{"uid":"cap_MH1bo5-aKUmpprNh_avRE","slug":"delx-commerce-evm-calldata-selector-extract-80442095","name":"Delx Commerce EVM Calldata Selector Extract","description":"Pay-per-result APIs for agents. No signup. Exact price. Verifiable delivery. USDC on Base + Solana via x402.","url":"https://commerce.delx.ai/api/v1/x402/evm-calldata-selector-extract?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"calldata":{"type":"string","maxLength":8192,"description":"Calldata supplied to EVM Calldata Selector Extract; used only for this bounded calculation and processed in memory without retention."}}},"responseSchema":{"type":"json","example":{"result":{"calldata":"0xa9059cbb0000000000000000000000001111111111111111111111111111111111111111","selector":"0xa9059cbb","byte_count":36,"shape_valid":true},"schema":"delx/util-evm-calldata-selector-extract/v1","status":"pass","evidence":{"retained":false,"input_sha256":"1048e8d74a53c6ea3249086735deac2cb24ee3dd131a3852df0439253301d8de","external_calls":0},"operation":"evm_preflight:evm_calldata_selector_extract"}},"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_URv11XoLM3ODYIo2Houzz","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":"Extracts the 4-byte function selector from raw EVM calldata and validates its basic structure","exampleAgentPrompt":"Can you extract the 4-byte function selector from this EVM calldata and tell me if it's valid: 0xa9059cbb0000000000000000000000001111111111111111111111111111111111111111?","exampleUseCases":[{"title":"Pre-flight check before submitting transaction","prompt":"Before I broadcast this transaction, can you pull the function selector out of this calldata and confirm it's well-formed: 0x23b872dd000000000000000000000000abcdef1234567890abcdef1234567890abcdef12?"},{"title":"Identify contract method from raw calldata","prompt":"I have this raw calldata from an Ethereum transaction and I need to know which function it's calling — can you extract the selector for me: 0x095ea7b3000000000000000000000000deadbeefdeadbeefdeadbeefdeadbeefdeadbeef?"},{"title":"Validate calldata shape in agent workflow","prompt":"My agent just built this calldata to approve a token spend and I need to verify it's properly structured before sending it on-chain: 0x095ea7b300000000000000000000000012345678901234567890123456789012345678900000000000000000000000000000000000000000000000000de0b6b3a7640000"}],"resultDescription":"Returns a JSON object with the extracted 4-byte function selector, total byte count of the calldata, a boolean indicating whether the calldata shape is valid, and an evidence block including whether input was retained (always false), the SHA256 hash of the input for verifiability, and the count of external calls made (always 0).","failureModes":["Malformed or non-hex calldata string causes validation failure","Calldata exceeding 8192 character limit is rejected","Empty calldata input returns shape_valid: false","Missing required calldata field returns a 4xx error","Payment not included or insufficient USDC causes HTTP 402 response"],"whenToPreferThis":"Choose this endpoint when you need a fast, verifiable, privacy-preserving way to extract the function selector from EVM calldata without setting up local ABI parsing infrastructure. It is ideal for agent workflows that need to preflight or audit transaction calldata before submission, especially when verifiable evidence (SHA256, no-retention proof, zero external calls) is required for audit trails. It costs only $0.001 USDC per call, requires no signup, and supports x402 micropayment flows natively.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-01T00:54:05.707Z","isFirstParty":false,"canonicalSlug":"delx-commerce-evm-calldata-selector-extract-80442095"}