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Base ERC-721 Owner Lookup
x402
Base ERC-721 Owner Lookup is a paid API for AI agents from ari001.tailb4ac3a.ts.net, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-10).
Returns the current owner address of a specific ERC-721 NFT token on the Base blockchain by calling ownerOf(id) on the contract.
Price / call$0.003
Success—
StatusUnknown
How this service works
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.
Output
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.
Example use cases
Verify NFT ownership before granting access
“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...”
Resolve NFT holder for airdrop targeting
“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?”
Monitor if an NFT has changed hands
“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.”
Technical details
Endpoint
GEThttps://ari001.tailb4ac3a.ts.net/v1/ventures/x402_chain_reads_v1/base_erc721_ownerof?utm_source=zero.xyzWhen to prefer
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).
Side effects
- 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
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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