Astro implementation checklist

Verify that all collections in src/content/config.ts have a defined schema and that 'npm run build' passes without validation errors.

Ensure no duplicate slugs exist across content collections to prevent build-time routing conflicts.

Audit all .md and .mdx files to ensure frontmatter fields match the required Zod schema types exactly, specifically for dates and booleans.

Use the reference() function in Zod schemas for related content (e.g., authors or categories) to ensure referential integrity.

Confirm that build scripts or collection queries explicitly filter out items where 'draft: true' is present in the frontmatter.

Review all components for 'client:load', 'client:idle', or 'client:visible' and remove directives from components that do not require interactivity.

Ensure no server-side only data (like Node.js FS modules) is passed to hydrated client components to avoid bundling errors.

Verify that only one framework (e.g., React or Svelte) is used per page unless strictly necessary to minimize JS payload.

Confirm that 'client:only' is only used for components that rely on browser-specific APIs and that a fallback loading state is provided.

Validate that shared state between islands is handled via Nano Stores or custom events rather than a heavy global provider if possible.

Replace all standard <img> tags with the <Image /> component from 'astro:assets' for automatic WebP conversion and resizing.

Configure 'image.remotePatterns' in astro.config.mjs to authorize external domains used for dynamic images or pSEO content.

Apply 'loading="eager"' and 'fetchpriority="high"' to images appearing in the initial viewport to improve Largest Contentful Paint.

Define width and height attributes for all images to prevent Layout Shift (CLS) during page load.

Pass SVGs through an optimizer like SVGO or use a dedicated Astro icon integration to remove unnecessary metadata.

Define the 'site' property in astro.config.mjs with the final production URL to enable correct absolute URL generation for sitemaps.

Install and configure '@astrojs/sitemap' and verify that the sitemap.xml is generated in the /dist folder after build.

Ensure every page includes a <link rel="canonical"> tag generated using Astro.url to prevent duplicate content issues.

Verify that dynamic meta tags (title, description, og:image) are correctly populated from content collection frontmatter.

Add a robots.txt file to the public/ directory that correctly points to the sitemap and defines crawl rules.

Install the correct SSR adapter (e.g., @astrojs/cloudflare, @astrojs/vercel) if using Hybrid or SSR mode.

Define all production secrets in the hosting provider's dashboard and verify they are accessed via import.meta.env.

Create a src/pages/404.astro file to ensure custom branding for broken links and verify it renders correctly in the build output.

Confirm that the CI/CD pipeline is configured to cache the .astro directory to speed up subsequent builds.

Configure _headers or _redirects files in the public/ folder if required by your specific hosting provider (e.g., Cloudflare Pages).