> ## Documentation Index
> Fetch the complete documentation index at: https://docs.rebellapp.com/llms.txt
> Use this file to discover all available pages before exploring further.

# my.getBLEDeviceCharacteristics

> Get the characteristic list of a BLE device service.

Returns the list of characteristics for a given service on a connected Bluetooth Low Energy device.

## Parameters

| Property  | Type     | Required | Description                   |
| --------- | -------- | -------- | ----------------------------- |
| deviceId  | String   | Yes      | Device identifier             |
| serviceId | String   | Yes      | Service UUID                  |
| success   | Function | No       | Callback on success           |
| fail      | Function | No       | Callback on failure           |
| complete  | Function | No       | Callback that always executes |

## Success Callback Parameters

| Property        | Type  | Description                    |
| --------------- | ----- | ------------------------------ |
| characteristics | Array | List of characteristic objects |

### Characteristic Object

| Property         | Type       | Description                                                 |
| ---------------- | ---------- | ----------------------------------------------------------- |
| characteristicId | String     | Characteristic UUID                                         |
| serviceId        | String     | Parent service UUID                                         |
| value            | Hex String | Hexadecimal value of the characteristic                     |
| properties       | Object     | Supported operations: `read`, `write`, `notify`, `indicate` |

## Code Example

```javascript theme={null}
my.getBLEDeviceCharacteristics({
  deviceId: 'XX:XX:XX:XX:XX:XX',
  serviceId: '0000FFF0-0000-1000-8000-00805F9B34FB',
  success: (res) => {
    res.characteristics.forEach((char) => {
      console.log('Characteristic:', char.characteristicId);
      console.log('Can read:', char.properties.read);
      console.log('Can notify:', char.properties.notify);
    });
  },
  fail: (err) => {
    console.error('Failed:', err);
  }
});
```

## Related APIs

<CardGroup cols={2}>
  <Card title="my.getBLEDeviceServices" icon="list" href="/jsapi/device/bluetooth/my.getBLEDeviceServices">
    Get device services
  </Card>

  <Card title="my.readBLECharacteristicValue" icon="arrow-down" href="/jsapi/device/bluetooth/my.readBLECharacteristicValue">
    Read a characteristic value
  </Card>
</CardGroup>