run-arbitrage.js

require('dotenv').config();
const Web3 = require('web3');
const { ChainId, Token, TokenAmount, Fetcher } = require('@uniswap/sdk');
const abis = require('./abis');
const {mainnet: addresses } = require('./addresses');
const Flashloan = require('./build/contracts/Flashloan.json');

const web3 = new Web3(
    new Web3.providers.WebsocketProvider(process.env.INFURA_URL)
);

const {address: admin} = web3.eth.accounts.wallet.add(process.env.INFURA_URL);

const kyber = new web3.eth.Contract(
    abis.kyber.kyberNetworkProxy,
    addresses.kyber.kyberNetworkProxy
);

const AMOUNT_ETH = 100;
const RECENT_ETH_PRICE = 1521;
const AMOUNT_ETH_WEI = web3.utils.toWei(AMOUNT_ETH.toString());
const AMOUNT_DAI_WEI = web3.utils.toWei((AMOUNT_ETH * RECENT_ETH_PRICE).toString());
const DIRECTION = {KYBER_TO_UNISWAP: 0, UNISWAP_TO_KYBER: 1};

const init = async () => {
    const networkId = await web3.eyh.net.getId();
    const flashloan = new web3.eth.Contract(Flashloan.abi, Flashloan.networks[networkId].address);

    const [dai, weth] = await Promise.all(
        [addresses.tokens.dai, addresses.tokens.weth].map(tokenAddress => (
            Fetcher.fetchTokenData(
                ChainId.MAINNET,
                tokenAddress
            )
        )));
        const daiWeth = await Fetcher.fetchPairData(
            dai,
            weth
        );

    web3.eth.subscribe('newBlockHeaders')
        .on('data', async block => {
            console.log(`New block received. Block # ${block.number}`);

            const kyberResults = await Promise.all([
                kyber.methods.getExpectedRate(
                        addresses.tokens.dai,
                        '0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee',
                        AMOUNT_DAI_WEI
                    ).call(),
                kyber.methods.getExpectedRate(
                        '0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee',
                        addresses.tokens.dai,
                        AMOUNT_ETH_WEI
                    ).call()
            ]);
            const kyberRates = {
                buy: parseFloat(1 / (kyberResults[0].expectedRate / (10 ** 18))),
                sell: parseFloat(kyberResults[1].expectedRate / (10 ** 18))
            };
            console.log('Kyber ETH/DAI');
            console.log(kyberRates);

            const uniswapResults = await Promise.all([
                daiWeth.getOutputAmount(new TokenAmount(dai, AMOUNT_DAI_WEI)),
                daiWeth.getOutputAmount(new TokenAmount(weth, AMOUNT_ETH_WEI)),
            ]);

            const uniswapRates = {
                buy: parseFloat(AMOUNT_DAI_WEI / (uniswapResults[0][0].toExact() * 10 ** 18)),
                sell: parseFloat(uniswapResults[1][0].toExact() / AMOUNT_ETH)
            };

            console.log('Uniswap ETH/DAI');
            console.log(uniswapRates);

            const [tx1, tx2] = Object.keys(DIRECTION).map(direction => flashloan.methods.initiateFlashloan)(
            (
                addresses.dydx.solo,
                addresses.tokens.dai,
                AMOUNT_DAI_WEI,
                DIRECTION[direction]
            ));
            const [gasPrice, gasCost1, gasCost2] = await Promise.all([
                web3.eth.getGasPrice(),
                tx1.estimateGas({from: admin }), 
                tx2.estimateGas({from: admin })
            ]);

            const txCost1 = parseInt(gasCost1) * parseInt(gasPrice);
            const txCost2 = parseInt(gasCost2) * parseInt(gasPrice);
            const currentEthPrice = (uniswapRates.buy + uniswapRates.sell) / 2;
            const profit1 = (parseInt(AMOUNT_ETH_WEI) / 10 ** 18) * (uniswapRates.sell - kyberRates.buy) - (txCost1 / 10 ** 18) * currentEthPrice;
            const profit2 = (parseInt(AMOUNT_ETH_WEI) / 10 ** 18) * (kyberRates.sell - uniswapRates.buy) - (txCost2 / 10 ** 18) * currentEthPrice;
            
            if (profit1 > 0){
                console.log('Arb opportunity found!');
                console.log(`Buy ETH on Kyber at ${kyberRates.buy} dai`);
                console.log(`Sell ETH on Uniswap at ${uniswapRates.sell} dai`);
                console.log(`Expected profit ${profit1} dai`);
                const data = tx1.encodeABI();
                const txData = {
                    from: admin,
                    to: flashloan.options.address,
                    data,
                    gas: gasCost1,
                    gasPrice
                };
                const receipt = await web3.eth.sendTransaction(txData);
                console.log(`Transaction hash: ${receipt.transactionHash}`);
            }
            else if(profit2 > 0){
                console.log('Arb opportunity found!');
                console.log(`Buy ETH on Uniswap at ${uniswapRates.buy} dai`);
                console.log(`Sell ETH on Kyber at ${kyberRates.sell} dai`);
                console.log(`Expected profit ${profit2} dai`);
                const data = tx2.encodeABI();
                const txData = {
                    from: admin,
                    to: flashloan.options.address,
                    data,
                    gas: gasCost2,
                    gasPrice
                };
                const receipt = await web3.eth.sendTransaction(txData);
                console.log(`Transaction hash: ${receipt.transactionHash}`);
            }
        })
        .on('error', error => {
            console.log(error);
        });
}
init();