I used this guide to deploy a smart contract with Node-js. I followed as far as my contract was created as an object. Because the mentioned guide is old some web3 methods changed nowadays. So it looks like i cannot continue following that. My question is "how do i assign address and data and gas to my contract object for deploying?". Please guide me with an appropriate code to deploy contract.


var Web3=require('web3');
var fs=require('fs');
var solc=require('solc');
var web3=new Web3('ws://');
var address="0xdC3881248306fd62bbA5d9F0FDD39b5693bd1737";
var contractAbi=[
        "constant": true,
        "inputs": [],
        "name": "notation",
        "outputs": [
                "internalType": "string",
                "name": "",
                "type": "string"
        "payable": false,
        "stateMutability": "pure",
        "type": "function"
var contract_sol=fs.readFileSync('E:/Deploy/contracts/Deploy.sol','utf8');
var contract_compiled=solc.compile(contract_sol);
for (let contractName in contract_compiled.contracts) {
var contract_byteCode=contract_compiled.contracts[contractName].bytecode;
var gasEstimate=web3.eth.estimateGas({data:contract_byteCode});
var contract_object=new web3.eth.Contract(contractAbi);
  • what is var address="0xdC3881248306fd62bbA5d9F0FDD39b5693bd1737"; for??? Mar 8, 2020 at 15:11
  • This is my Truffle address. I want to use it as address of contract creator.
    – Alireza
    Mar 8, 2020 at 15:28
  • Is your contract already deployed at that address? Mar 8, 2020 at 15:36
  • No, i didn't deploy the contract.
    – Alireza
    Mar 8, 2020 at 15:38
  • So how are you planning to deploy it specifically at that address (why and how did you choose it)? Mar 8, 2020 at 15:46

4 Answers 4


Just add the below code in the end of the question's code:

contract_object.deploy().send({from:<...>, gas:<...>, gasPrice:<...>});

I suggest you to read the below document to clear the syntax:



Assuming that you have already compiled the contract, and that its abi and bytecode are in files <ContractName>.abi and <ContractName>.bin respectively, you can use this script (web3 v1.2.1):

const fs   = require("fs");
const Web3 = require("web3");

const NODE_ADDRESS  = "...";
const PRIVATE_KEY   = "...";
const CONTRACT_NAME = "...";
const CONTRACT_ARGS = [...];

async function scan(message) {
    return await new Promise(function(resolve, reject) {
        process.stdin.once("data", function(data) {

async function getGasPrice(web3) {
    while (true) {
        const nodeGasPrice = await web3.eth.getGasPrice();
        const userGasPrice = await scan(`Enter gas-price or leave empty to use ${nodeGasPrice}: `);
        if (/^\d+$/.test(userGasPrice))
            return userGasPrice;
        if (userGasPrice == "")
            return nodeGasPrice;
        console.log("Illegal gas-price");

async function getTransactionReceipt(web3) {
    while (true) {
        const hash = await scan("Enter transaction-hash or leave empty to retry: ");
        if (/^0x([0-9A-Fa-f]{64})$/.test(hash)) {
            const receipt = await web3.eth.getTransactionReceipt(hash);
            if (receipt)
                return receipt;
            console.log("Invalid transaction-hash");
        else if (hash) {
            console.log("Illegal transaction-hash");
        else {
            return null;

async function send(web3, account, transaction) {
    while (true) {
        try {
            const options = {
                data    : transaction.encodeABI(),
                gas     : await transaction.estimateGas({from: account.address}),
                gasPrice: await getGasPrice(web3),
            const signed  = await web3.eth.accounts.signTransaction(options, account.privateKey);
            const receipt = await web3.eth.sendSignedTransaction(signed.rawTransaction);
            return receipt;
        catch (error) {
            const receipt = await getTransactionReceipt(web3);
            if (receipt)
                return receipt;

async function run() {
    const web3        = new Web3(NODE_ADDRESS);
    const account     = web3.eth.accounts.privateKeyToAccount(PRIVATE_KEY);
    const abi         = fs.readFileSync(CONTRACT_NAME + ".abi", {encoding: "utf8"});
    const bin         = fs.readFileSync(CONTRACT_NAME + ".bin", {encoding: "utf8"});
    const contract    = new web3.eth.Contract(JSON.parse(abi));
    const options     = {data: "0x" + bin, arguments: CONTRACT_ARGS};
    const transaction = contract.deploy(options);
    const receipt     = await send(web3, account, transaction);
    if (web3.currentProvider.constructor.name == "WebsocketProvider")

  • Thanks for your code. These two messages emerged and i don't know what should i do? 1- The data field must be HEX encoded data. and after that 2- Enter transaction-hash or leave empty to retry:. I don't know which transaction hash that means. Data field is const options = {data: "0x" + bin};. I set const NODE_ADDRESS = "ws://"; and const PRIVATE_KEY = to a private key belongs to a Ganache account.
    – Alireza
    Mar 9, 2020 at 6:45
  • Now that problem is eliminated. I set const options = {data: "0x" + bin}; to the bytecode that exists in Truffle json file and the mentioned messages never emerge.
    – Alireza
    Mar 9, 2020 at 6:49
  • @A.Kiakojouri: It means that you don't have a proper byte code in the file <CONTRACT_NAME >.bin. Mar 9, 2020 at 6:50
  • As I wrote at the top of the answer, it assumes that your bytecode is in file <CONTRACT_NAME >.bin. If you take it from the Truffle json output file, then I believe that it is already prefixed with "0x". Run console.log(bin) and find out for sure. Mar 9, 2020 at 6:52
  • Another problem. By this code the contract deployment occurs and Ganache shows it by a block mining. In the mined block it is mentioned that a smart contract created. But in contracts list of Ganache it is mentioned that the given contract is not deployed. What is the reason?
    – Alireza
    Mar 9, 2020 at 7:19

Hey if you are using truffle framework you can set your gas limit and gas price in your truffle-config.js file for different network and env like this:

module.exports = {

  networks: {
    development: {
    host: "",
    port: 7545,
    network_id: "*" // Match any network id
develop: {
  port: 8545
rinkeby: {
  provider: () => new HDWalletProvider(mnemonic, `https://rinkeby.infura.io/v3/${infuraKey}`),
    network_id: 4,       // rinkeby's id
    gas: 6500000,        // rinkeby has a lower block limit than mainnet
    gasPrice: 10000000000
  • I think you are using Rinkeby in your answer. But i want to use my own testnet. I think i should put gas and gasPrice in development field.
    – Alireza
    Mar 8, 2020 at 15:33

The code provided in the question lacks just the followed command in the end of itself to a smart contract be deployed:

contract_object.deploy().send({from: address, gas: gasEstimate, gasPrice:1000000});

address is the address of deployer account and gasEstimate determines the required value of gas to deploy this contract. If you put the both in .send(…) just as

 send({from: address, gas: gasEstimate});

In fact, you are telling contract_object should be deployed from the account with address address and with gasEstimate gas in the network.

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