Event topic
Last updated:
Applies to: EVM chains
In more detail
For Transfer(address,address,uint256), topic 0 is keccak256 of exactly that string — no spaces, no parameter names, full type names. Indexed parameters fill topics 1 to 3, left-padded to 32 bytes; non-indexed parameters go into the data field and cannot be filtered on. Anonymous events have no signature topic.
In an eth_getLogs filter, each topic position matches a value, an array of alternatives (OR), or null for any value; the positions combine with AND.