Edge Cache

The Web Cache API is supported on Deno Deploy. The cache is designed to provide microsecond-level read latency, multi-GB/s write throughput and unbounded storage, with the tradeoff of best-effort consistency and durability.

const cache = await caches.open("my-cache");

Deno.serve(async (req) => {
  const cached = await cache.match(req);
  if (cached) {
    return cached;
  }

  const res = new Response("cached at " + new Date().toISOString());
  await cache.put(req, res.clone());
  return res;
});

Cached data is stored in the same Deno Deploy region that runs your code. Usually your isolate observes read-after-write (RAW) and write-after-write (WAW) consistency within the same region; however, in rare cases recent writes can be lost, out-of-order or temporarily invisible.

Expiration Jump to heading#

By default, cached data is persisted for an indefinite period of time. While we periodically scan and delete inactive objects, an object is usually kept in cache for at least 30 days.

Edge Cache understands standard HTTP response headers Expires and Cache-Control. You can use them to specify an expiration time for every cached object, for example:

Expires: Thu, 22 Aug 2024 01:22:31 GMT

or:

Cache-Control: max-age=86400

Limitations Jump to heading#

• If a response is not constructed from a Uint8Array or string body, the Content-Length header needs to be manually set.
• Deletion is not yet supported.