astro

Astro Web Framework

Overview

Astro is a web framework designed for content-rich websites — blogs, docs, portfolios, marketing sites, and e-commerce. Its core innovation is the Islands Architecture: by default, Astro ships zero JavaScript to the browser. Interactive components are selectively hydrated as isolated "islands." Astro supports React, Vue, Svelte, Solid, and other UI frameworks simultaneously in the same project, letting you pick the right tool per component.

When to Use This Skill

• Use when building a blog, documentation site, marketing page, or portfolio
• Use when performance and Core Web Vitals are the top priority
• Use when the project is content-heavy with Markdown or MDX files
• Use when you want SSG (static) output with optional SSR for dynamic routes
• Use when the user asks about .astro files, Astro.props, content collections, or client: directives

How It Works

Step 1: Project Setup

npm create astro@latest my-site
cd my-site
npm install
npm run dev

Add integrations as needed:

npx astro add tailwind        # Tailwind CSS
npx astro add react           # React component support
npx astro add mdx             # MDX support
npx astro add sitemap         # Auto sitemap.xml
npx astro add vercel          # Vercel SSR adapter

Project structure:

src/
  pages/          ← File-based routing (.astro, .md, .mdx)
  layouts/        ← Reusable page shells
  components/     ← UI components (.astro, .tsx, .vue, etc.)
  content/        ← Type-safe content collections (Markdown/MDX)
  styles/         ← Global CSS
public/           ← Static assets (copied as-is)
astro.config.mjs  ← Framework config

Step 2: Astro Component Syntax

.astro files have a code fence at the top (server-only) and a template below:

---
// src/components/Card.astro
// This block runs on the server ONLY — never in the browser
interface Props {
  title: string;
  href: string;
  description: string;
}

const { title, href, description } = Astro.props;
---

<article class="card">
  <h2><a href={href}>{title}</a></h2>
  <p>{description}</p>
</article>

<style>
  /* Scoped to this component automatically */
  .card { border: 1px solid #eee; padding: 1rem; }
</style>