Using Hardhat

Deploy and test smart contracts on MANTRA Chain using Hardhat

Hardhat is a development environment for Ethereum software that helps developers manage and automate recurring tasks involved in building smart contracts and decentralized applications (dApps).

Hardhat Tutorial: For new users, the Hardhat tutorial provides step-by-step instructions and explains essential concepts for developing smart contracts.

Prerequisites

Node.js

Install Node.js following the official documentation. MANTRA Chain requires Node.js ≥ 18.0, but we recommend using the latest LTS version (currently v22).

nvm is an excellent tool to easily manage multiple Node.js versions on your local machine. More details here!

Installation

Create a new Hardhat project:

mkdir my-project
cd my-project
npm init -y
npm install --save-dev hardhat
npx hardhat init

Follow the prompts to set up your project. Choose:

• JavaScript or TypeScript project
• Create a sample project to get started quickly

Configuring for MANTRA Chain

Update hardhat.config.js (or hardhat.config.ts) to add MANTRA Chain networks:

require("@nomicfoundation/hardhat-toolbox");

module.exports = {
  solidity: "0.8.23",
  networks: {
    mantra_mainnet: {
      url: "https://evm.mantrachain.io",
      chainId: 5888,
      accounts: process.env.PRIVATE_KEY ? [process.env.PRIVATE_KEY] : [],
    },
    mantra_testnet: {
      url: "https://evm.dukong.mantrachain.io",
      chainId: 5887,
      accounts: process.env.PRIVATE_KEY ? [process.env.PRIVATE_KEY] : [],
    },
  },
};

Building Contracts

Compile your contracts:

npx hardhat compile

Testing

Run tests:

npx hardhat test

Deploying

Create a deployment script in scripts/deploy.js:

async function main() {
  const MyContract = await ethers.getContractFactory("MyContract");
  const myContract = await MyContract.deploy();
  
  await myContract.waitForDeployment();
  console.log("Contract deployed to:", await myContract.getAddress());
}

main()
  .then(() => process.exit(0))
  .catch((error) => {
    console.error(error);
    process.exit(1);
  });

Deploy to testnet:

npx hardhat run scripts/deploy.js --network mantra_testnet

Hardhat Ignition (recommended for structured deployments)

Hardhat Ignition is useful when you want repeatable deployments as “modules”.

1. Add a network entry (example using Hardhat config vars):

require("@nomicfoundation/hardhat-toolbox");
const { vars } = require("hardhat/config");

const TEST_PRIVATE_KEY = vars.get("TEST_PRIVATE_KEY");

module.exports = {
  solidity: "0.8.23",
  networks: {
    mantra_testnet: {
      url: "https://evm.dukong.mantrachain.io",
      chainId: 5887,
      accounts: [TEST_PRIVATE_KEY],
    },
  },
};

2. Set the private key (interactive):

npx hardhat vars set TEST_PRIVATE_KEY

3. Deploy an Ignition module:

npx hardhat ignition deploy ./ignition/modules/Token.js --network mantra_testnet

Example Project

Check out our example project and follow the README for a complete walkthrough.

Next Steps

• Learn about deploying contracts
• Understand contract verification
• Explore EVM development