Usage
Caching
Multi-layer caching architecture, response headers, and purge policy
Caching Architecture
Assets API uses a multi-layer caching strategy for maximum performance:
Browser ──▶ Edge CDN ──▶ Memory Cache ──▶ Disk Cache ──▶ Transform + Store
1yr 1yr immutable 200 MB / 30min Persistent On-demand
| Layer | TTL | Size | Notes |
|---|---|---|---|
| Browser | 1 year (max-age=31536000, immutable) | — | Use c param for cache busting |
| Edge CDN | Follows Cache-Control | — | Global edge distribution |
| In-memory (originals) | 5 minutes | 100 MB | Hot originals |
| In-memory (processed) | 30 minutes | 200 MB | Hot transformed variants |
| Disk cache (processed) | Permanent | — | Stored in processed-assets container |
Response headers
| Header | Example | Meaning |
|---|---|---|
Cache-Control | public, max-age=31536000, immutable | Cached forever at all layers |
ETag | "a1b2c3..." | Content-based hash for conditional requests |
X-Cache | MEM / DISK / PROC | Where the response was served from |
Content-Type | image/webp | Output format |