create2-patterns

CREATE2 Deterministic Deployment Patterns

Address Calculation

CREATE2 address is determined by four inputs:

address = keccak256(0xff ++ deployer ++ salt ++ keccak256(initCode))[12:]

function computeAddress(bytes32 salt, bytes32 initCodeHash, address deployer)
    internal pure returns (address)
{
    return address(uint160(uint256(keccak256(abi.encodePacked(
        bytes1(0xff), deployer, salt, initCodeHash
    )))));
}

Basic CREATE2 Factory

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

contract Create2Factory {
    event Deployed(address indexed addr, bytes32 indexed salt);

    function deploy(bytes32 salt, bytes memory creationCode)
        external payable returns (address deployed)
    {
        assembly {
            deployed := create2(callvalue(), add(creationCode, 0x20), mload(creationCode), salt)
        }
        require(deployed != address(0), "CREATE2: deployment failed");
        emit Deployed(deployed, salt);
    }

    function computeAddress(bytes32 salt, bytes memory creationCode)
        external view returns (address)
    {
        bytes32 hash = keccak256(abi.encodePacked(
            bytes1(0xff), address(this), salt, keccak256(creationCode)
        ));
        return address(uint160(uint256(hash)));
    }
}

Salt Selection Strategies

// Simple: use deployer address + nonce
bytes32 salt = keccak256(abi.encode(msg.sender, nonce));

// Access-controlled: only specific deployer can use this salt
bytes32 salt = keccak256(abi.encode(msg.sender, "MyContract-v1"));

// Include constructor args in salt for uniqueness
bytes32 salt = keccak256(abi.encode(msg.sender, name, symbol, initialSupply));

Cross-Chain Same-Address Deployment

To deploy at the same address on multiple chains:

1. Use the same factory contract address on all chains (deploy factory with CREATE2 from an EOA at same nonce, or use a known factory like Arachnid's)
2. Use the same salt
3. Use the same creation code (including constructor arguments)