EVM: compute a CREATE or CREATE2 address

⚠️ DANGEROUS: use at your own risk. Code that handles keys and signs transactions should always be read and audited by you before you trust it with real funds. Used incorrectly, it can destroy your money.

Task: know where a contract is (or will be) deployed before you trust or fund that address. Part of the EVM contract recipes.

Fixtures are raw Ethereum mainnet JSON-RPC responses in fixtures/evm-mainnet/; the request behind each file is in PROVENANCE.md. Live curl lines are UNTESTED here: CI never touches the network.

CREATE: keccak256(rlp([deployer, nonce])). 05a is a deployment tx; create-address reads from and nonce, and the result matches contractAddress in its receipt 05b:

create-address < recipes/fixtures/evm-mainnet/05a-create-tx.json

CREATE2 (EIP-1014): keccak256(0xff ++ deployer ++ salt ++ keccak256(init_code)). 05c/05d create the Uniswap V3 USDT pool (token0 0x3246…8edb, token1 USDT, fee 100). The salt is keccak256(abi.encode(token0, token1, fee)); the init-code hash is the factory's fixed POOL_INIT_CODE_HASH from Uniswap's PoolAddress.sol (not fetched):

abi-encode --raw '(address,address,uint24)' 0x3246806c924fab68dd6db5d39b516ade72618edb 0xdac17f958d2ee523a2206206994597c13d831ec7 100 | sig-hash --keccak | jq -c '{deployer: "0x1F98431c8aD98523631AE4a59f267346ea31F984", salt: .keccak256, init_code_hash: "0xe34f199b19b2b4f47f68442619d555527d244f78a3297ea89325f843f87b8b54"}' | create-address | jq -c '{scheme,address}'

It matches the pool address in the PoolCreated log of 05d:

jq -r '.result.logs[0].data' recipes/fixtures/evm-mainnet/05d-create2-pool-receipt.json | abi-decode --types '(int24,address)' | jq -r '.args[1].value' | tr A-F a-f

Live (UNTESTED here): curl -s -X POST -H 'Content-Type: application/json' --data '{"jsonrpc":"2.0","id":1,"method":"eth_getTransactionByHash","params":["0x…"]}' "$RPC" | create-address