@contracts:codeHash

Code hash of an address, with EXTCODEHASH semantics: bytes32(0) for a nonexistent account (zero nonce, balance and code), keccak256 of the code otherwise.

On-chain (@contracts:codeHash!): The account may be a :: call resolving to an address, such as a proxy implementation.

Returns: bytes32

Syntax

@contracts:codeHash(address)

Arguments

Name	Type	Description
address	address	Address to read

@codeHash snapshots the hash at script build time (frozen into the script), with the same EXTCODEHASH semantics as its on-chain face @codeHash!, which instead reads it on-chain at assertion time.

Examples

load contracts [@codeHash]

assert @codeHash!(0x9C58BAcC331c9aa871AFD802DB6379a98e80CEdb) == @codeHash(0xf8D1677c8a0c961938bf2f9aDc3F3CFDA759A9d9) "implementation changed"

See Also

• assert

On-chain face (@codeHash!)

The EXTCODEHASH of an account, read on-chain at assertion time: bytes32(0) for a nonexistent account, keccak256 of the code otherwise. The account can be a :: call resolving to an address, such as a proxy implementation.

Unlike the plain @codeHash face, which snapshots the hash at script build time, @codeHash! reads it at assertion time — the value the chain holds when the batch executes. Both follow EXTCODEHASH semantics, so they agree on every account; reach for @codeHash! when the code could change between building and executing, or when the address itself is only known on-chain.

Examples

load contracts

set $proxy 0x9C58BAcC331c9aa871AFD802DB6379a98e80CEdb

# The proxy's current implementation is the audited contract
assert @codeHash!($proxy::{implementation()(address)}) == 0xf5175b73708be1e8daf1aad42b8788d13ac9adbcc61a5945743c167a76ba7dc5 "implementation changed"

# Two deployments share the same runtime code
assert @codeHash!(0xf8D1677c8a0c961938bf2f9aDc3F3CFDA759A9d9) == @codeHash!(0x1E80A006ce9B0F42a1E1AAf47e6e63e63aae60d5)

See Also

• assert