# Domain Intel – MX Retarus Check

> Domain Intel – MX Retarus Check is a paid API for AI agents from dns.halowerk.com, paid per call via x402, $0.009/call, status unknown (last checked 2026-10-12).

Looks up WHOIS, DNS, mail policy (SPF/DKIM/DMARC), TLS certificate, and subdomains for a given domain, with optional MX record baseline comparison against Retarus mail infrastructure.

## Facts

- Endpoint: POST https://dns.halowerk.com/domain/articles/mx-retarus?utm_source=zero.xyz
- Price: $0.009/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/domain-intel-mx-retarus-check-56ebfc16
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_b_ZjMWb7nb1NX96PvTIfw

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 domain-intel-mx-retarus-check-56ebfc16 -d '<json body>'
```

Example prompt: Pull full domain intelligence on halowerk.com — I need WHOIS, DNS records, mail policy, TLS cert details, and subdomains, and compare the MX records against this baseline: exchange=mx.retarus.net priority=10, observed 2024-01-15T00:00:00Z.

## When to prefer this

Choose this endpoint when you need a comprehensive, single-call domain intelligence snapshot covering WHOIS, DNS, mail policy, TLS, and subdomains without managing API keys or subscriptions. Especially useful when you want to compare current MX records against a known Retarus mail infrastructure baseline to detect drift. Prefer over general DNS lookup tools when you need the full multi-layer view in one pay-per-call request.

## Known failure modes

- Domain not found or unresolvable — returns empty or error response
- Invalid domain format (exceeds 253 characters or malformed) — schema validation error
- WHOIS data unavailable for some TLDs — partial response
- TLS certificate lookup fails if domain has no HTTPS — missing cert data
- Baseline MX comparison returns no diff if baseline format is malformed
- Payment failure over x402 — 402 response, call not executed

## How this service works

Requires an unauthenticated caller-owned baseline; returns real current NS/MX records, added/removed sets and tri-state target-provider transition. Current DNS comes from one bounded native recursive-resolver query; existing Dossier provides context. Resolver caching may apply; no account ownership or global migration-completion claim. Existing provider patterns are reused without new invented attribution. At most50records,domain253chars,9sbudget; DNSsubquery2s/oneattempt. Unknown provider remai

## Output

Returns aggregated domain intelligence including WHOIS registration data, DNS records, mail policy records (SPF, DKIM, DMARC), TLS/SSL certificate details, discovered subdomains, and optionally a comparison of current MX records against a provided baseline showing any deviations.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "domain": {
   "type": "string",
   "maxLength": 253
  },
  "baseline": {
   "type": "object",
   "required": [
    "domain",
    "observed_at",
    "records"
   ],
   "properties": {
    "domain": {
     "type": "string",
     "maxLength": 253
    },
    "records": {
     "type": "array",
     "items": {
      "type": "object",
      "required": [
       "exchange",
       "priority"
      ],
      "properties": {
       "exchange": {
        "type": "string",
        "maxLength": 254
       },
       "priority": {
        "type": "integer",
        "maximum": 65535,
        "minimum": 0
       }
      },
      "additionalProperties": false
     },
     "maxItems": 50
    },
    "observed_at": {
     "type": "string",
     "maxLength": 40
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/domain-intel-mx-retarus-check-56ebfc16/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from dns.halowerk.com](https://www.zero.xyz/host/dns.halowerk.com/llms.txt)