# DomainRef - Domain and Email Security Check

> DomainRef - Domain and Email Security Check is a paid API for AI agents from domainref.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-30).

Returns a graded security report for a domain covering SPF, DKIM, DMARC, MX, MTA-STS, DNSSEC, CAA, TLS, domain age, BIMI, and blocklist status with exact fix records.

## Facts

- Endpoint: GET https://domainref.dev/v1/domain/check?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/domainref-domain-and-email-security-check-5db3e89d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JjnYfJeSmNfyrBHFy8IpY

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 domainref-domain-and-email-security-check-5db3e89d
```

Example prompt: Can you run a full email security check on acmecorp.com and tell me what grade it gets, whether SPF, DKIM, and DMARC are configured correctly, and what I need to fix?

## When to prefer this

Choose this endpoint when you need a comprehensive, graded, non-intrusive audit of a domain's email authentication and DNS security posture in a single call. It is especially useful pre-campaign, for spam troubleshooting, vendor due diligence, or Microsoft 365 tenant validation — where you need actionable fix records rather than raw DNS lookups. Prefer it over manual DNS lookup tools or generic WHOIS services when you want a structured score and remediation guidance.

## Known failure modes

- Invalid or non-existent domain returns an error or empty result
- DNS timeout may cause incomplete check results
- Newly registered domains may have incomplete DNS propagation affecting results
- Punycode or internationalized domain names may not be handled correctly
- Rate limiting or payment failure returns a 402 or 429 error

## How this service works

Use when mail lands in spam, before an email campaign, for vendor due diligence or to confirm a Microsoft 365 tenant: graded SPF, DKIM, DMARC, MX, MTA-STS, DNSSEC, CAA, TLS and domain age, plus BIMI and blocklist info, each with the exact fix record. Non-intrusive. $0.01 per domain.

## Output

A JSON object containing a numeric score (0–100), a letter grade (A–F), and an array of individual security checks. Each check includes the check name (e.g. 'dmarc'), a pass/fail/warn grade, a human-readable finding, and an exact fix record where remediation is needed.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "queryParams"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "domain"
     ],
     "properties": {
      "domain": {
       "type": "string",
       "maxLength": 253,
       "minLength": 1,
       "description": "Required. The domain to check, sent as ?domain=example.com."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "score": 100,
  "checks": [
   {
    "fix": null,
    "check": "dmarc",
    "grade": "pass",
    "finding": "DMARC enforces p=reject on 100% of mail."
   }
  ],
  "domain": "example.com",
  "letter": "A"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/domainref-domain-and-email-security-check-5db3e89d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from domainref.dev](https://www.zero.xyz/host/domainref.dev/llms.txt)