How do I get the correct 4bytes?

By 4bytes for executeOrder, you might be referring to the bytes corresponding to its function selector.

You can get the same, by using solidity (i.e., by adding a function within the same contract) as well as by using library like ethers.js in javascript.

Using Solidity:

// SPDX-License-Identifier: MIT pragma solidity ^0.8.24; contract Market { struct Props { address marketToken; address indexToken; address longToken; address shortToken; } } contract YourContract { // Define the ExecuteOrderParams struct struct ExecuteOrderParams { // Define struct properties here string stringParam; uint256 uintParam; Market.Props market; Market.Props[] swapPathMarkets; } // Function to execute order function executeOrder(ExecuteOrderParams memory params) external { // Implementation of the executeOrder function } // Function to get function signature bytes for executeOrder function getExecuteOrderSignature() external pure returns (bytes4) { return this.executeOrder.selector; } } 

Using Javascript:

const { ethers } = require("ethers"); // ABI of the contract containing the executeOrder() function const abi = [ { "inputs": [ { "components": [ { "internalType": "string", "name": "stringParam", "type": "string" }, { "internalType": "uint256", "name": "uintParam", "type": "uint256" }, { "components": [ { "internalType": "address", "name": "marketToken", "type": "address" }, { "internalType": "address", "name": "indexToken", "type": "address" }, { "internalType": "address", "name": "longToken", "type": "address" }, { "internalType": "address", "name": "shortToken", "type": "address" } ], "internalType": "struct Market.Props", "name": "market", "type": "tuple" }, { "components": [ { "internalType": "address", "name": "marketToken", "type": "address" }, { "internalType": "address", "name": "indexToken", "type": "address" }, { "internalType": "address", "name": "longToken", "type": "address" }, { "internalType": "address", "name": "shortToken", "type": "address" } ], "internalType": "struct Market.Props[]", "name": "swapPathMarkets", "type": "tuple[]" } ], "internalType": "struct YourContract.ExecuteOrderParams", "name": "params", "type": "tuple" } ], "name": "executeOrder", "outputs": [], "stateMutability": "nonpayable", "type": "function" }, { "inputs": [], "name": "getExecuteOrderSignature", "outputs": [ { "internalType": "bytes4", "name": "", "type": "bytes4" } ], "stateMutability": "pure", "type": "function" } ] // Create an instance of the Contract interface const iface = new ethers.utils.Interface(abi); // Get the function selector for the executeOrder function const executeOrderSelector = iface.getSighash("executeOrder"); console.log(executeOrderSelector); 

P.S., You can modify the properties of the struct ExecuteOrderParams as per your use-case. Also, use the contract's ABI accordingly.

In Solidity you can do:

import "contract.sol"; function getSelector() public view returns (bytes4) { return contract.executeOrder.selector; }