DNS lookup

Resolve any DNS record type for a host: A, AAAA, MX, TXT, CNAME, NS, SOA, CAA, SRV, PTR. Send POST /api/dns-lookup with the required field host and pay $0.002 per call over x402 or MPP (there is no free tier). It returns a JSON object with host, type, records, count and queriedAt.

Returns the records plus a count. Built on Node's native resolver - no external API.

Category: Network & domains · Tags: dns lookup network diagnostic a aaaa mx txt

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Parameters

Example request

curl -i -X POST https://agent402.tools/api/dns-lookup \
  -H "Content-Type: application/json" \
  -d '{"host":"google.com","type":"MX"}'

Without payment this returns HTTP 402 Payment Required with the exact price for dns-lookup; any x402 v2 or MPP client pays it and retries.

Example response

{
  "host": "google.com",
  "type": "MX",
  "records": [
    {
      "priority": 10,
      "exchange": "smtp.google.com"
    }
  ],
  "count": 1,
  "queriedAt": "2026-06-19T20:00:00.000Z"
}

From an MCP client

catalog.call {
  "slug": "dns-lookup",
  "params": {
    "host": "google.com",
    "type": "MX"
  }
}

The hosted connector at https://agent402.tools/mcp needs a payment for dns-lookup; the stdio package pays it from a wallet or from AGENT402_CREDITS_KEY. Local install: npx -y agent402-mcp.

Errors and behavior

• host is required. An input the tool rejects returns an HTTP 4xx whose body carries error, tool, expected, required and example, so the caller can correct it.
• A paid call that ends in any status of 400 or above is not charged over x402, MPP or a prepaid credits key: settlement is cancelled when the tool fails. The exception is a Tempo push credential, a transfer the buyer sent before the call: it settles before the tool runs, so if the tool then fails the payment is recorded as a refund owed to the paying wallet.
• Wallet-only: this tool reaches the network or stored state, so it has no proof-of-work tier. A prepaid card-credits key issued earlier (Authorization: Bearer a402_...) also pays it.
• A GET or HEAD to /api/dns-lookup returns the same 402 quote, so the price can be read without a body.
• An Idempotency-Key header makes a retried paid call replay the first 200 instead of charging again (an answer larger than 1 MB is not replayed).

Paid call (JavaScript agent)

import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const client = new x402Client();
client.setSpendControls?.(false); // keep your own spending ceiling in code
registerExactEvmScheme(client, { signer: privateKeyToAccount(KEY) });
const payFetch = wrapFetchWithPayment(fetch, client);

const res = await payFetch("https://agent402.tools/api/dns-lookup", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    "host": "google.com",
    "type": "MX"
  }),
});

Part of these workflows

DNS lookup is one step in these 10 skill packs, each sold as a single call:

• Security audit - Enumerate a domain's external attack surface in one workflow: certs, DNS posture, email auth, HTTP security headers, and tech stack.
• Email deliverability - Diagnose why a domain's email lands in spam: SPF posture, DMARC policy, DKIM key strength, MX targets, and a composite 0–100 score.
• DNS & network ops - End-to-end DNS health check: records, multi-resolver propagation, WHOIS, ASN, robots.txt, and reachability.
• Fraud signals - Is this domain trustworthy, or is it a phishing site / typosquat / scam? Pull the reputation signals an analyst checks before clicking anything: domain age, cert issuance history, hosting reputation, DNS topology, tech-stack fingerprint, and page-content red flags. Different from a security audit - this is about whether the domain is what it claims to be.
• Site status snapshot - The 'is this site healthy, addressable, and crawlable - right now?' workflow. DNS resolution → HTTP reachability → security headers → TLS certificate expiry → robots policy. Five tools, one structured status payload an operator (or an uptime bot, or a pre-flight check before an extract/crawl) can act on.
• Domain intel - Full domain security and SEO intelligence in one call: WHOIS, DNS, TLS cert, HTTP headers, tech stack, robots policy, and certificate transparency.
• SSL audit - TLS/SSL security posture check: live certificate inspection, HTTP security headers, and CAA DNS records.
• Brand protection - Is this domain legitimate? WHOIS age, DNS resolution, scam/phishing search results, and HTTP headers for a quick trust assessment.
• Contact verification - Verify an email address is deliverable - syntax validation plus MX record check on the domain.
• Domain age and legitimacy - How old and legit is this domain? WHOIS registration, DNS resolution, and TLS certificate in one pass.

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