/debug
Show console errors and failed network requests
$ npx -y skills add mozilla/firefox-devtools-mcp --skill debug --agent claude-codeHow it fires
How this skill gets triggered: by you, by Claude, or both.
- Fires itselfAuto-invocation. Claude auto-loads it when your prompt matches the work.Auto-invocation is when the right skill fires by itself at the right moment, driven by a FLOW.md router and a hook, instead of you invoking it by name. It is the difference between a skill being installed and a skill actually getting used.Read the full definition →
- You can call itInvoke it directly when you want it.
- Slash command
/debug
Context preview
The summary Claude sees to decide when to auto-load this skill.
Show console errors and failed network requests
SKILL.md
debug.SKILL.mddescription: Show console errors and failed network requests argument-hint: [console|network|all]
/firefox-devtools-mcp:debug
Displays debugging information from the current page.
Usage
/firefox-devtools-mcp:debug # Show all (console errors + failed requests) /firefox-devtools-mcp:debug console # Console messages only /firefox-devtools-mcp:debug network # Network requests only
Examples
/firefox-devtools-mcp:debug /firefox-devtools-mcp:debug console /firefox-devtools-mcp:debug network
What Happens
- `console`: Calls `list_console_messages` with `level="error"`
- `network`: Calls `list_network_requests` with `statusMin=400`
- `all` (default): Shows both console errors and failed network requests
Requires Firefox to already be running and on the page you want to debug. If Firefox is not running or is on about:blank, call `navigate_page` first.
Model Context Protocol server for automating Firefox via WebDriver BiDi (through Selenium WebDriver). Works with Claude Code, Claude Desktop, Cursor, Cline and other MCP clients.
Repo: mozilla/firefox-devtools-mcp
Other skills on firefox-devtools-mcp.
- /browser-automation
This skill should be used when the user asks about browser automation, testing web pages, extracting content, filling forms, taking screenshots, or monitoring console/network activity. Activates for E2E testing, form automation, browsing tasks, or debugging web applications.
Open skill - /navigate
Navigate Firefox to a URL and take a DOM snapshot for interaction
Open skill - /screenshot
Take a screenshot of a URL or the current page. Use when the user asks to capture, screenshot, or photograph a web page or URL.
Open skill - /diagnose
Diagnose Firefox DevTools MCP setup issues. Activate when the firefox-devtools-mcp plugin fails to connect, its tools are not available, or the user reports Firefox DevTools not working in Cowork.
Open skill