Kyber Network Web3 Calls (created to fixed errors in the gist: https://gist.github.com/RohanKapurDEV/5fc4dc3cd73e54268b0f5895be58228a)

kyberTrade.js

var Tx = require('ethereumjs-tx');
var Web3 = require('web3');
var web3 = new Web3('https://ropsten.infura.io');

const PRIVATE_KEY = Buffer.from('257C463ADDD55B757CCF109E4D7A3CC0E47F04D8EE591C4F7432C7501AC4C875', 'hex');
const srcTokenAddress = '0x4BFBa4a8F28755Cb2061c413459EE562c6B9c51b'; // OMG Token Address
const srcTokenABI = [{"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":"INITIAL_SUPPLY","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_value","type":"uint256"}],"name":"burn","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"_owner","type":"address"}],"name":"balanceOf","outputs":[{"name":"balance","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_from","type":"address"},{"name":"_value","type":"uint256"}],"name":"burnFrom","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","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":"remaining","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"inputs":[{"name":"_name","type":"string"},{"name":"_symbol","type":"string"},{"name":"_decimals","type":"uint256"}],"payable":false,"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"name":"_burner","type":"address"},{"indexed":false,"name":"_value","type":"uint256"}],"name":"Burn","type":"event"},{"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"}];
const destTokenAddress = '0x4E470dc7321E84CA96FcAEDD0C8aBCebbAEB68C6'; // KNC Token Address
const kyberNetProxyAddress = '0x818E6FECD516Ecc3849DAf6845e3EC868087B755';
const kyberNetProxyABI = [{"constant":false,"inputs":[{"name":"alerter","type":"address"}],"name":"removeAlerter","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"enabled","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"pendingAdmin","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"getOperators","outputs":[{"name":"","type":"address[]"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"src","type":"address"},{"name":"srcAmount","type":"uint256"},{"name":"dest","type":"address"},{"name":"destAddress","type":"address"},{"name":"maxDestAmount","type":"uint256"},{"name":"minConversionRate","type":"uint256"},{"name":"walletId","type":"address"},{"name":"hint","type":"bytes"}],"name":"tradeWithHint","outputs":[{"name":"","type":"uint256"}],"payable":true,"stateMutability":"payable","type":"function"},{"constant":false,"inputs":[{"name":"token","type":"address"},{"name":"srcAmount","type":"uint256"},{"name":"minConversionRate","type":"uint256"}],"name":"swapTokenToEther","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"token","type":"address"},{"name":"amount","type":"uint256"},{"name":"sendTo","type":"address"}],"name":"withdrawToken","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"maxGasPrice","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"newAlerter","type":"address"}],"name":"addAlerter","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"kyberNetworkContract","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"user","type":"address"}],"name":"getUserCapInWei","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"src","type":"address"},{"name":"srcAmount","type":"uint256"},{"name":"dest","type":"address"},{"name":"minConversionRate","type":"uint256"}],"name":"swapTokenToToken","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"newAdmin","type":"address"}],"name":"transferAdmin","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[],"name":"claimAdmin","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"token","type":"address"},{"name":"minConversionRate","type":"uint256"}],"name":"swapEtherToToken","outputs":[{"name":"","type":"uint256"}],"payable":true,"stateMutability":"payable","type":"function"},{"constant":false,"inputs":[{"name":"newAdmin","type":"address"}],"name":"transferAdminQuickly","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"getAlerters","outputs":[{"name":"","type":"address[]"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"src","type":"address"},{"name":"dest","type":"address"},{"name":"srcQty","type":"uint256"}],"name":"getExpectedRate","outputs":[{"name":"expectedRate","type":"uint256"},{"name":"slippageRate","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"user","type":"address"},{"name":"token","type":"address"}],"name":"getUserCapInTokenWei","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"newOperator","type":"address"}],"name":"addOperator","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_kyberNetworkContract","type":"address"}],"name":"setKyberNetworkContract","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"operator","type":"address"}],"name":"removeOperator","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"field","type":"bytes32"}],"name":"info","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"src","type":"address"},{"name":"srcAmount","type":"uint256"},{"name":"dest","type":"address"},{"name":"destAddress","type":"address"},{"name":"maxDestAmount","type":"uint256"},{"name":"minConversionRate","type":"uint256"},{"name":"walletId","type":"address"}],"name":"trade","outputs":[{"name":"","type":"uint256"}],"payable":true,"stateMutability":"payable","type":"function"},{"constant":false,"inputs":[{"name":"amount","type":"uint256"},{"name":"sendTo","type":"address"}],"name":"withdrawEther","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"token","type":"address"},{"name":"user","type":"address"}],"name":"getBalance","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"admin","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"inputs":[{"name":"_admin","type":"address"}],"payable":false,"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"name":"trader","type":"address"},{"indexed":false,"name":"src","type":"address"},{"indexed":false,"name":"dest","type":"address"},{"indexed":false,"name":"actualSrcAmount","type":"uint256"},{"indexed":false,"name":"actualDestAmount","type":"uint256"}],"name":"ExecuteTrade","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"newNetworkContract","type":"address"},{"indexed":false,"name":"oldNetworkContract","type":"address"}],"name":"KyberNetworkSet","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"token","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"sendTo","type":"address"}],"name":"TokenWithdraw","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"sendTo","type":"address"}],"name":"EtherWithdraw","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"pendingAdmin","type":"address"}],"name":"TransferAdminPending","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"newAdmin","type":"address"},{"indexed":false,"name":"previousAdmin","type":"address"}],"name":"AdminClaimed","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"newAlerter","type":"address"},{"indexed":false,"name":"isAdd","type":"bool"}],"name":"AlerterAdded","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"newOperator","type":"address"},{"indexed":false,"name":"isAdd","type":"bool"}],"name":"OperatorAdded","type":"event"}];

const kyberNetProxyContract = new web3.eth.Contract(kyberNetProxyABI, kyberNetProxyAddress);
const userAddress = '0x1751152e20E80a87618591cABd6CF821cad61E34';

const srcTokenContract = new web3.eth.Contract(srcTokenABI, srcTokenAddress);

const srcTokenAmountNative = '1';

async function approveContract() {
    const txCount = await web3.eth.getTransactionCount(userAddress);
    const txData = srcTokenContract.methods.approve(
        kyberNetProxyAddress,
        web3.utils.toWei('10000')
    ).encodeABI();

    const rawTransaction = new Tx({
        from: userAddress,
        to: srcTokenAddress,
        data: txData,
        gasLimit: web3.utils.toHex('120000'),
        gasPrice: web3.utils.toHex(web3.utils.toWei('20', 'gwei')), 
        nonce: txCount
    });

    rawTransaction.sign(PRIVATE_KEY);
    const serializedTransaction = rawTransaction.serialize();
    txReceipt = await web3.eth.sendSignedTransaction('0x' + serializedTransaction.toString('hex')).catch(error => console.log(error));
    console.log(txReceipt);
}

async function trade(txNum) {
    const txCount = await web3.eth.getTransactionCount(userAddress) + txNum;
    const expectedRateCall = await kyberNetProxyContract.methods.getExpectedRate(srcTokenAddress, destTokenAddress, web3.utils.toWei(srcTokenAmountNative)).call();
    console.log(expectedRateCall);
    const expectedRate = expectedRateCall.expectedRate;
    const slippageRate = expectedRateCall.slippageRate;

    const srcAmount = web3.utils.toWei(srcTokenAmountNative);
    const maxDestAmount = web3.utils.toWei('9999999');
    const minConversionRate = slippageRate;
    const walletId = '0x0000000000000000000000000000000000000000';

    const txData = kyberNetProxyContract.methods.trade(
        srcTokenAddress,
        srcAmount,
        destTokenAddress,
        userAddress,
        maxDestAmount,
        minConversionRate,
        walletId
    ).encodeABI();

    const rawTransaction = new Tx({
        from: userAddress,
        to: kyberNetProxyAddress,
        data: txData,
        gasLimit: web3.utils.toHex('500000'),
        gasPrice: web3.utils.toHex(web3.utils.toWei('20', 'gwei')),
        nonce: txCount
    });

    rawTransaction.sign(PRIVATE_KEY);
    const serializedTransaction = rawTransaction.serialize();
    txReceipt = await web3.eth.sendSignedTransaction('0x' + serializedTransaction.toString('hex')).catch(error => console.log(error));
    console.log(txReceipt);
}

async function initTrade() {
    const contractAllowance = await srcTokenContract.methods.allowance(userAddress, kyberNetProxyAddress).call();
    if (web3.utils.toWei(srcTokenAmountNative) <= contractAllowance) {
        trade(0);
    } else {
        approveContract();
        trade(1);
    }
}

initTrade();