Claude in Chrome MCP Troubleshooting

Use this skill when Claude in Chrome MCP tools fail to connect or work unreliably.

When to Use

• mcp__claude-in-chrome__* tools fail with "Browser extension is not connected"
• Browser automation works erratically or times out
• After updating Claude Code or Claude.app
• When switching between Claude Code CLI and Claude.app (Cowork)
• Native host process is running but MCP tools still fail

When NOT to Use

• Linux or Windows users - This skill covers macOS-specific paths and tools (~/Library/Application Support/, osascript)
• General Chrome automation issues unrelated to the Claude extension
• Claude.app desktop issues (not browser-related)
• Network connectivity problems
• Chrome extension installation issues (use Chrome Web Store support)

The Claude.app vs Claude Code Conflict (Primary Issue)

Background: When Claude.app added Cowork support (browser automation from the desktop app), it introduced a competing native messaging host that conflicts with Claude Code CLI.

Two Native Hosts, Two Socket Formats

Component	Native Host Binary	Socket Location
Claude.app (Cowork)	/Applications/Claude.app/Contents/Helpers/chrome-native-host	/tmp/claude-mcp-browser-bridge-$USER/<PID>.sock
Claude Code CLI	~/.local/share/claude/versions/<version> --chrome-native-host	$TMPDIR/claude-mcp-browser-bridge-$USER (single file)

Why They Conflict

1. Both register native messaging configs in Chrome:
   • com.anthropic.claude_browser_extension.json → Claude.app helper
   • com.anthropic.claude_code_browser_extension.json → Claude Code wrapper