posthog-core-workflow-b

# 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) ```typescript 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('banner-config'); // payload: { text: "Spring sale!", color: "#ff6b35", discount: 20 } // React: Wait for flags to load before rendering posthog.onFeatureFlags(() => { // Flags are now loaded and ready const enabled = posthog.isFeatureEnabled('new-feature')...