Send a transaction

send_a_transaction.js

// require dependencies
const Web3 = require('web3');
const EthTx = require('ethereumjs-tx').Transaction;

// assign address and private key to account
const account = {
    address: 'YOUR_ETHEREUM_ADDRESS_GOES_HERE', // Your address goes here
    privateKey: 'YOUR_PRIVATE_KEY_GOES_HERE' // Your private key goes here
};

const rpcURL = 'YOUR_URL_GOES_HERE'; // Your RPC URL goes here

const username = 'YOUR_USERNAME_GOES_HERE'; // your BLOCKCHAIN GATEWAY username goes here
const password = 'YOUR_PASSWORD_GOES_HERE'; // your BLOCKCHAIN GATEWAY password goes here
let creds = username + ':' + password;
const secURL = 'https://' + creds + '@' +  rpcURL;

const provider = new Web3.providers.HttpProvider(secURL);
const web3 = new Web3(provider);


const transact = async () => {
    const txnCount = await web3.eth.getTransactionCount(account.address);

    const rawTx = {
        nonce: web3.utils.toHex(txnCount),
        gasLimit: web3.utils.toHex(21008),
        gasPrice: web3.utils.toHex(web3.utils.toWei('100', 'gwei')),
        to: account.address,
        value: '0x00'
    };

    // sign and serialize the transaction

    const tx = new EthTx(rawTx, {chain: 'ropsten'});
    const privKey = Buffer.from(account.privateKey, 'hex');
    tx.sign(privKey);

    let serializedTx = tx.serialize();

    web3.eth.sendSignedTransaction('0x' + serializedTx.toString('hex'))
        .once('transactionHash', console.log)
        .on('receipt', console.log)
        .on('error', err => console.error(err))
        .catch((err) => console.log);
};

transact();