{"slug":"agent402-tools-api-calldata-decode-7e77f1","title":"Decode EVM smart-contract transaction calldata into the function name and typed ","host":"agent402.tools","method":"POST","resource":"https://agent402.tools/api/calldata-decode","category":"other","description":"Decode EVM smart-contract transaction calldata into the function name and typed parameters. Supply an ABI (from /api/contract-abi) or a signature like transfer(address,uint256) for a fully offline decode; with neither, the 4-byte selector is resolved via the openchain.xyz signature database (4byte.d","price_listed":0.003,"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":6,"reported_payers_30d":1,"networks":["algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=","eip155:10","eip155:1329","eip155:137","eip155:143","eip155:42161","eip155:42220","eip155:43114","eip155:4663","eip155:8453","solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp","stellar:pubnet"],"badge":"unverified","paid_checks_7d":0,"paid_ok_7d":0,"example_input":{"body":{"data":"0xa9059cbb000000000000000000000000abf4fabd7c416fb67202e5f9002389fc75e2a9d000000000000000000000000000000000000000000000000000000000000f4240"},"bodyType":"json","method":"POST","type":"http"},"output_schema":{"$schema":"https://json-schema.org/draft/2020-12/schema","properties":{"input":{"additionalProperties":false,"properties":{"body":{"properties":{"abi":{"description":"Optional contract ABI (JSON array) - enables a fully offline decode with parameter names.","type":"array"},"data":{"description":"0x-prefixed calldata (selector + encoded args). Max 100KB.","type":"string"},"signature":{"description":"Optional function signature, e.g. transfer(address,uint256) - offline decode without a full ABI.","type":"string"}},"required":["data"]},"bodyType":{"enum":["json","form-data","text"],"type":"string"},"method":{"enum":["POST"],"type":"string"},"type":{"const":"http","type":"string"}},"required":["type","method","bodyType","body"],"type":"object"},"output":{"properties":{"example":{"properties":{"decoded":{"type":"boolean"},"name":{"type":"string"},"params":{"items":{"properties":{"name":{},"type":{"type":"string"},"value":{"type":"string"}},"type":"object"},"type":"array"},"selector":{"type":"string"},"signature":{"type":"string"},"source":{"type":"string"}},"required":["selector","decoded","name","signature","params","source"],"type":"object"},"type":{"type":"string"}},"required":["type"],"type":"object"}},"required":["input"],"type":"object"},"history":[],"description_full":"Decode EVM smart-contract transaction calldata into the function name and typed parameters. Supply an ABI (from /api/contract-abi) or a signature like transfer(address,uint256) for a fully offline decode; with neither, the 4-byte selector is resolved via the openchain.xyz signature database (4byte.directory fallback) and each candidate signature is tried. Unknown selectors return a documented partial decode (selector + raw 32-byte words) instead of an error.","last_updated":"2026-09-22T11:51:45.01Z","schemes":["exact","upto"]}