View source for Registration Data Access Protocol

{{Short description|Computer network protocol}}
{{confused|Residential Drug Abuse Program}} 
{{Infobox networking protocol
| logo         = 
| logo alt     = 
| image        = 
| image alt    = 
| caption      = 
| is stack     = No
| abbreviation = RDAP
| purpose      = Domain lookup
| developer    = [[Organization:Internet Engineering Task Force|Internet Engineering Task Force]] (IETF)
| date         = {{Start date and age|2015}}
| based on     = [[JSON]]
| influenced   = 
| osilayer     = [[Application layer]] (7)
| ports        = 
| rfcs         = {{IETF RFC|7483|plainlink=yes}}
}}
The '''Registration Data Access Protocol''' ('''RDAP''') is a computer network communications protocol standardized by a working group at the [[Organization:Internet Engineering Task Force|Internet Engineering Task Force]] in 2015, after experimental developments and thorough discussions.  It is a successor to the [[Software:WHOIS|WHOIS]] protocol, used to look up relevant registration data from such Internet resources as [[Domain name|domain name]]s, [[IP address]]es, and [[Autonomous system (Internet)|autonomous system numbers]].

While WHOIS essentially retrieves free text, RDAP delivers data in a standard, machine-readable [[JSON]] format.<ref>{{cite IETF
| title = JSON Responses for the Registration Data Access Protocol (RDAP)
| rfc = 7483
| last1 = Newton
| first1 = Andrew
| last2 = Hollenbeck
| first2 = Scott
|date=March 2015
| publisher = [[Organization:Internet Engineering Task Force|IETF]]
| accessdate = 2016-11-10
}}</ref>  In order to accomplish this goal, the output of all operative WHOIS servers was analyzed, taking a census of the labels they used.<ref>{{cite IETF
| title = Inventory and Analysis of WHOIS Registration Objects
| rfc = 7485
| last1 = Zhou
| first1 = L.
| last2 = Kong
| first2 = N.
| last3 = Shen
| first3 = S.
| last4 = Sheng
| first4 = S.
| last5 = Servin
| first5 = A.
|date=March 2015
| publisher = [[Organization:Internet Engineering Task Force|IETF]]
| accessdate = 2016-11-10
}}</ref>  RDAP designers, many of whom are members of [[Organization:Regional Internet registry|number]] or [[Domain name registry|name]] registries, strove to keep the protocol as simple as possible, since complexity was considered one of the reasons why previous attempts, such as CRISP, failed.  RDAP is based on [[REST|RESTful web services]], so that error codes,  user identification, authentication, and access control can be delivered through [[HTTP]].<ref>{{cite web
| url=https://www.ietf.org/wg/concluded/weirds
| title=Web Extensible Internet Registration Data Service (weirds)
| date=2015-03-25
| publisher=[[Organization:Internet Engineering Task Force|IETF]]
| access-date=2016-11-10
| archive-date=2015-07-11
| archive-url=https://web.archive.org/web/20150711224619/http://www.ietf.org/wg/concluded/weirds
| url-status=live
}}</ref>

The biggest delay in getting RDAP done turned out to be the ''bootstrap'', figuring out where the server is for each [[Top-level domain|top-level domain]], IP range, or ASN range.  [[Organization:Internet Assigned Numbers Authority|IANA]] agreed to host the bootstrap information in suitable registries, and publish it at a well-known location URLs in JSON format. Those registries started  empty and will be gradually populated as registrants of domains and address spaces provide RDAP server information to IANA.<ref>{{cite web
| url=https://jl.ly/ICANN/weirds14.writeback
| title=The replacement for WHOIS is surprisingly close
| author=John Levine
| date=2014-09-10
| website=jl.ly
| accessdate=2016-11-10
| archive-date=2022-12-25
| archive-url=https://web.archive.org/web/20221225110924/https://jl.ly/ICANN/weirds14.writeback
| url-status=live
}}</ref><ref>{{cite IETF
| title = Finding the Authoritative Registration Data (RDAP) Service
| rfc = 7484
| last1 = Blanchet
| first1 = Marc
|date=March 2015
| publisher = [[Organization:Internet Engineering Task Force|IETF]]
| accessdate = 2016-11-10
}}
</ref>  For number registries, ARIN set up a public RDAP service which also features a bootstrap URL, similar to what they do for WHOIS.<ref>{{cite web
| url=https://www.arin.net/resources/rdap.html
| title=The Registration Data Access Protocol (RDAP)
| date=2015-06-22
| publisher=ARIN
| accessdate=2016-11-10
| archive-date=2023-08-01
| archive-url=https://web.archive.org/web/20230801120619/https://www.arin.net/resources/rdap.html
| url-status=live
}}</ref>  For name registries, [[Organization:ICANN|ICANN]] requires RDAP compliance since 2013.<ref name="icann2013">{{cite web
 |url         = https://www.icann.org/resources/pages/approved-with-specs-2013-09-17-en
 |title       = 2013 Registrar Accreditation Agreement
 |publisher   = [[Organization:ICANN|ICANN]]
 |quote       = Following the publication by the IETF of a Proposed Standard, Draft Standard or Internet Standard and any revisions thereto (as specified in RFC 2026) relating to the web-based directory service as specified in the IETF Web Extensible Internet Registration Data Service working group, Registrar shall implement the directory service specified in any such standard (or any revision thereto) no later than 135 days after such implementation is requested by ICANN
 |accessdate  = 2016-11-10
 |url-status     = dead
 |archiveurl  = https://web.archive.org/web/20170607183437/https://www.icann.org/resources/pages/approved-with-specs-2013-09-17-en
 |archivedate = 2017-06-07
}}</ref><ref>{{cite web
| url=https://newgtlds.icann.org/en/applicants/agb/agreement-approved-02jul13-en.pdf
| title=New gTLD Agreement
| date=2013-07-02
| author=New gTLD Program Committee (NGPC)
| publisher=[[Organization:ICANN|ICANN]]
| quote=Registry Operator shall implement a new standard supporting access to domain name registration data (SAC 051) no later than one hundred thirty-five (135) days after it is requested by ICANN if: 1) the IETF produces a standard (i.e., it is published, at least, as a Proposed Standard RFC as specified in RFC 2026); and 2) its implementation is commercially reasonable in the context of the overall operation of the registry
| accessdate=2016-11-10
| archive-date=2022-09-01
| archive-url=https://web.archive.org/web/20220901042744/https://newgtlds.icann.org/en/applicants/agb/agreement-approved-02jul13-en.pdf
| url-status=live
}}</ref>

==Number resources==
RDAP databases for assigned IP numbers are maintained by five [[Organization:Regional Internet registry|regional Internet registries]]. ARIN maintains a bootstrap database.<ref>{{cite web |url=https://www.arin.net/resources/registry/whois/rdap/rdap.pdf |title=RDAP at ARIN |date=September 17, 2019 |access-date=June 8, 2020 |archive-date=November 28, 2022 |archive-url=https://web.archive.org/web/20221128172749/https://www.arin.net/resources/registry/whois/rdap/rdap.pdf |url-status=live }}</ref>  Thanks to the standard document format, tasks such as, for example, getting the abuse team address of a given IP number can be accomplished in a fully automated manner.<ref>{{cite web |title=abuserdap |url=https://savannah.nongnu.org/support/?110246 |access-date=2020-06-08 |archive-date=2022-12-25 |archive-url=https://web.archive.org/web/20221225032817/https://savannah.nongnu.org/support/?110246 |url-status=live }}</ref>

==Name resources==
RDAP databases for registered names are maintained after ICANN agreement.<ref name="icann2013"/>  Name resources are much slower, as the number of registries under ICANN is huge. In addition, as the [[General Data Protection Regulation|GDPR]] became enforceable, in May 2018, the problem of personal data divulged via WHOIS or RDAP slowed adoption further.<ref>{{cite web |title=Haunted by Europe's GDPR, ICANN sharpens wooden stake to finally slay the Whois vampire |author=Kieren McCarthy |date=October 23, 2019 |url=https://www.theregister.com/2019/10/23/icann_kills_whois/ |work=The Register |access-date=June 8, 2020 |archive-date=May 25, 2023 |archive-url=https://web.archive.org/web/20230525235553/https://www.theregister.com/2019/10/23/icann_kills_whois/ |url-status=live }}</ref> To solve the conflict between GDPR and ICANN policies ICANN published a temporary specification according to which all contact details need to be redacted for privacy reasons if they fall under the GDPR, unless the contact explicitly allows publication. This includes email addresses, however the registrar has to offer an anonymized [[Email address|email address]] or a web form to allow forwarding of information to contacts. The registry RDAP/WHOIS response has to contain a notice that these options to contact the contacts are only available in the registrar RDAP/WHOIS.<ref name=":0">{{Cite web |title=Temporary Specification for gTLD Registration Data – ICANN |url=https://www.icann.org/resources/pages/gtld-registration-data-specs-en/#appendixA |access-date=2023-04-08 |website=www.icann.org}}</ref>

To keep RDAP information accurate, registrars have to send a yearly Whois Data Reminder Policy (WDRP) notice to the registrant contact. This is commonly done via email containing all the RDAP information the registrar has and asking the registrant to update it immediately if it is incorrect, while at the same time reminding the registrant that incorrect RDAP information can lead to the deletion of the domain name.<ref>{{Cite web |title=Whois Data Reminder Policy – ICANN |url=https://www.icann.org/resources/pages/registrars/consensus-policies/wdrp-en |access-date=2023-04-08 |website=www.icann.org}}</ref> Additionally each registrar has to offer an abuse contact and after being informed about incorrect RDAP information has to make sure that it is corrected quickly or suspend the domain.<ref name="icann2013" />

== WHOIS replacement ==
On January 19, 2023 ICANN opened voting on a global amendment to all its registry and registrar agreements. In it they defined a RDAP Ramp-Up Period of 180 days starting with the effectiveness of this amendment. 360 days after this period is defined as the WHOIS Services Sunset Date, after which it is not a requirement for registries and registrars to offer a WHOIS service and instead only a RDAP service is required. All voting thresholds were met within the 60-day voting period and the amendment will be submitted to the ICANN Board for approval and implementation.<ref>{{Cite web |title=2023 Global Amendments to the Base gTLD Registry Agreement (RA), Specification 13, and 2013 Registrar Accreditation Agreement (RAA) – ICANN |url=https://www.icann.org/resources/pages/global-amendment-2023-en |access-date=2023-04-07 |website=www.icann.org |archive-date=2023-04-07 |archive-url=https://web.archive.org/web/20230407062429/https://www.icann.org/resources/pages/global-amendment-2023-en |url-status=live }}</ref>

== Query example ==
To query RDAP, there are several software and web clients including icann-rdap (reference implementation command-line client by ICANN), OpenRDAP (independent command-line client), and rdap.dev web client.

In certain jurisdictions, RDAP redacted contact information as required by regulations such as [[General Data Protection Regulation]] (GDPR). Contact information for RDAP may be accessed with Registration Data Directory Services (RDDS) such as ICANN Lookup.<ref name=":0" /><ref>{{Cite web |title=ICANN Lookup |url=https://lookup.icann.org/en/lookup |access-date=2025-06-04 |website=lookup.icann.org |archive-date=2025-05-31 |archive-url=https://web.archive.org/web/20250531085849/https://lookup.icann.org/en/lookup |url-status=live }}</ref> Non-public contact information can be requested with Registration Data Request Service (RDRS).<ref>{{Cite web |title=Home – Registration Data Request Service |url=https://rdrs.icann.org/ |access-date=2025-05-31 |website=rdrs.icann.org}}</ref>

Below is an example of RDAP data returned for an individual resource holder. This is the result of a RDAP query in raw format (using OpenRDAP client) for the website of ''[[Software:Final Fantasy XIV|Final Fantasy XIV]]'', with Markmonitor as registrar:<syntaxhighlight lang="doscon" highlight="1">
> rdap finalfantasyxiv.com
Domain:
  Domain Name: FINALFANTASYXIV.COM
  Handle: 19576356_DOMAIN_COM-VRSN
  Status: client delete prohibited
  Status: client transfer prohibited
  Status: client update prohibited
  Conformance: rdap_level_0
  Conformance: icann_rdap_technical_implementation_guide_0
  Conformance: icann_rdap_response_profile_0
  Notice:
    Title: Terms of Use
    Description: Service subject to Terms of Use.
    Link: https://www.verisign.com/domain-names/registration-data-access-protocol/terms-service/index.xhtml
  Notice:
    Title: Status Codes
    Description: For more information on domain status codes, please visit https://icann.org/epp
    Link: https://icann.org/epp
  Notice:
    Title: RDDS Inaccuracy Complaint Form
    Description: URL of the ICANN RDDS Inaccuracy Complaint Form: https://icann.org/wicf
    Link: https://icann.org/wicf
  Link: https://rdap.verisign.com/com/v1/domain/FINALFANTASYXIV.COM
  Link: https://rdap.markmonitor.com/rdap/domain/FINALFANTASYXIV.COM
  Event:
    Action: registration
    Date: 2000-02-10T15:58:28Z
  Event:
    Action: expiration
    Date: 2026-02-10T15:58:28Z
  Event:
    Action: last changed
    Date: 2024-02-09T05:41:13Z
  Event:
    Action: last update of RDAP database
    Date: 2025-05-31T07:42:09Z
  Secure DNS:
    Delegation Signed: false
  Entity:
    Handle: 292
    Public ID:
      Type: IANA Registrar ID
      Identifier: 292
    Role: registrar
    vCard version: 4.0
    vCard fn: MarkMonitor Inc.
    Entity:
      Role: abuse
      vCard version: 4.0
      vCard tel: tel:+1.2086851750
      vCard email: abusecomplaints@markmonitor.com
  Nameserver:
    Nameserver: A1-211.AKAM.NET
  Nameserver:
    Nameserver: A13-66.AKAM.NET
  Nameserver:
    Nameserver: A2-67.AKAM.NET
  Nameserver:
    Nameserver: A22-64.AKAM.NET
  Nameserver:
    Nameserver: A24-65.AKAM.NET
  Nameserver:
    Nameserver: A3-66.AKAM.NET
</syntaxhighlight>

== Extensions ==
The RDAP protocol allows for extensions and IANA is maintaining a list of known RDAP extensions. Some of these extensions are defined by RFCs, such as for sorting and paging, others are just for specific TLDs.<ref>{{Cite web |title=RDAP Extensions |url=https://www.iana.org/assignments/rdap-extensions/rdap-extensions.xhtml |access-date=2023-04-08 |website=www.iana.org}}</ref>

==Related standards==
* [https://www.rfc-editor.org/info/std95 STD 95]
* {{IETF RFC|7480|link=no}}, ''HTTP Usage in the Registration Data Access Protocol (RDAP)''
* {{IETF RFC|7481|link=no}}, ''Security Services for the Registration Data Access Protocol (RDAP)''
* {{IETF RFC|8056|link=no}}, ''Extensible Provisioning Protocol (EPP) and Registration Data Access Protocol (RDAP) Status Mapping''
* {{IETF RFC|9082|link=no}}, ''Registration Data Access Protocol (RDAP) Query Format''
* {{IETF RFC|9083|link=no}}, ''JSON Responses for the Registration Data Access Protocol (RDAP)''
* {{IETF RFC|9224|link=no}}, ''Finding the Authoritative Registration Data Access Protocol (RDAP) Service''
Additionally ICANN has created [https://www.icann.org/gtld-rdap-profile 2 standards] that need to be implemented by gTLD registries and registrars to have common output formats and require the implementation of some extensions.

=== Extensions ===

* {{IETF RFC|8977|link=no}}, ''Registration Data Access Protocol (RDAP) Query Parameters for Result Sorting and Paging''
* {{IETF RFC|8521|link=no}}, ''Registration Data Access Protocol (RDAP) Object Tagging''
* {{IETF RFC|8982|link=no}}, ''Registration Data Access Protocol (RDAP) Partial Response''
* {{IETF RFC|9537|link=no}}, ''Redacted Fields in the Registration Data Access Protocol (RDAP) Response''

== See also ==
* [[Domain name registry]]
* [[Domain name registrar]]
* [[Extensible Provisioning Protocol]]{{dash}}standard for changing the domain data that is displayed by RDAP

==References==
{{Reflist}}

== External links ==
* [https://data.iana.org/rdap/ IANA registry for RDAP services]
* [https://www.iana.org/assignments/rdap-extensions/rdap-extensions.xhtml IANA RDAP Extensions]
* [https://www.iana.org/assignments/rdap-json-values/rdap-json-values.xhtml IANA RDAP JSON Values]
* {{Github|icann/icann-rdap}}{{dash}}A command line RDAP client by [[Organization:ICANN|ICANN]]
* {{Github|openrdap/rdap}}{{dash}}An alternative command line RDAP client by OpenRDAP, written in [[Go (programming language)|Go]]
* [https://rdap.dev/ rdap.dev]{{dash}}A simplified web-based RDAP client
* [https://about.rdap.org/ rdap.org]{{dash}}An end point for RDAP queries
* [https://www.apnic.net/apnic-info/whois_search/about/rdap RDAP page at APNIC]
* [https://www.arin.net/resources/rdap.html RDAP page at ARIN]

[[Category:Internet protocols]]
[[Category:Internet Standards]]

{{Sourceattribution|Registration Data Access Protocol}}