Skip to main content

Documentation Index

Fetch the complete documentation index at: https://growthbook-preview.mintlify.app/llms.txt

Use this file to discover all available pages before exploring further.

Get GrowthBook running in your application in minutes.
The SDK Overview covers how SDKs work and helps you choose the right one for your use case.
  • React
  • JavaScript
  • Node.js
  • Python
  • 22+ More SDKs
1 Get your SDK Client Key Go to SDK Configuration, create a new SDK Connection, and copy the Client Key (starts with sdk-). 1 Install the SDK
  • npm
  • Yarn
  • pnpm
  • Bun
npm install @growthbook/growthbook-react @growthbook/growthbook

yarn add @growthbook/growthbook-react @growthbook/growthbook

pnpm add @growthbook/growthbook-react @growthbook/growthbook

bun add @growthbook/growthbook-react @growthbook/growthbook
1 Wrap your app with GrowthBookProvider 
import { GrowthBook, GrowthBookProvider } from "@growthbook/growthbook-react";  
import { thirdPartyTrackingPlugin, autoAttributesPlugin } from "@growthbook/growthbook/plugins";  

// Create a GrowthBook instance  
const gb = new GrowthBook({  
  apiHost: "https://cdn.growthbook.io",  
  clientKey: "sdk-abc123", // Your SDK client key  
  enableDevMode: true,  
  plugins: [  
    thirdPartyTrackingPlugin(), // Optional, sends "Experiment Viewed" events via GrowthBook Managed Warehouse, Google Analytics, Google Tag Manager, and Segment.  
    autoAttributesPlugin(), // Optional, sets common attributes (browser, session_id, etc.)  
  ],  
});  

// Load feature definitions from the GrowthBook API  
gb.init();  

export default function App() {  
  return (  
    <GrowthBookProvider growthbook={gb}>  
      <MyApp />  
    </GrowthBookProvider>  
  );  
}
1 Use feature flags 
import { useFeatureIsOn, useFeatureValue } from "@growthbook/growthbook-react";  

function MyApp() {  
  const showNewFeature = useFeatureIsOn("new-feature");  
  const buttonColor = useFeatureValue("button-color", "blue");  

  return (  
    <div>  
      {showNewFeature && <NewFeature />}  
      <button style={{ backgroundColor: buttonColor }}>Click me</button>  
    </div>  
  );  
}
Next steps: - See the example Next.js app - See the React SDK docs 1 Get your SDK Client Key Go to SDK Configuration, create a new SDK Connection, and copy the Client Key (starts with sdk-). 1 Install the SDK
  • npm
  • Yarn
  • pnpm
  • Bun
npm install @growthbook/growthbook

yarn add @growthbook/growthbook

pnpm add @growthbook/growthbook

bun add @growthbook/growthbook
1 Initialize GrowthBook 
import { GrowthBook } from "@growthbook/growthbook";  
import { thirdPartyTrackingPlugin, autoAttributesPlugin } from "@growthbook/growthbook/plugins";  

const gb = new GrowthBook({  
  apiHost: "https://cdn.growthbook.io",  
  clientKey: "sdk-abc123",  
  plugins: [  
    thirdPartyTrackingPlugin(), // Optional, sends "Experiment Viewed" events via GrowthBook Managed Warehouse, Google Analytics, Google Tag Manager, and Segment.  
    autoAttributesPlugin(), // Optional, sets common attributes (browser, session_id, etc.)  
  ],  
});  

await gb.init();
1 Use feature flags 
if (gb.isOn("new-feature")) {  
  showNewFeature();  
}  

const color = gb.getFeatureValue("button-color", "blue");
Next steps: - See the JavaScript SDK docs for TypeScript, plugins, and more. - See an example Typescript app 1 Get your SDK Client Key Go to SDK Configuration, create a new SDK Connection, and copy the Client Key (starts with sdk-). 1 Install the SDK
  • npm
  • Yarn
  • pnpm
  • Bun
npm install @growthbook/growthbook

yarn add @growthbook/growthbook

pnpm add @growthbook/growthbook

bun add @growthbook/growthbook
1 Initialize GrowthBook 
import { GrowthBookClient } from "@growthbook/growthbook";  

const gbClient = new GrowthBookClient({  
  apiHost: "https://cdn.growthbook.io",  
  clientKey: "sdk-abc123",  
  trackingCallback: (experiment, result, userContext) => {  
    const userId = userContext.attributes.id;  
    // Required for A/B testing  
    // TODO: Replace with your own tracking implementation  
    console.log("Viewed Experiment", userId, {  
      experimentId: experiment.key,  
      variationId: result.key  
    });  
  }  
});  
await gbClient.init({timeout: 3000});
1 Use feature flags 
// User context with attributes that feature flags can use for targeting  
const userContext = {  
  attributes: {  
    id: "123",  
    country: "US",  
    // ... other attributes ...  
  }  
}  

// Boolean on/off flags  
if (gbClient.isOn("my-feature", userContext)) {  
  console.log("My feature is on!");  
}  

// String, Number, or JSON flags  
const value = gbClient.getFeatureValue("my-string-feature", "fallback", userContext);  
console.log(value);
Next steps: - See the full Node.js SDK docs - Use the SDK in Express middleware 1 Get your SDK Client Key Go to SDK Configuration, create a new SDK Connection, and copy the Client Key (starts with sdk-). 1 Install the SDK 
pip install growthbook
1 Initialize GrowthBook 
from growthbook import GrowthBookClient, Options, UserContext  

def on_experiment_viewed(experiment, result):  
    # TODO: track in your analytics system  
    print(f"Experiment: {experiment.key}, Variation: {result.key}")  

# Create and initialize client  
client = GrowthBookClient(  
    Options(  
        api_host="https://cdn.growthbook.io",  
        client_key="sdk-abc123",  
        on_experiment_viewed=on_experiment_viewed,  
    )  
)  
await client.initialize()  

# Create user context for targeting  
user = UserContext(  
    attributes={  
        "id": "user-123",  
        "country": "US",  
    }  
)
1 Use feature flags 
if await client.is_on("new-feature", user):  
    show_new_feature()  

color = await client.get_feature_value("button-color", "blue", user)
Next steps: - See the full Python SDK docs - See the how to integrate with FastAPI example.

​
All SDKs

Client [### HTML Script Tag Drop-in script for any website](/lib/script-tag)[### JavaScript Vanilla JS and TypeScript](/lib/js)[### React Hooks and providers with SSR](/lib/react)[### Vue Vue 3 composables](/lib/vue)[### Kotlin (Android) Native Android](/lib/kotlin)[### Swift (iOS) Native iOS](/lib/swift)[### Flutter Cross-platform mobile](/lib/flutter)[### React Native Cross-platform React](/lib/react-native) Server [### Node.js Express, Fastify, etc.](/lib/node)[### Python Flask, Django, FastAPI](/lib/python)[### Ruby Rails and Ruby apps](/lib/ruby)[### PHP Laravel, Symfony, etc.](/lib/php)[### Java Spring Boot and Java](/lib/java)[### Go High-performance Go](/lib/go)[### C# .NET Core and ASP.NET](/lib/csharp)[### Elixir Phoenix and Elixir](/lib/elixir)[### Rust Actix, Axum, Rocket, and more](/lib/rust) Edge [### Cloudflare Workers Edge computing on Cloudflare](/lib/edge/cloudflare)[### Fastly Compute WebAssembly-powered edge](/lib/edge/fastly)[### Lambda@Edge AWS CloudFront edge](/lib/edge/lambda)

​
Verify your setup

After setting up your SDK, verify it’s working by following these steps:
  1. Create a feature flag called test-flag in your GrowthBook
  2. Set its value to true and enable it for your environment
  3. Check that isOn("test-flag") returns true in your app
  4. Toggle the flag off and verify the change is reflected
Use the GrowthBook DevTools browser extension to inspect and test feature flags in development.