Using Hardhat

Hardhat is a flexible and extensible Ethereum development environment used for compiling, testing, debugging, and deploying smart contracts.

This guide walks you through deploying an ERC-721 smart contract on Celeschain Testnet using Hardhat.

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Objectives

By the end of this guide, you will be able to:

• Set up Hardhat for Celeschain Testnet

• Create an ERC-721 NFT smart contract

• Compile the smart contract

• Deploy the smart contract to Celeschain Testnet

• Interact with the deployed contract using Hardhat

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Prerequisites

Node v18+

Ensure you have Node.js v18 or higher installed.

Wallet funds

Deploying to Celeschain requires gas. Fund your wallet with CLES (native token of Celeschain) from the testnet faucet.

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Creating a Project

Start by setting up a new Node.js project:

npm init -y

Install Hardhat:

npm install --save-dev hardhat

Create a Hardhat project:

npx hardhat

Select:

• Create a TypeScript project

• Confirm project root

• Choose yes for .gitignore

• Choose yes to load the sample project

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Configuring Hardhat for Celeschain

Add Celeschain Testnet to your Hardhat configuration.

Edit hardhat.config.ts:

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

require("dotenv").config();

const config: HardhatUserConfig = {
  solidity: "0.8.17",
  networks: {
    "celes-testnet": {
      url: "https://rpc-testnet.celeschain.xyz",   // Celeschain Testnet RPC
      accounts: [process.env.WALLET_KEY as string],
      gasPrice: 1000000000
    },
  },
  defaultNetwork: "celes-testnet",
};

export default config;

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Install Hardhat Toolbox

npm install --save-dev @nomicfoundation/hardhat-toolbox

Load Environment Variables

Install dotenv:

npm install --save-dev dotenv

Create .env:

WALLET_KEY=<YOUR_PRIVATE_KEY>

⚠️ Never commit your private key to a public repository!

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Writing the NFT Smart Contract

Below is a simple ERC-721 contract that you will deploy:

contracts/NFT.sol:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.17;

import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/utils/Counters.sol";

contract NFT is ERC721 {
    using Counters for Counters.Counter;
    Counters.Counter private currentTokenId;

    constructor() ERC721("Celeschain NFT", "CELNFT") {}

    function mint(address recipient) public returns (uint256) {
        currentTokenId.increment();
        uint256 tokenId = currentTokenId.current();
        _safeMint(recipient, tokenId);
        return tokenId;
    }
}

Install OpenZeppelin:

npm install @openzeppelin/contracts

Delete the default Lock.sol file.

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Compiling the Smart Contract

Compile using:

npx hardhat compile

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Deploying the Smart Contract

Update scripts/deploy.ts:

import { ethers } from "hardhat";

async function main() {
  const nft = await ethers.deployContract("NFT");

  await nft.waitForDeployment();

  console.log("NFT Contract deployed at:", nft.target);
}

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

Deploy to Celeschain Testnet:

npx hardhat run scripts/deploy.ts

After deployment, view your contract on:

Celeschain Testnet Explorer https://testnet-explorer.celeschain.xyz