event_signature scalar function

Example

Local

SELECT event_signature('Transfer(address,address,uint256)') AS topic0;

-- ddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef

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API reference

Exact signatures with descriptions, requirements, inputs, returns, and examples.

event_signature(VARCHAR) #

Hashes already-canonical text such as Transfer(address,address,uint256) exactly, without normalization.

Inputs

Name	Type	Use
`signature`	VARCHAR Signature text such as Transfer(address,address,uint256), without the event keyword or indexed modifiers. The text is hashed exactly without normalization.	required positional

Returns

Name	Type
`hash`	BYTES32

Event topic0. Keccak-256 of the supplied canonical signature as BYTES32.

Guidance

Selector, topic0, calldata, and return data

Use event_signature or event_signature_json to build topic0 before filtering logs or validating decoded events. The JSON helper derives canonical input types and ignores names and indexed modifiers.

Anonymous logs omit topic0 even though this helper can still compute the event signature hash.
Indexed flags affect where values appear in log topics, but not the event signature hash.
The Transfer example is the USDC log at Ethereum block 20,000,000, transaction 0x5cbf...3dde, log index 97; its topics and data are reconstructed offline.
Use function_selector for the first four bytes of calldata.
Use error_selector for the first four bytes of custom error revert data.
Use event_decode_json when you already have topics and data to decode.

Local SQL