{"uid":"cap_OLq6zL9pgHLdsAMJhVZgy","slug":"evm-calldata-decoder-dab1bc3f","name":"EVM Calldata Decoder","description":"Resolve 29 common ERC-20, ERC-165, ERC-721, ERC-1155, ERC-2612, and ERC-3009 selectors without a network lookup, or strictly decode arbitrary Ethereum or EVM calldata using a supplied Solidity signature.","url":"https://apiacre.com/v1/crypto/calldata-decode","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"calldata":{"type":"string"},"input_mode":{"enum":["auto","selector_and_arguments","arguments_only"],"type":"string"},"function_signature":{"anyOf":[{"type":"string"},{"type":"null"}]}}},"responseSchema":{"type":"json","example":{"data":{"types":["address","uint256"],"values":["0x1111111111111111111111111111111111111111",42],"encoding":{"canonical":true,"argumentBytes":64,"calldataBytes":68,"calldataSha256":"f77b5da6ef3efa41f5084d653dc4a135a3978d541db97ce13225bd442b025198","argumentsSha256":"d3458da251349437abe3549042a49868dc5528422a63bb815f3e0b46725052c9"},"function":"transfer","selector":"0xa9059cbb","warnings":["Selector resolution is limited to 29 published standard signatures; four-byte..."],"arguments":[{"type":"address","index":0,"value":"0x1111111111111111111111111111111111111111"}],"inputMode":"selector_and_arguments","signature":"transfer(address,uint256)","resolution":{"method":"built_in_standard","candidates":["transfer(address,uint256)"],"candidateCount":1,"matchedStandards":["ERC-20"],"signatureProvided":false},"selectorPresent":true,"signatureSource":"built_in_standard","canonicalSignature":"transfer(address,uint256)"},"meta":{"cached":false,"sources":[],"warnings":[],"duration_ms":42,"next_actions":[]},"service":"crypto.calldata-decode","version":"1","request_id":"018f1f54-7f38-7ba2-8dc3-5f90272d9f1a"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","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":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_Q-dfucLSyzgNtp5TTS_51","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Decodes EVM transaction calldata into human-readable form using a supplied function signature.","exampleAgentPrompt":"Decode this EVM calldata for me — the raw hex is 0xa9059cbb000000000000000000000000ab5801a7d398351b8be11c439e05c5b3259aec9b0000000000000000000000000000000000000000000000000de0b6b3a7640000 and the function signature is transfer(address,uint256).","exampleUseCases":[{"title":"Debug failing smart contract transaction","prompt":"I have a failed Ethereum transaction and I want to know exactly what parameters were passed. The calldata is 0x23b872dd000000000000000000000000abc...000000000000000000000000000000000000000000000000016345785d8a0000 and the function signature is transferFrom(address,address,uint256). Can you decode it?"},{"title":"Audit on-chain governance vote calldata","prompt":"Can you decode this calldata from a DAO governance proposal so I can see what function was called and with what arguments? The hex is 0x7d5e81e2... and the signature is propose(address[],uint256[],bytes[],string)."},{"title":"Monitor and interpret contract interactions","prompt":"I'm watching transactions to a DeFi protocol and I need to understand what swap parameters were used. Decode this calldata 0x38ed1739...000000 using the function signature swapExactTokensForTokens(uint256,uint256,address[],address,uint256)."}],"resultDescription":"Returns the decoded function name along with each parameter's name, type, and decoded value extracted from the supplied calldata hex string using the provided function signature.","failureModes":["Invalid or malformed calldata hex returns a parsing error","Mismatched function signature causes decoding failure or garbage output","Missing or incomplete function signature returns an error","Calldata too short for the specified parameter types causes a decode error","Unsupported ABI types may not decode correctly"],"whenToPreferThis":"Choose this endpoint when you have raw EVM calldata hex and a known function signature and need to extract human-readable parameter values without setting up a local ABI decoder or Web3 library. Ideal for agents inspecting on-chain transactions, auditing contract calls, or building blockchain analytics pipelines where decoding is a single step in a larger workflow.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T12:41:52.130Z","isFirstParty":false}