{"slug":"saylorinnovations-com-api-chain-signature-hash-d86f00","title":"Function selector and event topic hash from a signature such as Transfer(address","host":"saylorinnovations.com","method":"GET","resource":"https://saylorinnovations.com/api/chain/signature-hash","category":"other","description":"Function selector and event topic hash from a signature such as Transfer(address,address,uint256): 4-byte id and 32-byte keccak256, computed locally.","price_listed":0.01,"price_asked":null,"state":"effects","state_label":"Not tested: has real-world effects","checks_7d":0,"answered_7d":0,"latency_ms_median":null,"reported_calls_30d":1,"reported_payers_30d":1,"networks":["eip155:137","eip155:42161","eip155:8453","solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp"],"badge":"unverified","paid_checks_7d":0,"paid_ok_7d":0,"example_input":{"method":"GET","queryParams":{"signature":"Transfer(address,address,uint256)"},"type":"http"},"output_schema":{"$schema":"https://json-schema.org/draft/2020-12/schema","properties":{"input":{"additionalProperties":false,"properties":{"method":{"enum":["GET"],"type":"string"},"queryParams":{"properties":{"signature":{"description":"a function, event or error signature with types only, for example Transfer(address,address,uint256)","type":"string"}},"required":["signature"],"type":"object"},"type":{"const":"http","type":"string"}},"required":["type","method"],"type":"object"},"output":{"properties":{"example":{"properties":{"error_selector":{"description":"first 4 bytes, used for custom errors","type":"string"},"event_topic0":{"description":"full 32-byte hash for event logs","type":"string"},"function_selector":{"description":"first 4 bytes of the keccak256 hash","type":"string"},"known_function":{"description":"matching common function if any","type":["string","null"]},"note":{"description":"plain-language reading of the result","type":"string"},"signature":{"description":"the normalised signature hashed","type":"string"},"source":{"description":"where the data was read from or how it was computed","type":"string"}},"required":["signature","function_selector","event_topic0","note","source"],"type":"object"},"type":{"const":"json","type":"string"}},"required":["type"],"type":"object"}},"required":["input"],"type":"object"},"history":[],"description_full":"Function selector and event topic hash from a signature such as Transfer(address,address,uint256): 4-byte id and 32-byte keccak256, computed locally.","last_updated":"2026-10-21T04:11:39.042Z","schemes":["exact"]}