# Chrome MCP Troubleshooting

Diagnose and fix Claude in Chrome MCP extension connectivity issues.

- Repository: https://github.com/trailofbits/skills (7935 stars)
- Category: AI and agents
- License: CC-BY-SA-4.0
- Last updated: 2026-10-28
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add trailofbits/skills --skill chrome-mcp-troubleshooting -g -a claude-code -y`
Codex: `npx skills add trailofbits/skills --skill chrome-mcp-troubleshooting -g -a codex -y`
Cursor: `npx skills add trailofbits/skills --skill chrome-mcp-troubleshooting -g -a cursor -y`
Gemini CLI: `npx skills add trailofbits/skills --skill chrome-mcp-troubleshooting -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add trailofbits/skills`

## Description

Diagnose and fix Claude in Chrome MCP extension connectivity issues. Use when mcp__claude-in-chrome__* tools fail, return "Browser extension is not connected", or behave erratically.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# 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

The rest: https://github.com/trailofbits/skills/blob/HEAD/plugins/chrome-mcp-troubleshooting/skills/chrome-mcp-troubleshooting/SKILL.md