Event log

An event log is a structured entry a smart contract writes during a transaction, consisting of indexed topics and unindexed data, stored in the transaction receipt for off-chain consumers to read.

Contracts emit events — a Transfer, a Swap, an Approval — and the resulting logs are the primary way applications observe on-chain activity without re-executing contracts. Each log has topics (the event signature plus indexed arguments) and a data blob for the rest. Raw logs are hex, so consumers pair them with the contract ABI to decode them into named fields. Our API returns decoded logs alongside the raw entry, so you skip building your own decoder while still keeping the underlying receipt.