Wanx NPM | npm.io

WanX

WanX is a utility package for making crosschain transactions into and out of the Wanchain network.

Install

Use NPM or Yarn to install the library:

npm install --save wanx

Configure

If you do not plan to have WanX connect to Wanchain or Ethereum nodes, you can initialize WanX with just the network (mainnet or testnet).

import WanX from 'wanx';
// or
const WanX = require('wanx');

const wanx = new WanX('testnet');

If you would like WanX to connect to Wanchain and/or Ethereum nodes, to do things like submit transactions or listen for events, you can do so by either defining the node urls or by passing in the web3 objects directly.

(Note: WanX does not connect to the Bitcoin network, and instead expects you to manage the connection to a node.)

// configure with node urls
const config = {
  wanchain: {
    url: 'http://localhost:8545',
  },
  ethereum: {
    url: 'http://13.57.92.468:8545',
  }
};

// or configure with pre-initialized web3 objects
const config = {
  wanchain: {
    web3: wan3,
  },
  ethereum: {
    web3: web3
  },
};

const wanx = new WanX('testnet', config);

Basic Usage

Define the transaction

Start by generating a new redeem key. The redeem key contains the x and its hash, xHash, which are used as the identifier and locking keys for the crosschain transaction.

const redeemKey = wanx.newRedeemKey();

The default hash algorithm for the redeem key is keccak256. If you are working with Bitcoin, you will instead need a redeem key based on sha256.

const redeemKey = wanx.newRedeemKey('sha256');

Then define the details of the crosschain transaction. Basically all of the WanX crosschain methods require you to pass in this transaction object. The required values depend on chain and direction (more documentation is coming, but for now, check out the examples to see what is required).

// ETH inbound
const opts = {
  // from ETH address
  from: '0x8a964f3932ba80aa1c2310a6cf3fbe5ddbabc673',

  // to WAN address
  to: '0xa6d72746a4bb19f46c99bf19b6592828435540b0',

  // amount of ETH to convert to WETH
  value: '10000000000000000',

  // storeman addresses
  storeman: {
    wan: '0x06daa9379cbe241a84a65b217a11b38fe3b4b063',
    eth: '0x41623962c5d44565de623d53eb677e0f300467d2',
  },

  // add in the redeem key
  redeemKey,
};

Do the transaction

If you have web3 objects that are already able to sign (where the provider is an unlocked account or something else that can sign, like MetaMask), then sending is as easy as creating the new transaction object and calling send. You then can use events to log or react to each step of the crosschain transaction.

// create a new crosschain tx (chain = 'ETH', inbound = true)
const cctx = wanx.newChain('ETH', true);

// do the inbound crosschain tx
cctx.send(opts);

// set up event handlers
cctx.on('info', info => {
  console.log('INFO:', info);
});

cctx.on('error', err => {
  console.log('ERROR:', err);
  cctx.removeAllListeners();
});

cctx.on('complete', res => {
  console.log('COMPLETE!!!', res);
  cctx.removeAllListeners();
});

If you need to handle the signing separately, you can get the raw transactions to be signed. For example, use the buildLockTx method to get the raw lock tx.

// get the raw lock tx
const lockTx = cctx.buildLockTx(opts);

// set the nonce on the tx
lockTx.nonce = web3eth.utils.toHex(txCount);

// sign the tx with the private key
const transaction = new EthTx(lockTx);
transaction.sign(ethPrivateKey);
const serializedTx = transaction.serialize().toString('hex');

There are generally several independent transactions that comprise a crosschain transaction, and thus the downside of signing manually is that you will have to handle the steps yourself. See examples below for a full crosschain transaction with signing handled outside of WanX.