Overview

TTL stands for time to live. In localstorage-platform, TTL is provided in milliseconds when writing a value.

Why

Some browser state should expire automatically: cached responses, temporary handoff tokens, in-progress flows, and feature-flag snapshots.

How it works

When you pass ttl, metadata receives an expiresAt timestamp. When the value is read after that timestamp, the manager removes the record and returns null.

Usage

const FIVE_MINUTES = 1000 * 60 * 5;

storage.set("feature-flags", flags, {
  group: "cache",
  ttl: FIVE_MINUTES,
});

const flags = storage.get<Record<string, boolean>>("feature-flags");

Best Practices

• Name TTL constants in milliseconds.
• Handle null reads by refetching or reconstructing state.
• Use TTL for cache-like data, not for required source-of-truth data.

Common Mistakes

• Passing seconds instead of milliseconds.
• Expecting background cleanup. Expired records are removed on read.
• Using TTL without a fallback path for expired state.

Related Concepts

• Metadata
• Storage Engine
• StorageManager