Getting Started with Foundry on INK

This guide will walk you through setting up a new project using Foundry, a blazing fast toolkit for Ethereum application development written in Rust.

Installing Foundry

First, you'll need to install Foundry. Run this command in your terminal:

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

Then run:

foundryup

This will install forge, cast, and anvil - the core tools of Foundry. You can also use foundryup to update the tools to the latest version.

Creating a New Project

To create a new project, navigate to the directory where you want to create your project and use the forge init command:

forge init my_project
cd my_project

This will create a new directory with the following structure:

my_project/
├── lib/
├── src/
│   └── Counter.sol
├── test/
│   └── Counter.t.sol
├── script/
├── .gitignore
└── foundry.toml

Writing Your First Contract

Replace the default Counter.sol with your own contract in src/:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.19;
contract InkContract {
    string public greeting = "Hello, Ink!";
    
    function setGreeting(string memory _greeting) public {
        greeting = _greeting;
    }
}

Building and Testing

Build your project:

forge build

Run tests:

forge test

Deployment

First, create a .env file in your project root:

PRIVATE_KEY=your_private_key_here
RPC_URL=https://rpc-gel-sepolia.inkonchain.com/
BLOCKSCOUT_API_KEY=your_blockscout_api_key_here

Create a deployment script in script/Deploy.s.sol:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.19;
import "forge-std/Script.sol";
import "../src/InkContract.sol";
contract DeployScript is Script {
    function run() external {
        uint256 deployerPrivateKey = vm.envUint("PRIVATE_KEY");
        
        vm.startBroadcast(deployerPrivateKey);
        
        InkContract inkContract = new InkContract();
        
        vm.stopBroadcast();
    }
}

Deploy your contract:

# Load environment variables
source .env
 
# Deploy to InkSepolia Testnet
forge script script/Deploy.s.sol:DeployScript --rpc-url $RPC_URL --broadcast --verify

Verifying Your Contract

If you want to verify your contract on Etherscan:

forge verify-contract <DEPLOYED_CONTRACT_ADDRESS> src/MyContract.sol:MyContract \
    --chain-id 763373 \
    --etherscan-api-key $BLOCKSCOUT_API_KEY

Additional Configuration

You can customize your Foundry setup in foundry.toml:

[profile.default]
src = "src"
out = "out"
libs = ["lib"]
solc = "0.8.19"
optimizer = true
optimizer_runs = 200
 
[rpc_endpoints]
inksepolia = "${INKSEPOLIA_RPC_URL}"

Next Steps

Check out Get Foundry Book for more information on Foundry.

Tutorials Hardhat