# NFT Owner and Metadata Lookup

> NFT Owner and Metadata Lookup is a paid API for AI agents from flat-rate-llm.kikoribera03.workers.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Returns the current owner address, tokenURI, and collection name for a given ERC721 token ID via on-chain eth_call, no indexer or API key required.

## Facts

- Endpoint: POST https://flat-rate-llm.kikoribera03.workers.dev/v1/evm/nft-owner
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/nft-owner-and-metadata-lookup-6cb3f77b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4tqe2KanybaHOHQ_iZhgp

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-and-metadata-lookup-6cb3f77b -d '<json body>'
```

Example prompt: Who currently owns token ID 42 of the ERC721 contract 0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13d on Ethereum — and what's its tokenURI and collection name?

## When to prefer this

Choose this endpoint when you need a fast, keyless, real-time on-chain ownership check for a single ERC721 token without setting up an NFT indexer (like Alchemy, Moralis, or OpenSea APIs). Ideal for agents that need to verify current ownership state before executing logic (e.g. gating access, confirming a trade), especially on Base, Ethereum, Polygon, Arbitrum, or Optimism. Not suitable for bulk lookups, ERC1155 tokens, or off-chain metadata resolution.

## Known failure modes

- Invalid or non-ERC721 contract address returns an error or empty response
- Token ID does not exist on the contract (not yet minted or burned) returns a revert error
- Unsupported chain name causes a 400 or unrecognized parameter error
- Network congestion or RPC timeout may delay or fail the call
- Malformed token ID (non-decimal or out-of-range) returns a validation error

## How this service works

60 paid endpoints with no metering, no API key and no account. Each endpoint has one flat price per call, whatever the size of the request: LLM completions with automatic failover across several large models, read-only EVM tooling over Base, Ethereum, Polygon, Arbitrum and Optimism, and pure crypto utilities that touch no network.

## Output

Returns a JSON object with three fields: `owner` (the current holder's Ethereum address), `tokenURI` (the metadata URI stored on-chain for the token), and `collection` (the ERC721 contract's name). All data is fetched live via eth_call so it reflects the current on-chain state.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "tokenId",
  "contract"
 ],
 "properties": {
  "chain": {
   "type": "string",
   "description": "base | ethereum | polygon | arbitrum | optimism."
  },
  "tokenId": {
   "type": "string",
   "description": "Token id, in decimal."
  },
  "contract": {
   "type": "string",
   "description": "ERC721 contract address."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "owner": {
   "type": "string"
  },
  "tokenURI": {
   "type": "string"
  },
  "collection": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nft-owner-and-metadata-lookup-6cb3f77b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from flat-rate-llm.kikoribera03.workers.dev](https://www.zero.xyz/host/flat-rate-llm.kikoribera03.workers.dev/llms.txt)