Launch a Token on Rootstock: Leverage Bitcoin's Security with Smart Contracts

In this tutorial, you will create and deploy your own Bitcoin-based token on the Rootstock (RSK) blockchain, using the security and functionality of Bitcoin while using Rootstock's smart contract capabilities. By the end of this guide, you will have a working Bitcoin-based token that is deployed on Rootstock and can be interacted with via a decentralized application (DApp). We’ll cover the following: Setting up the development environment Writing a Bitcoin-based token smart contract using Solidity Deploying the smart contract on the Rootstock network Interacting with your token through a DApp Prerequisites Before we begin: Make sure you have Node.js installed. Make sure you have NPM (Node Package Manager) installed. Hardhat (Ethereum development environment) MetaMask (or any web3 wallet) A Rootstock (RSK) testnet account Basic understanding of Solidity and JavaScript With all of that ready, let’s dive into the setup. Step 1: Setting Up Your Development Environment First, let's create a new project directory for our token and initialize it as a Node.js project. Open your terminal and run the following commands to create a project folder and initialize the project: mkdir bitcoin-token-rsk cd bitcoin-token-rsk npm init -y

Next, install Hardhat, which we will use to write and deploy the smart contract: npm install --save-dev hardhat

Now, initialize Hardhat: npx hardhat Reply to the following Hardhat options when prompted: what do you want to do: Select Create a Javascript project

Hardhat project root: /root/bitcoin-token-rsk

Do you want to add a .gitignore?: Enter y

Install Project’s Dependencies with npm: Enter y Install other necessary dependencies: npm install --save-dev @nomicfoundation/hardhat-toolbox dotenv

dotenv will help us manage environment variables, and hardhat-toolbox comes with useful plugins for development.

Create a .env file at the root of your project to store your private keys securely: PRIVATE_KEY= Now that our environment is set up, we can move on to writing the smart contract. Step 2: Writing the Bitcoin-based Token Smart Contract For this token, we'll write a simple ERC-20 contract in Solidity that adheres to the standard of fungible tokens on Ethereum-like networks. In the root directory, create a new folder called contracts: mkdir contracts

Inside the contracts folder, create a new file called BitcoinToken.sol and add the following contract code: // SPDX-License-Identifier: MIT pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

contract BitcoinToken is ERC20 { constructor(uint256 initialSupply) ERC20("BitcoinToken", "BTK") { _mint(msg.sender, initialSupply); } } This smart contract uses the ERC-20 standard from OpenZeppelin, which is a well-known and trusted library for Ethereum-based contracts. The contract defines a token named "BitcoinToken" with the symbol "BTK" and mints the initial supply to the deployer's address. Install the OpenZeppelin library: npm install @openzeppelin/contracts Step 3: Configuring Hardhat for Rootstock We need to update the hardhat.config.js file to configure the Rootstock network and use our environment variables. Open hardhat.config.js and replace its contents with the following code: require("@nomicfoundation/hardhat-toolbox"); require("dotenv").config();

const { PRIVATE_KEY } = process.env;

module.exports = { solidity: "0.8.0", networks: { rootstock: { url: "https://public-node.testnet.rsk.co", accounts: [PRIVATE_KEY], chainId: 31, }, }, }; Get the URL from your RootstockRPC Dashboard. This configuration adds the Rootstock testnet and sets the private key from the .env file. Step 4: Deploying the Smart Contract on Rootstock Now that we’ve written the contract, it’s time to deploy it. Inside the root directory, create a new folder called scripts: mkdir scripts

Inside the scripts folder, create a file called deploy.js with the following code: async function main() { const [deployer] = await ethers.getSigners(); console.log("Deploying contracts with the account:", deployer.address);

// Use ethers.parseUnits instead of ethers.utils.parseUnits const initialSupply = ethers.parseUnits("1000000", 18); // 1 million tokens

const BitcoinToken = await ethers.getContractFactory("BitcoinToken"); const token = await BitcoinToken.deploy(initialSupply);

await token.waitForDeployment(); // Wait for the deployment to be mined

console.log("BitcoinToken deployed to:", await token.getAddress()); }

main() .then(() => process.exit(0)) .catch((error) => { console.error(error); process.exit(1); }); This script will deploy the BitcoinToken contract with an initial supply of 1 million tokens, where each token has 18 decimal places. Compile and deploy the contract to Rootstock: npx hardhat compile npx hardhat run scripts/deploy.js --network rootstock Once deployed, the terminal will output the contract address. You can interact with this contract using the deployed address and a web3 wallet like MetaMask. Step 5: Interacting with the Token With the contract deployed, we can now interact with it through a DApp. In this section, we will set up a basic frontend to connect to the Rootstock network and interact with the token. Install Next.js and create a new frontend project: npx create-next-app@latest bitcoin-token-dapp cd bitcoin-token-dapp

Install the required web3 libraries: npm install ethers wagmi

Inside the pages/index.js file, modify it to add the following code: import { useEffect, useState } from "react"; import { ethers } from "ethers";

export default function Home() { const [account, setAccount] = useState(null); const [balance, setBalance] = useState("0");

useEffect(() => { const loadProvider = async () => { if (window.ethereum) { const provider = new ethers.providers.Web3Provider(window.ethereum); const accounts = await provider.send("eth_requestAccounts", []); setAccount(accounts[0]);

const tokenAddress = " "; const abi = [ "function balanceOf(address) view returns (uint256)", ]; const contract = new ethers.Contract(tokenAddress, abi, provider); const balance = await contract.balanceOf(accounts[0]); setBalance(ethers.utils.formatUnits(balance, 18)); } }; loadProvider(); }, []);

return ( BitcoinToken DApp Connected account: {account}

Token balance: {balance} BTK

); } This basic DApp connects to MetaMask, retrieves the connected account’s token balance, and displays it. Run the DApp locally: npm run dev Visit http://localhost:3000 or http:// :3000 in your browser, and MetaMask should prompt you to connect your account. After connecting, the DApp will display your Bitcoin-based token balance. Step 6: Testing and Verifying the Contract To ensure everything works as expected, we can run some basic tests using Hardhat. Inside the test folder, create a new test file called BitcoinToken.js with the following content: const { expect } = require("chai");

describe("BitcoinToken", function () { it("should return the correct total supply and balance of deployer", async function () { const [owner] = await ethers.getSigners(); const BitcoinToken = await ethers.getContractFactory("BitcoinToken"); const token = await BitcoinToken.deploy(ethers.utils.parseUnits("1000000", 18));

expect(await token.totalSupply()).to.equal(ethers.utils.parseUnits("1000000", 18)); expect(await token.balanceOf(owner.address)).to.equal(ethers.utils.parseUnits("1000000", 18)); }); }); To run the tests: npx hardhat test Troubleshooting If you encounter the following error WARNING: You are currently using Node.js v16.20.2, which is not supported by Hardhat. This can lead to unexpected behavior. See https://hardhat.org/nodejs-versions` Upgrade Node.js: Upgrade your Node.js installation to version 18 or later nvm install 18 nvm use 18 If you encounter the following error Error HH1: You are not inside a Hardhat project.

HardhatError: HH1: You are not inside a Hardhat project. at main (/root/.npm/_npx/ef9ef3f50c7d7dc1/node_modules/hardhat/src/internal/cli/cli.ts:191:13) at Object. (/root/.npm/_npx/ef9ef3f50c7d7dc1/node_modules/hardhat/src/internal/cli/cli.ts:473:1) at Module._compile (node:internal/modules/cjs/loader:1198:14) at Object.Module._extensions..js (node:internal/modules/cjs/loader:1252:10) at Module.load (node:internal/modules/cjs/loader:1076:32) at Function.Module._load (node:internal/modules/cjs/loader:911:12) at Module.require (node:internal/modules/cjs/loader:1100:19) at require (node:internal/modules/cjs/helpers:119:18) at Object. (/root/.npm/_npx/ef9ef3f50c7d7dc1/node_modules/hardhat/src/internal/cli/bootstrap.ts:16:1) at Module._compile (node:internal/modules/cjs/loader:1198:14) Move to the bitcoin-token-rsk directory. cd bitcoin-token-rsk If you encounter the following error Error HH8: There's one or more errors in your config file: * Invalid account: #0 for network: rootstock - Expected string, received undefined To learn more about Hardhat's configuration, please go to https://hardhat.org/config/ HardhatError: HH8: There's one or more errors in your config file: * Invalid account: #0 for network: rootstock - Expected string, received undefined To learn more about Hardhat's configuration, please go to https://hardhat.org/config/ at validateConfig (/root/bitcoin-token-rsk/node_modules/hardhat/src/internal/core/config/config-validation.ts:374:9) at loadConfigAndTasks (/root/bitcoin-token-rsk/node_modules/hardhat/src/internal/core/config/config-loading.ts:109:3) at main (/root/bitcoin-token-rsk/node_modules/hardhat/src/internal/cli/cli.ts:218:62) at Object. (/root/bitcoin-token-rsk/node_modules/hardhat/src/internal/cli/cli.ts:473:1) at Module._compile (node:internal/modules/cjs/loader:1364:14) at Object.Module._extensions..js (node:internal/modules/cjs/loader:1422:10) at Module.load (node:internal/modules/cjs/loader:1203:32) at Function.Module._load (node:internal/modules/cjs/loader:1019:12) at Module.require (node:internal/modules/cjs/loader:1231:19) at require (node:internal/modules/helpers:177:18) Find the section where you define the "rootstock" network. It should look something like this: module.exports = { networks: { rootstock: { url: "https://public-node.rsk.co", accounts: ["0x your private key here"] // Replace with your actual private key “process.env.PRIVATE_KEY” // or use a mnemonic // accounts: { mnemonic: "your mnemonic phrase here" } } }, // ... other configurations }; Install the dotenv package. npm install dotenv Conclusion In this guide, you successfully created and deployed a Bitcoin-based token on the Rootstock network. Visit RootStock official documentation for more information. In this tutorial, you will create and deploy your own Bitcoin-based token on the Rootstock (RSK) blockchain, using the security and functionality of Bitcoin while using Rootstock's smart contract capabilities. By the end of this guide, you will have a working Bitcoin-based token that is deployed on Rootstock and can be interacted with via a decentralized application (DApp). We’ll cover the following: Setting up the development environment Writing a Bitcoin-based token smart contract using Solidity Deploying the smart contract on the Rootstock network Interacting with your token through a DApp Setting up the development environment Writing a Bitcoin-based token smart contract using Solidity Deploying the smart contract on the Rootstock network Interacting with your token through a DApp Prerequisites Before we begin: Make sure you have Node.js installed. Make sure you have NPM (Node Package Manager) installed. Hardhat (Ethereum development environment) MetaMask (or any web3 wallet) A Rootstock (RSK) testnet account Basic understanding of Solidity and JavaScript Make sure you have Node.js installed. Make sure you have NPM (Node Package Manager) installed. Hardhat (Ethereum development environment) Hardhat (Ethereum development environment) MetaMask (or any web3 wallet) A Rootstock (RSK) testnet account A Rootstock (RSK) testnet account Basic understanding of Solidity and JavaScript With all of that ready, let’s dive into the setup. Step 1: Setting Up Your Development Environment First, let's create a new project directory for our token and initialize it as a Node.js project. Open your terminal and run the following commands to create a project folder and initialize the project: mkdir bitcoin-token-rsk cd bitcoin-token-rsk npm init -y Next, install Hardhat, which we will use to write and deploy the smart contract: npm install --save-dev hardhat Now, initialize Hardhat: npx hardhat Open your terminal and run the following commands to create a project folder and initialize the project: mkdir bitcoin-token-rsk cd bitcoin-token-rsk npm init -y Open your terminal and run the following commands to create a project folder and initialize the project: mkdir bitcoin-token-rsk cd bitcoin-token-rsk npm init -y mkdir bitcoin-token-rsk cd bitcoin-token-rsk npm init -y Next, install Hardhat, which we will use to write and deploy the smart contract: npm install --save-dev hardhat Next, install Hardhat, which we will use to write and deploy the smart contract: npm install --save-dev hardhat npm install --save-dev hardhat Now, initialize Hardhat: npx hardhat Now, initialize Hardhat: npx hardhat npx hardhat Reply to the following Hardhat options when prompted: what do you want to do: Select Create a Javascript project Hardhat project root: /root/bitcoin-token-rsk Do you want to add a .gitignore?: Enter y Install Project’s Dependencies with npm: Enter y what do you want to do: Select Create a Javascript project what do you want to do : Select Create a Javascript project what do you want to do Create a Javascript project Hardhat project root: /root/bitcoin-token-rsk Hardhat project root : /root/bitcoin-token-rsk Hardhat project root /root/bitcoin-token-rsk Do you want to add a .gitignore?: Enter y Do you want to add a .gitignore? : Enter y Do you want to add a .gitignore? y Install Project’s Dependencies with npm: Enter y Install Project’s Dependencies with npm : Enter y Install Project’s Dependencies with npm y Install other necessary dependencies: npm install --save-dev @nomicfoundation/hardhat-toolbox dotenv dotenv will help us manage environment variables, and hardhat-toolbox comes with useful plugins for development. Create a .env file at the root of your project to store your private keys securely: PRIVATE_KEY= Install other necessary dependencies: npm install --save-dev @nomicfoundation/hardhat-toolbox dotenv Install other necessary dependencies: npm install --save-dev @nomicfoundation/hardhat-toolbox dotenv npm install --save-dev @nomicfoundation/hardhat-toolbox dotenv dotenv will help us manage environment variables, and hardhat-toolbox comes with useful plugins for development. dotenv will help us manage environment variables, and hardhat-toolbox comes with useful plugins for development. dotenv hardhat-toolbox Create a .env file at the root of your project to store your private keys securely: PRIVATE_KEY= Create a .env file at the root of your project to store your private keys securely: .env PRIVATE_KEY= PRIVATE_KEY= Now that our environment is set up, we can move on to writing the smart contract. Step 2: Writing the Bitcoin-based Token Smart Contract For this token, we'll write a simple ERC-20 contract in Solidity that adheres to the standard of fungible tokens on Ethereum-like networks. In the root directory, create a new folder called contracts: mkdir contracts Inside the contracts folder, create a new file called BitcoinToken.sol and add the following contract code: // SPDX-License-Identifier: MIT pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

contract BitcoinToken is ERC20 { constructor(uint256 initialSupply) ERC20("BitcoinToken", "BTK") { _mint(msg.sender, initialSupply); } } In the root directory, create a new folder called contracts: mkdir contracts In the root directory, create a new folder called contracts : contracts mkdir contracts mkdir contracts Inside the contracts folder, create a new file called BitcoinToken.sol and add the following contract code: // SPDX-License-Identifier: MIT pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

contract BitcoinToken is ERC20 { constructor(uint256 initialSupply) ERC20("BitcoinToken", "BTK") { _mint(msg.sender, initialSupply); } } Inside the contracts folder, create a new file called BitcoinToken.sol and add the following contract code: contracts BitcoinToken.sol // SPDX-License-Identifier: MIT pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

contract BitcoinToken is ERC20 { constructor(uint256 initialSupply) ERC20("BitcoinToken", "BTK") { _mint(msg.sender, initialSupply); } } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

contract BitcoinToken is ERC20 { constructor(uint256 initialSupply) ERC20("BitcoinToken", "BTK") { _mint(msg.sender, initialSupply); } } This smart contract uses the ERC-20 standard from OpenZeppelin, which is a well-known and trusted library for Ethereum-based contracts. The contract defines a token named "BitcoinToken" with the symbol "BTK" and mints the initial supply to the deployer's address. Install the OpenZeppelin library: npm install @openzeppelin/contracts Install the OpenZeppelin library: npm install @openzeppelin/contracts Install the OpenZeppelin library: npm install @openzeppelin/contracts npm install @openzeppelin/contracts Step 3: Configuring Hardhat for Rootstock We need to update the hardhat.config.js file to configure the Rootstock network and use our environment variables. hardhat.config.js Open hardhat.config.js and replace its contents with the following code: require("@nomicfoundation/hardhat-toolbox"); require("dotenv").config();

const { PRIVATE_KEY } = process.env;

module.exports = { solidity: "0.8.0", networks: { rootstock: { url: "https://public-node.testnet.rsk.co", accounts: [PRIVATE_KEY], chainId: 31, }, }, }; Open hardhat.config.js and replace its contents with the following code: require("@nomicfoundation/hardhat-toolbox"); require("dotenv").config();

const { PRIVATE_KEY } = process.env;

module.exports = { solidity: "0.8.0", networks: { rootstock: { url: "https://public-node.testnet.rsk.co", accounts: [PRIVATE_KEY], chainId: 31, }, }, }; Open hardhat.config.js and replace its contents with the following code: hardhat.config.js require("@nomicfoundation/hardhat-toolbox"); require("dotenv").config();

const { PRIVATE_KEY } = process.env;

module.exports = { solidity: "0.8.0", networks: { rootstock: { url: "https://public-node.testnet.rsk.co", accounts: [PRIVATE_KEY], chainId: 31, }, }, }; require("@nomicfoundation/hardhat-toolbox"); require("dotenv").config();

const { PRIVATE_KEY } = process.env;

module.exports = { solidity: "0.8.0", networks: { rootstock: { url: "https://public-node.testnet.rsk.co", accounts: [PRIVATE_KEY], chainId: 31, }, }, }; Get the URL from your RootstockRPC Dashboard. This configuration adds the Rootstock testnet and sets the private key from the .env file. .env Step 4: Deploying the Smart Contract on Rootstock Now that we’ve written the contract, it’s time to deploy it. Inside the root directory, create a new folder called scripts: mkdir scripts Inside the scripts folder, create a file called deploy.js with the following code: async function main() { const [deployer] = await ethers.getSigners(); console.log("Deploying contracts with the account:", deployer.address);

// Use ethers.parseUnits instead of ethers.utils.parseUnits const initialSupply = ethers.parseUnits("1000000", 18); // 1 million tokens

const BitcoinToken = await ethers.getContractFactory("BitcoinToken"); const token = await BitcoinToken.deploy(initialSupply);

await token.waitForDeployment(); // Wait for the deployment to be mined

console.log("BitcoinToken deployed to:", await token.getAddress()); }

main() .then(() => process.exit(0)) .catch((error) => { console.error(error); process.exit(1); }); Inside the root directory, create a new folder called scripts: mkdir scripts Inside the root directory, create a new folder called scripts : scripts mkdir scripts mkdir scripts Inside the scripts folder, create a file called deploy.js with the following code: async function main() { const [deployer] = await ethers.getSigners(); console.log("Deploying contracts with the account:", deployer.address);

// Use ethers.parseUnits instead of ethers.utils.parseUnits const initialSupply = ethers.parseUnits("1000000", 18); // 1 million tokens

const BitcoinToken = await ethers.getContractFactory("BitcoinToken"); const token = await BitcoinToken.deploy(initialSupply);

await token.waitForDeployment(); // Wait for the deployment to be mined

console.log("BitcoinToken deployed to:", await token.getAddress()); }

main() .then(() => process.exit(0)) .catch((error) => { console.error(error); process.exit(1); }); Inside the scripts folder, create a file called deploy.js with the following code: scripts deploy.js async function main() { const [deployer] = await ethers.getSigners(); console.log("Deploying contracts with the account:", deployer.address);

// Use ethers.parseUnits instead of ethers.utils.parseUnits const initialSupply = ethers.parseUnits("1000000", 18); // 1 million tokens

const BitcoinToken = await ethers.getContractFactory("BitcoinToken"); const token = await BitcoinToken.deploy(initialSupply);

await token.waitForDeployment(); // Wait for the deployment to be mined

console.log("BitcoinToken deployed to:", await token.getAddress()); }

main() .then(() => process.exit(0)) .catch((error) => { console.error(error); process.exit(1); }); async function main() { const [deployer] = await ethers.getSigners(); console.log("Deploying contracts with the account:", deployer.address);

// Use ethers.parseUnits instead of ethers.utils.parseUnits const initialSupply = ethers.parseUnits("1000000", 18); // 1 million tokens

const BitcoinToken = await ethers.getContractFactory("BitcoinToken"); const token = await BitcoinToken.deploy(initialSupply);

await token.waitForDeployment(); // Wait for the deployment to be mined

console.log("BitcoinToken deployed to:", await token.getAddress()); }

main() .then(() => process.exit(0)) .catch((error) => { console.error(error); process.exit(1); }); This script will deploy the BitcoinToken contract with an initial supply of 1 million tokens, where each token has 18 decimal places. Compile and deploy the contract to Rootstock: npx hardhat compile npx hardhat run scripts/deploy.js --network rootstock Compile and deploy the contract to Rootstock: npx hardhat compile npx hardhat run scripts/deploy.js --network rootstock Compile and deploy the contract to Rootstock: npx hardhat compile npx hardhat run scripts/deploy.js --network rootstock npx hardhat compile npx hardhat run scripts/deploy.js --network rootstock Once deployed, the terminal will output the contract address. You can interact with this contract using the deployed address and a web3 wallet like MetaMask. Step 5: Interacting with the Token With the contract deployed, we can now interact with it through a DApp. In this section, we will set up a basic frontend to connect to the Rootstock network and interact with the token. Install Next.js and create a new frontend project: npx create-next-app@latest bitcoin-token-dapp cd bitcoin-token-dapp Install the required web3 libraries: npm install ethers wagmi Inside the pages/index.js file, modify it to add the following code: import { useEffect, useState } from "react"; import { ethers } from "ethers";

export default function Home() { const [account, setAccount] = useState(null); const [balance, setBalance] = useState("0");

useEffect(() => { const loadProvider = async () => { if (window.ethereum) { const provider = new ethers.providers.Web3Provider(window.ethereum); const accounts = await provider.send("eth_requestAccounts", []); setAccount(accounts[0]);

const tokenAddress = " "; const abi = [ "function balanceOf(address) view returns (uint256)", ]; const contract = new ethers.Contract(tokenAddress, abi, provider); const balance = await contract.balanceOf(accounts[0]); setBalance(ethers.utils.formatUnits(balance, 18)); } }; loadProvider(); }, []);

return ( BitcoinToken DApp Connected account: {account}

Token balance: {balance} BTK

); } Install Next.js and create a new frontend project: npx create-next-app@latest bitcoin-token-dapp cd bitcoin-token-dapp Install Next.js and create a new frontend project: npx create-next-app@latest bitcoin-token-dapp cd bitcoin-token-dapp npx create-next-app@latest bitcoin-token-dapp cd bitcoin-token-dapp Install the required web3 libraries: npm install ethers wagmi Install the required web3 libraries: npm install ethers wagmi npm install ethers wagmi Inside the pages/index.js file, modify it to add the following code: import { useEffect, useState } from "react"; import { ethers } from "ethers";

export default function Home() { const [account, setAccount] = useState(null); const [balance, setBalance] = useState("0");

useEffect(() => { const loadProvider = async () => { if (window.ethereum) { const provider = new ethers.providers.Web3Provider(window.ethereum); const accounts = await provider.send("eth_requestAccounts", []); setAccount(accounts[0]);

const tokenAddress = " "; const abi = [ "function balanceOf(address) view returns (uint256)", ]; const contract = new ethers.Contract(tokenAddress, abi, provider); const balance = await contract.balanceOf(accounts[0]); setBalance(ethers.utils.formatUnits(balance, 18)); } }; loadProvider(); }, []);

return ( BitcoinToken DApp Connected account: {account}

Token balance: {balance} BTK

); } Inside the pages/index.js file, modify it to add the following code: pages/index.js import { useEffect, useState } from "react"; import { ethers } from "ethers";

export default function Home() { const [account, setAccount] = useState(null); const [balance, setBalance] = useState("0");

useEffect(() => { const loadProvider = async () => { if (window.ethereum) { const provider = new ethers.providers.Web3Provider(window.ethereum); const accounts = await provider.send("eth_requestAccounts", []); setAccount(accounts[0]);

const tokenAddress = " "; const abi = [ "function balanceOf(address) view returns (uint256)", ]; const contract = new ethers.Contract(tokenAddress, abi, provider); const balance = await contract.balanceOf(accounts[0]); setBalance(ethers.utils.formatUnits(balance, 18)); } }; loadProvider(); }, []);

return ( BitcoinToken DApp Connected account: {account}

Token balance: {balance} BTK

); } import { useEffect, useState } from "react"; import { ethers } from "ethers";

export default function Home() { const [account, setAccount] = useState(null); const [balance, setBalance] = useState("0");

useEffect(() => { const loadProvider = async () => { if (window.ethereum) { const provider = new ethers.providers.Web3Provider(window.ethereum); const accounts = await provider.send("eth_requestAccounts", []); setAccount(accounts[0]);

const tokenAddress = " "; const abi = [ "function balanceOf(address) view returns (uint256)", ]; const contract = new ethers.Contract(tokenAddress, abi, provider); const balance = await contract.balanceOf(accounts[0]); setBalance(ethers.utils.formatUnits(balance, 18)); } }; loadProvider(); }, []);

return ( BitcoinToken DApp Connected account: {account}

Token balance: {balance} BTK

); } This basic DApp connects to MetaMask, retrieves the connected account’s token balance, and displays it. Run the DApp locally: npm run dev Run the DApp locally: npm run dev Run the DApp locally: npm run dev npm run dev Visit http://localhost:3000 or http:// :3000 in your browser, and MetaMask should prompt you to connect your account. After connecting, the DApp will display your Bitcoin-based token balance. http://localhost:3000 http:// :3000 Step 6: Testing and Verifying the Contract To ensure everything works as expected, we can run some basic tests using Hardhat. Inside the test folder, create a new test file called BitcoinToken.js with the following content: test BitcoinToken.js const { expect } = require("chai");

describe("BitcoinToken", function () { it("should return the correct total supply and balance of deployer", async function () { const [owner] = await ethers.getSigners(); const BitcoinToken = await ethers.getContractFactory("BitcoinToken"); const token = await BitcoinToken.deploy(ethers.utils.parseUnits("1000000", 18));

expect(await token.totalSupply()).to.equal(ethers.utils.parseUnits("1000000", 18)); expect(await token.balanceOf(owner.address)).to.equal(ethers.utils.parseUnits("1000000", 18)); }); }); const { expect } = require("chai");

describe("BitcoinToken", function () { it("should return the correct total supply and balance of deployer", async function () { const [owner] = await ethers.getSigners(); const BitcoinToken = await ethers.getContractFactory("BitcoinToken"); const token = await BitcoinToken.deploy(ethers.utils.parseUnits("1000000", 18));

expect(await token.totalSupply()).to.equal(ethers.utils.parseUnits("1000000", 18)); expect(await token.balanceOf(owner.address)).to.equal(ethers.utils.parseUnits("1000000", 18)); }); }); To run the tests: npx hardhat test npx hardhat test Troubleshooting If you encounter the following error If you encounter the following error If you encounter the following error WARNING: You are currently using Node.js v16.20.2, which is not supported by Hardhat. This can lead to unexpected behavior. See https://hardhat.org/nodejs-versions` WARNING: You are currently using Node.js v16.20.2, which is not supported by Hardhat. This can lead to unexpected behavior. See https://hardhat.org/nodejs-versions` Upgrade Node.js: Upgrade your Node.js installation to version 18 or later nvm install 18 nvm use 18 nvm install 18 nvm use 18 If you encounter the following error If you encounter the following error If you encounter the following error Error HH1: You are not inside a Hardhat project.

HardhatError: HH1: You are not inside a Hardhat project. at main (/root/.npm/_npx/ef9ef3f50c7d7dc1/node_modules/hardhat/src/internal/cli/cli.ts:191:13) at Object. (/root/.npm/_npx/ef9ef3f50c7d7dc1/node_modules/hardhat/src/internal/cli/cli.ts:473:1) at Module._compile (node:internal/modules/cjs/loader:1198:14) at Object.Module._extensions..js (node:internal/modules/cjs/loader:1252:10) at Module.load (node:internal/modules/cjs/loader:1076:32) at Function.Module._load (node:internal/modules/cjs/loader:911:12) at Module.require (node:internal/modules/cjs/loader:1100:19) at require (node:internal/modules/cjs/helpers:119:18) at Object. (/root/.npm/_npx/ef9ef3f50c7d7dc1/node_modules/hardhat/src/internal/cli/bootstrap.ts:16:1) at Module._compile (node:internal/modules/cjs/loader:1198:14) Error HH1: You are not inside a Hardhat project.

HardhatError: HH1: You are not inside a Hardhat project. at main (/root/.npm/_npx/ef9ef3f50c7d7dc1/node_modules/hardhat/src/internal/cli/cli.ts:191:13) at Object. (/root/.npm/_npx/ef9ef3f50c7d7dc1/node_modules/hardhat/src/internal/cli/cli.ts:473:1) at Module._compile (node:internal/modules/cjs/loader:1198:14) at Object.Module._extensions..js (node:internal/modules/cjs/loader:1252:10) at Module.load (node:internal/modules/cjs/loader:1076:32) at Function.Module._load (node:internal/modules/cjs/loader:911:12) at Module.require (node:internal/modules/cjs/loader:1100:19) at require (node:internal/modules/cjs/helpers:119:18) at Object. (/root/.npm/_npx/ef9ef3f50c7d7dc1/node_modules/hardhat/src/internal/cli/bootstrap.ts:16:1) at Module._compile (node:internal/modules/cjs/loader:1198:14) Move to the bitcoin-token-rsk directory. bitcoin-token-rsk cd bitcoin-token-rsk cd bitcoin-token-rsk If you encounter the following error If you encounter the following error If you encounter the following error Error HH8: There's one or more errors in your config file: * Invalid account: #0 for network: rootstock - Expected string, received undefined To learn more about Hardhat's configuration, please go to https://hardhat.org/config/ HardhatError: HH8: There's one or more errors in your config file: * Invalid account: #0 for network: rootstock - Expected string, received undefined To learn more about Hardhat's configuration, please go to https://hardhat.org/config/ at validateConfig (/root/bitcoin-token-rsk/node_modules/hardhat/src/internal/core/config/config-validation.ts:374:9) at loadConfigAndTasks (/root/bitcoin-token-rsk/node_modules/hardhat/src/internal/core/config/config-loading.ts:109:3) at main (/root/bitcoin-token-rsk/node_modules/hardhat/src/internal/cli/cli.ts:218:62) at Object. (/root/bitcoin-token-rsk/node_modules/hardhat/src/internal/cli/cli.ts:473:1) at Module._compile (node:internal/modules/cjs/loader:1364:14) at Object.Module._extensions..js (node:internal/modules/cjs/loader:1422:10) at Module.load (node:internal/modules/cjs/loader:1203:32) at Function.Module._load (node:internal/modules/cjs/loader:1019:12) at Module.require (node:internal/modules/cjs/loader:1231:19) at require (node:internal/modules/helpers:177:18) Error HH8: There's one or more errors in your config file: * Invalid account: #0 for network: rootstock - Expected string, received undefined To learn more about Hardhat's configuration, please go to https://hardhat.org/config/ HardhatError: HH8: There's one or more errors in your config file: * Invalid account: #0 for network: rootstock - Expected string, received undefined To learn more about Hardhat's configuration, please go to https://hardhat.org/config/ at validateConfig (/root/bitcoin-token-rsk/node_modules/hardhat/src/internal/core/config/config-validation.ts:374:9) at loadConfigAndTasks (/root/bitcoin-token-rsk/node_modules/hardhat/src/internal/core/config/config-loading.ts:109:3) at main (/root/bitcoin-token-rsk/node_modules/hardhat/src/internal/cli/cli.ts:218:62) at Object. (/root/bitcoin-token-rsk/node_modules/hardhat/src/internal/cli/cli.ts:473:1) at Module._compile (node:internal/modules/cjs/loader:1364:14) at Object.Module._extensions..js (node:internal/modules/cjs/loader:1422:10) at Module.load (node:internal/modules/cjs/loader:1203:32) at Function.Module._load (node:internal/modules/cjs/loader:1019:12) at Module.require (node:internal/modules/cjs/loader:1231:19) at require (node:internal/modules/helpers:177:18) Find the section where you define the "rootstock" network. It should look something like this: module.exports = { networks: { rootstock: { url: "https://public-node.rsk.co", accounts: ["0x your private key here"] // Replace with your actual private key “process.env.PRIVATE_KEY” // or use a mnemonic // accounts: { mnemonic: "your mnemonic phrase here" } } }, // ... other configurations }; module.exports = { networks: { rootstock: { url: "https://public-node.rsk.co", accounts: ["0x your private key here"] // Replace with your actual private key “process.env.PRIVATE_KEY” // or use a mnemonic // accounts: { mnemonic: "your mnemonic phrase here" } } }, // ... other configurations }; Install the dotenv package. npm install dotenv npm install dotenv Conclusion In this guide, you successfully created and deployed a Bitcoin-based token on the Rootstock network. Visit RootStock official documentation for more information. RootStock official documentation