SDK Quickstart

Get GrowthBook running in your application in minutes.

New to GrowthBook SDKs?

The SDK Overview covers how SDKs work and helps you choose the right one for your use case.

React

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

npm install @growthbook/growthbook-react @growthbook/growthbook

Yarn

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

pnpm

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

Bun

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

JavaScript

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

npm install @growthbook/growthbook

Yarn

yarn add @growthbook/growthbook

pnpm

pnpm add @growthbook/growthbook

Bun

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

Node.js

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

npm install @growthbook/growthbook

Yarn

yarn add @growthbook/growthbook

pnpm

pnpm add @growthbook/growthbook

Bun

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

Python

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.

22+ More SDKs

All SDKs

Front-end

HTML Script Tag

Drop-in script for any website

JavaScript

Vanilla JS and TypeScript

React

Hooks and providers with SSR

Vue

Vue 3 composables

Mobile

Kotlin (Android)

Native Android

Swift (iOS)

Native iOS

Flutter

Cross-platform mobile

React Native

Cross-platform React

Back-end

Node.js

Express, Fastify, etc.

Python

Flask, Django, FastAPI

Ruby

Rails and Ruby apps

PHP

Laravel, Symfony, etc.

Java

Spring Boot and Java

Go

High-performance Go

C#

.NET Core and ASP.NET

Elixir

Phoenix and Elixir

Rust

Actix, Axum, Rocket, and more

Edge

Cloudflare Workers

Edge computing on Cloudflare

Fastly Compute

WebAssembly-powered edge

Lambda@Edge

AWS CloudFront edge

---

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

tip

Use the GrowthBook DevTools browser extension to inspect and test feature flags in development.