posthog-core-workflow-b

name	posthog-core-workflow-b
description	Implement PostHog feature flags, A/B experiments, and cohort management. Use when rolling out features with flags, running A/B tests, creating cohorts, or evaluating multivariate experiments with PostHog. Trigger: "posthog feature flag", "posthog experiment", "posthog A/B test", "posthog cohort", "feature rollout posthog", "posthog multivariate".
allowed-tools	Read, Write, Edit, Bash(npm:*), Grep
version	1.12.0
license	MIT
author	Jeremy Longshore <[e-mail]>
tags	["saas","posthog","workflow","feature-flags","experiments"]
compatibility	Designed for Claude Code

PostHog Core Workflow B — Feature Flags & Experiments

Overview

Feature flag management, A/B experiment evaluation, and cohort analysis with PostHog. Covers boolean and multivariate flags, local evaluation for performance, experiment setup and statistical significance, and cohort creation via the API.

Prerequisites

• Completed posthog-install-auth setup
• Familiarity with posthog-core-workflow-a (event capture)
• Personal API key (phx_...) for flag management API

Instructions

Step 1: Evaluate Feature Flags (Browser)

import posthog from 'posthog-js';

// Boolean flag
if (posthog.isFeatureEnabled('new-checkout-flow')) {
  renderNewCheckout();
} else {
  renderLegacyCheckout();
}

// Multivariate flag (returns string variant name)
const variant = posthog.getFeatureFlag('pricing-page-experiment');
switch (variant) {
  case 'control':
    renderOriginalPricing();
    break;
  case 'annual-first':
    renderAnnualFirstPricing();
    break;
  case 'social-proof':
    renderSocialProofPricing();
    break;
  default:
    renderOriginalPricing(); // Fallback if flag not loaded yet
}

// Get flag payload (JSON data attached to a flag variant)
const payload = posthog.getFeatureFlagPayload();



posthog.( {
  
   enabled = posthog.();
  (enabled ?? );
});