{"uid":"cap_pUmHxI57OfEds4ZzafhNS","slug":"bot-bazaar-evm-function-selector-lookup-32c6177f","name":"Bot Bazaar EVM Function Selector Lookup","description":"Identify 4-byte EVM function selectors (transfer, approve, transferWithAuthorization, balanceOf) or compute selector from an ABI signature.","url":"https://bot-bazaar.fly.dev/v1/x402/selector-lookup?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","properties":{"selector":{"type":"string","description":"4-byte hex selector (e.g. 0xe3ee160e)"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_6DoofZB0xWTKPay666Sr4","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Look up EVM function names from 4-byte hex selectors, or compute a selector hash from an ABI function signature.","exampleAgentPrompt":"What function name does the EVM selector 0xa9059cbb map to? Look it up for me.","exampleUseCases":[{"title":"Decode unknown calldata prefix","prompt":"I'm inspecting an Ethereum transaction and the calldata starts with 0x23b872dd — can you look up what EVM function that selector belongs to?"},{"title":"Verify token approval selector","prompt":"What's the 4-byte selector for the ERC-20 approve(address,uint256) ABI signature? I want to confirm I'm encoding it correctly in my contract calls."},{"title":"Identify balanceOf selector in audit","prompt":"During a smart contract audit I found a call with selector 0x70a08231 — can you decode what function that is?"}],"resultDescription":"Returns the human-readable function name and full ABI signature matching the given 4-byte selector, or computes the selector hex value from a provided ABI signature string. Covers common ERC-20 functions including transfer, approve, transferWithAuthorization, and balanceOf.","failureModes":["Selector not found in known database — returns null or 404 for obscure custom functions","Malformed selector format (missing 0x prefix or wrong byte length) causes validation error","Invalid ABI signature syntax prevents selector computation","Network timeout or service unavailability on fly.dev host","Payment not fulfilled (x402 402 response) if USDC not provided"],"whenToPreferThis":"Choose this endpoint when you need to decode 4-byte function selectors from raw Ethereum transaction calldata, or when you need to verify the canonical selector hash for a known ERC-20 ABI signature. It is purpose-built for EVM smart contract function identification and is more lightweight than spinning up a full ABI decoder or querying Etherscan's API for the same purpose.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-30T19:07:10.542Z","isFirstParty":false,"canonicalSlug":"bot-bazaar-evm-function-selector-lookup-32c6177f"}