From Unleash

import { initialize } from 'unleash-client';const unleash = initialize({  url: 'https://unleash.example.com/api',  appName: 'my-app',  customHeaders: { Authorization: 'YOUR_API_TOKEN' },});unleash.on('synchronized', () => {  // Client is ready});

import { AvsbServer } from '@avsbhq/node';const server = new AvsbServer({ sdkKey: process.env.AVSB_SDK_KEY! });const result = await server.onReady();// result.success  →  a datafile loaded, so flags are answerable// result.degraded →  browser client only; the server SDK never sets it

import { FlagProvider } from '@unleash/proxy-client-react';const config = {  url: 'https://unleash-proxy.example.com/proxy',  clientKey: 'proxy-client-secret',  appName: 'my-app',};<FlagProvider config={config}>  <YourApp /></FlagProvider>

import { AvsbProvider } from '@avsbhq/react';<AvsbProvider  sdkKey="sdk_production_xxxxxxxxxxxxxxxx"  context={{ kind: 'user', key: 'u_123' }}>  <YourApp /></AvsbProvider>

const ctx = {  userId: 'u_123',  sessionId: 'sess_abc',  remoteAddress: '192.168.1.1',  properties: {    plan: 'pro',    country: 'US',  },};const enabled = unleash.isEnabled('show_banner', ctx);

import { AvsbClient } from '@avsbhq/browser';// Flatten userId, sessionId, and properties into a single EvalContextconst ctx = {  kind: 'user',  key: 'u_123',       // was userId  sessionId: 'sess_abc',  remoteAddress: '192.168.1.1',  plan: 'pro',        // was properties.plan  country: 'US',      // was properties.country};// Server: per callserver.forUser(ctx).getBoolFlag('show_banner', false);// Browser: bound at construction, updated via mutationsconst client = new AvsbClient({ sdkKey: 'sdk_production_xxxxxxxxxxxxxxxx' });client.identify(ctx);client.updateAttributes({ plan: 'enterprise' });// Anonymous → identified stitching at sign-up. Synchronous: it records the// moment, it does not move past decisions.client.alias(  { kind: 'user', key: 'anon_xyz' },  { kind: 'user', key: 'u_123' });

// Boolean toggleconst showBanner = unleash.isEnabled('show_banner', ctx);// Variant toggleconst variant = unleash.getVariant('homepage_theme', ctx);// variant.name       → 'blue' | 'green' | 'disabled'// variant.enabled    → true/false// variant.payload    → { type: 'string', value: 'blue' } | undefinedconst theme = variant.enabled ? variant.payload?.value ?? 'default' : 'default';

// Boolean flagconst showBanner = server.forUser(ctx).getBoolFlag('show_banner', false).isEnabled();// String variant: variationKey is the variant nameconst themeFlag = server.forUser(ctx).getStringFlag('homepage_theme', 'default');const theme    = themeFlag.value;        // 'blue' | 'green' | 'default'const variantName = themeFlag.variationKey; // 'blue' | 'green' | null// Full envelopeconst flag = server.forUser(ctx).getStringFlag('homepage_theme', 'default');flag.isEnabled()   // true for a real decision (rule, holdout, bandit, or                    // override, not just the default) with a truthy valueflag.source        // 'rule' | 'default' | 'holdout' | 'sticky' | ...flag.ruleId        // matched rule id or nullflag.reasons       // string[]

// Browser. `revenue` is money in major units; `value` is the separate// numeric-metric column (items in a cart, seats on a plan).client.track('purchase_completed', { revenue: 49.99 });// Server: the context to attribute the conversion to is explicitserver.track('purchase_completed', {  context: { kind: 'user', key: 'u_123' },  revenue: 49.99,});

import type { MultiContext } from '@avsbhq/core';const ctx: MultiContext = {  kind: 'multi',  user:         { kind: 'user',         key: 'u_123', plan: 'pro' },  organization: { kind: 'organization', key: 'org_42', tier: 'enterprise' },};server.forUser(ctx).getBoolFlag('enterprise_feature', false);

unleash.on('update', () => {  // Toggle definitions refreshed});

client.on('configUpdate', ({ publishedAt, reason }) => {  // reason: 'poll' | 'stream' | 'manual'});client.on('flagChange', ({ flagKey, previousValue, newValue }) => {  // A specific flag value changed});

import { fetchDatafile } from '@avsbhq/browser/server';const datafile = await fetchDatafile(process.env.AVSB_SDK_KEY!);<AvsbProvider sdkKey="..." context={ctx} bootstrap={datafile ?? undefined}>  <YourApp /></AvsbProvider>

unleash.destroy();

await server.close(); // flushes events, stops polling

import { createTestUnleashInstance } from 'unleash-client/test';const { client, repo } = createTestUnleashInstance();repo.setToggle('show_banner', true);

import { createMockClient } from '@avsbhq/test';const mock = createMockClient({  flags: {    show_banner: true,    homepage_theme: 'blue',  },});