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Key Expiration (TTL for keys)

Deno KV is currently in beta

Deno KV and related cloud primitive APIs like queues and cron are currently experimental and subject to change. While we do our best to ensure data durability, data loss is possible, especially around Deno updates.

Deno programs that use KV require the --unstable flag when launching the program, as shown below:

deno run -A --unstable my_kv_code.ts

Since version 1.36.2, Deno KV supports key expiration, allowing developers to control time to live (TTL) for keys in a KV database. This allows an expiration timestamp to be associated with a key, after which the key will be automatically deleted from the database:

const kv = await Deno.openKv();

// `expireIn` is the number of milliseconds after which the key will expire.
function addSession(session: Session, expireIn: number) {
  await kv.set(["sessions", session.id], session, { expireIn });
}

Key expiration is supported on both Deno CLI and Deno Deploy.

Atomic expiration of multiple keys​

If multiple keys are set in the same atomic operation and have the same expireIn value, the expiration of those keys will be atomic. For example:

const kv = await Deno.openKv();

function addUnverifiedUser(
  user: User,
  verificationToken: string,
  expireIn: number,
) {
  await kv.atomic()
    .set(["users", user.id], user, { expireIn })
    .set(["verificationTokens", verificationToken], user.id, { expireIn })
    .commit();
}

Caveats​

The expire timestamp specifies the earliest time after which the key can be deleted from the database. An implementation is allowed to expire a key at any time after the specified timestamp, but not before. If you need to strictly enforce an expiration time (e.g. for security purposes), please also add it as a field of your value and do a check after retrieving the value from the database.