🍔 FAT Agent — Fix, Audit, Test
A Claude plugin that acts as your post-launch QA engineer.
FAT Agent systematically audits deployed websites for SEO, performance, security, accessibility, and content issues — then walks you through fixing every one.
What It Does
After you deploy a site, say "run FAT agent" and it will:
- Gather context — Asks smart questions about your site, stack, and critical user flows
- Audit — Runs 8 automated check categories against your live URL
- Report — Generates a prioritised punch list (P0 Critical → P3 Nice-to-have)
- Fix — Offers to generate code fixes for every issue found
- Re-test — After you redeploy, verifies the fixes are live
Audit Categories
| Category | Automated? | What It Checks |
|---|
| 🌐 Availability & Response | ✅ | HTTP status, redirects, response headers, caching |
| 🔍 SEO Essentials | ✅ | Title, meta, headings, OG tags, structured data, sitemap, robots.txt |
| ⚡ Performance | ✅ | HTML size, render-blocking scripts, lazy loading, resource hints |
| 🔒 Security Headers | ✅ | HSTS, CSP, X-Frame-Options, Referrer-Policy, Permissions-Policy |
| ♿ Accessibility | Partial | Alt text, labels, landmarks, skip links + targeted user questions |
| 🧪 Functional Checks | 👤 User | Forms, navigation, mobile, 404 page, integrations |
| 📝 Content & Legal | Partial | Placeholder text, privacy policy, copyright year |
| 📊 Analytics & Tracking | ✅ | GA4, GTM, Facebook Pixel, Plausible, Hotjar, Fathom, Umami, Mixpanel, PostHog + 10 more |
Installation
Claude Code Plugin (Recommended)
claude plugins add https://github.com/spruikco/fat-agent-skill
This installs the FAT Agent plugin with the /fat-audit slash command.
Claude Code (Manual)
git clone https://github.com/spruikco/fat-agent-skill ~/.claude/skills/fat-agent
Claude Code reads SKILL.md automatically and activates the skill when it detects trigger phrases.
Then in any conversation:
You: Run FAT agent on https://mysite.com
You: Audit my site
You: I just deployed — is everything working?
You: Post-launch check on https://example.com
You: /fat-audit https://example.com
Claude.ai (Projects)
- Create a new Project in Claude.ai
- Upload
plugins/fat-agent/skills/fat-agent/SKILL.md as a project file — this is the core instruction set Claude follows
- Upload the reference files you want available:
plugins/fat-agent/references/security-headers.mdplugins/fat-agent/references/seo-checklist.mdplugins/fat-agent/references/accessibility-guide.md- Any relevant
plugins/fat-agent/references/platform-fixes/*.md for your hosting platform
- Any relevant
plugins/fat-agent/references/framework-fixes/*.md for your tech stack
- Start a conversation and say "audit my site" or "run FAT agent"
Note: The Python scripts (analyse-html.py, calculate-score.py) are designed for Claude Code, which can execute them directly. Claude.ai performs the same checks conversationally using web_fetch.
What Happens When You Trigger It
- Phase 0 — Context — FAT Agent asks for your live URL, site type, tech stack, and hosting platform
- Phase 1 — Audit — Fetches your URL, runs 9 check categories (SEO, security, accessibility, performance, analytics, content, functional, platform-specific), asks targeted yes/no questions for things that can't be automated
- Phase 2 — Fix — Generates a prioritised punch list (P0 Critical → P3 Low) with specific code/config fixes tailored to your stack and hosting platform
- Phase 3 — Test — After you redeploy with fixes, re-fetches the URL and verifies each issue is resolved
Fix suggestions are loaded on-demand from the references/platform-fixes/ and references/framework-fixes/ directories based on what you told it in Phase 0. A Next.js site on Vercel gets different fix code than a WordPress site on Apache.
Works With Any Hosting Platform
FAT Agent is platform-agnostic. It audits the live URL regardless of where it's hosted:
- Netlify, Vercel, Cloudflare Pages
- AWS (S3, CloudFront, Amplify, EC2)
- DigitalOcean, shared hosting (cPanel, Plesk)
- Self-hosted (Nginx, Apache)
- WordPress hosting (WP Engine, Kinsta, etc.)
- Any platform that serves a URL
Project Structure