# Domain RDAP Lookup & Registration Checker

> Domain RDAP Lookup & Registration Checker is a paid API for AI agents from x402.agentutility.ai, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Checks whether a domain is registered and returns registrar, registration date, expiry date, days until expiry, and EPP status flags via RDAP protocol.

## Facts

- Endpoint: POST https://x402.agentutility.ai/domain-availability
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/domain-rdap-lookup-registration-checker-e5bc6f16
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_e4ujKh-A6yJrmZDz6mtup

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-rdap-lookup-registration-checker-e5bc6f16 -d '<json body>'
```

Example prompt: Can you check whether 'coolstartup.io' is currently registered, and if so tell me the registrar, when it was registered, when it expires, and how many days are left before it expires?

## When to prefer this

Choose this endpoint when you need structured, machine-readable domain registration data (registrar, dates, EPP flags) without scraping WHOIS. It is ideal for gTLDs and most ccTLDs, works as a drop-in WHOIS replacement, and returns clean JSON. It handles 404s gracefully as 'not registered' rather than errors, making it safe for batch or automated checks. Prefer it over raw WHOIS when you need reliable expiry date or days_until_expiry fields.

## Known failure modes

- Domain not found in RDAP returns is_registered: false (not a 404 error)
- ccTLDs without RDAP support may return incomplete or no data
- Recently registered or deleted domains may have stale RDAP data
- Rate limits from upstream rdap.org may cause transient failures
- Invalid domain format input causes a validation error

## How this service works

Checks whether a domain is registered and returns registrar, registration date, expiry date, days_until_expiry, and current EPP status flags. Works for any TLD that supports RDAP (effectively all gTLDs and most ccTLDs). Backed by rdap.org, the public RFC-7480-compliant aggregator; 404s map to is_registered: false rather than an error. Use it as an RDAP lookup, WHOIS replacement, domain registration checker, or expiry date lookup.

## Output

Returns a JSON object with is_registered (boolean), registrar name, registration date, expiry date, days_until_expiry (integer), and EPP status flags (e.g. clientTransferProhibited). If the domain is not found via RDAP, returns is_registered: false rather than an error.

## 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": "Domain to check (e.g. 'example.com'). Strip protocol/path automatically."
      }
     },
     "required": [
      "domain"
     ]
    }
   },
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "domain": {
       "type": "string"
      },
      "is_registered": {
       "type": "boolean"
      },
      "registrar": {
       "type": "string"
      },
      "status": {
       "type": "array",
       "items": {
        "type": "string"
       }
      },
      "registered_date": {
       "type": "string"
      },
      "expires_date": {
       "type": "string"
      },
      "last_changed": {
       "type": "string"
      },
      "days_until_expiry": {
       "type": "integer"
      },
      "source": {
       "type": "string"
      }
     }
    }
   },
   "required": [
    "type"
   ]
  }
 },
 "required": [
  "input"
 ]
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "domain": "example.com",
  "source": "rdap.org",
  "status": [
   "client transfer prohibited"
  ],
  "registrar": "Reserved by IANA",
  "expires_date": "2026-08-13T04:00:00Z",
  "last_changed": "2025-08-14T07:01:31Z",
  "is_registered": true,
  "registered_date": "1995-08-14T04:00:00Z",
  "days_until_expiry": 97
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/domain-rdap-lookup-registration-checker-e5bc6f16/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)