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
JavaScript
Node.js
Python
22+ More SDKs

Get your SDK Client Key

Go to SDK Configuration, create a new SDK Connection, and copy the Client Key (starts with sdk-).

Install the SDK

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

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>
  );
}

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

Get your SDK Client Key

Go to SDK Configuration, create a new SDK Connection, and copy the Client Key (starts with sdk-).

Install the SDK

npm install @growthbook/growthbook

yarn add @growthbook/growthbook

pnpm add @growthbook/growthbook

bun add @growthbook/growthbook

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();

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

Get your SDK Client Key

Go to SDK Configuration, create a new SDK Connection, and copy the Client Key (starts with sdk-).

Install the SDK

npm install @growthbook/growthbook

yarn add @growthbook/growthbook

pnpm add @growthbook/growthbook

bun add @growthbook/growthbook

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});

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

Get your SDK Client Key

Go to SDK Configuration, create a new SDK Connection, and copy the Client Key (starts with sdk-).

Install the SDK

pip

pip install growthbook

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",
    }
)

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.

Verify your setup

After setting up your SDK, verify it’s working by following these steps:

Create a feature flag called test-flag in your GrowthBook
Set its value to true and enable it for your environment
Check that isOn("test-flag") returns true in your app
Toggle the flag off and verify the change is reflected

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

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​All SDKs

HTML Script Tag

JavaScript

React

Vue

Kotlin (Android)

Swift (iOS)

Flutter

React Native

Node.js

Python

Ruby

PHP

Java

Go

C#

Elixir

Rust

Cloudflare Workers

Fastly Compute

Lambda@Edge

​Verify your setup

All SDKs

Verify your setup