Introduction[Link]

Registration Data Access Protocol (RDAP) is a standardized system designed to provide secure, structured, and machine-readable access to domain name, IP address, and Autonomous System registration data. It was developed to replace the older WHOIS protocol by offering improved data accuracy, standardized query and response formats (using JSON), support for internationalization, and built‑in authentication and access control. RDAP enables more reliable, privacy‑aware, and consistent access to registration information across registries and registrars.

RDAP is standerdised in STD 95 and consists of:

RFC 7480 : HTTP Usage in the Registration Data Access Protocol (RDAP)
RFC 7481 : Security Services for the Registration Data Access Protocol (RDAP)
RFC 9082 : Registration Data Access Protocol (RDAP) Query Format
RFC 9083 : JSON Responses for the Registration Data Access Protocol (RDAP)
RFC 9224 : Finding the Authoritative Registration Data Access Protocol (RDAP) Service

Specifically for .brussels and .vlaanderen and according to ICANN specifications, we have also implemented:

RFC 8056 : Extensible Provisioning Protocol (EPP) and Registration Data Access Protocol (RDAP) Status Mapping
RFC 8605 : vCard Format Extensions: ICANN Extensions for the Registration Data Access Protocol (RDAP)
RFC 9537 : Redacted Fields in the Registration Data Access Protocol (RDAP) Response

Beside RFC compliance, we also adhere to the gTLD RDAP Profile February 2024:

There are a lot of clients specifically implemented for RDAP, but you can invoke RDAP queries by using curl or wget.

Example:

curl https://rdap.nic.brussels/domain/nic.brussels

When invoking RDAP calls programmatically, in general we advise you to look for a generic REST client to invoke the RDAP calls.