Can anyone deduce why this doesn't show me all the PairCreated on Uniswap? It seems odd as I have seen it work once or twice during the day and ouput a log for a 'PairCreated', but I know there are many more that get added! Normally every 15mins or so.

Here is the beginning of the script...

const ethers = require('ethers');
const isTesting = false; // Kovan for testnet

const infuraWSS = isTesting ? 'wss://kovan.infura.io-------------' : 'wss://mainnet.infura.io----------------';

const addresses = {
  WETH: '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2',
  factory: '0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f', //uniswap v2 factory
  router: '0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D', //uniswap v2 router
  recipient: '-------------------' //this address receives the tokens (currently my main test account)

const mnemonic = '----------------------';

const provider = new ethers.providers.WebSocketProvider(infuraWSS);
const wallet = ethers.Wallet.fromMnemonic(mnemonic);
const account = wallet.connect(provider);

const factory = new ethers.Contract(
  ['event PairCreated(address indexed token0, address indexed token1, address pair, uint)'],
const router = new ethers.Contract(
    'function getAmountsOut(uint amountIn, address[] memory path) public view returns (uint[] memory amounts)',
    'function swapExactTokensForTokens(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline) external returns (uint[] memory amounts)'

factory.on('PairCreated', async (token0, token1, pairAddress) => {
  console.log(`** New Pair Detected **`);

Does anyone know why this might not be working? I took this from a repository, not all my code but I understand all of it - or at least think I do.


1 Answer 1


The issue seems to have been that the mnemonic did not match the 'recipient' wallet.

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