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ERC-721 Token Owner Lookup
x402
ERC-721 Token Owner Lookup is a paid API for AI agents from biosfera.46-62-215-147.sslip.io, paid per call via x402, $0.0015/call, status unknown (last checked 2026-10-01).
Returns the current owner address of a specific ERC-721 NFT token ID, along with the collection's name and symbol, across Base, Ethereum, Arbitrum, Optimism, and Polygon.
Price / call$0.0015
Success—
StatusUnknown
How this service works
Use when you need the current owner of an ERC-721 token id on Base, Ethereum, Arbitrum, Optimism or Polygon via ownerOf, plus the collection's name and symbol. Returns exists=false if the id has no owner.
Output
Returns the owner's wallet address (a 0x Ethereum address), the collection's name, the collection's symbol, and an exists boolean. If the token ID has no owner (unminted or burned), exists is false and no owner address is returned.
Example use cases
NFT Ownership Verification for Gating
“Can you check who currently owns token ID 7495 of the contract 0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13D on Ethereum? I need to verify ownership before granting access.”
NFT Provenance Research
“I'm researching a Polygon NFT — can you find the current owner of token ID 42 at contract address 0x2953399124F0cBB46d2CbACD8A89cF0599974963 on Polygon and tell me the collection name?”
NFT Transfer Confirmation
“We just transferred token ID 101 of our NFT collection at 0xa7d8d9ef8D8Ce8992Df33D8b8CF4Aebabd5bD270 on Base — can you confirm the new owner address and that it exists?”
Technical details
Endpoint
GEThttps://biosfera.46-62-215-147.sslip.io/o/erc721-owner?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need to look up the current owner of a specific ERC-721 NFT token on Base, Ethereum, Arbitrum, Optimism, or Polygon. It is the right choice for ownership verification, NFT-gating, provenance research, or post-transfer confirmation. Prefer this over general blockchain explorers when you need a structured, machine-readable response with collection metadata (name and symbol) included.
Side effects
- Token ID does not exist or has no owner — returns exists=false
- Invalid contract address format — rejected by schema validation
- Contract is not a valid ERC-721 contract — may return an error or unexpected response
- Unsupported chain requested — rejected by enum validation
- Token ID out of range or malformed — rejected by pattern validation
- Network RPC timeout or congestion — may result in a delayed or failed response
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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