Skip to main content

Using Foundry

Foundry is a fast, Rust-based development toolkit for Ethereum. It handles everything from compilation and testing to deployment and on-chain interaction via the command line.

Install Foundry​

Foundry runs natively on macOS and Linux. On Windows, you must use WSL 2 — Foundry does not support PowerShell or CMD. Make sure curl and git are installed before proceeding.

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

Verify the installation:

forge --version

Create a new project​

forge init hello_horizen && cd hello_horizen

This scaffolds a new Foundry project with a sample Counter.sol contract at src/Counter.sol, a test file, and a default foundry.toml config.

Configure Horizen in foundry.toml​

Open foundry.toml and add the Horizen Testnet as a named network:

[rpc_endpoints]
horizen_testnet = "https://horizen-testnet.rpc.caldera.xyz/http"
horizen_mainnet = "https://horizen.calderachain.xyz/http"

This lets you reference networks by name in scripts and commands instead of pasting the full RPC URL each time.

Compile your contracts​

forge build

Deploy to Horizen Testnet​

forge create src/Counter.sol:Counter \
  --rpc-url https://horizen-testnet.rpc.caldera.xyz/http \
  --private-key <YOUR_PRIVATE_KEY>

On success, the output will include the deployed contract address:

Deployer: 0xYourWalletAddress
Deployed to: 0xYourContractAddress
Transaction hash: 0xYourTxHash

Deploy to Horizen Mainnet​

Swap the RPC URL to the mainnet endpoint and make sure your wallet has mainnet ETH:

forge create src/Counter.sol:Counter \
  --rpc-url https://horizen.calderachain.xyz/http \
  --private-key <YOUR_PRIVATE_KEY>

Avoid exposing your private key in terminal history by storing it in a .env file:

# .env
PRIVATE_KEY=your_private_key_here
RPC_URL=https://horizen-testnet.rpc.caldera.xyz/http

Then load it in your deploy command:

source .env
forge create src/Counter.sol:Counter \
  --rpc-url $RPC_URL \
  --private-key $PRIVATE_KEY

Add .env to your .gitignore — never commit private keys to a repository.

Run tests​

forge test

To run tests against a live fork of Horizen:

forge test --fork-url https://horizen-testnet.rpc.caldera.xyz/http

For contract verification after deployment, see Verify a Contract.

On this page