@worktango/feature-flags-node

A Node.js-specific feature flag management package for WorkTango applications, built on top of DevCycle and OpenFeature.

Installation

npm install @worktango/feature-flags-node

Usage

import {
  initializeFeatureFlagProvider,
  getBooleanFlagValue,
  getOpenFeatureClient,
} from '@worktango/feature-flags-node';

// Initialize with your DevCycle SDK key
await initializeFeatureFlagProvider({
  sdkKey: 'your-devcycle-sdk-key',
  options: {
    disableAutomaticEventLogging: true,
    configPollingIntervalMS: 5 * 1000,
    eventFlushIntervalMS: 1000,
  },
});

// Get boolean feature flag value with user context
const isEnabled = await getBooleanFlagValue('my-feature', false, userContext);

Setting User Context

import { getOpenFeatureClient } from '@worktango/feature-flags-node';

// Set user context for feature flag evaluation
// Note: Custom data should be placed under privateCustomData
const userContext = {
  user_id: 'user123',
  email: '[e-mail]',
  privateCustomData: {
    companyId: 123,
    isAdmin: true,
  },
};

const client = getOpenFeatureClient();
await client.setContext(userContext);

API Reference

Types

• FeatureFlagConfig: Interface for feature flag configuration

  interface FeatureFlagConfig {
    sdkKey: string;
    options?: DevCycleOptionsLocalEnabled; // Optional DevCycle configuration
    strictMode?: boolean; // Optional: When enabled (default: false), will throw an error if the Feature Flag Provider/Client is not properly configured.
    // When disabled, will only log a warning if the Provider/Client is not correctly configured.
  }

Functions

• initializeFeatureFlagProvider(config: FeatureFlagConfig): Initialize the feature flag provider with DevCycle
• getBooleanFlagValue(flag: string, defaultValue: boolean, context?: FeatureFlagUser, options?: FlagEvaluationOptions): Get boolean feature flag value
• getOpenFeatureClient(): Get the OpenFeature client for additional flag types (string, number)
• getFeatureFlagProvider(): Get the DevCycle provider instance
• getFeatureFlagClient(): Get the DevCycle client instance

Constants

• ANONYMOUS_FEATURE_FLAG_USER: Default anonymous user context