> For the complete documentation index, see [llms.txt](https://docs.appetize.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.appetize.io/javascript-sdk/api-reference/initialization.md).

# Initialization

## getClient(selector)

Get an instance of the Appetize client.

{% hint style="warning" %}
When using `getClient(selector)`, you **must set** the iframe’s `src` attribute *before* calling `getClient` to configure the initial session.
{% endhint %}

```javascript
const client = await window.appetize.getClient('#my_iframe')
```

**Parameters**

| Name     | Type     | Description                                             |
| -------- | -------- | ------------------------------------------------------- |
| selector | `string` | A query selector string pointing to the embedded iframe |

## getClient(selector, config)

Get an instance of the Appetize client as well as set the initial config when loading the client.

*Useful when the embed link might not be known up front and the configuration has to be applied at runtime.*

{% hint style="warning" %}
When using `getClient(selector, config)`, **do not set** `iframe.src`.\
Setting the `src` manually may cause a race condition where the iframe loads before the SDK connects.\
\
For Private Cloud embeds, use `data-appetize-url` on the iframe instead of `src`.
{% endhint %}

```javascript
const client = await window.appetize.getClient('#my_iframe', {
    buildId: '{buildId|publicKey}',
    device: 'iphone11pro',
    osVersion: '15.0'
    ...
})
```

**Parameters**

| Name     | Type                                                                  | Description                                                                                                                  |
| -------- | --------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------- |
| selector | `string`                                                              | A query selector string pointing to the embedded iframe                                                                      |
| config   | [SessionConfig](/javascript-sdk/api-reference/types/sessionconfig.md) | A JSON object describing the [Configuration options](/javascript-sdk/configuration.md#configuration-options) for the device. |