Build a dApp Using Scaffold-ETH 2 on Kaia

Creating decentralized applications (dApps) has become increasingly accessible thanks to modern development toolkits. One of the most powerful tools available today is Scaffold-ETH 2, an open-source boilerplate designed to streamline dApp development on Ethereum and other EVM-compatible blockchains — including Kaia.

With Scaffold-ETH 2, developers can rapidly deploy Solidity smart contracts and launch interactive React-based frontends with minimal setup. Built using modern tools like Next.js, RainbowKit, Hardhat, Foundry, Wagmi, and TypeScript, this toolkit empowers both beginners and experienced developers to focus on innovation rather than infrastructure.

In this comprehensive guide, you’ll learn how to set up a development environment, configure Scaffold-ETH 2 for the Kaia blockchain, deploy smart contracts, verify them on-chain, and run a fully functional dApp locally.

Prerequisites

Before diving into the setup process, ensure your system meets the following requirements:

Node.js (version >= v18.17) — Download from nodejs.org
Yarn (v1 or v2+) — Install via Yarn's official guide
Basic knowledge of JavaScript and React, especially hooks
A MetaMask wallet installed and configured
Test KAIA tokens from the Kaia faucet
Access to a Kaia RPC endpoint — retrieve from one of the supported providers

Once these prerequisites are in place, you're ready to begin building.

Setting Up Your Development Environment

Scaffold-ETH 2 can be initialized in two ways: by cloning the GitHub repository or using the npx command. For simplicity and speed, we’ll use the latter method.

Run the following command in your terminal:

npx create-eth@latest

You'll be prompted with several configuration options:

Project Name: Enter a name such as kaia-scaffold-example
Framework: Choose between Hardhat or Foundry. In this tutorial, we'll use Hardhat
Install Packages?: Press Enter to accept the default "Yes"

After setup completes, navigate into your project directory:

cd kaia-scaffold-example

This initializes a full-stack dApp environment with both backend (smart contracts) and frontend (React UI) pre-configured.

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Key Steps in the Scaffold-ETH 2 Workflow

The typical development cycle using Scaffold-ETH 2 involves the following stages:

Update network configuration in Hardhat for Kaia
Add smart contracts to packages/hardhat/contracts
Edit deployment scripts in packages/hardhat/deploy
Deploy contracts to the Kaia testnet
Verify deployed contracts using Hardhat plugins
Configure the frontend in packages/nextjs/scaffold.config.ts to target Kaia
Customize UI components under packages/nextjs/pages as needed

In this guide, we’ll use the default example contract and frontend included in Scaffold-ETH 2, modifying only what’s necessary for Kaia integration.

Configuring Hardhat for Kaia

To deploy contracts on Kaia, you must configure Hardhat to recognize the Kaia network — specifically the Kairos Testnet (chain ID: 1001).

Step 1: Create a `.env` File

First, create a .env file inside the Hardhat package to securely store sensitive data:

touch packages/hardhat/.env

Refer to .env.example for guidance on structure. For Kaia, you only need one variable:

deployer_private_key=insert_your_private_key_here

🔐 Never commit this file to version control. The private key corresponds to the wallet funding and deploying contracts.

Step 2: Update `hardhat.config.ts`

Modify the network configuration in packages/hardhat/hardhat.config.ts. Add the following network definition under networks:

kairos: {
  chainId: 1001,
  url: "https://public-en-kairos.node.kaia.io", // Official public endpoint
  accounts: [process.env.deployer_private_key],
},

Set defaultNetwork to "kairos" if you want deployments to target Kaia by default.

For more details, see Kaia’s official Hardhat integration guide.

Deploying Contracts to Kaia

With configuration complete, it's time to compile and deploy your smart contract.

First, compile the contract:

yarn compile

Then deploy using:

yarn deploy --network kairos

If no default network is set, always specify --network kairos explicitly.

Upon successful deployment, the terminal will display the deployed contract address — copy this for verification and frontend integration.

Verifying Your Deployed Contract

Source code verification increases transparency and trust. On Kaia, you can verify contracts via Kaiascope, equivalent to Etherscan.

Add this configuration to hardhat.config.ts under the etherscan object:

etherscan: {
  apiKey: {
    kairos: "unnecessary",
  },
  customChains: [
    {
      network: "kairos",
      chainId: 1001,
      urls: {
        apiURL: "https://api-kairos.kaiascope.com/api",
        browserURL: "https://kairos.kaiascope.com",
      },
    },
  ],
},

Now verify your contract:

yarn hardhat verify --network kairos CONTRACT_ADDRESS "constructorArg1"

Example:

yarn hardhat verify --network kairos 0x7fc9656fc8c8ab433867e58b7c6afc19ec4275da

After a few moments, you’ll receive confirmation and a link to view the verified contract on Kaiascope.

Frontend Configuration with Next.js

Now that your contract is live, connect your frontend so users can interact with it.

Update Target Network in `scaffold.config.ts`

Navigate to packages/nextjs/scaffold.config.ts and locate the targetNetworks array. Replace its value with Kaia’s testnet:

targetNetworks: [chains.klaytnBaobab],

This ensures the frontend connects to the correct chain and enables wallet interactions via RainbowKit and Wagmi.

Launching Your dApp Locally

With all configurations complete, start the development server:

yarn dev

Visit http://localhost:3001 in your browser. You should now see your dApp interface.

👉 Start building and testing dApps with real-time blockchain interactions now.

Connect your MetaMask wallet (ensure it’s switched to Kairos Testnet), interact with the contract functions, and explore features like transaction debugging and address management built into the Scaffold-ETH 2 UI.

Frequently Asked Questions (FAQ)

Q: What is Scaffold-ETH 2 used for?
A: Scaffold-ETH 2 is a full-stack development kit that accelerates dApp creation on EVM-compatible chains like Ethereum, Polygon, and Kaia. It includes smart contract tooling, deployment scripts, and a React frontend boilerplate.

Q: Can I use Foundry instead of Hardhat?
A: Yes! During project initialization, you can select Foundry as your preferred framework. Both support Kaia deployment with minor configuration tweaks.

Q: Why do I need a .env file?
A: The .env file securely stores private keys and API secrets without exposing them in code. This prevents accidental leaks when sharing or publishing code.

Q: Is Kaia fully EVM-compatible?
A: Yes. Kaia supports EVM-based smart contracts written in Solidity, allowing seamless migration from Ethereum or other EVM chains using tools like Hardhat and Foundry.

Q: How do I get testnet KAIA tokens?
A: Visit the official Kaia faucet, connect your wallet, and request test tokens for development and testing.

Q: Can I customize the React frontend?
A: Absolutely. The Next.js frontend is highly modular. You can modify pages, styles, components, and add new features tailored to your dApp’s functionality.

Conclusion

You’ve successfully built and deployed a dApp on the Kaia blockchain using Scaffold-ETH 2! From setting up your environment to deploying verified smart contracts and launching an interactive frontend, you now have a solid foundation for further exploration.

Whether you're prototyping a DeFi platform, NFT marketplace, or Web3 social app, Scaffold-ETH 2 dramatically reduces development time while maintaining flexibility and scalability.

Continue experimenting with custom contracts, advanced UI components, and cross-chain integrations. For deeper learning, refer to the official Scaffold-ETH 2 documentation or engage with the community on the Kaia Developer Forum.

👉 Accelerate your next blockchain project with seamless tools and resources.