# NFT Owner Lookup

> NFT Owner Lookup is a paid API for AI agents from bess-x402.onrender.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-30).

Returns the current owner address of an ERC-721 NFT given its contract address and token ID, on EVM-compatible chains.

## Facts

- Endpoint: GET https://bess-x402.onrender.com/v1/evm/nft-owner?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/nft-owner-lookup-335a7b63
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dikLh2-sYrNxG6k61RQ4B

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability nft-owner-lookup-335a7b63
```

Example prompt: Who currently owns token ID 4821 on the Bored Ape Yacht Club contract 0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13d on Ethereum?

## When to prefer this

Use this endpoint when you need a quick, pay-per-call on-chain ownership lookup for a single ERC-721 NFT without setting up your own RPC node. Ideal for token gating, airdrop verification, and pre-sale ownership checks across Ethereum, Base, Arbitrum, Optimism, and Polygon. Prefer this over indexer APIs when you need real-time on-chain accuracy rather than indexed data that may lag.

## Known failure modes

- Invalid contract address returns an error or null owner
- Token ID does not exist on the contract (reverts on-chain)
- Unsupported chain name returns a validation error
- Network/RPC timeout causes a failed response
- Contract is not ERC-721 compliant and does not support ownerOf

## How this service works

Current owner of an ERC-721 NFT by contract and token ID. Use to verify ownership for token gating, sales or airdrops.

## Output

Returns the current owner's wallet address for the specified ERC-721 NFT token, identified by contract address and token ID on the requested EVM chain (Ethereum, Base, Arbitrum, Optimism, or Polygon).

## Request schema (JSON Schema)

```json
{
 "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",
     "required": [
      "contract",
      "token_id"
     ],
     "properties": {
      "chain": {
       "type": "string",
       "description": "ethereum, base, arbitrum, optimism or polygon"
      },
      "contract": {
       "type": "string",
       "description": "NFT contract"
      },
      "token_id": {
       "type": "string",
       "description": "Token ID"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nft-owner-lookup-335a7b63/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bess-x402.onrender.com](https://www.zero.xyz/host/bess-x402.onrender.com/llms.txt)