133

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

fish (Ghostty terminal)

Additional Information

• Verified emailAddress in ~/.claude.json matches the claude.ai account signed into the extension.
• Native messaging host config:

``json
{
"name": "com.anthropic.claude_code_browser_extension",
"description": "Claude Code Browser Extension Native Host",
"path": "/Users/<user>/.claude/chrome/chrome-native-host",
"type": "stdio",
"allowed_origins": [
"chrome-extension://fcoeoabgfenejglbffodgkkbkcdhcgfn/"
]
}
``

• Chrome 147.0.7727.138 (stable), macOS Darwin 25.2.0 (arm64).
• Install method: volta (global npm package).