{"uid":"cap_amEZ-ZJ2lToQY1kw-D2hW","slug":"evm-calldata-return-data-decoder-4243d382","name":"EVM Calldata & Return Data Decoder","description":"Decode EVM calldata (transaction input) with the function signature or, if omitted, by looking up the selector on 4byte; or decode return data with its output types (e.g. uint256,address).","url":"https://api.vextorium.com/abi-decodificar-pago?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"datos":{"type":"string"},"funcion":{"type":"string"},"tipos_salida":{"type":"string"}}},"responseSchema":{"type":"json","example":{"funcion":"transfer(address,uint256)","selector":"0xa9059cbb","argumentos":["0x7E5F4552091A69125d5DfCb7b8C2659029395Bdf","1000000"],"fuente_firma":"4byte.directory"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.003","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.003/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_jbLueXJ9559OoA9t1RiLC","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.003","costPer":"request","priority":0,"asset":"EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Decodes EVM transaction input (calldata) into a human-readable function signature and arguments, or decodes return data given output types, using 4byte.directory as fallback for unknown selectors.","exampleAgentPrompt":"Decode this EVM calldata for me: 0xa9059cbb0000000000000000000000007e5f4552091a69125d5dfcb7b8c2659029395bdf0000000000000000000000000000000000000000000000000000000000000001 — use the function signature transfer(address,uint256) to decode the arguments.","exampleUseCases":[{"title":"Decode an unknown transaction input","prompt":"I have this raw transaction input from Etherscan: 0xa9059cbb000000000000000000000000abc...0001. Can you decode it for me without knowing the ABI — use 4byte to look up the selector?"},{"title":"Parse calldata with known function signature","prompt":"Decode this calldata using the signature transfer(address,uint256): 0xa9059cbb0000000000000000000000007E5F4552091A69125d5DfCb7b8C2659029395Bdf00000000000000000000000000000000000000000000000000000000000f4240"},{"title":"Decode smart contract return data","prompt":"I called a contract and got back this hex return value: 0x0000000000000000000000000000000000000000000000000de0b6b3a7640000 — decode it as a uint256 so I can see the actual number."}],"resultDescription":"Returns the decoded function name (e.g. 'transfer(address,uint256)'), the 4-byte selector (e.g. '0xa9059cbb'), a list of decoded argument values as strings, and the source of the signature (e.g. '4byte.directory' or 'provided').","failureModes":["Unknown selector not found on 4byte.directory — returns null signature","Malformed calldata hex causes decoding failure","Wrong function signature provided causes ABI mismatch error","Output types mismatch actual return data length","Missing required 'datos' field returns validation error"],"whenToPreferThis":"Use this endpoint when you need to decode EVM transaction input (calldata) or return data into human-readable arguments without running a full node or maintaining a local ABI database. Especially useful when the function signature is unknown and 4byte.directory lookup is needed. Prefer over manual ABI decoding or ethers.js when operating in a serverless or agent context that calls external APIs.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-16T18:44:56.110Z","isFirstParty":false,"canonicalSlug":"evm-calldata-return-data-decoder-4243d382"}