Offline grace

import { browserStorage, withOfflineGrace } from "@sweberdev/integral";
import { createPolarClient } from "@sweberdev/integral/polar";

const polar = createPolarClient({ organizationId: ORG_ID });

const checkLicense = withOfflineGrace(() => polar.validate(key), {
  key: `polar:${key}`,
  storage: browserStorage(),
  ttl: 60 * 60 * 1000, // re-use a good answer for an hour
  grace: 7 * 24 * 60 * 60 * 1000, // tolerate a week without connection
});

const outcome = await checkLicense();
outcome.valid; // boolean
outcome.source; // "network" | "cache" | "grace"

How it decides:

1. A valid cached answer younger than ttl is returned without a request.
2. Otherwise the check runs. Its answer, valid or invalid, is stored.
3. If the check throws (network error, server error), a valid cached answer younger than grace is returned with source: "grace". Otherwise the result is { valid: false, reason: "unreachable" }.

Invalid answers are never served from the cache, so a customer who just bought a license is not stuck with an old "invalid".

Storage

withOfflineGrace takes any object with get, set and delete (sync or async). Included:

• memoryStorage(): for servers and tests.
• browserStorage(prefix?): localStorage, with an in-memory fallback in private windows or when storage is blocked.

For Electron or a CLI, store a small JSON file in the user's config directory.