rsk3.js - RSK Javascript API


npm install @rsksmart/rsk3


import Rsk3 from '@rsksmart/rsk3';

// Create a Rsk3 instance
const rsk3Instance = new Rsk3('http://localhost:4444');

// Get gas estimate
const gas = await rsk3Instance.estimateGas(txObject);
console.log('gas', gas);
> 5940000

// Get balance of a RSK address
const balance = await rsk3Instance.getBalance(address);
console.log('balance', balance);
> 200000000000000

// Send a signed transaction

// Methods in Rsk3.utils can be used without Rsk3 instantiation, for example
> true


This example shows a complete code snippet to construct and send a transaction with Rsk3.

import Rsk3 from '@rsksmart/rsk3';
const rsk3 = new Rsk3('http://localhost:4444');
const publicKey = '';
const privateKey = '';
const toAddress = '';

const accountInfo = await rsk3.accounts.privateKeyToAccount(privateKey);
const nonce = await rsk3.getTransactionCount(publicKey);
const chainId = await;
const gasPrice = await rsk3.getGasPrice();

// 1. Construct rawTransaction object to get gas estimate; note that estimateGas's parameter object can not include chainId
const value = new BigNumber(10).exponentiatedBy(15); // 10^15 wei

const rawTransaction = {
    from: publicKey,
    to: toAddress,
    value: Rsk3.utils.toHex(value.toNumber()),
    nonce: Rsk3.utils.toHex(nonce),
    data: '',

const gas = await rsk3.estimateGas(rawTransaction);

// 2. Add both chainId and gas to rawTransaction object
_.extend(rawTransaction, { chainId, gas });

// 3. Sign the rawTransaction with a specific private key
const signedTransaction = await accountInfo.signTransaction(rawTransaction, privateKey);

// 4. Send the signed transaction and use event emitter to capture response
await new Promise((resolve, reject) => {
    .on('transactionHash', (hash) => {
        console.log('Get Transaction Hash: unconfirmed.', hash);
        return resolve();
    .on('receipt', (receipt) => {
        console.log('receipt', receipt);
        return resolve();
    .on('confirmation', (confirmationNumber, receipt) => {
        console.log('Get Transaction Hash: confirmation No.: ', confirmationNumber, ', receipt', receipt);
        return resolve();
    .on('error', (error) => {
        console.error('error', error);
        return reject();


Install all dependencies for npm run bootstrap

npm run bootstrap

Examine formatting of source code using eslint

npm run lint

Run all tests

npm run test

Remove all the node_modules folders in all modules

npm run clean


Testing is done using jest. The configuration file jest.config.js and jest.preprocessor.js apply to tests in all packages.

To run all tests, under the root run

  1. npm run bootstrap
  2. npm run test OR npm run test:coverage

To run single package tests, under the root run

  1. npm run bootstrap
  2. npx lerna run --scope package_name test


Code Formatting is done using eslint. .eslintrc.json under root configures formatting rules for the whole project, and .eslintignore file exclude files watched by eslint.

Release process

Decide on the new version number, in this example we shall use 12.34.56.

Check out a release branch to prepare a pull request:

git checkout -b proj/release-12.34.56

This command uses lerna to bump the version number in all of the packages:

npm run release -- 12.34.56

$ git status
On branch proj/release-12.34.56
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

        modified:   lerna.json
        modified:   packages/rsk3-abi/package.json
        modified:   packages/rsk3-account/package.json
        modified:   packages/rsk3-contract/package.json
        modified:   packages/rsk3-net/package.json
        modified:   packages/rsk3-personal/package.json
        modified:   packages/rsk3-utils/package.json
        modified:   packages/rsk3/package.json

Add, commit, tag, and push:

git add -p
git commit -m "proj: release v12.34.56"
git push origin proj/release-12.34.56

Create a pull request, get it reviewed, and merge to master

Create a tag for the new version number:

git fetch origin master:master
git checkout master
git tag v12.34.56 -m v12.34.56
git push origin --tags

Publish new versions of all the packages on npm:

npm run publish


The majority of code in packages are similar to those with the same name in Web3.js, and will be upgraded in sync with Web3.js