Tool detail

nft-owner

Returns the current owner address of an ERC721 NFT token_id on an EVM chain, via an eth_call to ownerOf.

Categories: Onchain data, Token analytics

Use when

find who currently owns a specific ERC721 NFT token_id
verify NFT ownership before a trade or transfer

Not for

not for ERC1155 balance counts (use erc1155-balance)
not NFT metadata, images, or collection stats

Inputs

GET query: contract (0x... 40-hex address, required), token_id (digit string, required); network (ethereum|sepolia|robinhood, optional, default ethereum)

Admitted input schema

{
  "type": "object",
  "properties": {
    "contract": {
      "type": "string",
      "minLength": 0,
      "maxLength": 4096,
      "pattern": "^0x[a-fA-F0-9]{40}$"
    },
    "network": {
      "type": "string",
      "minLength": 0,
      "maxLength": 4096,
      "enum": [
        "ethereum",
        "sepolia",
        "robinhood"
      ],
      "default": "ethereum"
    },
    "token_id": {
      "type": "string",
      "minLength": 0,
      "maxLength": 4096,
      "pattern": "^[0-9]+$"
    }
  },
  "required": [
    "contract",
    "token_id"
  ],
  "additionalProperties": false
}

Endpoint

Method: GET
URL: https://api.onesource.io/api/chain/nft-owner

Payment

Protocol: x402
Listed price: 0.003 USDC per call on Base (eip155:8453)
Payment method: exact
Network: eip155:8453
Asset: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

Listed terms are catalog metadata. The caller supplies inputs and calls the tool outside Onelayer. If payment is required, the caller uses a compatible wallet to pay.

Source

Directory: Coinbase x402 Bazaar
Record: GET https://api.onesource.io/api/chain/nft-owner
Retrieved: 2026-09-30T20:37:07.382Z
Catalog file SHA-256: 6837ccddf886f0007cf3727ea9d27faaa5047b51b4f425345c554ce1c271a524
Catalog built: 2026-09-30T22:31:58.034Z