Deploy smart contracts to an Ethereum chain

This tutorial shows you how to deploy smart contracts as transactions to a network.

Prerequisites

This tutorial requires a local blockchain network. You can use the Developer Quickstart to rapidly generate one.

Use eth_sendSignedTransaction

To deploy a smart contract using eth_sendSignedTransaction, use an account's private key to sign and serialize the transaction, and send the API request.

This example uses the web3js library to make the API calls.

Using the SimpleStorage.sol smart contract as an example, create a new file called compile.js with the following content:

compile.js

const fs = require("fs").promises;
const solc = require("solc");

async function main() {
  // Load the contract source code
  const sourceCode = await fs.readFile("SimpleStorage.sol", "utf8");
  // Compile the source code and retrieve the ABI and bytecode
  const { abi, bytecode } = compile(sourceCode, "SimpleStorage");
  // Store the ABI and bytecode into a JSON file
  const artifact = JSON.stringify({ abi, bytecode }, null, 2);
  await fs.writeFile("SimpleStorage.json", artifact);
}

function compile(sourceCode, contractName) {
  // Create the Solidity Compiler Standard Input and Output JSON
  const input = {
    language: "Solidity",
    sources: { main: { content: sourceCode } },
    settings: { outputSelection: { "*": { "*": ["abi", "evm.bytecode"] } } },
  };
  // Parse the compiler output to retrieve the ABI and bytecode
  const output = solc.compile(JSON.stringify(input));
  const artifact = JSON.parse(output).contracts.main[contractName];
  return {
    abi: artifact.abi,
    bytecode: artifact.evm.bytecode.object,
  };
}

main().then(() => process.exit(0));

Run compile.js to get the smart contract's output JSON:

node compile.js

Run solc to get the contract's bytecode and ABI:

solc SimpleStorage.sol --bin --abi

Once you have the bytecode and ABI, you can rename the output files to make them easier to use; this tutorial refers to them as SimpleStorage.bin and SimpleStorage.abi.

Create a new file named public_tx.js to send the transaction (or run the following commands in a JavaScript console). The Developer Quickstart provides an example of a public transaction script.

const web3 = new Web3(host);
// use an existing account, or make an account
const privateKey =
  "0x8f2a55949038a9610f50fb23b5883af3b4ecb3c3bb792cbcefbd1542c692be63";
const account = web3.eth.accounts.privateKeyToAccount(privateKey);

// read in the contracts
const contractJsonPath = path.resolve(__dirname, "SimpleStorage.json");
const contractJson = JSON.parse(fs.readFileSync(contractJsonPath));
const contractAbi = contractJson.abi;
const contractBinPath = path.resolve(__dirname, "SimpleStorage.bin");
const contractBin = fs.readFileSync(contractBinPath);
// initialize the default constructor with a value `47 = 0x2F`; this value is appended to the bytecode
const contractConstructorInit =
  "000000000000000000000000000000000000000000000000000000000000002F";

// get txnCount for the nonce value
const txnCount = await web3.eth.getTransactionCount(account.address);

const rawTxOptions = {
  nonce: web3.utils.numberToHex(txnCount),
  from: account.address,
  to: null, //public tx
  value: "0x00",
  data: "0x" + contractBin + contractConstructorInit, // contract binary appended with initialization value
  gasPrice: "0x0", //ETH per unit of gas
  gasLimit: "0x24A22", //max number of gas units the tx is allowed to use
};
console.log("Creating transaction...");
const tx = new Tx(rawTxOptions);
console.log("Signing transaction...");
tx.sign(privateKey);
console.log("Sending transaction...");
var serializedTx = tx.serialize();
const pTx = await web3.eth.sendSignedTransaction(
  "0x" + serializedTx.toString("hex").toString("hex"),
);
console.log("tx transactionHash: " + pTx.transactionHash);
console.log("tx contractAddress: " + pTx.contractAddress);

rawTxOptions contains the following fields:

• nonce - the number of transactions sent from an address.
• from - address of the sending account. For example 0xfe3b557e8fb62b89f4916b721be55ceb828dbd73.
• to - address of the receiver. To deploy a contract, set to null.
• gas - amount of gas provided by the sender for the transaction.
• gasPrice - price for each unit of gas the sender is willing to pay.
• data - binary of the contract (in this example there's also a constructor initialization value, so we append that to the binary value).
• value - amount of Ether/Wei transferred from the sender to the recipient.

Run the public_tx.js to send the transaction:

node public_tx.js

This example code creates the transaction tx, signs it with the private key of the account, serializes it, then calls eth_sendSignedTransaction to deploy the contract.

Use eth_sendTransaction

You can use eth_sendTransaction as an alternative to eth_sendSignedTransaction. However, Besu does not support the eth_sendTransaction API call and keeps account management separate for stronger security. Configure Web3Signer with your Besu node to make the eth_sendTransaction API call.

Pass the following parameters to the eth_sendTransaction call to Web3Signer. Web3Signer converts the request to an eth_sendRawTransaction call that Besu uses:

• to - address of the receiver. To deploy a contract, set to null.
• from - address of the sender account. For example 0x9b790656b9ec0db1936ed84b3bea605873558198.
• gas - amount of gas provided by the sender for the transaction
• gasPrice - price for each unit of gas the sender is willing to pay
• data - one of the following:
  • For contract deployments (this use case) - compiled code of the contract
  • For contract interactions - hash of the invoked method signature and encoded parameters (see Ethereum Contract ABI)
  • For simple ether transfers - empty

'eth_sendTransaction' parameters

params: {
  "to": null,
  "from": "0x9b790656b9ec0db1936ed84b3bea605873558198",
  "gas": "0x76c0",
  "gasPrice": "0x9184e72a000",
  "data": "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"
}

Make the request using eth_sendTransaction:

'eth_sendTransaction' curl HTTP request

curl -X POST --data '{"jsonrpc":"2.0","method":"eth_sendTransaction","params":[{"from":"0x9b790656b9ec0db1936ed84b3bea605873558198", "to":null, "gas":"0x7600","gasPrice":"0x9184e72a000", "data":"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"}], "id":1}' <JSON-RPC-endpoint:port>