# WHOIS/RDAP Lookup API

> WHOIS/RDAP Lookup API is a paid API for AI agents from rdap-api-production.up.railway.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-30).

Returns domain registration data (registrar, registrant, dates, nameservers, status) for any domain via the public RDAP protocol, paid per lookup on Base mainnet.

## Facts

- Endpoint: POST https://rdap-api-production.up.railway.app/lookup?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/whois-rdap-lookup-api-fec3a0e6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xK3Z-7lzpNIFkbU6l9bae

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 whois-rdap-lookup-api-fec3a0e6 -d '<json body>'
```

Example prompt: Can you pull up the WHOIS registration details for openai.com — I want to know who registered it, when it expires, and which nameservers it's using?

## When to prefer this

Choose this endpoint when you need programmatic, structured RDAP/WHOIS data for a domain without requiring an API key or account sign-up, and you are operating in a context where micropayments on Base mainnet (USDC) are acceptable. It is ideal for agents that need on-demand domain intelligence — ownership verification, expiry monitoring, registrar identification — without pre-negotiating a subscription. Prefer alternatives if you need bulk lookups at scale or if Base mainnet payments are not available in your environment.

## Known failure modes

- Domain not found or not yet registered returns an error or empty RDAP record
- TLDs with no RDAP bootstrap support may fail to resolve
- Rate limits or upstream RDAP server downtime can cause timeouts
- Invalid domain string format returns a validation error
- Payment failure on Base mainnet prevents the lookup from executing

## How this service works

Domain registration data via public RDAP protocol. No API key. No account. Pay per lookup on Base mainnet.

## Output

Returns structured RDAP data for the queried domain, including registrar name, registration and expiration dates, domain status codes (e.g. clientTransferProhibited), nameservers, and registrant contact information where publicly available. Response follows the RDAP JSON format.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "domain"
 ],
 "properties": {
  "domain": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/whois-rdap-lookup-api-fec3a0e6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from rdap-api-production.up.railway.app](https://www.zero.xyz/host/rdap-api-production.up.railway.app/llms.txt)