Deploy smart contract on Kaia

This guide covers adding the network to a browser wallet, then deploying a simple contract using Foundry and Hardhat — pick whichever you prefer on Kaia.

Kaia is EVM-compatible, so contracts deploy with standard Ethereum tooling such as Foundry, Hardhat, and Remix. This guide covers adding Kaia to a wallet and deploying a first contract with Foundry and Hardhat through a GetBlock endpoint. Kaia contracts are verified either through Sourcify or through the KaiaScan verification API.

Prerequisites

• A wallet holding KAIA for gas (see Add Network to Your Wallet below)

• A GetBlock access token from the GetBlock dashboard, used as <ACCESS-TOKEN> in the endpoint https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/

• Node.js version 20 or later, for Hardhat

• A funded deployer address, on Kairos Testnet for testing (see Testnet Faucets)

Network Details

Property	Kaia Mainnet	Kairos Testnet
Chain ID	8217 (0x2019)	1001 (0x3e9)
RPC URL	https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/	https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/
Currency Symbol	KAIA	KAIA
Block Explorer	kaiascan.io	kairos.kaiascan.io

Kaia is not pre-configured in MetaMask by default, and is well supported by the Kaia Wallet extension. To use MetaMask, add Kaia manually or through an add-network button before it appears in the wallet.

Every command below defaults to Mainnet — replace environment variable values with testnet ones for a dry run before touching real funds.

Never commit a real private key. Use environment variables and prefer a throwaway deployer key for testing. Private keys committed to a public repo are drained within seconds by automated bots.

Add Network to Your Wallet

1

Open your wallet

Open the Kaia Wallet extension, or MetaMask.

2

Open the network dropdown

Click the network dropdown at the top of the wallet.

3

Add a network manually

Click Add network, then Add a network manually.

4

Enter network details

Enter the network details from the Prerequisites section above.

5

Save and switch networks

Save and switch to the newly added network.

Deploy with Foundry

1

Install Foundry

curl -L https://foundry.paradigm.xyz | bash
foundryup

2

Create a project

mkdir kaia-deploy && cd kaia-deploy
forge init

3

Create a contract

Create src/HelloKaia.sol:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

contract HelloKaia {
    function hello() external pure returns (string memory) {
        return "Hello from Kaia";
    }
}

4

Deploy

export PRIVATE_KEY=<your-deployer-private-key>
export KAIA_RPC_URL=https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/

forge create src/HelloKaia.sol:HelloKaia \
  --rpc-url $KAIA_RPC_URL \
  --private-key $PRIVATE_KEY \
  --broadcast

5

Verify with Sourcify

Foundry has native Sourcify support. Verify the deployed contract against Sourcify:

forge verify-contract <contract_address> \
  src/HelloKaia.sol:HelloKaia \
  --chain-id 8217 \
  --verifier sourcify \
  --verifier-url https://sourcify.dev/server/

Deploy with Hardhat

1

Create a project

mkdir kaia-deploy && cd kaia-deploy
npm init -y
npm install --save-dev hardhat
npx hardhat init

Select a JavaScript project when prompted.

2

Configure networks and verification

KaiaScan exposes an Etherscan-compatible verification endpoint, configured as a custom chain. The API key value is not used and can be any placeholder.

hardhat.config.js

require('@nomicfoundation/hardhat-toolbox');

const PRIVATE_KEY = process.env.PRIVATE_KEY;

module.exports = {
  solidity: '0.8.24',
  networks: {
    kaia: {
      url: 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/',
      chainId: 8217,
      accounts: [PRIVATE_KEY]
    },
    kairos: {
      url: 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/',
      chainId: 1001,
      accounts: [PRIVATE_KEY]
    }
  },
  etherscan: {
    apiKey: {
      kaia: 'unnecessary',
      kairos: 'unnecessary'
    },
    customChains: [
      {
        network: 'kaia',
        chainId: 8217,
        urls: {
          apiURL: 'https://mainnet-api.kaiascan.io/hardhat-verify',
          browserURL: 'https://kaiascan.io'
        }
      },
      {
        network: 'kairos',
        chainId: 1001,
        urls: {
          apiURL: 'https://kairos-api.kaiascan.io/hardhat-verify',
          browserURL: 'https://kairos.kaiascan.io'
        }
      }
    ]
  }
};

3

Create a contract

Create contracts/HelloKaia.sol:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

contract HelloKaia {
    function hello() external pure returns (string memory) {
        return "Hello from Kaia";
    }
}

4

Compile and Deploy

Create scripts/deploy.js:

scripts/deploy.js

const hre = require('hardhat');

async function main() {
  const contract = await hre.ethers.deployContract('HelloKaia');
  await contract.waitForDeployment();
  console.log('HelloKaia deployed to:', await contract.getAddress());
}

main().catch((error) => {
  console.error(error);
  process.exitCode = 1;
});

Then compile and deploy:

npx hardhat compile
npx hardhat run scripts/deploy.js --network kaia

5

Verify on KaiaScan

npx hardhat verify --network kaia \
  --contract contracts/HelloKaia.sol:HelloKaia <contract_address>

On success, the output links to the verified contract on KaiaScan.

Testnet Faucets

Kairos Testnet

• Kaia Faucet — dispenses Kairos test KAIA to a connected wallet (verify)