How to use ethereum-multicall on a local hardhat node

ethers-multicall actually uses MakerDAO multicall contracts for multicall functionality. On a local chain this contract is not deployed, therefore the request fails with

Uncaught (in promise) Error: invalid contract address or ENS name (argument="addressOrName", value=undefined, code=INVALID_ARGUMENT, version=contracts/5.6.2)

To fix this issue, the MakerDAO-s multicall contract needs to be deployed on the local node.

Copy the Multicall.sol contract to your local project. The contract is available in MakerDAO repository
Add this contract to your deployments. Be sure to only deploy to localhost.

const deploy: DeployFunction = async function (hre: HardhatRuntimeEnvironment) {
    // @ts-ignore
    const { deployments, getNamedAccounts, network } = hre
    const chainId = network.config.chainId ?? 31337

    // only deploy to local chain
    if (chainId !== LOCAL_CHAIN_ID) return

    const { deployer } = await getNamedAccounts()
    const { deploy  } = deployments

    console.log("--- deploying Multicall")
    await deploy("Multicall", {
        from: deployer,
        args: [],
        log: true,
        waitConfirmations: 1,
    })
    console.log("---")
}

Result of the deployment:

--- deploying Multicall
deploying "Multicall" (tx: 0x5305de50721abf4b55da6cc4147d72abc5efb5b1e41de984ca6e9456905c26f4)...: deployed at 0x5FbDB2315678afecb367f032d93F642f64180aa3 with 646671 gas
---

Make the ethereum-multicall use this contract for local chain

import { setMulticallAddress } from "ethers-multicall"

setMulticallAddress(LOCAL_CHAIN_ID, "0x5FbDB2315678afecb367f032d93F642f64180aa3")

Now when using multicall on localhost, the contract queries are forwarded to the correct multicall contract, and they return without error.

Note

Please note that ethers-multicall is all or nothing. If one call fails, the whole batch fails. Consider ethereum-multicall or MakerDAO-s multicall.js, which use the Multicall2 contract. This contract returns both successful and failed calls.

Source code

Mint a Knowledge Token to access the example Typescript project with Multicall2 deployment to a hardhat local node. Also included is a React frontend that reads values from a contract with ethereum-multicall.