> Fetch clean Markdown by appending `.md` to any page URL under https://signalwire.com/docs or requesting it with the HTTP header `Accept: text/markdown`. The root index at https://signalwire.com/docs/llms.txt lists the available documentation indexes.

# isValidDevice

> Checks whether a device is still available and usable.

```ts
isValidDevice(deviceInfo): Promise<boolean>
```

Checks whether a device is still available and usable.

## **Parameters**

**`deviceInfo`** `MediaDeviceInfo | null`

The device to validate, or `null`. See [`MediaDeviceInfo`](https://developer.mozilla.org/en-US/docs/Web/API/MediaDeviceInfo).

---

## **Returns**

`Promise<boolean>`

`true` if the device is valid and available. Returns `false` for `null`, audio output devices, or unavailable devices.

## **Examples**

```ts
await client.isValidDevice(deviceInfo);
```

> Checks whether a device is still available and usable.