> perf-astro
Astro-specific performance optimizations for 95+ Lighthouse scores. Covers critical CSS inlining, compression, font loading, and LCP optimization. Use when optimizing Astro site performance, improving Astro Lighthouse scores, or configuring astro-critters. Do NOT use for non-Astro sites (use perf-web-optimization or core-web-vitals) or running Lighthouse audits (use perf-lighthouse).
curl "https://skillshub.wtf/tech-leads-club/agent-skills/perf-astro?format=md"Astro Performance Playbook
Astro-specific optimizations for 95+ Lighthouse scores.
Quick Setup
npm install astro-critters @playform/compress
// astro.config.mjs
import { defineConfig } from 'astro/config'
import critters from 'astro-critters'
import compress from '@playform/compress'
export default defineConfig({
integrations: [
critters(),
compress({
CSS: true,
HTML: true,
JavaScript: true,
Image: false,
SVG: false,
}),
],
})
Integrations
astro-critters
Automatically extracts and inlines critical CSS. No configuration needed.
What it does:
- Scans rendered HTML for above-the-fold elements
- Inlines only the CSS those elements need
- Lazy-loads the rest
Build output shows what it inlined:
Inlined 40.70 kB (80% of original 50.50 kB) of _astro/index.xxx.css.
@playform/compress
Minifies HTML, CSS, and JavaScript in the final build.
Options:
compress({
CSS: true, // Minify CSS
HTML: true, // Minify HTML
JavaScript: true, // Minify JS
Image: false, // Skip if using external image optimization
SVG: false, // Skip if SVGs are already optimized
})
Layout Pattern
Structure your Layout.astro for performance:
---
import '../styles/global.css'
---
<!doctype html>
<html lang="pt-BR">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<!-- Font fallback (prevents FOIT) -->
<style>
@font-face {
font-family: 'Inter';
font-display: swap;
src: local('Inter');
}
</style>
<!-- Non-blocking Google Fonts -->
<link rel="preconnect" href="https://fonts.googleapis.com">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link
rel="stylesheet"
href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700&display=swap"
media="print"
onload="this.media='all'"
/>
<noscript>
<link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700&display=swap">
</noscript>
<!-- Preload LCP images -->
<link rel="preload" as="image" href="/hero.png" fetchpriority="high">
<title>{title}</title>
<!-- Defer third-party scripts -->
<script>
let loaded = false;
function loadAnalytics() {
if (loaded) return;
loaded = true;
// Load GTM, analytics, etc.
}
['scroll', 'click', 'touchstart'].forEach(e => {
document.addEventListener(e, loadAnalytics, { once: true, passive: true });
});
setTimeout(loadAnalytics, 5000);
</script>
</head>
<body>
<slot />
</body>
</html>
Measuring
npx lighthouse https://your-site.com --preset=perf --form-factor=mobile
See also:
- perf-lighthouse - Running audits, reading reports, setting budgets
- perf-web-optimization - Core Web Vitals, bundle size, caching strategies
Checklist
-
astro-crittersinstalled and configured -
@playform/compressinstalled and configured - Google Fonts use
media="print" onloadpattern - Third-party scripts deferred to user interaction
- LCP images preloaded in
<head>
> related_skills --same-repo
> gh-fix-ci
Use when a user asks to debug or fix failing GitHub PR checks that run in GitHub Actions. Uses `gh` to inspect checks and logs, summarize failure context, draft a fix plan, and implement only after explicit approval. Treats external providers (for example Buildkite) as out of scope and reports only the details URL. Do NOT use for addressing PR review comments (use gh-address-comments) or general CI outside GitHub Actions.
> security-threat-model
Repository-grounded threat modeling that enumerates trust boundaries, assets, attacker capabilities, abuse paths, and mitigations, and writes a concise Markdown threat model. Use when the user asks to threat model a codebase or path, enumerate threats or abuse paths, or perform AppSec threat modeling. Do NOT use for general architecture summaries, code review, security best practices (use security-best-practices), or non-security design work.
> security-ownership-map
Analyze git repositories to build a security ownership topology (people-to-file), compute bus factor and sensitive-code ownership, and export CSV/JSON for graph databases and visualization. Use when the user explicitly wants a security-oriented ownership or bus-factor analysis grounded in git history (for example: orphaned sensitive code, security maintainers, CODEOWNERS reality checks for risk, sensitive hotspots, or ownership clusters). Do NOT use for general maintainer lists, non-security own
> security-best-practices
Perform language and framework specific security best-practice reviews and suggest improvements. Use when the user explicitly requests security best practices guidance, a security review or report, or secure-by-default coding help. Supports Python, JavaScript/TypeScript, and Go. Do NOT use for general code review, debugging, threat modeling (use security-threat-model), or non-security tasks.