Use the Node.js SDK to initialize FlagPilot, evaluate flags, pass target users, and handle fallback behavior in production.
Installation
Terminal
npm install @flagpilot/node
Initialization
index.ts
import { FlagPilot } from '@flagpilot/node';
const flagpilot = new FlagPilot({
apiKey: process.env.FLAGPILOT_SECRET_KEY,
environment: 'production'
});
await flagpilot.initialize();
// Evaluate a feature flag
const isEnabled = await flagpilot.evaluate('checkout-redesign', {
userId: user.id
});
if (isEnabled) {
// Serve new checkout experience
}Evaluating a flag
index.ts
const isEnabled = await flagpilot.evaluate('checkout-redesign', { userId: 'user_123' });Target users
Send stable opaque user IDs and optional attributes to keep percentage rollouts and targeting rules consistent.
index.ts
await flagpilot.evaluate('checkout-redesign', {
userId: 'user_123',
plan: 'pro'
});Error handling
Use a conservative fallback value when evaluation fails or the SDK cannot reach its configured source.
Best practices
- Reuse one SDK client instance per app runtime.
- Set the SDK environment option to development, staging, or production.
- Hash or pseudonymize sensitive user identifiers before sending them to evaluations.
API reference links
FAQ
How does Node.js SDK interact with local caches?
Configurations are synced down using Edge Config or fallback REST triggers. The client automatically reads evaluations in-memory, resulting in sub-millisecond local evaluation times.
Where can I obtain support for Node.js SDK?
You can open a support ticket in your dashboard, check the community roadmap, or consult the FlagPilot Platform Status page.