## overview

The Device handlers provides methods for handling the physical device,
including opening low-level transport and selecting a device in the connected wallet.

## request handlers:

### "device.close" - Close Device

Close a device in the connected wallet.

| parameter (in req.params) | required? | note                     |
| ------------------------- | --------- | ------------------------ |
| _transportId_             | ✅         | A device's transport id. |

| walletHandler used | note |
| ------------------ | ---- |
| _device.close_     |      |

- **Returns**: A promise that resolves the transport id.

### "device.exchange" -

| parameter (in req.params) | required? | note |
| ------------------------- | --------- | ---- |
| _transportId_             | ✅         |      |
| _apduHex_                 | ✅         |      |

| walletHandler used | note |
| ------------------ | ---- |
| _device.exchange_  |      |

- **Returns**: A promise that resolves with _responseHex_

### "device.open" - Open Device

Open a device in the connected wallet.

| parameter    | required? | note                                                    |
| ------------ | --------- | ------------------------------------------------------- |
| _req.params_ | ✅         | An object containing the parameters to open the device. |

| walletHandler used | note |
| ------------------ | ---- |
| _device.open_      |      |

- **Returns**: A promise that resolves with a _transportId_

### "device.select" - Select Device

Select a device in the connected wallet.

| parameter | required? | note                                                                |
| --------- | --------- | ------------------------------------------------------------------- |
| params    | ✅         | An object containing the parameters to select and check the device. |

| walletHandler used | note |
| ------------------ | ---- |
| _device.select_    |      |

- **Returns**: A promise that resolves with a `deviceId` which can be used with the `device.open` method.

### "device.transport" - Open Low-Level Transport

Open low-level transport in the connected wallet.

| parameter    | required? | note                                                   |
| ------------ | --------- | ------------------------------------------------------ |
| _req.params_ | ✅         | An object containing the parameters for the transport. |

| walletHandler used | note |
| ------------------ | ---- |
| _device.transport_ |      |

- Calls the wallet handler _device.transport_
- **Returns**: **Returns**: A promise that resolves with an instance of Transport compatible with `@ledgerhq/hw-transport`.