How to Mint & Burn an ERC-721 Token Using Hardhat and Ethers (Part 1)
In this tutorial, you’ll learn how to deploy, mint, and burn ERC-721 tokens (NFTs) using Hardhat, Ethers, and OpenZeppelin contracts on the Hedera Testnet. We’ll cover setting up your project, writing and deploying an ERC-721 smart contract, minting an NFT to your account, and finally, burning an NFT.By the end, you’ll have hands-on experience with essential ERC-721 operations and interacting with smart contracts on Hedera.
You can watch the video tutorial (which uses Hardhat version 2) or follow the step-by-step tutorial below (which uses Hardhat version 3).
🚧 What's new: Hardhat 2 → 3
Key differences in Hardhat 3:
compile → build npx hardhat compile is now npx hardhat build. This is the big one. The v3 migration guide explicitly shows using the build task.
project init switch
v2 commonly used npx hardhat or npx hardhat init to bootstrap. In v3 it’s npx hardhat --init.
keystore helper commands are new
v3’s recommended flow includes a keystore plugin with commands like npx hardhat keystore set HEDERA_RPC_URL and npx hardhat keystore set HEDERA_PRIVATE_KEY. These weren’t standard in v2.
Foundry-compatiable Solidity tests
In addition to offering Javascript/Typescript integration tests, Hardhat v3 also integrates Foundry-compatible Solidity tests that allows developers to write unit tests directly in Solidity
Enhanced Network Management
v3 allows tasks to create and manage multiple network connections simultaneously which is a significant improvement over the single, fixed connection available in version 2. This provides greater flexibility for scripts and tests that interact with multiple networks.
Make sure to select “Hardhat 3 -> Typescript Hardhat Project using Mocha and Ethers.js” and accept the default values. Hardhat will configure your project correctly and install the required dependencies.
Hashiois intended for development and testing purposes only. For production use cases, it’s recommended to use commercial-grade JSON-RPC Relay or host your own instance of theHiero JSON-RPC Relay.
Update your hardhat.config.tsfile in the root directory of your project. This file contains the network settings so Hardhat knows how to interact with the Hedera Testnet.
This command launches an interactive JavaScript console connected directly to the Hedera Testnet, providing access to the Ethers.js library for blockchain interactions. If you successfully enter this interactive environment, your Hardhat configuration is correct. To exit the interactive console, press ctrl + c twice.We won’t be using ignition and we will be removing the default contracts that comes with hardhat default project so we will remove all the unnecessary directories and files first:
Create a new Solidity file (MyToken.sol) in our contracts directory:
contracts/MyToken.sol
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// SPDX-License-Identifier: MIT// Compatible with OpenZeppelin Contracts ^5.0.0pragma solidity ^0.8.28;import {ERC721} from "@openzeppelin/contracts/token/ERC721/ERC721.sol";import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";contract MyToken is ERC721, Ownable { uint256 private _nextTokenId; constructor(address initialOwner) ERC721("MyToken", "MTK") Ownable(initialOwner) {} function safeMint(address to) public onlyOwner returns (uint256) { uint256 tokenId = _nextTokenId++; _safeMint(to, tokenId); return tokenId; }}
This contract was created using the OpenZeppelin Contracts Wizard and OpenZeppelin’s ERC-721 standard implementation with an ownership model. The ERC-721 token’s name has been set to “MyToken.” The contract implements the safeMint function, which accepts the address of the owner of the new token and uses auto-increment IDs, starting from 0.Let’s compile this contract by running:
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npx hardhat build
This command will generate the smart contract artifacts, including the ABI. We are now ready to deploy the smart contract.
Create a deployment script (deploy.ts) in scripts directory:
scripts/deploy.ts
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import { network } from "hardhat";const { ethers } = await network.connect({ network: "testnet",});async function main() { // Get the signer of the tx and address for minting the token const [deployer] = await ethers.getSigners(); console.log("Deploying contract with the account:", deployer.address); // The deployer will also be the owner of our NFT contract const MyToken = await ethers.getContractFactory("MyToken", deployer); const contract = await MyToken.deploy(deployer.address); await contract.waitForDeployment(); const address = await contract.getAddress(); console.log("Contract deployed at:", address);}main().catch(console.error);
In this script, we first retrieve your account (the deployer) using Ethers.js. This account will own the deployed smart contract. Next, we use this account to deploy the contract by calling MyToken.deploy(deployer.address). This passes your account address as the initial owner and signer of the deployment transaction.Deploy your contract by executing the script:
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npx hardhat run scripts/deploy.ts --network testnet
Copy the deployed address—you’ll need this in subsequent steps.
The output looks like this:
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~/projects/hardhat-erc-721-mint-burn >> npx hardhat run scripts/deploy.ts --network testnetCompiling your Solidity contracts...Compiled 1 Solidity file with solc 0.8.28 (evm target: cancun)Deploying contract with the account: 0xA98556A4deeB07f21f8a66093989078eF86faa30Contract deployed at: 0x6035bA3BCa9595637B463Aa514c3a1cE3f67f3de
Create a mint.ts script in your scripts directory to mint an NFT. Don’t forget to replace the <your-contract-address> with the address you’ve just copied.
scripts/mint.ts
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import { network } from "hardhat";const { ethers } = await network.connect({ network: "testnet",});async function main() { const [deployer] = await ethers.getSigners(); // Get the ContractFactory of your MyToken ERC-721 contract const MyToken = await ethers.getContractFactory("MyToken", deployer); // Connect to the deployed contract // (REPLACE WITH YOUR CONTRACT ADDRESS) const contractAddress = "<your-contract-address>"; const contract = MyToken.attach(contractAddress); // Mint a token to ourselves const mintTx = await contract.safeMint(deployer.address); const receipt = await mintTx.wait(); console.log("receipt: ", JSON.stringify(receipt, null, 2)); const mintedTokenId = receipt?.logs[0].topics[3]; console.log("Minted token ID:", mintedTokenId); // Check the balance of the token const balance = await contract.balanceOf(deployer.address); console.log("Balance:", balance.toString(), "NFTs");}main().catch(console.error);
The code mints a new NFT to your account ( deployer.address ). Then we verify the balance to see if we own an ERC-721 token of type MyToken.Mint an NFT:
Update your contract to add NFT burning capability by importing the burnable extension and adding it to the interfaces list for your contract:
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// [...]import {ERC721Burnable} from "@openzeppelin/contracts/token/ERC721/extensions/ERC721Burnable.sol";contract MyToken is ERC721, ERC721Burnable, Ownable {// [...]
Redeploy:
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npx hardhat run scripts/deploy.ts --network testnet
Copy the new smart contract address and replace the address in the scripts/mint.ts script with your new address. Let’s mint a new NFT for the redeployed contract:
Create a burn script (burn.ts ) in your scripts directory:
scripts/burn.ts
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import { network } from "hardhat";const { ethers } = await network.connect({ network: "testnet",});async function main() { const [deployer] = await ethers.getSigners(); // Get the ContractFactory of your MyToken ERC-721 contract const MyToken = await ethers.getContractFactory("MyToken", deployer); // Connect to the deployed contract // (REPLACE WITH YOUR CONTRACT ADDRESS) const contractAddress = "0x00f2753A689C3bdd1a733430c7b63A3993B1eFBc"; const contract = MyToken.attach(contractAddress); // Burn the token const burnTx = await contract.burn(0); const receipt = await burnTx.wait(); console.log("receipt: ", JSON.stringify(receipt, null, 2)); const burnedTokenId = receipt?.logs[0].topics[3]; console.log("Burned token with ID:", burnedTokenId); // Check the balance of the token const balance = await contract.balanceOf(deployer.address); console.log("Balance:", balance.toString(), "NFTs");}main().catch(console.error);
Again, ensure you update <your-contract-address> to interact with your correct contract. The script will burn the ERC-721 token with the ID set to 0, which is the ERC-721 token you’ve just minted. To be sure the token has been deleted, let’s print the balance for our account to the terminal. The balance should show a balance of 0.Burn the NFT:
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npx hardhat run scripts/burn.ts --network testnet
Congratulations! 🎉 You have successfully learned how to deploy an ERC-721 smart contract using Hardhat, OpenZeppelin, and Ethers. Feel free to reach out inDiscord!