Parses an ERC20 Transfer from the Ethereum API.

parseErc20Transfer.js

const converter = require("hex2dec");
const Eth = require("ethjs");
const eth = new Eth(new Eth.HttpProvider(process.env.INFURA));

async function getERC20TransferByHash(hash) {
  const ethTxData = await eth.getTransactionByHash(hash);
  if (ethTxData === null) throw "TX NOT FOUND";
  if (
    ethTxData.input.length !== 138 ||
    ethTxData.input.slice(2, 10) !== "a9059cbb"
  ) {
    throw "NO ERC20 TRANSFER";
  }
  const receiver = `0x${ethTxData.input.slice(34, 74)}`;
  const amount = converter.hexToDec(ethTxData.input.slice(74));
  const symbol = ethTxData.to;
  const sender = ethTxData.from;
  return { receiver, amount, symbol, hash, sender };
}
getERC20TransferByHash(
  "0xd1a2033b3a81d130241e097468554d7d626947c146c8ecd9a4c1b36fc6e45e54"
).then(console.log);

/*
{
  receiver: '0x7dcda8fd073a1dab84976d7876634efbc61f5f15',
  amount: '500000000000000000000',
  symbol: '0x8eef5a82e6aa222a60f009ac18c24ee12dbf4b41',
  hash: '0xd1a2033b3a81d130241e097468554d7d626947c146c8ecd9a4c1b36fc6e45e54',
  sender: '0x3aba231a90befc61224bac50529f9e5f5058606e'
}
*/

Full guide: https://berndstrehl.medium.com/parsing-an-erc20-transfer-with-javascript-from-the-eth-api-2790da37e55f