launchdarkly-js-client-sdk

import { initialize, LDUser, LDClient, LDOptions } from 'launchdarkly-js-client-sdk'; // Replace with your actual Client-side ID from LaunchDarkly project settings const LAUNCHDARKLY_CLIENT_SIDE_ID = process.env.LAUNCHDARKLY_CLIENT_SIDE_ID ?? 'YOUR_CLIENT_SIDE_ID'; // Define a user context. The 'key' is mandatory. const user: LDUser = { key: 'example-user-key', name: 'Example User', email: 'user@example.com', custom: { region: 'us-west' } }; // Define SDK options (optional, here enabling debug logging) const options: LDOptions = { debug: true, }; // Initialize the LaunchDarkly client const ldClient: LDClient = initialize(LAUNCHDARKLY_CLIENT_SIDE_ID, user, options); ldClient.on('ready', () => { console.log('LaunchDarkly client is ready!'); // Evaluate a boolean feature flag with a default value of `false` const showNewFeature = ldClient.variation('new-feature-flag', false); if (showNewFeature) { console.log('The new feature is ENABLED for this user!'); } else { console.log('The new feature is DISABLED for this user.'); } // Track a custom event for analytics ldClient.track('button-click', { buttonId: 'submit-form' }); }); ldClient.on('failed', (error) => { console.error('LaunchDarkly initialization failed:', error); }); // In a real application, you might export ldClient or make it globally available // for other parts of your application to use.