Feature Flags Made Simple

Ship features safely with boolean flags and percentage rollouts. Built for indie hackers who value simplicity.

Quick Start

npm install @featsync/sdk

import { Featsync } from '@featsync/sdk';

const featsync = new Featsync({
  apiKey: 'fs_your_api_key',
});

if (await featsync.isEnabled('new-feature')) {
  showNewFeature();
}

Why Featsync?

Simple

Boolean flags and percentage rollouts. No complex targeting rules or user segments.

Affordable

Start free with 5 flags. Pro is $19/month with unlimited team members.

Fast

Edge-cached evaluations with sub-50ms response times. SDK caches locally.

Safe

If our API goes down, your app keeps working with cached flag values.

Next Steps

Quick Start

Get up and running in under 5 minutes. Read the guide →

SDK Reference

Full API reference for the JavaScript SDK. View reference →

Percentage Rollouts

Learn how to gradually release features. Learn more →

React Integration

Use hooks for a clean React integration. Get started →