# Domain WHOIS Lookup

> Domain WHOIS Lookup is a paid API for AI agents from x402.agentutility.ai, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Returns comprehensive domain registration information including registrar, nameservers, expiration dates, DNSSEC status, and SSL certificate summary for a given domain name.

## Facts

- Endpoint: POST https://x402.agentutility.ai/whois
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/domain-whois-lookup-da57f43f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_iAmDEpD-dkbnGln03iuK7

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-whois-lookup-da57f43f -d '<json body>'
```

Example prompt: Can you look up the WHOIS registration info for openai.com — I want to know who the registrar is, when it was registered and expires, whether DNSSEC is enabled, and what nameservers it's using?

## When to prefer this

Choose this endpoint when you need structured, machine-readable domain registration metadata including expiry dates, registrar identity, nameservers, and DNSSEC status for a single domain. Prefer this over raw WHOIS text parsers when you need a clean JSON response suitable for downstream processing. Ideal for domain monitoring, due diligence workflows, or cybersecurity investigations where programmatic access to domain lifecycle data is required.

## Known failure modes

- Domain not found or does not exist — returns empty or error response
- Invalid domain format — malformed input rejected
- RDAP/WHOIS data unavailable for certain TLDs or private registrations
- Payment not settled in USDC over x402 — request rejected with 402 status
- Rate limiting or quota exceeded

## How this service works

WHOIS / RDAP / domain age / domain expiry / registrar finder / nameserver lookup / DNSSEC check / TLD registration record / brand-protection triage. Short alias of whois-lookup. Queries the IANA-mandated RDAP endpoint and returns registered_date, age_days, expiration_date, days_until_expiry, last_changed, registrar (name + IANA id), contacts, nameservers, dnssec_signed, EPP statuses, and risk flags. Optionally appends a crt.sh certificate-transparency summary.

## Output

Returns a JSON object with the domain's registrar name and IANA ID, list of nameservers, registration and expiration dates, days until expiry, domain age in days, DNSSEC signing status, RDAP server URL, current domain status flags (e.g. client delete prohibited), and an SSL certificate summary if available.

## Request schema (JSON Schema)

```json
{
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "type": "object",
 "properties": {
  "input": {
   "type": "object",
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "type": "string",
     "enum": [
      "POST"
     ]
    },
    "bodyType": {
     "type": "string",
     "enum": [
      "json",
      "form-data",
      "text"
     ]
    },
    "body": {
     "properties": {
      "domain": {
       "type": "string",
       "description": "Apex domain to look up (e.g. 'example.com'). Subdomains are stripped to the registrable domain."
      },
      "include_certificates": {
       "type": "boolean",
       "description": "If true, attaches a crt.sh certificate-transparency summary. Default false."
      }
     },
     "required": [
      "domain"
     ]
    }
   },
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "domain": {
       "type": "string"
      },
      "rdap_server": {
       "type": "string"
      },
      "registered_date": {
       "type": "string"
      },
      "expiration_date": {
       "type": "string"
      },
      "age_days": {
       "type": "integer"
      },
      "days_until_expiry": {
       "type": "integer"
      },
      "registrar": {
       "type": "object",
       "properties": {
        "name": {
         "type": "string"
        },
        "iana_id": {
         "type": "string"
        }
       }
      },
      "nameservers": {
       "type": "array",
       "items": {
        "type": "string"
       }
      },
      "dnssec_signed": {
       "type": "boolean"
      },
      "statuses": {
       "type": "array",
       "items": {
        "type": "string"
       }
      },
      "flags": {
       "type": "array"
      },
      "cert_summary": {
       "type": "null"
      }
     }
    }
   },
   "required": [
    "type"
   ]
  }
 },
 "required": [
  "input"
 ]
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "flags": [],
  "domain": "example.com",
  "age_days": 11223,
  "statuses": [
   "client delete prohibited"
  ],
  "registrar": {
   "name": "RESERVED-Internet Assigned Numbers Authority",
   "iana_id": "376"
  },
  "nameservers": [
   "A.IANA-SERVERS.NET",
   "B.IANA-SERVERS.NET"
  ],
  "rdap_server": "https://rdap.verisign.com/com/v1/",
  "cert_summary": null,
  "dnssec_signed": true,
  "expiration_date": "2026-08-13T04:00:00Z",
  "registered_date": "1995-08-14T04:00:00Z",
  "days_until_expiry": 98
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/domain-whois-lookup-da57f43f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.agentutility.ai](https://www.zero.xyz/host/x402.agentutility.ai/llms.txt)