{"uid":"cap_16RNiCNC2YsL2GkZG4x_3","slug":"erc-721-approved-operator-lookup-121a858d","name":"ERC-721 Approved Operator Lookup","description":"Which address is approved to move one NFT — Genesis402 / UnyKorn Operator Network","url":"https://twin.unykorn.org/erc721-approved?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"params":{"type":"object","properties":{"chain":{"enum":["ethereum","base","polygon","arbitrum","optimism","bsc","avalanche","gnosis","linea","scroll"],"type":"string"},"tokenId":{"type":"integer","minimum":0},"contract":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$"}}}}},"responseSchema":{"type":"json","example":{"ok":true,"type":"erc721-approved","receipt":{"tx_hash":"0x<64hex>","amount_usd":0.003,"receipt_id":"g402-<16hex>"},"generated_at":"<iso8601>"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.003","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":"$0.003/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_SwHexBmuYMdMGbQrrApBK","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.003","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the address approved to transfer a specific ERC-721 NFT token on a given EVM chain","exampleAgentPrompt":"Who is approved to transfer token ID 88 on the NFT contract 0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13d on Ethereum?","exampleUseCases":[{"title":"Pre-sale NFT approval audit","prompt":"Before I list this NFT for sale, check who is currently approved to move token ID 512 on the contract 0xb47e3cd837dDF8e4c57F05d70Ab865de6e193BBB on Ethereum — I want to make sure no marketplace already has approval."},{"title":"NFT custody verification on Base","prompt":"Can you check whether any address is approved to transfer token ID 7 from the contract 0x123456789abcdef123456789abcdef1234567890 on Base? I'm doing a custody check before I accept this NFT as collateral."},{"title":"Marketplace approval debugging","prompt":"I'm debugging a failed NFT transfer — can you look up the approved address for token ID 1001 on contract 0xAbCd1234AbCd1234AbCd1234AbCd1234AbCd1234 on Polygon and tell me what comes back?"}],"resultDescription":"Returns a JSON object indicating success, the approved operator address for the specified NFT token, and a payment receipt including transaction hash, USD amount charged, and a unique receipt ID.","failureModes":["Invalid contract address format (not a valid 0x hex address) — returns error","Token ID does not exist on the given contract — may return null approved address or error","Unsupported chain name — enum validation failure","Network timeout or RPC unavailability for the specified chain","Payment failure via x402 protocol — call not executed"],"whenToPreferThis":"Use this endpoint when you need to determine the single-token approval (ERC-721 getApproved) for a specific NFT — distinct from operator-level approvals (setApprovalForAll). Prefer this over general blockchain RPC calls when you want a simple pay-per-call REST interface across ten EVM chains without managing your own RPC keys. Best for agents doing NFT custody checks, pre-transfer validations, or marketplace integrations.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-01T18:55:49.876Z","isFirstParty":false,"canonicalSlug":"erc-721-approved-operator-lookup-121a858d"}