{"uid":"cap_FApLGtWNPGb0uYa_4Be9u","slug":"evm-calldata-decoder-via-openchain-38ea06cc","name":"EVM Calldata Decoder via Openchain","description":"Decode raw EVM calldata into function + typed params (GET wrapper) — $0.001 USDC","url":"https://1c09pdnrx1.execute-api.us-east-1.amazonaws.com/v1/decode/calldata","method":"POST","headers":{},"bodySchema":{"type":"object","title":"DatetimeParseRequest","required":["input"],"properties":{"input":{"type":"string","title":"Input","maxLength":500,"minLength":1,"description":"Freeform datetime string in any format."},"timezone":{"type":"string","title":"Timezone","default":"UTC","description":"IANA tz name (e.g. 'America/New_York')."},"base_time":{"anyOf":[{"type":"string"},{"type":"null"}],"title":"Base Time","description":"ISO 8601 reference; defaults to now UTC."}}},"responseSchema":{"type":"object","required":["params","source","decoded","candidates","function_name","function_selector","function_signature"],"properties":{"params":{"type":"array","items":{"type":"object","required":["name","type","value"],"properties":{"name":{"type":"null"},"type":{"type":"string"},"value":{"type":"string"}}}},"source":{"type":"string"},"decoded":{"type":"boolean"},"candidates":{"type":"array","items":{"type":"unknown"}},"function_name":{"type":"string"},"function_selector":{"type":"string"},"function_signature":{"type":"string"}}},"example":{"request":{"chain":"ethereum","calldata_hex":"0xa9059cbb000000000000000000000000ab5801a7d398351b8be11c439e05c5b3259aec9b0000000000000000000000000000000000000000000000000de0b6b3a7640000","contract_address":null},"response":{"params":[{"name":null,"type":"address","value":"0xab5801a7d398351b8be11c439e05c5b3259aec9b"},{"name":null,"type":"uint256","value":"1000000000000000000"}],"source":"openchain.xyz","decoded":true,"candidates":[],"function_name":"transfer","function_selector":"0xa9059cbb","function_signature":"transfer(address,uint256)"}},"exampleRequest":{"chain":"ethereum","calldata_hex":"0xa9059cbb000000000000000000000000ab5801a7d398351b8be11c439e05c5b3259aec9b0000000000000000000000000000000000000000000000000de0b6b3a7640000","contract_address":null},"tags":["x402"],"displayCostAmount":"0.001","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"settled","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__QTvOPWKFeFfDNrXtz_Bz","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":null,"unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Decodes raw EVM calldata into a human-readable function name and typed parameters using openchain.xyz","exampleAgentPrompt":"Can you decode this raw EVM calldata for me and tell me what function it's calling and what the parameters are: 0xa9059cbb000000000000000000000000ab5801a7d398351b8be11c439e05c5b3259aec9b0000000000000000000000000000000000000000000000000de0b6b3a7640000","exampleUseCases":null,"resultDescription":"Returns the decoded function name, full function signature, and an array of typed parameters with their names, ABI types, and decoded values extracted from the calldata hex string.","failureModes":["Unknown or unregistered function selector — openchain.xyz may not have the ABI for every contract, returning a not-found or unknown selector error","Malformed calldata — if the hex string is not valid or too short, returns a parsing or validation error","Calldata with no selector — bare bytes without a 4-byte selector cannot be decoded as a function call","Rate limiting or upstream openchain.xyz unavailability — returns 5xx or timeout"],"whenToPreferThis":"Use this endpoint when you have raw hex calldata from an EVM transaction input and need to understand what function is being called and with what arguments. Prefer this over a full transaction decoder when you only have the calldata bytes (not a full tx hash) and need fast, targeted ABI decoding. Backed by openchain.xyz's extensive signature database for broad coverage.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T00:30:25.602Z","isFirstParty":false}