Registration Data Access Protocol (RDAP)

The Registration Data Access Protocol (RDAP) is the successor to the ageing WHOIS protocol. Like WHOIS, RDAP provides access to information about Internet resources: domain names, autonomous systems, and IP addresses.

Unlike WHOIS, RDAP provides:

  • A machine-readable representation of registration data;
  • Differentiated access;
  • Structured request and response semantics;
  • Internationalisation;
  • Extensibility.

RDAP.org aims to support users and developers of RDAP clients by providing a single end point for RDAP queries. RDAP.org aggregates information about all known RDAP servers. RDAP clients can send RDAP queries to RDAP.org, which will then redirect requests to the appropriate RDAP service.

How To Use RDAP.org

Client Implementers

If you are developing an RDAP client, configure it to send HTTP requests to http://rdap.org/<type>/<object>, where <type> is the object type (one of domain, ip, autnum etc) and <object> is the object identifier (eg example.com, 192.168.0.1, 64496, etc).

HTTP Status Codes

  • 302 – occurs when RDAP.org knows of an RDAP service which is authoritative for the requested resource. Follow the URL listed in the Location header.
  • 400 – occurs when RDAP.org receives an invalid request (malformed path, unsupported object type, invalid IP address, etc).
  • 404 – occurs when RDAP.org doesn’t know of an RDAP service which is authoritative for the requested resource.
  • 429 – occurs if you have exceeded the rate limits.
  • 500 – occurs when RDAP.org is broken in some way.
  • 504 – occurs if RDAP.org needs to refresh the IANA bootstrap registry, but cannot.

Rate Limits

RDAP.org will return a 429 response if you send more than 30 requests in a 300-second (5 minute) window.

If you are interested in doing high-volume data mining of registration data, please (a) don’t, but if you must, (b) consume the IANA registries directly. Net::RDAP::Registry, which is part of Net::RDAP, provides a simple interface to these registries.

References

Submit Feedback

If you would like to submit feedback, or operate an RDAP service that you would like to be added to RDAP.org, please click here.

About RDAP.org

RDAP.org is maintained by Gavin Brown.

You can review the code which RDAP.org uses on GitHub.