Deploy Smart Contract on Unichain

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

Unichain is an EVM-equivalent OP Stack Layer 2 that runs standard EVM bytecode, so contracts deploy with the usual Ethereum tooling such as Foundry, Hardhat, and Remix without modification. This guide covers adding Unichain to a wallet and deploying a first contract with Foundry and Hardhat through a GetBlock endpoint.

Prerequisites

• A wallet holding ETH on Unichain 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 Unichain Sepolia for testing (see Testnet Faucets)

Network Details

Property	Unichain Mainnet	Unichain Sepolia Testnet
Chain ID	130 (0x82)	1301 (0x515)
RPC URL	https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/	https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/
Currency Symbol	ETH	ETH
Block Explorer	uniscan.xyz	sepolia.uniscan.xyz

Unichain is not pre-configured in MetaMask by default. Only Ethereum Mainnet and Sepolia ship pre-configured, so Unichain must be added 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 MetaMask, or the EVM wallet of choice.

2

Open network settings

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 unichain-deploy && cd unichain-deploy
forge init

3

Create a contract

Create src/HelloUnichain.sol:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.30;

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

4

Deploy

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

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

5

Verify on Block Explorer

Uniscan uses the Etherscan V2 unified API. Use the chain ID and a single Etherscan API key:

export ETHERSCAN_API_KEY=<your-etherscan-api-key>

forge verify-contract <contract_address> \
  src/HelloUnichain.sol:HelloUnichain \
  --chain-id 130 \
  --etherscan-api-key $ETHERSCAN_API_KEY

Deploy with Hardhat

1

Create a project

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

Select a JavaScript project when prompted.

2

Configure networks

hardhat.config.js

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

const PRIVATE_KEY = process.env.PRIVATE_KEY;

module.exports = {
  solidity: '0.8.30',
  networks: {
    unichain: {
      url: 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/',
      chainId: 130,
      accounts: [PRIVATE_KEY]
    },
    unichainSepolia: {
      url: 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/',
      chainId: 1301,
      accounts: [PRIVATE_KEY]
    }
  },
  etherscan: {
    apiKey: process.env.ETHERSCAN_API_KEY
  }
};

3

Create a contract

Create contracts/HelloUnichain.sol:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.30;

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

4

Compile and Deploy

Create scripts/deploy.js:

scripts/deploy.js

const hre = require('hardhat');

async function main() {
  const contract = await hre.ethers.deployContract('HelloUnichain');
  await contract.waitForDeployment();
  console.log('HelloUnichain 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 unichain

5

Verify on Block Explorer

npx hardhat verify --network unichain <contract_address>

Testnet Faucets

Unichain Sepolia

• Unichain Faucet — dispenses Unichain Sepolia ETH to a connected wallet (verify)

• Superchain Faucet — Sepolia ETH across OP Stack testnets, including Unichain Sepolia (verify)

• Bridge Sepolia ETH from Ethereum Sepolia through the Unichain Bridge as an alternative to faucets