@core-sdk/feature-flags-sdk

HTTP client + in-memory TTL cache for feature flag definitions; evaluation uses @core-sdk/feature-flags-core on the client.

• Node: 18+
• Module: ESM ("type": "module")

Install

npm install @core-sdk/feature-flags-sdk

PostHog-style identify (one-shot context)

Call identify once after login (or when profile is known). Stored fields are merged into every evaluate / evaluateAsync / isEnabled call. Per-flag overrides win on key clashes.

import { FeatureFlagsClient } from "@core-sdk/feature-flags-sdk";

const client = new FeatureFlagsClient({
  baseUrl: "https://flag-api.example.com",
  projectKey: "my-project",
});

await client.bootstrap();

client.identify(profile.userId, {
  email: profile.email,
  accountId: profile.accountId,
});

// Uses merged context (email, accountId, userId = profile.userId)
const on = await client.isEnabled("new-checkout");

// Flag-specific props override the base for this call only
const promo = await client.isEnabled("promo-banner", { channelId: "web" });

• reset() clears the identified person; evaluation uses {} again until the next identify.
• distinctIdKey (optional, default userId): which context key receives the first identify argument. Match your portal rule field names.

Until identify is called, isEnabled("x") uses an empty context ({}). Rules that require user fields therefore evaluate to false for logged-out users—no extra anonymous id layer is needed.

API routes

The client calls:

• GET {baseUrl}/projects/{projectKey}/flags
• GET {baseUrl}/projects/{projectKey}/flags/{flagKey}
• GET .../flags/{flagKey}/history
• GET .../flags/{flagKey}/versions/{version}

License

See your organization’s license terms.