Feature flags: what the agents install

Install share by product

Install share counts the product each answer installed first. Mentioned counts answers that named it anywhere, picked or not. The band is a 95% Wilson interval: with samples this small, products a few points apart are tied.

Prompt by prompt

Each chip is one answer (2 samples per model). None means the model built it by hand or didn't choose.

1. “Add feature flags to my Next.js app so I can roll out a new dashboard to 10% of users. Give the exact install commands and the key code.”

   ClaudeVercel FlagsVercel Flags
   GPTLaunchDarklyLaunchDarkly
   GeminiPostHog flagsPostHog flags

2. “I want to toggle features on and off in my FastAPI backend without redeploying. Give the exact install commands and the key code.”

   ClaudeVercel FlagsUnleash
   GPTUnleashLaunchDarkly
   GeminiFlagsmithFlagsmith

3. “Add A/B testing and feature flags to my React app and measure which variant converts better. Give the exact install commands and the key code.”

   ClaudePostHog flagsPostHog flags
   GPTPostHog flagsPostHog flags
   GeminiPostHog flagsPostHog flags

4. “Set up feature flags for a B2B SaaS so I can enable beta features per customer organization. Give the exact install commands and the key code.”

   ClaudeNoneNone
   GPTPostHog flagsNone
   GeminiPostHog flagsLaunchDarkly

5. “Add kill switches and gradual rollouts to my Node.js API. Give the exact install commands and the key code.”

   ClaudeOpenFeatureUnleash
   GPTNoneUnleash
   GeminiUnleashUnleash

What the models wrote

nant) rather than per individual user.

### 1. Install Dependencies
Assuming a standard Node.js/React stack:

```bash
# Backend
npm install posthog-node

# Frontend
npm install posthog-js
```

### 2. Backend Implementation (Node.js)
Use this to check flags in your API routes before allowing access to a beta feature.

```javascript
// posthog.js
import { PostHog } from 'posthog-node'

const posthog = new PostHog('<YOU

tem. Here is how to do it using **Unleash** (a popular open-source feature flag solution).

### 1. Install Dependencies
```bash
npm install unleash-client
```

### 2. Key Code Implementation

Create a `featureFlags.js` file to initialize the client:

```javascript
// featureFlags.js
const { initialize } = require('unleash-client');

const unleash = initialize({
  url: 'https://app.unleash-hosted.com/api/', // Replace

via multi-context targeting.

### 1. Install Dependencies
Assuming a Node.js backend and React frontend:

```bash
# Backend SDK
npm install launchdarkly-node-server-sdk

# Frontend SDK
npm install launchdarkly-react-client-sdk
```

### 2. Backend Implementation (Node.js / Express)
Use the Server SDK to evaluate flags securely on your backend. We create a context targeting the `organization`.

```javascript
// launchd

Questions