# ERC-721 Tokens Owned by Address

> ERC-721 Tokens Owned by Address is a paid API for AI agents from ari001.tailb4ac3a.ts.net, paid per call via x402, $0.008/call, status unknown (last checked 2026-10-02).

Returns all token IDs owned by a specific address for a given ERC-721 Enumerable contract on Ethereum mainnet

## Facts

- Endpoint: GET https://ari001.tailb4ac3a.ts.net/v1/ventures/ethereum_contract_abi_service/erc721_tokensof?utm_source=zero.xyz
- Price: $0.008/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/erc-721-tokens-owned-by-address-f0474b48
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_K5uQUtLsFeZ-shZH_zYhW

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 erc-721-tokens-owned-by-address-f0474b48
```

Example prompt: What token IDs does the wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 own in the NFT collection at contract 0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13d?

## When to prefer this

Use this endpoint when you need to enumerate the specific token IDs held by a wallet in a known ERC-721 Enumerable contract on Ethereum mainnet. It is the right choice when you need the full list of owned token IDs, not just a balance count. Prefer this over a raw balanceOf call when you need actionable token IDs for downstream operations like metadata fetching, transfer checks, or airdrop eligibility. Not suitable for ERC-1155 tokens or contracts that do not implement the Enumerable extension.

## Known failure modes

- Contract is not ERC-721 Enumerable — returns ok:false with an error
- Invalid contract or owner address format (not 0x + 40 hex) — schema validation error
- Contract address is an EOA or non-NFT contract — call reverts
- Owner holds more than 50 tokens — result is truncated and truncated flag is true
- Network timeout or RPC node unavailability — service error response

## How this service works

Returns the token IDs owned by a given address for an ERC-721 Enumerable contract. Inputs: token (ERC-721 contract address, 0x + 40 hex), owner (owner address, 0x + 40 hex). Output: array of token IDs as decimal strings. Query: token (ERC-721 contract (Enumerable), 0x + 40 hex), owner (0x + 40 hex).

## Output

An array of up to 50 token ID strings owned by the specified address in the given ERC-721 contract, along with the owner address, token contract address, total balance count, and a truncated flag indicating whether more than 50 tokens exist. Returns ok:false with an error message if the contract is not Enumerable, the address is invalid, or the call fails.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "token",
      "owner"
     ],
     "properties": {
      "owner": {
       "type": "string",
       "pattern": "^0x[a-fA-F0-9]{40}$",
       "description": "0x + 40 hex"
      },
      "token": {
       "type": "string",
       "pattern": "^0x[a-fA-F0-9]{40}$",
       "description": "ERC-721 contract (Enumerable), 0x + 40 hex"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "ok",
      "service"
     ],
     "properties": {
      "ok": {
       "type": "boolean"
      },
      "chain": {
       "type": "string"
      },
      "error": {
       "type": "string",
       "description": "present when ok is false"
      },
      "method": {
       "type": "string"
      },
      "result": {
       "type": "object",
       "properties": {
        "ids": {
         "type": "array",
         "items": {
          "type": "string"
         },
         "maxItems": 50
        },
        "owner": {
         "type": "string",
         "pattern": "^0x[0-9a-fA-F]{40}$"
        },
        "token": {
         "type": "string",
         "pattern": "^0x[0-9a-fA-F]{40}$"
        },
        "balance": {
         "type": "integer"
        },
        "truncated": {
         "type": "boolean"
        }
       }
      },
      "service": {
       "type": "string"
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/erc-721-tokens-owned-by-address-f0474b48/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from ari001.tailb4ac3a.ts.net](https://www.zero.xyz/host/ari001.tailb4ac3a.ts.net/llms.txt)