Domain security & deliverability audit (graded)

Hand over a domain and get one graded security & email-deliverability audit: SPF, DMARC, DKIM and MX (why your mail lands in spam), the web security headers, and the TLS certificate - every finding from a live probe, with an overall letter grade, a downloadable checks appendix, and a prioritized, specific list of fixes. Send POST /v1/domain-audit with the required field domain and pay $0.60 per call over x402 with USDC on an EVM chain. It returns a JSON object with report, domain, grade, composite, sources and 2 more.

USDC (x402/MPP) or card (Stripe). Not cached.

Category: LLM gateway · Tags: security domain email deliverability spf dmarc dkim tls

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Parameters

Example request

curl -i -X POST https://agent402.tools/v1/domain-audit \
  -H "Content-Type: application/json" \
  -d '{"domain":"example.com"}'

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

Example response

{
  "report": "# Domain Security Audit: example.com\n\n**Overall grade: B** (82/100)\n\n## Overall grade\n...",
  "domain": "example.com",
  "grade": "B",
  "composite": 82,
  "sources": [],
  "tables": [
    {
      "name": "email-checks",
      "label": "Email authentication checks",
      "columns": [
        "Check",
        "Status",
        "Detail"
      ],
      "rows": [
        [
          "spf",
          "pass",
          "SPF record present, 1 DNS lookup, ~all qualifier"
        ]
      ]
    }
  ],
  "meta": {
    "tier": "domain-audit",
    "domain": "example.com",
    "grade": "B",
    "composite": 82,
    "email_score": 90,
    "header_score": 70,
    "tls_days_remaining": 204,
    "synthesis_model": "anthropic/claude-opus-5"
  }
}

From an MCP client

catalog.call {
  "slug": "domain-audit",
  "params": {
    "domain": "example.com"
  }
}

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

Errors and behavior

• domain 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.
• Wallet-only: this tool runs a model, so it has no proof-of-work tier. A prepaid card-credits key (Authorization: Bearer a402_...) also pays it.
• Model-backed: the answer is generated by a model, so the same input can produce different wording.
• Long-running: payment settles after the work finishes, so only EVM exact payments are offered.
• A GET or HEAD to /v1/domain-audit 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 and a streamed response are 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/v1/domain-audit", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    "domain": "example.com"
  }),
});

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