{"uid":"cap_NF9rdHj23On7h8Fiv41co","slug":"calldata-selector-and-32-byte-word-splitter-52c25fa5","name":"Calldata Selector and 32-Byte Word Splitter","description":"Split calldata into its selector and 32-byte words — Genesis402 / UnyKorn Operator Network","url":"https://twin.unykorn.org/calldata-split?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"params":{"type":"object","properties":{"data":{"type":"string","pattern":"^0x[0-9a-fA-F]*$"}}}}},"responseSchema":{"type":"json","example":{"ok":true,"type":"calldata-split","receipt":{"tx_hash":"0x<64hex>","amount_usd":0.002,"receipt_id":"g402-<16hex>"},"generated_at":"<iso8601>"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_nRD1fC3VcXUa4qq_X1KYX","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Splits raw EVM calldata hex into its 4-byte function selector and individual 32-byte ABI-encoded word chunks","exampleAgentPrompt":"Can you split this calldata into its function selector and 32-byte words: 0xa9059cbb000000000000000000000000ab5801a7d398351b8be11c439e05c5b3259aec9000000000000000000000000000000000000000000000000016345785d8a0000?","exampleUseCases":[{"title":"Debugging a failed contract call","prompt":"I have this raw calldata from a failed transaction and I need to see what function was called and what each parameter was — can you split 0x23b872dd000000000000000000000000sender000000000000000000000000receiver00000000000000000000000000000000000000000000000000000000000003e8 into its selector and 32-byte word slots?"},{"title":"Inspecting a pending mempool transaction","prompt":"There's a suspicious pending transaction in the mempool with this input data: 0x095ea7b3000000000000000000000000spender00000000000000000000000000000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff — break it apart into the function selector and individual 32-byte chunks so I can see what it's approving."},{"title":"Smart contract audit calldata review","prompt":"During my audit I grabbed this raw calldata from a contract interaction: 0x40c10f190000000000000000000000001234567890abcdef1234567890abcdef1234567800000000000000000000000000000000000000000000003635c9adc5dea00000 — split it into the 4-byte selector and each 32-byte word so I can verify the function and arguments."}],"resultDescription":"Returns a JSON object with ok:true, the type field set to 'calldata-split', the parsed 4-byte function selector, and an array of 32-byte ABI word slots extracted from the calldata. Also includes a receipt with the transaction hash, USD amount charged, and a receipt ID for payment verification.","failureModes":["Invalid or non-hex calldata string returns an error","Calldata shorter than 4 bytes (missing selector) may fail parsing","Payment failure or insufficient x402 funds blocks the request","Malformed 0x prefix or odd-length hex string rejected by schema pattern","Network timeout if the UnyKorn node is unavailable"],"whenToPreferThis":"Choose this endpoint when you need a quick, pay-per-call decomposition of raw EVM calldata into its ABI components without running a local ABI decoder. Ideal for agents inspecting transaction inputs, debugging smart contract calls, or auditing calldata on the fly without needing the full ABI definition — particularly useful in pipelines where you already have other UnyKorn EVM tools (receipt lookup, ABI encoding, ENS resolution) and want a consistent x402 micropayment flow.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-03T00:48:06.809Z","isFirstParty":false,"canonicalSlug":"calldata-selector-and-32-byte-word-splitter-52c25fa5"}