Event log
Last updated:
Applies to: EVM chains
In more detail
Logs are not contract state: a contract cannot read them back, but off-chain clients can filter them cheaply with eth_getLogs or receive them live through a logs subscription. A log's address is the contract whose code emitted it in its own storage context — for a proxy using delegatecall, the proxy.
ERC-20 requires a Transfer event whenever tokens are transferred, so token movements are read from logs; the transaction's own value field only carries ether and is usually zero for a token transfer.