Deploy on Base

Welcome to the Base deployment quickstart guide! This comprehensive walkthrough will help you set up your environment and deploy smart contracts on Base. Whether you’re a seasoned developer or just starting out, this guide has got you covered.

What You’ll Achieve

By the end of this quickstart, you’ll be able to:

• Set up your development environment to deploy on Base
• Deploy your smart contracts to Base
• Connect your frontend to your smart contracts

Why Base?

Base is a fast, low-cost, builder-friendly Ethereum L2 built to bring the next billion users onchain. By following this guide, you’ll join a vibrant ecosystem of developers, creators, and innovators who are building a global onchain economy.

Set Up Your Development Environment

1. Create a new project directory

mkdir my-base-project && cd my-base-project

2. Install Foundry, a powerful framework for smart contract development

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

This installs Foundry and updates it to the latest version.

3. Initialize a new Solidity project

forge init

Your Foundry project is now ready. You’ll find an example contract in the src directory, which you can replace with your own contracts. For the purposes of this guide, we’ll use the Counter contract provided in /src/Counter.sol

Foundry provides a suite of tools for Ethereum application development, including Forge (for testing), Cast (for interacting with the chain), and Anvil (for setting up a local node). You can learn more about Foundry here.

Configure Foundry with Base

To deploy your smart contracts to Base, you need two key components:

1. A node connection to interact with the Base network
2. A funded private key to deploy the contract

Let’s set up both of these:

1. Set up your node connection

1. Create a .env file in your project’s root directory
2. Add the Base network RPC URL to your .env file

BASE_RPC_URL="https://mainnet.base.org"
BASE_SEPOLIA_RPC_URL="https://sepolia.base.org"

3. Load your environment variables

source .env

Base Sepolia is the test network for Base, which we will use for the rest of this guide. You can obtain free Base Sepolia ETH from one of the faucets listed here.

2. Secure your private key

1. Store your private key in Foundry’s secure keystore

cast wallet import deployer --interactive

2. When prompted enter your private key and a password.

Your private key is stored in ~/.foundry/keystores which is not tracked by git.

Never share or commit your private key. Always keep it secure and handle with care.

Deploy Your Contracts

Now that your environment is set up, let’s deploy your contracts to Base Sepolia.

1. (Optional) First, perform a dry run to simulate the deployment and verify everything is configured correctly:

forge create ./src/Counter.sol:Counter --rpc-url $BASE_SEPOLIA_RPC_URL --account deployer

This performs a simulation without broadcasting the transaction to the network. You’ll see the transaction details and contract ABI, but no actual deployment will occur.

2. Deploy your contract by adding the --broadcast flag:

forge create ./src/Counter.sol:Counter --rpc-url $BASE_SEPOLIA_RPC_URL --account deployer --broadcast

The --broadcast flag is required to actually deploy your contract to the network. Without it, Foundry only performs a dry run simulation.

Note the format of the contract being deployed is <contract-path>:<contract-name>.

3. After successful deployment, you’ll see output including:

Deployer: 0x...
Deployed to: 0x...  <-- YOUR CONTRACT ADDRESS
Transaction hash: 0x...

4. Copy the deployed contract address and add it to your .env file:

COUNTER_CONTRACT_ADDRESS="0x..."

Replace 0x... with your actual deployed contract address from the output above.

5. Load the new environment variable:

source .env

You need to run source .env after modifying your .env file to load the new variables in your current terminal session.

Verify Your Deployment

To ensure your contract was deployed successfully:

1. Check the transaction on Sepolia Basescan using your transaction hash
2. Use the cast command to interact with your deployed contract from the command line:

cast call $COUNTER_CONTRACT_ADDRESS "number()(uint256)" --rpc-url $BASE_SEPOLIA_RPC_URL

Make sure you’ve added COUNTER_CONTRACT_ADDRESS to your .env file and run source .env before running this command. Otherwise, the environment variable will be undefined and the command will fail.

This will return the initial value of the Counter contract’s number storage variable, which will be 0.

Congratulations! You’ve deployed your smart contracts to Base Sepolia!

Next Steps

• Use wagmi or viem to connect your frontend to your contracts.
• Learn more about interacting with your contracts in the command line using Foundry from our Foundry tutorial.