React Native Truflag SDK

Enterprise-grade feature flags for React Native.

Install

npm install react-native-featureflags

No separate core package install is required. Relay endpoint is baked into the SDK.

Quickstart

import { useEffect } from 'react';
import Flags from 'react-native-featureflags';

export default function App() {
  useEffect(() => {
    void Flags.configure({
      apiKey: 'pk_live_xxx',
      user: {
        id: 'user-123',
        attributes: { plan: 'pro', country: 'US' },
      },
    });
  }, []);

  return <RootScreen />;
}

Login Later

await Flags.login({
  id: 'user-123',
  attributes: { plan: 'pro' },
});

Flags.identify(user) is an alias for Flags.login(user). Flags.login(user) merges incoming attributes with existing attributes for that user ID. Unspecified keys are preserved.

Update Attributes

await Flags.setAttributes({
  country: 'US',
  role: 'admin',
});

Flags.setAttributes(attrs) updates attributes for the current logged-in user and also preserves keys you do not pass.

Evaluate Flags

import { useFlag, useFlagsReady } from 'react-native-featureflags';

export function CheckoutEntry() {
  const ready = useFlagsReady();
  const enabled = useFlag('new-checkout', false);

  if (!ready) return <LoadingSkeleton />;
  return enabled ? <CheckoutV2 /> : <CheckoutV1 />;
}

Non-hook usage:

const enabled = Flags.getFlag('new-checkout', false);
const all = Flags.getAllFlags();

Logout Semantics

Flags.logout() reverts to an anonymous user and immediately refreshes flags. The anonymous ID is persisted and reused across launches.

Persistence

Default persistence uses React Native AsyncStorage automatically. Install this dependency in your app:

npm install @react-native-async-storage/async-storage

You can still pass storage explicitly for custom adapters.

Best Practices

• Configure once at app launch.
• Gate critical UI behind useFlagsReady().
• Use public API keys only.
• Keep user attributes minimal and non-PII.

FAQ

• Anonymous IDs: created when user is omitted in configure.
• Offline mode: cached flags are used if cache is valid, then refreshed.
• Retries/timeouts: fetch requests use timeout plus exponential backoff with jitter.