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Debug Firefox-only browser issues with DevTools MCP before shipping web changes

Skill Detail

Debug Firefox-only browser issues with DevTools MCP before shipping web changes

<p>Use Firefox DevTools MCP when an agent needs to inspect pages, trace network and console activity, capture screenshots, and automate reproduction steps in Firefox instead of relying on Chrome-first tooling.</p>

Browser AutomationMCP
Browser Automation MCP Security Reviewed
⭐ 107 GitHub stars ⬇ 3k/wk npm
INSTALL WITH ANY AGENT
npx skills add agentskillexchange/skills --skill debug-firefox-only-browser-issues-with-devtools-mcp-before-shipping-web-changes Copy
Works best when you want a reusable capability, not another fragile one-off prompt.
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At a glance
Tools required
Node.js 20.19+; a local Firefox 100+ installation; an MCP-compatible client such as Claude Code, Claude Desktop, Cursor, or Cline.
Install & setup
<p>Use <code>npx firefox-devtools-mcp@latest</code> for the recommended install path, or add it directly to your MCP client config. For Claude Code, run <code>claude mcp add firefox-devtools npx firefox-devtools-mcp@latest</code>. Optional flags like <code>–headless</code>, <code>–viewport</code>, <code>–start-url</code>, and <code>–connect-existing</code> let you tune the Firefox session for debugging or attach to a real browser profile.</p>
Author
Mozilla
Publisher
Company
Last updated
Apr 13, 2026
Quick brief

This skill is for browser debugging work that specifically needs Firefox. An agent can launch or attach to Firefox, inspect pages, read console and network activity, take snapshots and screenshots, and reproduce UI issues through a DevTools-oriented MCP surface. That makes it a practical fit for web bugs that only show up in Firefox, extension debugging, standards-compliance checks, and cross-browser verification before a change ships.

How it works

What this skill actually does

The scope boundary is tight: this is not a generic browser platform card or a catch-all automation framework entry. The job is to investigate and reproduce Firefox browser behavior through an MCP-compatible debugging workflow. Invoke it when the missing piece is Firefox-aware inspection and reproduction, not when you just need a general-purpose browser SDK or a Chrome-based debugging stack.