Feature Flags

Evaluate feature flags locally with the JavaScript SDK. The SDK fetches your flag config with a public key, caches it, and evaluates every check in-process — no network call per isEnabled().

Setup

import { simplrFlags } from "@simplr-ai/js";

await simplrFlags.initialize({
  apiKey: "pk_live_xxx",      // public key only (pk_*)
  environment: "live",        // "live" | "test" (default "test")
  baseUrl: "https://api.simplr-ai.com", // optional
  refreshIntervalMs: 60000,   // optional; 0 disables auto-refresh
});

initialize() fetches the config once and starts a background refresh. Call it once at app startup.

Identifying the user

simplrFlags.setUser("user_123");

If you don't set a user, the SDK falls back to the device ID for bucketing, so anonymous users still get stable results.

Checking a flag

if (simplrFlags.isEnabled("new-checkout")) {
  // ...
}

// Per-call context for rules or a one-off user:
simplrFlags.isEnabled("new-checkout", {
  userId: "user_123",
  attributes: { plan: "growth", country: "GB" },
});

isEnabled() returns synchronously and is free — it never hits the network.

API

Method	Description
initialize(config)	Fetch config and start auto-refresh. Returns a promise.
setUser(userId)	Set the default identifier used for bucketing.
isEnabled(key, ctx?)	Evaluate a flag locally. ctx = { userId?, attributes? }.
refresh()	Manually re-fetch the config (counts as one billable request).
getAll()	Return the current cached flag map.
isReady()	true once the first fetch has completed.
dispose()	Stop the auto-refresh timer.

Billing note

Each initialize() and refresh() counts as one flag config request. Local isEnabled() calls are never billed. The first 1,000,000 requests per month are free — see Pricing.