Deploy with Hardhat

This page shows how to deploy and verify a contract on Whitechain Sepolia using Hardhat. Whitechain Sepolia is a standard EVM network, so you add it by chain ID and RPC URL. Hardhat needs no Whitechain-specific plugin. It is for developers who work from the command line.

Hardhat publishes its own Agent Skill for AI coding assistants. Install it with npx skills add nomicfoundation/hardhat-skills for AI-guided help with Hardhat 3 workflows and migrations. Pair it with the whitechain-dev skill for the Whitechain-specific steps below.

Before you deploy

Node.js 22 or later and npm. Hardhat 3 requires Node.js 22 or newer.
A funded testnet account. Claim test WBT from the faucet.
The private key for that account. Use a throwaway key for testing.

1. Create a project

npm install --save-dev hardhat
npx hardhat --init

When prompted:

Prompt	Response
Which version of Hardhat?	Choose Hardhat 3 (recommended for new projects)
Where would you like to initialize the project?	Press Enter for the current directory
What type of project?	Choose A TypeScript Hardhat project using Node Test Runner and Viem
Would you like to change `package.json` to turn your project into ESM?	Enter `y`
Confirm dependency installation?	Press Enter

2. Set environment variables

npm install --save-dev dotenv

Create a .env file:

PRIVATE_KEY=0x_your_private_key_here

The key must include the 0x prefix. Hardhat rejects the network configuration without it. Add .env to .gitignore so you do not commit the key.

Never commit a private key, and never reuse a mainnet key for testing. Anyone with the key controls the funds.

3. Configure the network

Replace the contents of hardhat.config.ts with:

import type { HardhatUserConfig } from "hardhat/config";
import hardhatToolboxViem from "@nomicfoundation/hardhat-toolbox-viem";
import "dotenv/config";

const config: HardhatUserConfig = {
  plugins: [hardhatToolboxViem],
  solidity: "0.8.30",
  networks: {
    whitechainTestnet: {
      type: "http",
      url: "https://rpc.testnet.whitechain.io",
      accounts: [process.env.PRIVATE_KEY!],
    },
  },
  verify: {
    sourcify: {
      enabled: true,
    },
  },
};

export default config;

4. Add a contract

Create contracts/Storage.sol.

// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.30;

contract Storage {
    uint256 number;

    function store(uint256 num) public {
        number = num;
    }

    function retrieve() public view returns (uint256) {
        return number;
    }
}

5. Add a deploy script

Create scripts/deploy.ts.

import { network } from "hardhat";

const { viem } = await network.create("whitechainSepolia");
const storage = await viem.deployContract("Storage");
console.log("Storage deployed to:", storage.address);

network.create("whitechainSepolia") opens a connection to the network defined in hardhat.config.ts. Passing the name makes the script explicit; network.create() with no argument uses whatever --network selects. Do not use network.connect(), which is deprecated in Hardhat 3 and will be removed. Hardhat 3 uses ESM with top-level await, so no main() wrapper is needed.

6. Deploy the contract

npx hardhat run scripts/deploy.ts --network whitechainSepolia

The contract address prints to the console. Copy it for verification.

7. Verify the contract

Storage takes no constructor arguments, so pass only the address.

npx hardhat verify --network whitechainSepolia <contract_address>

For a contract with constructor arguments, add them after the address.

Verify the result

Open the contract address on the explorer. The Contract tab shows the source code and a verified marker. The same submission also lands on Sourcify, because both verifiers are enabled in the config above.

Wallet

Dapps

Deploy

Bridge

Block Explorer

Ecosystem

Before you deploy

1. Create a project

2. Set environment variables

3. Configure the network

4. Add a contract

5. Add a deploy script

6. Deploy the contract

7. Verify the contract

Verify the result

​Before you deploy

​1. Create a project

​2. Set environment variables

​3. Configure the network

​4. Add a contract

​5. Add a deploy script

​6. Deploy the contract

​7. Verify the contract

​Verify the result

​Related

Before you deploy

1. Create a project

2. Set environment variables

3. Configure the network

4. Add a contract

5. Add a deploy script

6. Deploy the contract

7. Verify the contract

Verify the result

Related