Chrome MCP socket path exceeds Unix socket limit on macOS

Bug Description

The Chrome native host fails to create a Unix socket because the generated path exceeds the macOS socket path limit of 104 characters.

Error

[Claude Chrome Native Host] Creating socket listener: /var/folders/lj/2d1lbtpn09dcd3t1tfx7pkt40000gn/T/com.apple.shortcuts.mac-helper/claude-mcp-browser-bridge-kennetkusk

error: Failed to listen at /var/folders/lj/2d1lbtpn09dcd3t1tfx7pkt40000gn/T/com.apple.shortcuts.mac-helper/claude-mcp-browser-bridge-kennetkusk

When tested with Node.js directly:

Failed: listen EINVAL: invalid argument /var/folders/lj/.../claude-mcp-browser-bridge-kennetkusk

Root Cause

The socket path is 116 characters, but macOS Unix sockets have a maximum path length of 104 characters (from sun_path in sockaddr_un).

Path breakdown:

• /var/folders/lj/2d1lbtpn09dcd3t1tfx7pkt40000gn/T/ (52 chars) - macOS TMPDIR
• com.apple.shortcuts.mac-helper/ (31 chars) - subdirectory
• claude-mcp-browser-bridge- (25 chars) - socket prefix
• kennetkusk (10 chars) - username
• Total: 116 characters

Reproduction Steps

1. Install Claude Code 2.1.5
2. Install Claude Chrome extension
3. Configure native messaging host
4. Try to use Chrome MCP tools
5. Connection fails with "Browser extension is not connected"

Verification:

# This succeeds (shorter path):
node -e "require('net').createServer().listen('/tmp/test-socket', () => console.log('ok'))"

# This fails (exact Claude path):
node -e "require('net').createServer().listen('/var/folders/.../claude-mcp-browser-bridge-username', () => console.log('ok'))"
# Error: EINVAL

Environment

• Claude Code version: 2.1.5
• OS: macOS (Darwin 25.2.0, arm64)
• Chrome extension: Claude for Chrome (Beta) v1.0.36
• Bun: 1.3.5

Suggested Fix

Use a shorter socket path, for example:

• /tmp/claude-browser-{short-hash}.sock (~35 chars)
• Or use $HOME/.claude/browser.sock (~40 chars)

This would stay well under the 104 character limit regardless of username length or TMPDIR path.