Qtum Ethers

A module for using Qtum through an Ethers compliant library to make it simpler to use Qtum

Upgrading from 0.0.3

public key address generation now follows QTUM behavior, the same private keys will now generate different addresses

adds support for importing WIF private keys

gas price is now specified in WEI, not Satoshis

Installation

Open a console and run

npm install qtum-ethers-wrapper

Example

import {Contract} from "ethers"
import {
    QtumProvider as Provider,
    QtumWallet as Wallet,
    QtumContractFactory as ContractFactory,
    QTUM_BIP44_PATH, // Compatible with Qtum core wallet and electrum
    SLIP_BIP44_PATH  // Compatible with 3rd party wallets
} from "qtum-ethers-wrapper";
// point Qtum Provider at Janus node https://github.com/qtumproject/janus/
const mainnetProvider = new Provider("https://janus.qiswap.com/api/");
const testnetProvider = new Provider("https://testnet-janus.qiswap.com/api/");
// or deploy your own node locally with a regtest network
// see for a pre-built docker image https://hub.docker.com/r/ripply/janus
const regtestProvider = new Provider("http://localhost:23889");

const provider = testnetProvider;
// create a wallet
const privkey = "99dda7e1a59655c9e02de8592be3b914df7df320e72ce04ccf0427f9a366ec6e"
const signer = new Wallet(
    privkey,
    provider
)
// or create a random account and get the mnemonic
// const signer = Wallet.createRandom(/*{ path = SLIP_BIP44_PATH }*/}).connect(provider);
// const {locale, path, phrase} = signer._mnemonic();
// QRC20 ABI
const ABI = [{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"}],"name":"approve","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"totalSupply","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_from","type":"address"},{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transferFrom","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"name":"","type":"uint8"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"_owner","type":"address"}],"name":"balanceOf","outputs":[{"name":"balance","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"symbol","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"_owner","type":"address"},{"name":"_spender","type":"address"}],"name":"allowance","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"payable":true,"stateMutability":"payable","type":"fallback"},{"anonymous":false,"inputs":[{"indexed":true,"name":"owner","type":"address"},{"indexed":true,"name":"spender","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Transfer","type":"event"}];
// https://github.com/qtumproject/janus/blob/master/playground/pet-shop-tutorial/contracts/QRC20Token.sol
const BYTECODE = "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"
// QtumContractFactory is required to be used instead of standard ethers ContractFactory due to how contract addresses are computed differently
const simpleStore = new ContractFactory(ABI, BYTECODE, signer);

// simpleStore deployment example, returns address
async function deployToken() {
    const deployment = await simpleStore.deploy({
        gasLimit: "0x7a120", // 500,000
        gasPrice: "0x9502f9000" // in WEI, not Satoshis
    });
    await deployment.deployed();
    return deployment.address
}
// connect to QRC20 token and interact with it 
async function transferToken(contractAddress, from, to, value) {
    const qrc20 = new Contract(contractAddress, QRC_ABI, signer)
    const name = await qrc20.transfer(from, to, value,
        {
            gasLimit: "0x62521", // 62521
            gasPrice: "0x9502f9000", // in WEI, not Satoshis
        }
    );
}

const contractAddress = await deployToken();
await transferToken(contractAddress, "0x...", "0x...", 1);

Notes

• Issues

At the point of grabbing UTXO's from janus, the estimated TX size is unknown

Qtum estimate gas function is not perfect so eth_estimateGas has a 20% buffer for gas limit

Janus doesn't return a transaction receipt for p2pkh tx's

This extension works with p2pkh scripts only and asks Janus for p2pkh scripts only