# RDAP Guide

Registration Data Access Protocol (RDAP) is the modern way to read public domain registration data in JSON.

## What you can look up

For a domain name, RDAP may return:

- Domain handle and `ldhName`
- Registrar-related entities
- Domain status codes
- Nameservers
- Registration, expiration, and last-changed events
- Notices and links

Fields vary by registry and registrar. Personal data is often redacted.

## How OpenRDAP resolves servers

OpenRDAP uses the [IANA RDAP DNS bootstrap](https://data.iana.org/rdap/dns.json) to map a TLD to an authoritative RDAP base URL, then queries:

```text
{baseUrl}/domain/{domain}
```

## Limitations

- **404** does not prove a domain is available to register.
- **429** means the RDAP server rate-limited your request.
- **CORS** may block browser access for some registries.

OpenRDAP is not affiliated with ICANN, IANA, registries, or registrars.