{"uid":"cap_-Dhq6eUO4V_2irvnC2Ii9","slug":"base-erc-721-owner-lookup-337da17b","name":"Base ERC-721 Owner Lookup","description":"NFT owner read on Base: takes token (ERC-721 contract, 0x + 40 hex) and id (decimal token id) and returns the address that ownerOf(id) reports on the contract.","url":"https://ari001.tailb4ac3a.ts.net/v1/ventures/x402_chain_reads_v1/base_erc721_ownerof?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","properties":{"id":{"type":"string","description":"token id, decimal"},"token":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$","description":"ERC-721 contract, 0x + 40 hex"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"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_-hJobvY6l6XvfucSDG3wY","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 current owner address of a specific ERC-721 NFT token on the Base blockchain by calling ownerOf(id) on the contract.","exampleAgentPrompt":"Who currently owns token ID 1337 on the ERC-721 contract 0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48 on Base?","exampleUseCases":[{"title":"Verify NFT ownership before granting access","prompt":"Before unlocking this feature, check who owns token ID 7 on the Base NFT contract 0xbc4ca0eda7647a8ab7c2061c2e118a18a936f13d — I need to confirm if the holder is 0xAbCd1234..."},{"title":"Resolve NFT holder for airdrop targeting","prompt":"I'm running an airdrop and need to find the current owner of token ID 500 on the Base ERC-721 contract 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 — can you look that up?"},{"title":"Monitor if an NFT has changed hands","prompt":"Can you check who owns token ID 22 on the 0x1234abcd5678ef901234abcd5678ef901234abcd contract on Base? I want to see if it's still held by the same wallet as before."}],"resultDescription":"Returns the Ethereum address (0x + 40 hex characters) that the ERC-721 contract's ownerOf(id) function reports as the current holder of the specified token ID on the Base chain.","failureModes":["Invalid contract address format (not 0x + 40 hex) — returns 400 or validation error","Token ID does not exist on the contract — contract may revert, resulting in an error response","Contract address is not an ERC-721 contract — call may fail or return unexpected data","Base chain node unavailability — returns a 5xx error","Token ID provided in non-decimal format — query may fail or return incorrect results"],"whenToPreferThis":"Use this endpoint when you need to resolve the current owner of a specific ERC-721 NFT on the Base blockchain. Prefer this over generic RPC calls when you want a simple, paid-per-call abstraction that handles the eth_call to ownerOf without managing your own Base node connection. Particularly useful for agents verifying NFT-gated access, tracking provenance, or enriching NFT metadata with live ownership data on Base specifically (not Ethereum mainnet or other chains).","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-10T12:37:40.771Z","isFirstParty":false,"canonicalSlug":"base-erc-721-owner-lookup-337da17b"}