ToolVet
82trust / 100

Check

by Domain Availability Checker in Search & web

x402 APIPassing, checked 4 h ago

Give this API up to 10 domain names and it tells you whether each has a registration record at the official registry. It uses RDAP, the structured replacement for WHOIS, so there is no free-text parsing. Each domain comes back as 'registered', 'unregistered', or 'indeterminate' when the registry has no RDAP for that ending. 'Unregistered' means no record was found, which usually means available - but reserved and premium names also return no record. Registration status only; no pricing.

POST https://domain-availability-checker.underscoredone.com/check

Last 30 days

All checks passedSome failedAll failedNot checked
Uptime
100%
Response time
252 ms typical, 252 ms slowest 5%
Last check
4 h ago
Next check
any minute now

How to call it

# See the payment challenge (nothing is charged)
curl -i -X POST "https://domain-availability-checker.underscoredone.com/check" \
  -H "content-type: application/json" \
  -d '{"domains":["example.com","mybrand.ai","coolstartup.io"]}'
import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { ExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const client = new x402Client().register(
  "eip155:8453",
  new ExactEvmScheme(privateKeyToAccount(process.env.AGENT_KEY)),
);
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? Preflight it first for $0.005:
// GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fdomain-availability-checker.underscoredone.com%2Fcheck
const res = await pay("https://domain-availability-checker.underscoredone.com/check", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({"domains":["example.com","mybrand.ai","coolstartup.io"]}),
});
console.log(await res.json());

Example input

{
  "domains": [
    "example.com",
    "mybrand.ai",
    "coolstartup.io"
  ]
}

Example output

{
  "api_version": "1.0.0",
  "count": 2,
  "disclaimer": "Status reflects whether a registration record exists. It does not confirm price, premium status, or that an 'unregistered' name is purchasable at standard cost.",
  "queried_at": "2026-06-26T09:00:00Z",
  "results": [
    {
      "domain": "example.com",
      "note": "A registration record exists for this domain.",
      "rdap_source": "registry",
      "registered": true,
      "status": "registered",
      "tld_supported": true
    },
    {
      "domain": "thisnameprobablyhasnorecord12345.ai",
      "note": "No registration record found. Usually means unregistered, but reserved or premium names can also return this result.",
      "rdap_source": "registry",
      "registered": false,
      "status": "unregistered",
      "tld_supported": true
    }
  ]
}

Security scan

  • No findings. We scan names, descriptions and tool definitions for hidden instructions and other prompt-injection patterns.

Recent checks

WhenResultHTTPTimePrice
4 h agoPassed402252 ms$0.01