henkisdabro

devtools

This skill helps launch and configure the Chrome DevTools MCP server, giving Claude visual access to a live browser for debugging and automation. Use when the user asks to set up browser debugging, launch Chrome with DevTools, configure chrome-devtools-mcp, see what my app looks like, take screenshots of my web application, check the browser console, debug console errors, inspect network requests, analyse API responses, measure Core Web Vitals or page performance, run a Lighthouse audit, test button clicks or form submissions, automate browser interactions, fill out forms programmatically, simulate user actions, emulate mobile devices or slow networks, capture DOM snapshots, execute JavaScript in the browser, or troubleshoot Chrome DevTools MCP connection issues. Supports Windows, Linux, and WSL2 environments.

henkisdabro 64 9 Updated 3mo ago

Resources

2
GitHub

Install

npx skillscat add henkisdabro/wookstar-claude-plugins/devtools

Install via the SkillsCat registry.

SKILL.md

Chrome DevTools MCP

GitHub Repository: https://github.com/ChromeDevTools/chrome-devtools-mcp

Without browser access, Claude is "coding blindfolded" - making changes without seeing results. The Chrome DevTools MCP server provides 26 specialised tools across these categories:

Category Capabilities
Visual Inspection Take screenshots, capture DOM snapshots, see rendered output
Console & Logging Read console messages, catch JavaScript errors, debug issues
Network Analysis Inspect API requests/responses, analyse headers, debug fetch calls
Performance Record traces, measure Core Web Vitals (LCP, CLS, TBT), identify bottlenecks
User Simulation Click elements, fill forms, drag-and-drop, handle dialogs
Device Emulation Simulate mobile viewports, throttle CPU/network, test responsive design

Quick Start Workflow

Execute these steps in order:

Step 1: Detect Environment

bash scripts/detect_environment.sh

Returns one of: windows, linux, or wsl2

Step 2: Verify Chrome Installation

bash scripts/check_chrome.sh <environment>

Outputs status:installed or status:not_installed. If not installed, see references/chrome-installation.md for installation options.

IMPORTANT: Do not proceed until Chrome is installed and verified.

Step 3: Check MCP Server Status

claude mcp list | grep -i chrome

If not installed:

claude mcp add chrome-devtools -- npx chrome-devtools-mcp@latest --browserUrl http://127.0.0.1:9222

For advanced configuration options and alternative connection methods, see references/mcp-configuration.md.

Step 4: Detect Running Dev Server

bash scripts/detect_dev_server.sh

Checks ports 5173, 5174, 5175, 3000, 3001, 8080, and 8000. If no dev server is running and one is needed, offer to start it.

Step 5: Launch Chrome with Debugging

bash scripts/launch_chrome.sh <environment> <url> [headed]
  • <environment>: windows, linux, or wsl2
  • <url>: Target URL (e.g., http://localhost:5173)
  • [headed]: Optional - pass headed for visible browser, omit for headless (default)

Step 6: Verify Connection

curl -s http://127.0.0.1:9222/json/version

Once connected, test with the mcp__chrome-devtools__list_pages tool.

Quick Troubleshooting

Issue Solution
"Target closed" error Close all Chrome instances, restart with debugging
Module not found Clear npm cache: rm -rf ~/.npm/_npx && npm cache clean --force
Connection refused Ensure Chrome launched with --remote-debugging-port=9222
Port already in use Kill existing Chrome or use different port
Chrome won't start in sandbox Use --browserUrl to connect to manually-started Chrome
WebDriver sign-in blocked Use --autoConnect to connect to your normal browser session

For detailed troubleshooting steps, see references/troubleshooting.md.

References