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CDN and caching

Filebase operates its own global content delivery network. Every public-bucket request is served through edge locations close to your users — popular objects come back from cache in milliseconds, and origin reads to the underlying object store stay rare even under heavy load.

How it works​

When a client requests a public-bucket object:

  1. The request lands at the nearest edge location.
  2. If the edge has a fresh copy, it returns immediately. The origin is not contacted.
  3. If the edge doesn't have a copy (cache miss), it fetches from the origin, returns to the client, and caches the response for subsequent requests.
  4. Cached objects are evicted on a least-recently-used basis as new content replaces them.

This is transparent to your code. Your application uploads via the S3 API; readers see CDN-accelerated responses without any extra configuration.

What gets cached​

  • Public bucket objects — yes, aggressively.
  • Private bucket objects accessed via the S3 API — no. Authenticated requests bypass the edge cache and hit the origin every time.
  • Pre-signed URL responses — vary; the cache key includes the signature, so distinct pre-signed URLs for the same object are cached separately. For high-traffic distribution prefer a public bucket.

Cache headers​

Filebase respects standard HTTP caching headers on objects you upload:

  • Cache-Control — sets max-age and revalidation behavior. Recommended for static assets: 
    Cache-Control: public, max-age=31536000, immutable
    for hashed filenames, or: 
    Cache-Control: public, max-age=300
    for content that may change.
  • Content-Type — affects content-encoding negotiation at the edge.
  • Content-Encoding — Filebase does not transcode; if you serve gzip or Brotli, set this header at upload time.

Set headers when uploading:

AWS CLI
aws --endpoint https://s3.filebase.io s3 cp index.html s3://my-site/ \
  --content-type "text/html" \
  --cache-control "public, max-age=300"
AWS SDK v3
await s3.send(new PutObjectCommand({
  Bucket: 'my-site',
  Key: 'index.html',
  Body: html,
  ContentType: 'text/html',
  CacheControl: 'public, max-age=300',
}));

Invalidating cached content​

Today, the simplest way to invalidate an object at the edge is to upload a new version under the same key — Filebase invalidates the edge cache when an object is overwritten.

For workflows that absolutely require atomic deploys with cache busting, use content-hashed filenames (assets/app.a3f9d2.js) and reference the hash from your HTML. This is the same pattern most modern build tools (Vite, webpack, esbuild) apply by default.

CORS and the CDN​

CORS preflight responses are cached at the edge per the rules in your bucket's CORS configuration. See configure CORS.

Bandwidth​

Outbound bandwidth from the CDN for S3-compatible public buckets is free of charge on every paid plan. Bandwidth limits on the free tier are described in the pricing page.

What's next​