Delegate Call

One superpower that ZeroDev wallets have is delegatecall. Since ZeroDev wallets are smart contract wallets, they are able to delegate their execution to other contracts. This essentially allows the wallets' functionality to be infinitely extended.

As an example, say you want to, in a single transaction, sell a number of USDC for ETH, and then stake all the ETH via Lido.

If you had read the tutorial on batching, you might think that you can do this via a batch. The challenge, however, is that the amount of ETH you obtain from selling USDC is not precisely known until the sale is executed, so you wouldn't be able to precisely determine how much ETH you would be staking, at the time you execute the batch.

With delegatecall, however, you would be able to write a contract like this (in pseudo-solidity):

contract SellAndStake {
  function execute(uint256 usdcAmount) public {
    uint256 ethAmount = uniswap.sellUSDC(usdcAmount);
    lido.stake(ethAmount)
  }
}

And then you'd delegatecall this contract from your wallet:

const signer = await getZeroDevSigner(...)
const sellAndStakeContract = new ethers.Contract(address, abi, signer)
await signer.execDelegateCall({
  to: sellAndStakeContract.address,
  data: sellAndStakeContract.interface.encodeFunctionData('execute', [usdcAmount]),
})

Therefore, one way to think about delegatecall is that it's batching on steroids -- you can use the result from each step of the batch in later steps. Unlike batching, however, delegatecall requires you to write and deploy the smart contract you are delegating to, so it's mostly suitable for advanced multi-step transactions, while batching would suffice for simple multi-step transactions.

API

Ethers

// signer is an instance of ZeroDevSigner
const tx = await signer.execDelegateCall({
  to: contract.address,
  data: contract.interface.encodeFunctionData('functionName', [arg1, arg2]),
})
const receipt = await tx.wait()

• signer is an instance of ZeroDevSigner
• contract is an instance of Ethers Contract. This is the contract you are delegating to.
• functionName and arg1/arg2 should be replaced with the actual function name and arguments.