odcey / ethcall

ethers.js-compatible wrapper around Multicall

ethcall

Utility library to make calls to Ethereum blockchain.

Uses MakerDAO's Multicall contracts to make multiple requests in a single HTTP query. Encodes and decodes data automatically.

Powered by abi-coder and ethers.js.

npm install ethcall

API

• Contract(address, abi): create contract instance; calling contract.call_func_name will yield a call object.
• all(calls): execute all calls in a single request.
• tryAll(calls): execute all calls in a single request. Ignores reverted calls and returns null value in place of return data (wrapper on top of tryAggregate method).
• tryEach(calls, canFail): execute all calls in a single request. Ignores reverted calls and returns null value in place of return data for the calls that are allowed to fail (wrapper on top of aggregate3 method).
• calls: list of helper call methods
  • getEthBalance(address): returns account ether balance

Example

import { InfuraProvider } from '@ethersproject/providers';
import { Contract, Provider } from 'ethcall';

import erc20Abi from './abi/erc20.json';

const infuraKey = 'INSERT_YOUR_KEY_HERE';
const provider = new InfuraProvider('mainnet', infuraKey);

const daiAddress = '0x6b175474e89094c44da98b954eedeac495271d0f';

async function call() {
  const ethcallProvider = new Provider();
  await ethcallProvider.init(provider);

  const daiContract = new Contract(daiAddress, erc20Abi);

  const uniswapDaiPool = '0x2a1530c4c41db0b0b2bb646cb5eb1a67b7158667';

  const ethBalanceCall = ethcallProvider.getEthBalance(uniswapDaiPool);
  const daiBalanceCall = daiContract.balanceOf(uniswapDaiPool);

  const data = await ethcallProvider.all([ethBalanceCall, daiBalanceCall]);

  const ethBalance = data[0];
  const daiBalance = data[1];

  console.log('eth balance', ethBalance.toString());
  console.log('dai balance', daiBalance.toString());
}

call();

Deployless Multicall

If you query a chain on which Multicall is not deployed, or if you query a historical block before the deployment of the contract, the deployless version will be used instead. In short, deployless Multicall "emulates" the deployed contract and returns the exact same data. Note that you can't query ETH balance using deployless version.

You can read more about deployless Multicall here.