{"uid":"cap_pOkSue-w3aFIeboGOnqH6","slug":"solidity-function-selector-calculator-6e269865","name":"Solidity Function Selector Calculator","description":"Verify an x402 endpoint before paying: live payTo, USDC quote, network, asset, resource binding, TLS and endpoint safety for $0.001 on Base or Solana.","url":"https://agentresolver.vercel.app/api/solidity-selector","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"signature":{"type":"string","maxLength":1024,"minLength":3}}},"responseSchema":{"type":"json","example":{}},"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_39dPBwMBNSxM-vMPd1sCU","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":"Computes the 4-byte ABI function selector and full keccak256 hash for a given Solidity function signature","exampleAgentPrompt":"What's the 4-byte ABI selector and keccak256 hash for the Solidity function signature transfer(address,uint256)?","exampleUseCases":[{"title":"Decoding unknown contract calldata","prompt":"I'm seeing raw calldata starting with 0xa9059cbb on Etherscan — can you figure out which Solidity function signature produces that selector?"},{"title":"Building an ABI encoder tool","prompt":"I need the 4-byte selector and full keccak256 hash for the function signature approve(address,uint256) so I can encode a raw transaction."},{"title":"Auditing smart contract dispatch logic","prompt":"Can you compute the function selectors for transferFrom(address,address,uint256) and safeTransferFrom(address,address,uint256) so I can check for selector collision risks?"}],"resultDescription":"Returns a JSON object containing the original function signature, the 4-byte hex ABI function selector (e.g. 0xa9059cbb), and the full 32-byte keccak256 hash of the signature string.","failureModes":["Malformed or non-canonical Solidity signature causes validation error","Missing required 'signature' field returns 400 Bad Request","Network timeout or Vercel cold-start latency on first call","Payment failure via x402 protocol blocks the request"],"whenToPreferThis":"Use this endpoint when you need to deterministically compute ABI function selectors or keccak256 hashes for Solidity signatures without setting up a local Ethereum toolchain. Ideal for agents working with smart contract interaction, ABI encoding, calldata decoding, or selector collision audits.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-18T12:48:44.152Z","isFirstParty":false}