Hyphen React SDK

The Hyphen React SDK provides React components, hooks, and higher-order components (HOCs) for integrating Hyphen's feature flag and toggle service into your React applications.

Installation

npm install @hyphen/react-sdk

Quick Start

The SDK provides three ways to integrate Hyphen into your React application:

1. Higher-Order Component (HOC) Pattern

Wrap your root component with withToggleProvider():

import { withToggleProvider } from '@hyphen/react-sdk';
import App from './App';

export default withToggleProvider({
  publicApiKey: 'public_...',
  applicationId: 'my-app',
  environment: 'production',
  defaultContext: {
    user: {
      id: 'user-123',
      email: 'user@example.com'
    }
  }
})(App);

2. Provider Component Pattern

Use the ToggleProvider component directly:

import { ToggleProvider } from '@hyphen/react-sdk';
import App from './App';

function Root() {
  return (
    <ToggleProvider
      publicApiKey="public_..."
      applicationId="my-app"
      environment="production"
      defaultContext={{
        user: {
          id: 'user-123',
          email: 'user@example.com'
        }
      }}
    >
      <App />
    </ToggleProvider>
  );
}

3. Using the useToggle Hook

Access feature flags in any component:

import { useToggle } from '@hyphen/react-sdk';

function MyComponent() {
  const toggle = useToggle();

  // Get boolean feature flag
  const isNewFeatureEnabled = toggle.getBoolean('new-feature', false);

  // Get string feature flag
  const theme = toggle.getString('theme', 'light');

  // Get number feature flag
  const maxItems = toggle.getNumber('max-items', 10);

  // Get object feature flag
  const config = toggle.getObject('ui-config', { layout: 'grid' });

  return (
    <div>
      {isNewFeatureEnabled && <NewFeature />}
      <p>Theme: {theme}</p>
      <p>Max Items: {maxItems}</p>
    </div>
  );
}

Configuration Options

All configuration options are passed to the Toggle instance from @hyphen/browser-sdk:

Option	Type	Required	Description
publicApiKey	string	Yes	Your Hyphen public API key (starts with public_)
applicationId	string	No	Application identifier
environment	string	No	Environment name (e.g., 'development', 'production')
defaultContext	object	No	Default evaluation context (user, targeting, etc.)
horizonUrls	string[]	No	Custom Horizon endpoint URLs for load balancing
defaultTargetKey	string	No	Default targeting key

Default Context

The defaultContext option allows you to set default user and targeting information:

{
  defaultContext: {
    targetingKey: 'user-123',
    user: {
      id: 'user-123',
      email: 'user@example.com',
      name: 'John Doe',
      customAttributes: {
        plan: 'premium',
        region: 'us-west'
      }
    },
    ipAddress: '192.168.1.1',
    customAttributes: {
      deviceType: 'mobile'
    }
  }
}

API Reference

ToggleProvider

React context provider component that creates and provides a Toggle instance.

Props: Extends ToggleOptions from @hyphen/browser-sdk plus:

• children: ReactNode - Components to wrap with the provider

withToggleProvider(options)

Higher-order component that wraps a component with ToggleProvider.

Parameters:

• options: ToggleOptions - Configuration for the Toggle instance

Returns: Function that accepts a component and returns a wrapped component

useToggle()

React hook to access the Toggle instance from context.

Returns: Toggle instance from @hyphen/browser-sdk

Throws: Error if used outside of ToggleProvider

Toggle Methods

The Toggle instance provides these methods:

• getBoolean(key, defaultValue, options?) - Get a boolean feature flag
• getString(key, defaultValue, options?) - Get a string feature flag
• getNumber(key, defaultValue, options?) - Get a number feature flag
• getObject<T>(key, defaultValue, options?) - Get an object feature flag
• get<T>(key, defaultValue, options?) - Generic getter for any type

All methods accept an optional options parameter for context overrides:

const isEnabled = toggle.getBoolean('feature-key', false, {
  context: {
    user: { id: 'different-user' }
  }
});

TypeScript Support

The SDK is written in TypeScript and provides full type definitions out of the box.

import type { ToggleProviderProps } from '@hyphen/react-sdk';

const config: ToggleProviderProps = {
  publicApiKey: 'public_...',
  applicationId: 'my-app',
  children: <App />
};

Examples

Conditional Rendering

function FeatureFlag({ flagKey, children }) {
  const toggle = useToggle();
  const isEnabled = toggle.getBoolean(flagKey, false);

  return isEnabled ? <>{children}</> : null;
}

// Usage
<FeatureFlag flagKey="new-dashboard">
  <NewDashboard />
</FeatureFlag>

A/B Testing

function ABTest() {
  const toggle = useToggle();
  const variant = toggle.getString('homepage-variant', 'control');

  switch (variant) {
    case 'variant-a':
      return <HomepageVariantA />;
    case 'variant-b':
      return <HomepageVariantB />;
    default:
      return <HomepageControl />;
  }
}

Dynamic Configuration

function ConfigurableComponent() {
  const toggle = useToggle();
  const config = toggle.getObject('component-config', {
    maxItems: 10,
    showImages: true,
    layout: 'grid'
  });

  return (
    <Component
      maxItems={config.maxItems}
      showImages={config.showImages}
      layout={config.layout}
    />
  );
}

Contributing

We welcome contributions to the Hyphen Node.js SDK! If you have an idea for a new feature, bug fix, or improvement, please follow the Contribution guidelines and our Code of Conduct.

License and Copyright

This project is licensed under the MIT License. See the LICENSE file for details. The copyright for this project is held by Hyphen, Inc. All rights reserved.