TypeScript SDK

The core SDK uses the platform fetch API and has no runtime dependencies. Start from a source checkout; package publication is not assumed here.

Use the repository workspace

From the repo root:

cd sdk-js
npm ci

Save the example below as sdk-js/example.ts, and run it with node --conditions=source example.ts. Start the demo server first.

import { readFileSync } from 'node:fs';
import { Catalog, createClient, RemoteProvider } from '@openentitlement/core';

const catalog = Catalog.fromJSON(JSON.parse(
  readFileSync(new URL('../spec/assets/catalog.json', import.meta.url), 'utf8')
));
const client = createClient({
  catalog,
  provider: new RemoteProvider({
    baseUrl: 'http://localhost:8787',
    token: process.env.OE_EVAL_TOKEN,
    timeoutMs: 5000,
  }),
});

const context = { organizationId: 'acme' };
console.log(await client.getLimit('seats.max', context)); // 250
console.log(await client.isEnabled('sso', context));      // true
console.log(await client.getDetails('seats.max', context));

Gate a request

isEnabled checks a feature’s gate privilege. getLimit returns an integer or UNLIMITED. getEnum returns a declared option. getDetails returns the explanation.

await client.requireWithin('projects.max', 4, 1, { organizationId: 'globex' });
// Current 4 + requested 1 fits Pro's limit of 5.

requireWithin checks only; use guard when counting usage and acting must be serialized. Map an EntitlementDenied error with toHttpProblem for an RFC 9457-style 403 response.

The remote provider never caches decisions. Timeouts, HTTP failures, malformed responses, and catalog mismatches become evaluation errors using the local default. Evaluation tokens are backend credentials; do not put them in a browser bundle.

Full SDK source and examples.