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Using Hardhat

Hardhat is a flexible JavaScript/TypeScript development environment for Ethereum. It is well suited for teams that prefer a Node.js-based workflow, plugin ecosystem, and scripted deployments.

Initialize a new project​

Hardhat requires Node.js (v18+) and npm. It works on macOS, Linux, and Windows. On Windows, we recommend using WSL 2 for a smoother experience, though native CMD/PowerShell is also supported.

mkdir hardhat-tutorial
cd hardhat-tutorial
npx hardhat init

Follow the prompts to create a TypeScript project. Hardhat will scaffold the project with a sample contract, test, and ignition deployment module.

Install dependencies​

npm install

Configure Horizen in hardhat.config.ts​

Open hardhat.config.ts and add Horizen Testnet and Mainnet as named networks:

import { HardhatUserConfig } from "hardhat/config";
import "@nomicfoundation/hardhat-toolbox";

const config: HardhatUserConfig = {
  solidity: "0.8.28",
  networks: {
    horizen_testnet: {
      type: "http",
      url: "https://horizen-testnet.rpc.caldera.xyz/http",
      accounts: ["<YOUR_PRIVATE_KEY>"],
      chainId: 2651420,
    },
    horizen_mainnet: {
      type: "http",
      url: "https://horizen.calderachain.xyz/http",
      accounts: ["<YOUR_PRIVATE_KEY>"],
      chainId: 26514,
    },
  },
};

export default config;

Use environment variables for your private key in production. See the .env pattern in the Foundry section above — it works identically with process.env.PRIVATE_KEY in Hardhat configs.

Compile your contracts​

npx hardhat compile

Deploy to Horizen Testnet​

Hardhat uses Ignition for deployments. Your deployment module lives at ignition/modules/. Deploy with:

npx hardhat ignition deploy ignition/modules/Counter.ts --network horizen_testnet

Deploy to Horizen Mainnet​

npx hardhat ignition deploy ignition/modules/Counter.ts --network horizen_mainnet

Run tests​

npx hardhat test

For contract verification after deployment, see Verify a Contract.

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