Deploy contract

Deploy Contract to 0G Chain

Metadata

• Category: chain
• SDK: ethers ^6.13.0, Hardhat or Foundry
• Activation Triggers: "deploy contract", "Solidity", "0G Chain", "deploy smart contract"

Purpose

Deploy Solidity smart contracts to 0G Chain using Hardhat, Foundry, or ethers v6 directly. All contracts must be compiled with evmVersion: "cancun".

Prerequisites

• Node.js >= 18
• Hardhat or Foundry installed
• Funded wallet with 0G tokens
• .env with PRIVATE_KEY, RPC_URL

Quick Workflow

1. Write Solidity contract
2. Configure compiler with evmVersion: "cancun"
3. Compile contract
4. Deploy to 0G testnet
5. Verify on block explorer (optional)

Core Rules

ALWAYS

• Set evmVersion: "cancun" in compiler configuration
• Use ethers v6 syntax (NOT v5)
• Test on testnet before deploying to mainnet
• Wait for deployment confirmation (waitForDeployment())
• Store deployed contract addresses

NEVER

• Use any evmVersion other than "cancun" for 0G Chain
• Use ethers v5 patterns (.deployed(), contract.address, etc.)
• Deploy to mainnet without testnet testing
• Hardcode private keys

Code Examples

Hardhat Deployment

// contracts/MyContract.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

contract MyContract {
    uint256 public value;
    address public owner;

    event ValueChanged(uint256 newValue);

    constructor(uint256 _initialValue) {
        value = _initialValue;
        owner = msg.sender;
    }

    function setValue(uint256 _value) external {
        value = _value;
        emit ValueChanged(_value);
    }
}

// scripts/deploy.ts
import { ethers } from 'hardhat';

async function main() {
  const [deployer] = await ethers.getSigners();
  console.log('Deploying with:', deployer.address);

  const balance = await deployer.provider.getBalance(deployer.address);
  console.log('Balance:', ethers.formatEther(balance), '0G');

  const Contract = await ethers.getContractFactory('MyContract');
  const contract = await Contract.deploy(42);
  await contract.waitForDeployment();

  const address = await contract.getAddress();
  console.log('Deployed to:', address);
}

main().catch((error) => {
  console.error(error);
  process.exitCode = 1;
});

# Compile
npx hardhat compile

# Deploy to testnet
npx hardhat run scripts/deploy.ts --network 0g-testnet

# Verify
npx hardhat verify --network 0g-testnet <CONTRACT_ADDRESS> 42

Foundry Deployment

# Compile
forge build

# Deploy
forge create src/MyContract.sol:MyContract \
  --rpc-url https://evmrpc-testnet.0g.ai \
  --private-key $PRIVATE_KEY \
  --constructor-args 42

# Verify
forge verify-contract <CONTRACT_ADDRESS> src/MyContract.sol:MyContract \
  --chain-id 16602 \
  --verifier-url https://chainscan-galileo.0g.ai/api

Direct ethers v6 Deployment

import { ethers, ContractFactory } from 'ethers';
import * as fs from 'fs';
import 'dotenv/config';

async function deploy() {
  const provider = new ethers.JsonRpcProvider(process.env.RPC_URL);
  const wallet = new ethers.Wallet(process.env.PRIVATE_KEY!, provider);

  // Load compiled artifact
  const artifact = JSON.parse(
    fs.readFileSync('./artifacts/contracts/MyContract.sol/MyContract.json', 'utf8'),
  );

  const factory = new ContractFactory(artifact.abi, artifact.bytecode, wallet);
  const contract = await factory.deploy(42);
  await contract.waitForDeployment();

  const address = await contract.getAddress();
  console.log('Deployed to:', address);

  return { address, abi: artifact.abi };
}

Deploy with Constructor Arguments

// Complex constructor
const contract = await Contract.deploy(
  'My Token', // string name
  'MTK', // string symbol
  ethers.parseEther('1000000'), // uint256 initialSupply
  wallet.address, // address owner
);
await contract.waitForDeployment();

Anti-Patterns

// BAD: Missing evmVersion
// hardhat.config.ts
solidity: '0.8.24'; // WRONG — needs cancun setting

// BAD: ethers v5 deployment check
await contract.deployed(); // v5! Use waitForDeployment()

// BAD: Getting address v5 style
console.log(contract.address); // v5! Use await contract.getAddress()

// BAD: Deploying without balance check
await Contract.deploy(42); // May fail with insufficient funds

Common Errors & Fixes

Error	Cause	Fix
invalid opcode	Wrong evmVersion	Set evmVersion: "cancun"
insufficient funds	Wallet empty	Fund from faucet
nonce too low	Pending transaction	Wait or increment nonce
contract creation code storage out of gas	Complex contract	Increase gas limit
cannot estimate gas	Constructor will revert	Check constructor args

Related Skills

• Interact Contract — interact with deployed contracts
• Scaffold Project — project setup
• Storage + Chain — on-chain references

References

• Chain Patterns
• Network Config
• Hardhat Docs
• Foundry Docs