feature-flags-web

Name: feature-flags-web
Availability: InStock
Author: PostHog

Manage PostHog feature flags in frontend JavaScript applications.

58|5|Updated Jan 19, 2026

Search Tags:#frontend #javascript #sdk #web #posthog #feature-flags #flag-payloads

Ready to run

npx skills add https://github.com/PostHog/skills --skill feature-flags-web

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: feature-flags-web
Source: https://github.com/PostHog/skills/tree/main/skills/posthog/feature-flags/skills/web
Command: npx skills add https://github.com/PostHog/skills --skill feature-flags-web

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

Web applications often need controlled feature rollouts and A/B experiments, but implementing feature flags from scratch is error-prone and hard to maintain.

Core Features & Use Cases

Boolean flags: Enable or disable features per user or segment.
Multivariate flags: Run experiments with multiple variants.
Payloads: Retrieve extra data from feature flags to customize UI.
Use Case: Gate a new UI feature behind a flag in a React app and gradually roll it out.

Quick Start

Install the PostHog JavaScript SDK in your web app and start gating features using isFeatureEnabled or getFeatureFlag.

Frequently Asked Questions about feature-flags-web

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I implement feature flags in a JavaScript web app?▼

To implement feature flags in a JavaScript web app, integrate the PostHog JavaScript SDK and use the isFeatureEnabled or getFeatureFlag APIs to control boolean flags, multivariate variants, and payloads for dynamic UI changes.

What is the best way to run A/B experiments with multivariate flags in frontend code?▼

Running A/B experiments with multivariate flags in frontend code involves using the PostHog JavaScript SDK to retrieve multiple variants via getFeatureFlag, allowing you to test different UI experiences dynamically per user segment.

How do I retrieve custom data from feature flag payloads in a web application?▼

To retrieve custom data from feature flag payloads in a web application, use the PostHog JavaScript SDK's payload APIs alongside getFeatureFlag to fetch extra data needed for customizing your UI dynamically.

Why do my PostHog feature flags not update in my web application after changing them?▼

PostHog feature flags may not update in your web application if you are not following the SDK guidelines for properly loading, caching, and reloading flags after configuration changes.

Do I need to install dependencies to use feature flags for web projects?▼

Yes, you need to install the PostHog JavaScript SDK as a dependency in your frontend web project to start gating features and managing rollout strategies effectively.