Expiration

Set a TTL or an absolute expiration time and understand lazy cleanup.

import { createStorage } from 'ultrastorage';

const storage = createStorage();

Store data temporarily. Like Snapchat, but for your storage keys.

Note: Expired data behaves like a missing key. getItem() removes expired entries on read, while has(), key(), and length simply ignore them. Use clearExpired() to proactively sweep them.

// Expires in 60 seconds
storage.setItem('token', 'abc123', { ttl: 60_000 });

// Expires at a specific date
storage.setItem('session', { id: 1 }, { expiresAt: new Date('2025-12-31') });

// Expired items return null
storage.getItem('token'); // null (after 60s)

Cleanup and notifications

Passing an expiration timestamp does not schedule a timer or notify subscribers. Cleanup through getItem() or clearExpired() emits an expire event. Bookkeeping reads (has(), key(), and length) exclude expired entries without deleting them.

ttl and expiresAt cannot be used together. Both accept millisecond units; expiresAt also accepts a Date. An entry expires when the current time is strictly greater than its expiry timestamp. A new write without expiration options removes any previous expiration.

For React rendering, see snapshots and expiration.