{"uid":"cap_YjLZdTDZhCf6-HCck9TiW","slug":"tracefast-contract-function-selectors-2f6edc98","name":"TraceFast Contract Function Selectors","description":"TraceFast live Ethereum data: the 4-byte function selectors found in a contract's bytecode, each resolved to a known signature and name where one exists, with how many known signatures share the selector. `decodeStatus` says how confident each resolution is. Path address: The contract address, `0x`-prefixed, 40 hex characters, any case. Docs: https://docs.tracefast.xyz/api/contract-selectors.md","url":"https://mpp.tracefast.xyz/api/v1/chains/1/contracts/:address/selectors?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"properties":{"input":{"required":["method"],"properties":{"method":{"enum":["GET"],"type":"string"},"pathParams":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","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":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_QQunfP8iqY9UIB_ATSC5O","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the 4-byte function selectors found in an Ethereum contract's bytecode, each resolved to a known signature and name with a decode confidence status.","exampleAgentPrompt":"Look up all the function selectors in the bytecode of Ethereum contract 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2 and tell me which ones resolve to known function signatures and how confident each resolution is.","exampleUseCases":[{"title":"Reverse-engineer unknown contract interface","prompt":"I have this Ethereum contract address 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 and no ABI — can you pull all its function selectors from the bytecode and tell me which function names they map to?"},{"title":"Detect selector collisions in DeFi contract","prompt":"Check the contract at 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D for any 4-byte selector conflicts — I want to know if any selectors match more than one known function signature."},{"title":"Audit smart contract callable methods","prompt":"For my security audit of the contract at 0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984, give me a full list of its function selectors, their resolved names, and how confident TraceFast is about each one."}],"resultDescription":"A list of 4-byte function selectors found in the contract's deployed bytecode. Each entry includes the hex selector, the resolved human-readable function signature and name (if a match exists in the known signature database), the number of known signatures that share that selector (indicating potential ambiguity), and a decodeStatus field indicating confidence level of the resolution.","failureModes":["Invalid or malformed contract address returns 400 error","Address is an EOA (externally owned account) with no bytecode — returns empty selector list or error","Undeployed or self-destructed contract address — no bytecode found","Selector exists in bytecode but has no known signature match — resolved name will be null","Network or upstream Ethereum node unavailability causing 503 or timeout","Incorrect chain parameter causes lookup on wrong network"],"whenToPreferThis":"Use this endpoint when you need to programmatically identify what functions a smart contract exposes without having its ABI, or when you want to verify selector-to-signature mappings including collision detection. Prefer over manual ABI lookups when the ABI is unavailable or unverified, or when you need machine-readable decodeStatus confidence signals for automated tooling.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-12T00:41:31.754Z","isFirstParty":false,"canonicalSlug":"tracefast-contract-function-selectors-2f6edc98"}