Rootstock Hardhat Starter Kit

Whether you’re a seasoned developer or just starting your journey into smart contract development, the hardhat starter kit provides a solid foundation for building decentralized applications (dApps) on the Rootstock network.

Rootstock is fully EVM (Ethereum Virtual Machine) compatible. It brings the power of smart contracts to Bitcoin, allowing developers to leverage Bitcoin’s security while benefiting from Ethereum’s ecosystem.

Prerequisites

Before starting the dApp, make sure to have the following prerequisites:

1. Familiarity with Smart Contracts:

   • If you’re new to smart contracts, consider learning the basics. Understanding how smart contracts work will enhance your experience with Rootstock development.

2. Node.js and Hardhat Installed:

   • Ensure you have Node.js installed on your system. See the prerequisites section.

3. Install Hardhat Shorthand:

• We recommend installing hh autocomplete to use hh shorthand globally.

  npm i -g hardhat-shorthand

• For more details, refer to their official guide.

4. Metamask Setup with Rootstock:

• Install the Metamask browser extension if you haven’t already.
• Configure Metamask to connect to the Rootstock network. Visit the MetaMask Integration on the Rootstock Dev Portal.

5. Basic Knowledge of Hardhat:

• Familiarity with Hardhat's core concepts and functionalities is recommended. If you're new to Hardhat, refer to the Rootstock Hardhat Guide.

Rootstock Blockchain Developer Course

Learn how to write, test, secure, deploy and verify smart contracts on the Rootstock blockchain network. Enroll for the Rootstock Blockchain Developer Course.

Setting Up the Sample dApp

Clone the Repository

Open your terminal or command prompt and run the following command to clone the repository from GitHub:

git clone https://github.com/rsksmart/rootstock-hardhat-starterkit.git

Install Dependencies

Navigate to the cloned repository folder:

cd rootstock-hardhat-starterkit

Install all required dependencies using npm:

npm install

Obtain Rootstock Testnet and Mainnet RPC URLs

This section will walk you through adding Rootstock Testnet and Mainnet RPC URLs to your development environment. These URLs are essential for connecting your application to the Rootstock network and interacting with smart contracts.

There are two ways to obtain RPC URLs:

Using Public RPC URLs

• Visit the MetaMask Integration on the Rootstock Dev Portal. This guide provides instructions on setting up MetaMask for Rootstock. While following these steps, pay close attention to the sections on adding custom networks. You'll find the RPC URLs for Rootstock Testnet and Mainnet listed.

Using RPC API

• Create an account at the Rootstock RPC API. Once logged in, navigate to your dashboard and copy the API Key.

Adding the URLs to your project

After obtaining the RPC URLs, create a file named .env in your project's root directory (important: this file should not be committed to version control). Add the necessary environment variables to the .env file:

WALLET_PRIVATE_KEY= Your private key (e.g., from your Metamask account details).
RSK_MAINNET_RPC_URL= The RPC URL for the Rootstock mainnet.
RSK_TESTNET_RPC_URL= The RPC URL for the Rootstock testnet.

Deploying an ERC721 Token Contract

This section uses the Hardhat development framework to deploy an ERC721 token (a non-fungible token) on the Rootstock network.

Run the following command, replacing <network> with either rskTestnet or rskMainnet depending on your desired deployment environment:

hh deploy --network <network> --tags 721

Example command:

hh deploy --network rskTestnet --tags 721

This command will compile your Solidity contracts, generate type information, and deploy your ERC721 contract to the specified Rootstock network. The output will display the deployed contract address and the amount of gas used.

The above command will return an output similar to the following:

Generating typings for: 36 artifacts in dir: typechain-types for target: ethers-v6
Successfully generated 106 typings!
Compiled 34 Solidity files successfully (evm target: paris).
deploying "MockERC721" (tx: 0x9ad1dbc047b78594cf2cad105ded54c851fc0895ae69e4381908fecedd0ee3fc)...: deployed at 0x2E027a3a05f3de6777B23397a50a60ecd04fe34C with 2849621 gas

Interacting with the Contract - Minting a Token

On contract deployment, you can interact with it using Hardhat's erc721-mint command. This command allows you to mint (create) new ERC721 tokens.

Minting a Token:

In your terminal, run the following command, replacing the placeholders with actual values:

hh erc721-mint \
  --contract <ContractAddress> \
  --recipient <RecipientAddress> \
  --network rskTestnet

Example command:

hh erc721-mint --contract 0x2E027a3a05f3de6777B23397a50a60ecd04fe34C --recipient 0xB0f22816750851D18aD9bd54c32C5e09D1940F7d --network rskTestnet

• <ContractAddress>: Replace this with the address of your deployed ERC721 contract obtained from the previous step.
• <RecipientAddress>: Replace this with the wallet address to receive the newly minted token.
• <network>: Replace this with either rskTestnet or rskMainnet, depending on the network where your contract is deployed.

This command will initiate a transaction to mint a new ERC721 tokens and send it to the specified recipient address.

The output will display the transaction details:

Transaction Hash: 0xa127ff008e20d8b3944cecb374f28535cd84555881cde157708ec5545603a4e4
Transaction confirmed