@ledgerhq/hw-transport-node-hid-noevents/README.md

Ledger Hardware Wallet Node implementation of the communication layer, using node-hid. without usb events

<img src="https://user-images.githubusercontent.com/4631227/191834116-59cf590e-25cc-4956-ae5c-812ea464f324.png" height="100" />

[GitHub](https://github.com/LedgerHQ/ledger-live/),
[Ledger Devs Discord](https://developers.ledger.com/discord-pro),
[Developer Portal](https://developers.ledger.com/)

## @ledgerhq/hw-transport-node-hid-noevents

Allows to communicate with Ledger Hardware Wallets.

**\[Node]**/Electron **(HID)** – uses **only** `node-hid`. Does not provide USB events.

## API

<!-- Generated by documentation.js. Update this documentation by updating the source code. -->

#### Table of Contents

*   [createHIDframing](#createhidframing)
    *   [Parameters](#parameters)
*   [makeBlocks](#makeblocks)
    *   [Parameters](#parameters-1)
*   [reduceResponse](#reduceresponse)
    *   [Parameters](#parameters-2)
*   [getReducedResult](#getreducedresult)
    *   [Parameters](#parameters-3)
*   [TransportNodeHidNoEvents](#transportnodehidnoevents)
    *   [Parameters](#parameters-4)
    *   [Examples](#examples)
    *   [exchange](#exchange)
        *   [Parameters](#parameters-5)
    *   [close](#close)
    *   [isSupported](#issupported)
    *   [list](#list)
    *   [listen](#listen)
        *   [Parameters](#parameters-6)
    *   [open](#open)
        *   [Parameters](#parameters-7)

### createHIDframing

Object to handle HID frames (encoding and decoding)

#### Parameters

*   `channel` **[number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)**&#x20;
*   `packetSize` **[number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)** The HID protocol packet size in bytes (usually 64)

### makeBlocks

Frames/encodes an APDU message into HID USB packets/frames

#### Parameters

*   `apdu` **[Buffer](https://nodejs.org/api/buffer.html)** The APDU message to send, in a Buffer containing \[cla, ins, p1, p2, data length, data(if not empty)]

Returns **[Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)<[Uint8Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array)<[ArrayBuffer](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer)>>** an array of HID USB frames ready to be sent

### reduceResponse

Reduces HID USB packets/frames to one response.

#### Parameters

*   `acc` **ResponseAcc** The value resulting from (accumulating) the previous call of reduceResponse.
    On first call initialized to `initialAcc`. The accumulator enables handling multi-frames messages.
*   `chunk` **[Buffer](https://nodejs.org/api/buffer.html)** Current chunk to reduce into accumulator

Returns **ResponseAcc** An accumulator value updated with the current chunk

### getReducedResult

Returns the response message that has been reduced from the HID USB frames

#### Parameters

*   `acc` **ResponseAcc** The accumulator

Returns **([Buffer](https://nodejs.org/api/buffer.html) | null | [undefined](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/undefined))** A Buffer containing the cleaned response message, or null if no response message, or undefined if the
accumulator is incorrect (message length is not valid)

### TransportNodeHidNoEvents

**Extends Transport**

node-hid Transport minimal implementation

#### Parameters

*   `device` **HID.HID**&#x20;
*   `$1` **{context: TraceContext?, logType: LogType?}**  (optional, default `{}`)

    *   `$1.context` &#x20;
    *   `$1.logType` &#x20;

#### Examples

```javascript
import TransportNodeHid from "@ledgerhq/hw-transport-node-hid-noevents";
...
TransportNodeHid.create().then(transport => ...)
```

#### exchange

Exchange with the device using APDU protocol.

##### Parameters

*   `apdu` **[Buffer](https://nodejs.org/api/buffer.html)**&#x20;

Returns **[Promise](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise)<[Buffer](https://nodejs.org/api/buffer.html)>** a promise of apdu response

#### close

release the USB device.

Returns **[Promise](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise)\<void>**&#x20;

#### isSupported

Returns **[Promise](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise)<[boolean](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean)>**&#x20;

#### list

Returns **[Promise](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise)\<any>**&#x20;

#### listen

##### Parameters

*   `observer` **Observer\<DescriptorEvent\<any>>**&#x20;

Returns **Subscription**&#x20;

#### open

if path="" is not provided, the library will take the first device

##### Parameters

*   `path` **([string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String) | null | [undefined](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/undefined))**&#x20;