Multicalls

Multicall is a key advantage of Account abstraction that enables you to aggregate multiple transactions into one.

Think about the Approve + Swap feature present on most DEXes. What if you could aggregate both calls into one? That would create a huge impact on dApps UX right? Welcome to Multicalls.

To understand how to aggregate calls, we need to first take a look at the execute method on the account object.

The execute method

The execute method executes one or multiple calls using the account contract. If there is only one call, transactions will be an object that contains the parameters below. If there are multiple calls, transactions will be an array of transactions objects:

The transactions object structure:

• contractPayload.contractAddress - the address of the contract

• contractPayload.entrypoint - the entrypoint of the contract

• contractPayload.calldata - (defaults to []) the calldata

• contractPayload.signature - (defaults to []) the signature

abi - (optional) the abi of the contract for better displaying

The transactionsDetail object may include any of:

• transactionsDetail.maxFee - Max Fee that will be used to execute the call(s)

• transactionsDetail.nonce - Nonce for the transaction

• transactionsDetail.version - Version for the transaction (default is 1)

Single vs Multicalls

In this section, we are going to take a look at how you perform single vs multiple calls using the execute method.

Single call:

const call = await account.execute(
  {
    contractAddress: '0x049d36570d4e46f48e99674bd3fcc84644ddd6b96f7c741b1562b82f9e004dc7',  // ETH contract address
    entrypoint: 'approve',
    calldata: starknet.stark.compileCalldata(
      {
        spender: "0x15e90f807a00a01df845460324fbcd33986f2df3cc9d981e9e8b5005b7f595e",
        amount: {
          type: 'struct',
          low: '1',   // 1 wei
          high: '0',
        }
      }
    ),
  },
  undefined,
  {
    nonce: '10',
  }
);

multicalls:

const multiCall = await account.execute(
  [
    {
      contractAddress: '0x049d36570d4e46f48e99674bd3fcc84644ddd6b96f7c741b1562b82f9e004dc7',  // ETH contract address
      entrypoint: 'approve',
      calldata: starknet.stark.compileCalldata(
        {
          spender: "0x15e90f807a00a01df845460324fbcd33986f2df3cc9d981e9e8b5005b7f595e",
          amount: {
            type: 'struct',
            low: '1',   // 1 wei
            high: '0',
          }
        }
      ),
    },
    {
      contractAddress: '0x15e90f807a00a01df845460324fbcd33986f2df3cc9d981e9e8b5005b7f595e',
      entrypoint: 'transfer_ether',
      calldata: ['1', '0'],  // 1 wei
    }
  ],
  undefined,
  {
    nonce: '10',
  }
);