@coolwallet/zen/README.md

Coolwallet Horizen sdk

# CoolWallet ZenCash (ZEN) App
[![Version](https://img.shields.io/npm/v/@coolwallet/zen)](https://www.npmjs.com/package/@coolwallet/zen)

Typescript library with support for the integration of ZenCash for third party application, include the functionalities of generation of addresses and signed transactions. 

## Install

```shell
npm i @coolwallet/zen
```

## Usage

```javascript
import ZEN from '@coolwallet/zen'
const zen = new ZEN()

const address = await zen.getAddress(transport, appPrivateKey, appId, scriptType, 0);

const inputs = {
    preTxHash: "735153f57da91462a01c17937a397aa67f7b5faf9ab74ebcdd4c8f485aba26f5",
    preIndex: 1,
    preValue: "87302",
    sequence: 0xFFFFFFFF,
    addressIndex: 0,
    pubkeyBuf: Uint8Array(33)
}

const output = {
    value: "10000",
    address: "MSea9ZqgrZqsB5bvg8iTrcUQ2xpF1ckAsv",
    blockHash: "0000000000ab3ec2f5e8fe0bd065195bddf39373f99ccba4e9657e9d84dbf9ae",
    blockHeight: 1048203
}

const change = {
    value: "77301.99983500001",
    addressIndex: 0,
    pubkeyBuf: Uint8Array(33),
    blockHash: "0000000000ab3ec2f5e8fe0bd065195bddf39373f99ccba4e9657e9d84dbf9ae",
    blockHeight: 1048203
}

const signTxData = {
    transport,
    appPrivateKey,
    appId,
    scriptType,
    inputs,
    output,
    change,
    addressIndex
}

const transaction = await zen.signTransaction(signTxData)
```

## Methods

### getAddress

#### Description

Get address by address index.

The ZEN address generated is compatible to BIP44 with **account** and **change** set to 0, which means calling `getAddress` with `addressIndex = i` will get the address of folllowing path:

```none
m/44'/121'/0'/0/{i}
```

In the design of current hardware, we only support path `m/44'/121'/0'/0/{i}` for speed optimization. This might change in the future and we will then open a more general interface to deal with custom path.

```javascript
async getAddress(
    transport: Transport, 
    appPrivateKey: string, 
    appId: string, 
    scriptType: ScriptType, 
    addressIndex: number
    ): Promise<string> 
```

#### Arguments

|      Arg      |                  Description                 |    Type    | Required |
|:-------------:|:--------------------------------------------:|:----------:|:--------:|
|   transport   | Object to communicate with CoolWallet device |  Transport |   TRUE   |
| appPrivateKey |   Private key for the connected application  |   string   |   TRUE   |
|     appId     |       ID for the connected application       |   string   |   TRUE   |
|   scriptType  |   Define the type of script of the address   | ScriptType |   TRUE   |
|  addressIndex |  The from address index in BIP44 derivation  |   number   |   TRUE   |

### signTransaction

#### Description

Sign ZenCash Transaction.

```javascript
async signTransaction(signTxData: signTxType):Promise<string>
```

#### signTxType Arguments

|      Arg      |                              Description                             |    Type    | Required |
|:-------------:|:--------------------------------------------------------------------:|:----------:|:--------:|
|   transport   |             Object to communicate with CoolWallet device             |  Transport |   TRUE   |
| appPrivateKey |               Private key for the connected application              |   string   |   TRUE   |
|     appId     |                   ID for the connected application                   |   string   |   TRUE   |
|   scriptType  |               Define the type of script of the address               | ScriptType |   TRUE   |
|     inputs    |            Array of inputs of previous transactions (UTXO)           |   [Input]  |   TRUE   |
|     output    |                       Output of the transaction                      |   Output   |   TRUE   |
|     change    |                      Address to receive changes                      |   Change   |   TRUE   |
|   confirmCB   |      Callback of confirmation data to the connected application      |  Function  |   FALSE  |
|  authorizedCB | Callback of authorized transaction data to the connected application |  Function  |   FALSE  |