# Setup
To start using the Vanilla JS SDK, you will need to add a setup script to your body. Ensure you have completed the [Installation](https://docs.play.fun/build-on-play.fun/play-fun-sdk/vanilla-js-sdk/installation) steps first (including the `x-ogp-key` meta tag).
```js
document.addEventListener('DOMContentLoaded', () => {
const sdk = new OpenGameSDK({
ui: {
usePointsWidget: true, // Enable the points widget (default: true)
useCustomUI: false, // Set true to disable widget and modals
theme: 'system', // 'light', 'dark', or 'system' (default: 'system')
},
// apiKey is automatically read from the tag.
// You can also pass it explicitly here:
// apiKey: 'your-api-key',
});
sdk.on('OnReady', () => {
console.log('OpenGameSDK Ready');
// Start your game here
});
sdk
.init({ gameId: 'your-game-id' })
.then(() => console.log('OpenGameSDK Initialized'))
.catch(console.error);
});
```
{% hint style="info" %}
Your **API key** (creator key) is read from the `` tag in your HTML ``. If the meta tag is present, you do not need to pass `apiKey` in the constructor. The **gameId** is passed to `init()`, or can be provided via the constructor or URL query params.
{% endhint %}