Deploy & Verify Your First Contracts

📚 This tutorial is meant for developers that already understand the 🖍️ basics .

🧑‍🏫 If you would like a more gentle introduction for developers, watch our 15 video 🎥 Web2 to Web3 series.

🚀 Deploy and verify your first smart contracts on Lisk:

👷‍♀️ You'll compile and deploy both an ERC20 token and ERC721 NFT contract using modern Solidity best practices. Then, you'll use a template NextJS app full of important Lisk components and hooks. Finally, you'll deploy your contracts to Lisk Sepolia testnet and verify them on Lisk Blockscout! 🌟

🌟 The final deliverable is verified smart contracts on Lisk Sepolia testnet with a functional frontend that interacts with your contracts. Deploy your contracts to the testnet, then build and upload your app to a public web server. Submit the urls on SpeedRunLisk.xyz!

💬 Meet other builders working on this challenge and get help in the @LiskSEA Telegram!

Checkpoint 0: 📦 Environment 📚

Before you begin, you need to install the following tools:

• Node (>= v18.17)
• Yarn (v1 or v2+)
• Git

Then download the challenge to your computer and install dependencies by running:

git clone https://github.com/LiskHQ/scaffold-lisk.git ch1-deploy-verify
cd ch1-deploy-verify
yarn install

in the same terminal, start your local network (a blockchain emulator in your computer):

yarn chain

in a second terminal window, 🛰 deploy your contract (locally):

cd ch1-deploy-verify
yarn deploy

in a third terminal window, start your 📱 frontend:

cd ch1-deploy-verify
yarn start

📱 Open http://localhost:3000 to see the app.

Checkpoint 1: ⛽️ Gas & Wallets 👛

⛽️ You'll need to get some funds from the faucet for gas.

🦊 At first, don't connect MetaMask. If you are already connected, click Disconnect.

🔥 We'll use burner wallets on localhost.

👛 Explore how burner wallets work in 🏗 Scaffold-Lisk by opening a new incognito window and navigate to http://localhost:3000. You'll notice it has a new wallet address in the top right. Copy the incognito browser's address and send localhost test funds to it from your first browser (using the Faucet button in the bottom left).

👨🏻‍🚒 When you close the incognito window, the account is gone forever. Burner wallets are great for local development but you'll move to more permanent wallets when you interact with public networks.

Checkpoint 2: 📝 Create Your Smart Contracts

✏️ Now let's create the smart contracts we'll deploy and verify!

Create Your ERC20 Token Contract

Navigate to packages/hardhat/contracts/ and create a new file called MyToken.sol:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

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

contract MyToken is ERC20 {
    constructor() ERC20("Lisk SEA Token", "LSEA") {
        _mint(msg.sender, 1000000 * 10**decimals());
    }
}

Create Your ERC721 NFT Contract

In the same directory, create MyNFT.sol:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

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

contract MyNFT is ERC721 {
    uint256 private _tokenIdCounter;

    constructor() ERC721("Lisk Builder Badge", "LBB") {}

    function mint(address to) public {
        uint256 tokenId = _tokenIdCounter;
        _tokenIdCounter++;
        _mint(to, tokenId);
    }

    function totalSupply() public view returns (uint256) {
        return _tokenIdCounter;
    }
}

Update Your Deploy Script

Edit packages/hardhat/deploy/00_deploy_your_contract.ts to deploy both contracts:

import { DeployFunction } from "hardhat-deploy/types";
import { HardhatRuntimeEnvironment } from "hardhat/types";

const deployContracts: DeployFunction = async function (hre: HardhatRuntimeEnvironment) {
  const { deployer } = await hre.getNamedAccounts();
  const { deploy } = hre.deployments;

  // Deploy ERC20 Token
  await deploy("MyToken", {
    from: deployer,
    args: [],
    log: true,
    autoMine: true,
  });

  // Deploy ERC721 NFT
  await deploy("MyNFT", {
    from: deployer,
    args: [],
    log: true,
    autoMine: true,
  });
};

export default deployContracts;
deployContracts.tags = ["MyToken", "MyNFT"];

🏗 Test your contracts locally by running yarn deploy in your terminal. You should see both contracts deploy successfully!

Checkpoint 3: 💾 Deploy to Lisk Sepolia! 🛰

🛰 Ready to deploy to Lisk Sepolia testnet?!?

Change the defaultNetwork in packages/hardhat/hardhat.config.ts to liskSepolia.

Make sure your hardhat.config.ts includes the Lisk Sepolia network configuration:

liskSepolia: {
  url: "https://rpc.sepolia-api.lisk.com",
  accounts: [deployerPrivateKey],
  chainId: 4202,
},

And add the verification configuration in the main config object in packages/hardhat/hardhat.config.ts:

// configuration for harhdat-verify plugin
  etherscan: {
    apiKey: {
      liskSepolia: process.env.ETHERSCAN_API_KEY || "YOUR_BLOCKSCOUT_API_KEY"
    },
    customChains: [
      {
        network: "liskSepolia",
        chainId: 4202,
        urls: {
          apiURL: "https://sepolia-blockscout.lisk.com/api",
          browserURL: "https://sepolia-blockscout.lisk.com"
        }
      }
    ]
  },

🔐 Generate a deployer address with yarn generate. This creates a unique deployer address and saves the mnemonic locally.

This local account will deploy your contracts, allowing you to avoid entering a personal private key.

👩‍🚀 Use yarn account to view your deployer account balances.

⛽️ You will need to send ETH to your deployer address with your wallet, or get it from a public faucet.

Lisk Sepolia Faucets:

• Lisk Sepolia Faucet - Official Lisk faucet

🚀 Deploy your smart contracts with yarn deploy.

💬 Hint: You can set the defaultNetwork in hardhat.config.ts to liskSepolia OR you can yarn deploy --network liskSepolia.

🔧 For better reliability and to avoid rate limiting, consider setting up your own API keys in packages/hardhat/.env:

ALCHEMY_API_KEY="your_alchemy_api_key"
ETHERSCAN_API_KEY="your_blockscout_api_key"

📝 Save your contract addresses! You'll need them for verification and submission.

Checkpoint 4: 📜 Contract Verification 🔍

🔍 Now for the main event - verifying your smart contracts on Lisk Blockscout!

Method 1: Automated Verification (Recommended)

You can verify your smart contracts using Hardhat with the specific contract addresses:

yarn hardhat-verify --network liskSepolia --contract contracts/MyToken.sol:MyToken 0xE0158f92Dc219E40827F870AF0cee6207447ae0B

yarn hardhat-verify --network liskSepolia --contract contracts/MyNFT.sol:MyNFT 0x97eFEC5Fba1E6Afa7128a6B2FF49f7e2a120B1BE

✅ Replace the contract addresses with your actual deployed contract addresses from the deployment output.

⚠️ Note: If verification fails, make sure your hardhat.config.ts includes the correct verify configuration for Lisk Sepolia (see the network configuration section above).

Method 2: Manual Verification via Blockscout

If automated verification doesn't work, you can manually verify on Lisk Sepolia Blockscout:

1. Navigate to your contract:

   • Go to sepolia-blockscout.lisk.com
   • Paste your contract address in the search bar
   • Click on the contract address

2. Start verification:

   • Click the "Contract" tab
   • Click "Verify & Publish" button
   • Select "Via Solidity file"

3. Upload contract details:

   • Contract Address: (your deployed address)
   • Contract Name: MyToken or MyNFT
   • Compiler Version: v0.8.17+commit.8df45f5f (or the exact version from your hardhat.config.ts)
   • Open Source License: MIT
   • Optimization: Enabled (runs: 200)

4. Upload source code:

   • Copy and paste your complete contract source code
   • Include all import statements (OpenZeppelin imports will be automatically resolved)
   • Make sure the pragma version matches exactly: ^0.8.0
   • For the ERC20 contract, use the complete code including the OpenZeppelin import
   • For the ERC721 contract, use the updated version without Counters

5. Constructor Arguments (if any):

   • For these contracts, leave blank as they have no constructor arguments

6. Submit for verification:

   • Click "Verify & Publish"
   • Wait for the verification to complete

Verification Troubleshooting

If verification fails:

• ✅ Check that the compiler version matches exactly
• ✅ Ensure all OpenZeppelin imports are included
• ✅ Verify the contract name matches exactly
• ✅ Make sure there are no extra spaces or characters

🎯 Success! Once verified, you'll see a green checkmark and "Contract Source Code Verified" message.

Verify Both Contracts

Make sure to verify both:

• 🪙 MyToken (ERC20) contract
• 🎨 MyNFT (ERC721) contract

📝 Save the verification URLs! You'll need them for submission.

Checkpoint 5: 📋 Submit Your Challenge

🎯 Time to submit your completed challenge to the SEA Campaign!

Go to Week 1 Submission to submit your completed challenge.

💡 Tips for Success

• Test locally first: Always test with yarn chain and yarn deploy before deploying to testnet
• Keep private keys secure: Never commit mnemonics or private keys to Git repositories
• Double-check addresses: Verify contract addresses before submitting - copy them carefully
• Save everything: Keep a record of all addresses, transaction hashes, and URLs for submission
• Gas fees: Lisk Sepolia has very low gas fees, but still ensure you have enough ETH
• Ask for help: Join our Telegram if you get stuck - the community is very helpful!

🆘 Troubleshooting

Common Issues:

Deployment fails:

• Check you have enough ETH for gas fees on Lisk Sepolia
• Verify network configuration in hardhat.config.ts includes liskSepolia
• Ensure you're using yarn deploy --network liskSepolia or set defaultNetwork

Verification fails:

• Ensure compiler version matches exactly (contracts use ^0.8.0 but project compiles with 0.8.17)
• Check all imports are included in the source code
• Verify contract name spelling (case-sensitive)
• Make sure optimization settings match (enabled: true, runs: 200)

Frontend not connecting:

• Check scaffold.config.ts has targetNetwork: chains.liskSepolia
• Ensure wallet is connected to Lisk Sepolia network
• Verify contract addresses match your deployed contracts
• Clear browser cache and reconnect wallet if needed

Need help? Join our @LiskSEA Telegram! 💬

💬 Problems, questions, comments on the stack? Post them to @LiskSEA