Why Foundry?

Developing on CrossFi requires a robust and efficient toolset, and Foundry is one of the best frameworks for smart contract development. Foundry offers a fast, developer-friendly environment for writing, testing, and deploying smart contracts on Ethereum-compatible networks (EVM) like CrossFi.

In this guide, we’ll walk through the step-by-step process of setting up Foundry for CrossFi development. Whether you’re a seasoned blockchain developer or just getting started, this setup will prepare you to build and deploy smart contracts seamlessly.

What to expect

✅ Install and configure Foundry on your system.
✅ Set up CrossFi’s RPC for smart contract deployment.
✅ Verify your installation and prepare for development.

✅Deploy a simple Counter Smart contract

Github Repository

Setting up foundry

Incase you have configure foundry on your system you can skip this part

Step 1: Install foundry

Foundry provide a simple installation script that works across major installation systems

For Linux & MacOs

Open terminal and run

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

This will install Foundryup. Simply follow the on-screen instructions, and the foundryup command will become available in your CLI.

Step2: Verify Installation

Once you have run foundryup ,Run the following command to check if it has been installed:

forge --version

Which supposed to output something like “forge 0.2.0 (440ec52 2024-04-11T00:18:58.806922049Z)” depending on your version.

Step3: Initialize a Foundry Project

Open a new terminal (any directory of your choice)

forge init crossfi
cd crossfi

which will output as below

Step4: Configure Foundry for crossFi

Update your project's foundry.toml file to include CrossFi's RPC URL:

[rpc_endpoints]
crossfiRPC = "https://rpc.testnet.ms"

Now your foundry.toml should look like the figure below

To confirm The Rpc connection,run

forge test --fork-url  https://rpc.testnet.ms

Create a new .env file on the root directory To add your private key, Which will be used to deploy contracts to CrossFi as shown below:

To obtain your private_key you can use one from External Own wallets i.e metamask,Keprl Wallets.

For the testing purpose You can use cast command which comes with foundry to generate new private key:

cast wallet new

copy the private key and use it inside the .env file

Step 5: Writing Smart Contract

Foundry comes pre-installed with an existing counter smart contract which we will use.

The Smart Contract is located under the src/ directory:

Now this is the contract that we will deploy to crossFi chain.

Step6 : Writing Deploying Script

Open the Script folder and create a file Deploy.s.sol and add the below code snippet:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13 ;

import {Script,console} from "forge-std/Script.sol";
import {Counter} from "../src/Counter.sol";

contract DeployScript is Script{

    function setUp()public{}

    function run()external returns(Counter){
        uint256 my_privateKey = vm.envUint("PRIVATE_KEY");
        vm.startBroadcast(my_privateKey);
        //deploy the counter
        Counter counter = new Counter();
        console.log("Deployed to",address(counter));
        vm.stopBroadcast();
        return counter;

    }
}

• The {Script} is provided by foundry which used to run scripts for Smart contracts

• {Counter} Represents the Smart contract from the src/ folder

• {vm.envUint} Loading .env variables in our case the private key which will be used to deploy the Smart contract;

Step7: Configuring MakeFile for Executing the Script

Create a file Makefile under the root folder and add the below snapshot:

deploy:
     forge script script/Deploy.s.sol:DeployScript --rpc-url crossfiRPC --broadcast --verify -vvvv

Step8: Deploying the Contract

The resulted output should be as follows:

make deploy

Wrapping Up & What's Next

With Foundry set up for CrossFi, you're ready to start developing smart contracts.

Next Series: The next article will be a continuation, where we'll dive into writing, compiling, and optimizing your first smart contract on CrossFi

Thank you for your time, and stay tuned!