If you are using Windows, we strongly recommend you use Windows Subsystem for Linux (also known as WSL 2). You can use Hardhat and Hardhat ZKsync plugins without it, but it will work better if you use it.To install Node.js using WSL 2, please read this guide.
Hardhat is an Ethereum development environment, designed for easy smart contract development. One of its most prominent features is extendability: you can easily add new plugins to your hardhat project.
This command creates a demo folder and clones a Hardhat template project inside it. The downloaded project is already configured and contains all the required plugins.
For local Validium testing, modify url and ethNetwork in hardhat.config.ts to align with your local Validium and Ethereum node's L2 and L1 RPC URLs, respectively.This template project includes a basic unit test in the /test folder that runs with the local-setup and can be executed with yarn test.
Set your Private Key
Rename .env.example to .env and set your private key:
WALLET_PRIVATE_KEY=YourPrivateKeyHere
Your private key will be used for paying the costs of deploying the smart contract.
The artifacts-zk and cache-zk folders appear in the root directory (instead of the regular Hardhat's artifacts and cache). These folders contain the compilation artifacts (including contract's ABIs) and compiler cache files.
The artifacts-zk and cache-zk folders are included in the .gitignore file.
The deploy-greeter.ts script is in the deploy folder. This script uses the Deployer class from the hardhat-zksync-deploy package to deploy the Greeter.sol/Greeter.vy contract.
import { Wallet, utils } from "zksync-ethers";
import * as ethers from "ethers";
import { HardhatRuntimeEnvironment } from "hardhat/types";
import { Deployer } from "@matterlabs/hardhat-zksync-deploy";
// load env file
import dotenv from "dotenv";
dotenv.config();
// load wallet private key from env file
const PRIVATE_KEY = process.env.WALLET_PRIVATE_KEY || "";
if (!PRIVATE_KEY) throw "⛔️ Private key not detected! Add it to the .env file!";
// An example of a deploy script that will deploy and call a simple contract.
export default async function (hre: HardhatRuntimeEnvironment) {
console.log(`Running deploy script for the Greeter contract`);
// Initialize the wallet.
const wallet = new Wallet(PRIVATE_KEY);
// Create deployer object and load the artifact of the contract you want to deploy.
const deployer = new Deployer(hre, wallet);
const artifact = await deployer.loadArtifact("Greeter");
// Estimate contract deployment fee
const greeting = "Hi there!";
const deploymentFee = await deployer.estimateDeployFee(artifact, [greeting]);
// ⚠️ OPTIONAL: You can skip this block if your account already has funds in L2
// const depositHandle = await deployer.zkWallet.deposit({
// to: deployer.zkWallet.address,
// token: utils.ETH_ADDRESS,
// amount: deploymentFee.mul(2),
// });
// // Wait until the deposit is processed on ZKsync
// await depositHandle.wait();
// Deploy this contract. The returned object will be of a `Contract` type, similar to ones in `ethers`.
// `greeting` is an argument for contract constructor.
const parsedFee = ethers.formatEther(deploymentFee);
console.log(`The deployment is estimated to cost ${parsedFee} ETH`);
const greeterContract = await deployer.deploy(artifact, [greeting]);
// obtain the Constructor Arguments
console.log("constructor args:" + greeterContract.interface.encodeDeploy([greeting]));
// Show the contract info.
const contractAddress = await greeterContract.getAddress();
console.log(`${artifact.contractName} was deployed to ${contractAddress}`);
}
This script deploys the Greeting contract with the message "Hi there!" to Validium Sepolia Testnet.
You should see something like this:
Running deploy script for the Greeter contract
The deployment is estimated to cost 0.00579276320831943 ETH
constructor args:0x000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000094869207468657265210000000000000000000000000000000000000000000000
Greeter was deployed to 0x46f1d2d8A16DBD8b47e9D61175a826ac667288Be4D1293a22E8
✨ Done in 12.69s.
Congratulations! You have deployed a smart contract project to Validium Sepolia Testnet with Hardhat 🎉
Request-Rate Exceeded message:
This message is caused by using the default RPC endpoints provided by ethers.
To avoid this, use your own Sepolia RPC endpoint in the hardhat.config.ts file.
The template project contains another script to interact with the contract.
Enter the address of the deployed Greeter contract in the CONTRACT_ADDRESS variable of the use-greeter.ts script:use-greeter.ts
import { Provider } from "zksync-ethers";
import * as ethers from "ethers";
import { HardhatRuntimeEnvironment } from "hardhat/types";
// load env file
import dotenv from "dotenv";
dotenv.config();
// load contract artifact. Make sure to compile first! - Solidity Project
import * as ContractArtifact from "../artifacts-zk/contracts/Greeter.sol/Greeter.json";
// load contract artifact. Make sure to compile first! - Vyper Project
//import * as ContractArtifact from "../artifacts-zk/contracts/Greeter.vy/Greeter.json";
const PRIVATE_KEY = process.env.WALLET_PRIVATE_KEY || "";
if (!PRIVATE_KEY) throw "⛔️ Private key not detected! Add it to the .env file!";
// Address of the contract on Validium testnet
const CONTRACT_ADDRESS = "";
if (!CONTRACT_ADDRESS) throw "⛔️ Contract address not provided";
// An example of a deploy script that will deploy and call a simple contract.
export default async function (hre: HardhatRuntimeEnvironment) {
console.log(`Running script to interact with contract ${CONTRACT_ADDRESS}`);
// Initialize the provider.
// @ts-ignore
const provider = new Provider(hre.userConfig.networks?.zkSyncTestnet?.url);
const signer = new ethers.Wallet(PRIVATE_KEY, provider);
// Initialise contract instance
const contract = new ethers.Contract(CONTRACT_ADDRESS, ContractArtifact.abi, signer);
// Read message from contract
console.log(`The message is ${await contract.greet()}`);
// send transaction to update the message
const newMessage = "Hello people!";
const tx = await contract.setGreeting(newMessage);
console.log(`Transaction to change the message is ${tx.hash}`);
await tx.wait();
// Read message after transaction
console.log(`The message now is ${await contract.greet()}`);
}
Retrieve the message from the contract by calling the greet() method.
Update the greeting message in the contract with the setGreeting() method.
Retrieve the message from the contract again.
You should see something like this:
Running script to interact with contract Greeter
The message is Hello there!
Transaction to change the message is 0x12f16578A16DB0f47e9D61175a823ac214288Af
The message now is Hello people!
✨ Done in 14.32s.