Ethereum Nft Owner
by Saylor Innovations On-Chain Data in Onchain & crypto
NFT owner of an ERC-721 token (ownerOf) on Base, Ethereum, Arbitrum, Optimism or Polygon
https://saylorinnovations.com/api/evm/ethereum/nft-owner/:address/1- Price
- $0.002
- per call in USDC
- Uptime
- 0.0%
- last 30 days
- Response time
- -
- no timed checks yet
- Last check
- Failed
- 2 h ago, next any minute now
Reliability
Latest check failed 2 h ago: Expected HTTP 402, got 400
How to call it
GET https://saylorinnovations.com/api/evm/ethereum/nft-owner/:address/1
Each call costs $0.002 in USDC on Base, paid with the request over x402.
Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.
Example request
The listing has no example input.
GET https://saylorinnovations.com/api/evm/ethereum/nft-owner/:address/1Example response
The provider's example. We can't check it without paying.
{
"chain": "ethereum",
"contract": "0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13D",
"owner": "0x4444444444444444444444444444444444444444",
"token_id": "1"
}Call it from code
The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.002.
curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://saylorinnovations.com/api/evm/ethereum/nft-owner/:address/1'
# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://saylorinnovations.com/api/evm/ethereum/nft-owner/:address/1' \
| grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decodeJavaScript: pay and call
// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";
// Pays at most $0.002 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.002" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);
// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.002 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fsaylorinnovations.com%2Fapi%2Fevm%2Fethereum%2Fnft-owner%2F%3Aaddress%2F1
const res = await pay("https://saylorinnovations.com/api/evm/ethereum/nft-owner/:address/1");
console.log(res.status, await res.text());Python: pay and call
# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client
# Pays at most $0.002 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.002"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))
with x402_requests(client) as session:
res = session.get("https://saylorinnovations.com/api/evm/ethereum/nft-owner/:address/1")
print(res.status_code, res.text)Security scan
No findings
We scan names, descriptions and tool definitions for hidden instructions and other prompt-injection patterns.
Recent checks
| When | Result | HTTP | Time | Price |
|---|---|---|---|---|
| 2 h ago | Expected HTTP 402, got 400 | 400 | 274 ms | - |
| 7 h ago | Expected HTTP 402, got 400 | 400 | 204 ms | - |
| 11 h ago | Expected HTTP 402, got 400 | 400 | 619 ms | - |
| 16 h ago | Expected HTTP 402, got 400 | 400 | 704 ms | - |
| 20 h ago | Expected HTTP 402, got 400 | 400 | 948 ms | - |
Show 10 older checks
| 25 h ago | Expected HTTP 402, got 400 | 400 | 842 ms | - |
| 29 h ago | Expected HTTP 402, got 400 | 400 | 192 ms | - |
| 33 h ago | Expected HTTP 402, got 400 | 400 | 705 ms | - |
| 38 h ago | Expected HTTP 402, got 400 | 400 | 624 ms | - |
| 42 h ago | Expected HTTP 402, got 400 | 400 | 547 ms | - |
| 46 h ago | Expected HTTP 402, got 400 | 400 | 437 ms | - |
| 2 days ago | Expected HTTP 402, got 400 | 400 | 599 ms | - |
| 2 days ago | Expected HTTP 402, got 400 | 400 | 606 ms | - |
| 2 days ago | Expected HTTP 402, got 400 | 400 | 238 ms | - |
| 3 days ago | Expected HTTP 402, got 400 | 400 | 211 ms | - |