The Registration Data Access Protocol (RDAP) is built as a RESTful API using the benefits of HTTP(S).

The RDAP standard allows only two HTTP methods: HEAD and GET. More on usage of HTTP in RFC 7480.

Client authentication is not implemented, all data in responses is public.

IDNs are fully supported (both A-labels and U-labels, RFC 5890#section-

Registered RDAP servers can be found at

Conformance of this reference

  • RDAP Level 0

  • FRED Extension Version 0

Implemented interface overview

FRED RDAP does not implement any RIR (Regional Internet Registry) functionality, only some of DNR (Domain Name Registry) functionality as follows:

  • Lookup:
    • Domain by name (reverse lookup by IP not implemented)

    • Nameserver by hostname (reverse lookup by IP not implemented)

    • Entity by handle

  • Unimplemented lookup: IP (/ip), autonomous system (/as)

  • Lookup extensions:
    • FRED nsset by handle

    • FRED keyset by handle

  • Help (/help)

  • Search queries are not implemented (/domains, /nameservers, /entities)


  • RFC 7480 HTTP Usage in the Registration Data Access Protocol (RDAP)

  • RFC 7481 Security Services for the Registration Data Access Protocol (RDAP)

  • RFC 7482 Registration Data Access Protocol (RDAP) Query Format

  • RFC 7483 JSON Responses for the Registration Data Access Protocol (RDAP)

  • RFC 7484 Finding the Authoritative Registration Data (RDAP) Service

  • RFC 8056 Extensible Provisioning Protocol (EPP) and Registration Data Access Protocol (RDAP) Status Mapping

  • FRED RDAP Extension Specification