Cudos Blast

Cudos Blast is a Node.js CLI (command line interface) tool for working with the Cudos blockchain. You can scaffold, compile and test your Rust smart contracts. JavaScript and Rust testing is supported. Utilizing blast.config.js it provides a possibility for deploying and interacting with them on a specified network (local, test or public). By using this tool you can also spin up a local Cudos nodeopen in new window and interact with it.

Table of Contents


Make sure you have Node.jsopen in new window installed. Dockeropen in new window is also required.

PrerequisiteMinimum versionRecommended version
Docker engine19.03.1320.10.12
Docker compose1.

For Windows users we recommend using Windows Subsystem for Linux (WSLopen in new window). To avoid permission issues with WSL, you may have to changeopen in new window npm default directory.

Cudos Blast can be used through a local installation in your project or by installing it globally.

Local Installation

Create an npm project by going to an empty folder, then run npm init and follow the instructions. Once your project is ready, run npm install cudos-blast. To use your local installation of Cudos Blast, useĀ npx blast.

Global Installation

You can let npm completely manage Cudos Blast package just by using npx cudos-blast to directly run commands. That way you will always be using the latest version of Cudos Blast so it is possible to have future compatibility issues. We recommend running

npm install cudos-blast -g

to install globally and using Cudos Blast by blast as all the examples in this guide do.

Help and version

Run --help or help on any blast command to show all available subcommands, parameters and additional information.

blast --help
blast help
blast node --help
blast node start help

You can display cudos-blast version number using --version.

blast --version

Initializing a project

To scaffold a sample project navigate to empty directory (or your npm project for local cudos-blast installation) and run

blast init

You can also specify the full directory of the project using optional parameter --dir or -d

blast init --dir /Your/Location/Here

The project is now ready to work with the Cudos blockchain. It contains sample smart contracts and scripts to deploy or interact.

Make sure to initialize a new project in a directory other than the local repository folder, or else cudos-blast will break and the repository have to be cloned again.
Also, all blast commands are designed to be executed from the project root directory.

Compiling smart contracts

To compile all smart contracts run

blast compile

The contracts have to be in {project_root}/contracts/ folder. Cudos Blast comes with sample contracts you can use. All contracts are compiled in alphabetical order and as a Rust workspace. If you want to add more folders to compile, all you have to do is edit the base {project_root}/Cargo.toml file and add your folder under members. The compilation is done using rust-optimizeropen in new window and the artifacts in {project_root}/artifacts/ folder are optimized for deployment.

Running Rust tests

Rust tests are organized by the Rust convention for writing tests. You can check them in their corresponding contracts in {project_root}/contracts/{contract_name}/. To run smart contracts' Rust tests:

blast rusttest

To run the Rust tests without printing cargo log messages use --quiet or -q

blast rusttest -q

Testing contracts with JavaScript

Cudos Blast uses Jestopen in new window framework for testing. Test files must be in {project_root}/tests/ folder. You can use the provided sample test as a template or make one or more tests of your own. You can run the default local node in order to deploy or interact with the smart contracts in your tests. To connect to a non-local Cudos node such as testnet or your own node, follow these instructions.

describe('alpha contract', () => {
  const MSG_INIT = { count: 13 }
  const MSG_INCREMENT = { increment: {} }
  const MSG_RESET = { reset: { count: 1 } }
  const QUERY_GET_COUNT = { get_count: {} }

  let alice, bob, contract

  // deploying alpha contract once before test cases
  beforeAll(async () => {
    // 'bre' is available in global context
    [alice, bob] = await bre.getSigners()
    contract = await bre.getContractFactory('alpha')
    await contract.deploy(MSG_INIT, 'alpha', { signer: bob })

  // positive test case
  test('increment count', async () => {
    await contract.execute(MSG_INCREMENT, alice)
    return expect(contract.query(QUERY_GET_COUNT))
      .resolves.toEqual({ count: 14 })

  // ...

  // negative test case
  test('reset count from user throws unauthorized', () => {
    return expect(contract.execute(MSG_RESET, alice))

Run all test files with

blast test
blast test -n testnet

You can also run the tests with disabled console logging and show only essential test result information. To do this use --silent or -s

blast test --silent

Interacting with a Cudos node

You can interact with a local Cudos nodeopen in new window with blast node command.

Starting a local node

To start a fresh local Cudos node run

blast node start

or you can show the node logging output in current terminal window. To do this use --log or -l.

blast node start -l

To see how to manage local node accounts go here.

Stopping a running local node

To stop a running node run

blast node stop

Checking node status

To check whether any Cudos node is online or offline run

blast node status
blast node status -n testnet

More information about connecting to a non-local Cudos node here.

Deploying smart contracts, interacting with them and running custom script files

You can use the supplied {project_root}/scripts/deploy.js to deploy a sample smart contract.

async function main () {
  // functions such as 'getSigners' and 'getContractFactory' are available in global context
  const [alice, bob] = await bre.getSigners()

  // get contract object of 'alpha' contract in 'contracts/alpha'
  const contract = await bre.getContractFactory('alpha')

  // define instantiate message for the contract
  // in this message you can set called function and its parameters
  const MSG_INIT = { count: 13 }

  // deploying the contract with bob as a signer (default signer would be alice)
  const deploy = await contract.deploy(MSG_INIT, 'alpha', { signer: bob })

  // get useful info such as contractAddress from deploy transaction
  const contractAddress = deploy.instantiateTx.contractAddress

  // printing contract address so it can be copied and used in other scripts such as interact.js
  console.log(`Contract deployed at: ${contractAddress}`)
// ...

Deploy the contract by running the script:

blast run scripts/deploy.js

When the contract is deployed, its address will be printed. Then you can edit {project_root}/scripts/interact.js with the new address

async function main() {
  const [alice, bob] = await bre.getSigners()

  // replace the address with the new one from your deployed smart contract
  const contract = await bre.getContractFromAddress('cudos1uul3yzm2lgskp3dxpj0zg558hppxk6pt8t00qe')
// ...

and run the script to interact with the deployed smart contract.

blast run scripts/interact.js

When running scripts through blast run the bre object in injected. It provides various useful functions to interact with cudos blockchain network. You can also require the cudos-blast library to access the same functions and enable your code editor's intellisense.

const bre = require('cudos-blast')

You are free to use these sample files as templates or create your own custom .js scripts. You can specify your own script file path.

blast run scripts/myCustomScript.js
blast run newFolder/anotherScripts/myCustomScript.js

Available functions in global context

Here is a list of functions you can use in your scripts.

FunctionDescriptonSample usage
async getSigners()If the local node is used: Returns an array of predefined accounts ({project_root}/local-accounts.json) including the auto generated additional accounts.
For other networks: returns an array of user-defined private accounts from {project_root}/private-accounts.json.
const [alice, bob] = await bre.getSigners()
async getContractFactory(contractLabel)Returns an instance of a new contract by its label.const contract = await bre.getContractFactory('alpha')
async getContractFromCodeId(codeId)Returns an instance of a contract whose code is uploaded but not instantiated.const contract = await bre.getContractFromCodeId(123)
async getContractFromAddress(contractAddress)Returns an instance of an on-chain contract by its address.const contract = await bre.getContractFromAddress('cudos1uul3yzm2lgskp3dxpj0zg558hppxk6pt8t00qe')

You can get an instance of a contract (e.g. with getContractFactory()). Here is the functionality such an instance of a contract can offer.

Exposed functions of a contract instance

FunctionDescriptonSample usage
async uploadCode(options = { signer: null })Uploads the contract's source code on the network so it can be optimally used to instantiate a contract multiple times with different initial state. The default signer is the first one returned by getSigners()const uploadTx = await contract.uploadCode()
async instantiate(msg, label, options = { signer: null, funds: null })Instantiates an uploaded contract with given initMsg and label. The default signer is the first one returned by getSigners(). Can be used for undeployed as well as already deployed contracts. The new instantiated contract does not override the current contract object, and therefore it is designed to be accessed by its address.const instantiateTx = await contract.instantiate(MSG_INIT)
async deploy(msg, label, options = { signer: null, funds: null })Deploys the conttract with the given initMsg. The default signer is the first one returned by getSigners(). You cannot use deploy on an instance ot contract whose code is already uploaded.const deployTxs = await contract.deploy(MSG_INIT, { label: 'myLabel' })
async execute(msg, signer = null)Executes a transaction within the contract with the given message. The default signer is the first one returned by getSigners()const result = await contract.execute(MSG_INCREMENT, alice)
async query(queryMsg, signer = null)Executes a query within the contract with the given message. The default signer is the first one returned by getSigners()const count = await contract.query(QUERY_GET_COUNT)
getAddress()Returns the address of a deployed contract or null if undeployed.const address = contract.getAddress()
getCodeId()Returns the code ID of an uploaded contract or null if unuploaded.const codeId = contract.getCodeId()
getLabel()Returns the label of the contract or null if undeployed.const label = contract.getLabel()
getCreator()Returns the address of the contract's creator or null if unuploaded.const label = contract.getCreator()

Additional options

  • You can run your scripts on a different node. More information here
  • You can set a custom address prefix under addressPrefix in blast.config.js. The default prefix is cudos
blast run scripts/myCustomScript.js -n testnet
  • You can automatically fund smart contracts with tokens in your scripts
const { coin } = require('@cosmjs/stargate')

async function main () {
  const [alice, bob] = await getSigners()
  const contract = await getContractFactory('alpha')
  const MSG_INIT = { count: 13 }

  const tokens = [coin(321, "acudos")]
  const deploy = await contract.deploy(MSG_INIT, bob, 'alpha', tokens)
  // ...


You can connect to the default local node as well as a public one or you can use your own Cudos node. To do that, add a {custom_name}: {node_url} to networks field in blast.config.js, then call the run, test or node status command with --network or -n followed by {custom_name}. If no network is passed, blast commands connect to the default local node.
Here are Cudos nodes you can use to connect to Cudos network:







Managing accounts

By default local Cudos node starts with 10 predefined accounts funded with acudos. You can set how many additional random accounts to load when starting a local node in blast.config.js under additionalAccounts. If any additional accounts are added, customAccountBalances field must be set for the amount of tokens that these accounts will be funded with. Predefined and additionally generated accounts are written in {project_root}/local-accounts.json. Another way to manage custom accounts is through blast keys command.
You can put your private accounts in {project_root}/private-accounts.json. Initializing a new project automatically adds this file to .gitignore. Make sure you keep private-accounts.json in .gitignore in order to prevent accidentally committing and exposing your private accounts.. The private-accounts.json file is mainly meant to have existing accounts in other networks (testnet, mainnet, etc). If you also want to have these accounts in your local environment, make sure you add them to your local node keyringopen in new window.

Listing local node accounts

To list all accounts in the local node key storage run

blast keys ls

Adding a new local node account

To add a new account named myAccount1 to the local node key storage run

blast keys add myAccount1

After adding the new account, it is automatically funded with acudos tokens from the default local node faucet.

Removing an existing local node account

To remove an account from the node key storage run

blast keys rm myAccount1

You can skip the delete confirmation with --force or -f

blast keys rm myAccount1 -f

Funding an existing local node account

You can fund an account with additional tokens. To specify tokens amount use --tokens or -t.

blast keys fund myAccount1 --tokens 1000000

The tokens are funded from the default local node faucet in acudos.