astro-website/openspec/changes/archive/2026-02-10-service-workers/tasks.md

1. Setup

• 1.1 Add sw.js to site root output (place in site/public/sw.js)
• 1.2 Add service worker registration to the base layout (register only in production)

2. Pre-cache Site Shell

• 2.1 Implement versioned cache names and an explicit cache version constant
• 2.2 Implement install handler to pre-cache critical shell assets
• 2.3 Implement activate handler to delete old version caches

3. Runtime Caching

• 3.1 Implement network-first strategy for navigation/document requests with cache fallback
• 3.2 Implement cache-first strategy for images/media with network fallback
• 3.3 Add a bounded eviction policy for media cache size

4. Verification

• 4.1 Verify service worker registers in production build and does not register in dev
• 4.2 Verify repeat navigation and asset loads hit cache (Chrome DevTools Application tab)
• 4.3 Verify a new deploy triggers cache version update and old caches are removed