To follow this tutorial is necessary to setup the project folder accordingly to the method that you are going to be using for creating the account. Follow these instructions for setting up the project folder:

Using goloop CLI

Goloop CLI (opens in a new tab) is a terminal utility that you can use to generate accounts and make RPC JSON requests easily from the command line.

For a list of all the commands that you can use please visit the following link (opens in a new tab).

Generating private keys, public keys and addresses

Using the goloop CLI you can create keystores files (opens in a new tab) (accounts) easily by using the following command:

$ goloop ks gen -p 1234

The -p flag can be used to setup the password for the keystore file.

Generating a signature and sending an RPC JSON request

Authentication and generating the signature for a transaction is handled internally by the goloop CLI, you just need to specify the keystore file and the password to send the RPC JSON request for a transaction.

An example of a transaction for sending ICX to another account is described in the following code block:

$ goloop rpc sendtx transfer --uri "http://localhost:9000/api/v3" --nid "3" --step_limit "2000000" --to "hxb6b5791be0b5ef67063b3c10b840fb81514db2fd" --value "1000" --key_password "1234" --key_store ./path/to/wallet.json

For a list of all possible commands related to RPC JSON Requests please visit the following link (opens in a new tab).

Using icon-sdk-js

Generating private keys, public keys and addresses

To create a wallet we can simply call the .create() method of the IconWallet object in the icon-sdk-js.

const IconService = require("icon-sdk-js");
const { IconWallet } = IconService.default;
const wallet = IconWallet.create();
console.log(`Private Key: ${wallet.getAddress()}`);
console.log(`Private Key: ${wallet.getPrivateKey()}`);

You can call existing EOA by calling loadKeystore and loadPrivateKey function.

After creation, address and private Key can be looked up.

// Load Wallet with private key
const walletLoadedByPrivateKey = IconWallet.loadPrivateKey('38f792b95a5202ab431bfc799f7e1e5c74ec0b9ede5c6142ee7364f2c84d72f6');
// Output: hx902ecb51c109183ace539f247b4ea1347fbf23b5
// Output: 38f792b95a5202ab431bfc799f7e1e5c74ec0b9ede5c6142ee7364f2c84d72f6);
// Get keystore object from wallet. Keystore file will have a password
const keystoreFile ='qwer1234!');
// Load wallet with keystore file
const walletLoadedByKeyStore = IconWallet.loadKeystore(keystoreFile, 'qwer1234!');
// Output: hx902ecb51c109183ace539f247b4ea1347fbf23b5
// Output: 38f792b95a5202ab431bfc799f7e1e5c74ec0b9ede5c6142ee7364f2c84d72f6);

After Wallet object creation, Keystore file can be stored by calling store function. After calling store, Keystore JSON object can be looked up with the returned value.

const privateKey = '38f792b95a5202ab431bfc799f7e1e5c74ec0b9ede5c6142ee7364f2c84d72f6';
const wallet = IconWallet.loadPrivateKey(privateKey);
// Output:
// {
// "version": 3,
// "id": "e00e113c-1e45-47e4-b732-10f3d1903d75",
// "address": "hx7d3d4c743bb82b927ea8a0551a3b9288e722ac84",
// "crypto": {
//     "ciphertext": "d5df37230528bbfc0015e93c61e60041a31fb63266f61ffec60a31f474d4d7d0",
//     "cipherparams": {
//         "iv": "feaf0cc19678e4b78369904a99ba411e"
//     },
//     "cipher": "aes-128-ctr",
//     "kdf": "scrypt",
//     "kdfparams": {
//         "dklen": 32,
//         "salt": "e2e3666919161044f7b369d6ad4296380d4a13b9b5e844301c64a502ea3da240",
//         "n": 16384,
//         "r": 8,
//         "p": 1
//     },
//     "mac": "43789e78de4744d06c14cf966b9609fadbcd815b5380caf3f778797f9824d9d7"
// }
// }

Generating a signature and sending an RPC JSON request

Using the icon-sdk-js we can create a transaction object using the IcxTransactionBuilder class and then create the signature using the SignedTransaction class.

const IconService = require("icon-sdk-js");
const {
} = IconService.default;
const { IcxTransactionBuilder } = IconBuilder;
function signTx(wallet, to, amount) {
  try {
    // select the correct NID depending on the network
    const nid = 2;
    // convert amount to transfer into loop units, which is the smallest unit of currency
    const amountInLoop = IconAmount.of(amount, IconAmount.Unit.ICX).toLoop();
    const txObj = new IcxTransactionBuilder()
      .timestamp(new Date().getTime() * 1000)
    const signedTx = new SignedTransaction(txObj, wallet);
    return signedTx;
  } catch (err) {
    console.log("Unexpected error signing transaction");
    return null;
// private key of wallet sending transaction
const pk = "1111111111111111111111111111111111111111111111111111111111111111";
// create wallet from private key
const wallet = IconWallet.loadPrivateKey(pk);
// address receiving the transfer
const addressTo = "hx1111111111111111111111111111111111111111";
const signedTx = signTx(wallet, addressTo, 1);
console.log(`signed tx: ${JSON.stringify(signedTx.getProperties())}`);

The result will be the params of the RPC JSON call like in the following example:

  "to": "hx1111111111111111111111111111111111111111",
  "from": "hx396031be52ec56955bd7bf15eacdfa1a1c1fe19e",
  "nid": "0x2",
  "version": "0x3",
  "timestamp": "0x5f55518cac340",
  "stepLimit": "0x1e8480",
  "value": "0xde0b6b3a7640000",
  "nonce": "0x1",
  "signature": "TCaN1RDt8MpVKD2/Fk/PTrHfqHgyaN0ZiiyVkGOmzBYoCJ9iO5H+qyuI1M7nshONy7DHk5w3g+nmsSETOyd9FgE="

To send the transaction it will be necessary to first create an instance of the IconService with the correct HttpProvider depending on the network that you want to use and then run an async call to execute the transaction.

const IconService = require("icon-sdk-js");
const {
  HttpProvider // we import the HttpProvider class
} = IconService.default;
 // …
 // …
const httpProvider = new HttpProvider(
const iconService = new IconService.default(httpProvider);
async function runAsync() {
  const txHash = await iconService.sendTransaction(signedTx).execute();
  console.log(`TxHash: ${txHash}`);

Further Resources