Deploy a contract with Foundry or Hardhat

Select the network

Follow the target chain's integration guide (accessed via Supported Chains) to create network.mjs and export RPC_URL and CHAIN_ID. Chain guides read the chain ID and method policy from GET /v1/chains and explain the gas token, whether a separate broadcasting RPC is required, and chain-specific deployment settings.

Choose one tool below. Both deploy the same small contract without constructor arguments.

Fund the deployer with the selected network’s native gas token. Set DEPLOYER_PRIVATE_KEY securely in your local environment; never commit it. The following commands broadcast a transaction and spend gas.

Create Hello.sol with no constructor arguments:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;
contract Hello {
    event Ping(address indexed sender);
    function ping() external { emit Ping(msg.sender); }
    function hello() external pure returns (string memory) {
        return "hello";
    }
}

Foundry

In an initialized Foundry project, place the contract at src/Hello.sol and use this foundry.toml:

[profile.default]
src = "src"
out = "out"
libs = ["lib"]
solc_version = "0.8.24"
evm_version = "paris"

[rpc_endpoints]
target = "${RPC_URL}"

: "${RPC_URL:?Set RPC_URL}" "${CHAIN_ID:?Set CHAIN_ID}" "${DEPLOYER_PRIVATE_KEY:?Set deployer key}"
test "$(cast chain-id --rpc-url "$RPC_URL")" = "$CHAIN_ID" || exit 1
forge build
forge create src/Hello.sol:Hello --rpc-url target \
  --chain "$CHAIN_ID" --private-key "$DEPLOYER_PRIVATE_KEY" --broadcast

Keep the transaction hash and deployed address. Use cast receipt "$TX_HASH" --rpc-url "$RPC_URL" to inspect inclusion and status, then cast call "$CONTRACT_ADDRESS" "hello()(string)" --rpc-url "$RPC_URL" to read the contract. Set these two variables from the deployment output.

Hardhat 2 with ethers 6

In a separate CommonJS project (npm init -y), install npm install --save-dev hardhat@2 @nomicfoundation/hardhat-ethers@3 ethers@6. Place the same contract at contracts/Hello.sol. Save this as hardhat.config.cjs:

require('@nomicfoundation/hardhat-ethers');
const { RPC_URL, CHAIN_ID, DEPLOYER_PRIVATE_KEY } = process.env;
if (!RPC_URL || !/^[1-9][0-9]*$/.test(CHAIN_ID ?? '') || !DEPLOYER_PRIVATE_KEY) {
  throw new Error('Set RPC_URL, CHAIN_ID and DEPLOYER_PRIVATE_KEY');
}
module.exports = {
  solidity: { version: '0.8.24', settings: { evmVersion: 'paris' } },
  networks: {
    target: { url: RPC_URL, chainId: Number(CHAIN_ID), accounts: [DEPLOYER_PRIVATE_KEY] },
  },
};

Create the scripts directory and save as scripts/deploy.cjs:

const { ethers } = require('hardhat');
async function main() {
  const contract = await ethers.deployContract('Hello');
  console.log(contract.deploymentTransaction().hash);
  await contract.waitForDeployment();
  console.log(await contract.getAddress());
}
main().catch(error => { console.error(error); process.exitCode = 1; });

npx hardhat compile
npx hardhat run scripts/deploy.cjs --network target

The network’s chainId is checked against the RPC. See the Hardhat 2 network settings and Foundry settings (accessed: 2026-10-07).

Read events

Set LOG_ADDRESS to the deployed address. Follow the event reading method in the target chain's guide (WebSocket subscription or HTTP chunked polling, depending on the chain's ws field in /v1/chains) to read Ping events after calling ping().