RFC 5122  defines a Uniform Resource Identifier (URI) scheme for use in forming URIs and Internationalized Resource Identifiers (IRIs)  from the addresses of entities that can communicate using the Extensible Messaging and Presence Protocol (see XMPP Core ). Such identifiers enable identification of and interaction with XMPP entities by non-native applications such as databases and web browsers.
However, RFC 5122 intentionally leaves the potential values of the query component open-ended, does not provide a list of common "actions" for queries (e.g., send message or join chatroom), and does not specify recommended "key-value" pairs to be used in the context of such actions. Therefore, this document defines a registry of such actions and key-value pairs (to be maintained by the XMPP Registrar ) and specifies a set of initial values for that registry.
This document is organized as follows:
Note: The format of the XMPP URI scheme, including the format of the query component, is fully specified and formally defined in RFC 5122; this document does not modify the xmpp URI scheme in any way and assumes that the reader is familiar with all aspects of RFC 5122.
This document inherits terminology from RFC 3986 , RFC 3987 , and RFC 5122.
The range of actions that might be triggered by interaction with an XMPP entity by means of an XMPP IRI/URI is potentially as wide as the range of extensions to XMPP. This document does not seek to exhaustively define all such potential actions. However, the following actions might be of general interest:
For each such action, the XMPP Registrar maintains a RECOMMENDED "querytype" (this can be thought of as an action name or "verb"; see RFC 5122 for syntax and semantics) as well as an OPTIONAL list of keys to be used in key-value pairs if appropriate.
The querytypes and key-value pairs related to RFC 3920 and RFC 3921 are defined herein; the querytypes and key-value pairs related to protocols defined in the XMPP Standards Foundation's XEP series are defined in the relevant XMPP Extension Protocol specifications.
It may desirable for an XMPP IRI/URI to trigger a specialized interface for sending an XMPP message stanza. The RECOMMENDED querytype for this action is "message". If no key-value pair is provided, interacting with an XMPP IRI/URI that contains a querytype of "message" SHOULD trigger an interface that enables the user to input the text of an XMPP message and other relevant parameters (e.g., a message subject or XHTML-IM (XEP-0071)  markup).
A query component whose querytype is "message" MAY specify various key-value pairs. The following three keys are associated with the child elements of the <message/> stanza specified in the XML schema for the 'jabber:client' namespace as defined in XMPP IM :
In addition, the following three keys are associated with the attributes of the <message/> stanza specified in the XML schema for the 'jabber:client' namespace (the 'to' attribute is unnecessary, since it is provided by the XMPP address included in the IRI/URI):
Other keys MAY be registered with the XMPP Registrar but are not specified herein.
The 'jabber:iq:roster' namespace provides a mechanism for managing an XMPP roster (also called a "contact list"). This namespace is defined in RFC 3921. The following actions are defined.
The registered querytype for adding items to the roster or editing items in the roster is "roster" (effectively there is no difference between adding and editing). An XMPP IRI/URI containing a "roster" querytype MAY also include at most one "name" key whose value maps to the 'name' attribute of the <item/> element within the 'jabber:iq:roster' namespace, and MAY contain one "group" key whose value maps to the character data of the <group/> child element of <item/>.
Note: Methods (if any) for including more than one group are yet to be determined.
The 'jabber:iq:roster' namespace includes a mechanism for removing an XMPP roster item. The registered querytype for removing an item from the roster is "remove".
Closely coupled with roster management is presence subscription management. In XMPP, subscription management is handled via special values of the <presence/> stanza, as described in RFC 3921. The following actions are defined
When an entity subscribes to another entity's presence by means of an XMPP IRI/URI, the invoked XMPP application SHOULD first send a roster add stanza as shown below (this is consistent with the recommendations in RFC 3921).
XMPP includes a mechanism for unsubscribing from an entity. The registered querytype for doing so is "unsubscribe".
Internationalization considerations for XMPP IRIs/URIs are specified in RFC 5122; the reader is referred to that document for a complete discussion of the relevant issues.
Localization of application-specific data presented to a human user (e.g., as encapsulated in key-value pairs) is the responsibility of the "using protocol".
Security considerations for XMPP IRIs/URIs are specified in RFC 5122.
Completion of some of the actions defined herein will cause changes to an entity's account, subscriptions to information, registration with services, communication with other entities, completion of ad-hoc commands, and the like. Naturally, such changes, information, services, and communications are potentially undesirable (e.g., joining a chatroom whose discussion topic is not of interest to, or even patently offensive to, the joining user). The invoked application SHOULD appropriately warn a human user regarding the potential consequences of the action about to be completed.
This document requires no interaction with the Internet Assigned Numbers Authority (IANA) . If in the future the IANA should wish to maintain a registry of XMPP URI/IRI query components, the XMPP Registrar will cooperate with efforts to migrate the registry from the XMPP Registrar to the IANA.
The XMPP Registrar maintains a registry of querytype values (see <https://xmpp.org/registrar/querytypes.html>).
In order to submit new values to this registry, the registrant shall define an XML fragment of the following form and either include it in the relevant XMPP Extension Protocol or send it to the email address <email@example.com>:
Note: Within the <querytype/> element, the <keys/> child element is OPTIONAL; within any given <key/> element, the <values/> child element is also OPTIONAL.
The registrant may register more than one querytype at a time, each contained in a separate <querytype/> element.
The following submission registers parameters related to the XMPP RFCs. For submissions related to XMPP extensions, refer to the relevant XMPP Extension Protocol specifications.
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This XMPP Extension Protocol is copyright © 1999 – 2020 by the XMPP Standards Foundation (XSF).
Permission is hereby granted, free of charge, to any person obtaining a copy of this specification (the "Specification"), to make use of the Specification without restriction, including without limitation the rights to implement the Specification in a software program, deploy the Specification in a network service, and copy, modify, merge, publish, translate, distribute, sublicense, or sell copies of the Specification, and to permit persons to whom the Specification is furnished to do so, subject to the condition that the foregoing copyright notice and this permission notice shall be included in all copies or substantial portions of the Specification. Unless separate permission is granted, modified works that are redistributed shall not contain misleading information regarding the authors, title, number, or publisher of the Specification, and shall not claim endorsement of the modified works by the authors, any organization or project to which the authors belong, or the XMPP Standards Foundation.
## NOTE WELL: This Specification is provided on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, express or implied, including, without limitation, any warranties or conditions of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. ##
In no event and under no legal theory, whether in tort (including negligence), contract, or otherwise, unless required by applicable law (such as deliberate and grossly negligent acts) or agreed to in writing, shall the XMPP Standards Foundation or any author of this Specification be liable for damages, including any direct, indirect, special, incidental, or consequential damages of any character arising from, out of, or in connection with the Specification or the implementation, deployment, or other use of the Specification (including but not limited to damages for loss of goodwill, work stoppage, computer failure or malfunction, or any and all other commercial damages or losses), even if the XMPP Standards Foundation or such author has been advised of the possibility of such damages.
This XMPP Extension Protocol has been contributed in full conformance with the XSF's Intellectual Property Rights Policy (a copy of which can be found at <https://xmpp.org/about/xsf/ipr-policy> or obtained by writing to XMPP Standards Foundation, P.O. Box 787, Parker, CO 80134 USA).
The Extensible Messaging and Presence Protocol (XMPP) is defined in the XMPP Core (RFC 6120) and XMPP IM (RFC 6121) specifications contributed by the XMPP Standards Foundation to the Internet Standards Process, which is managed by the Internet Engineering Task Force in accordance with RFC 2026. Any protocol defined in this document has been developed outside the Internet Standards Process and is to be understood as an extension to XMPP rather than as an evolution, development, or modification of XMPP itself.
The primary venue for discussion of XMPP Extension Protocols is the <firstname.lastname@example.org> discussion list.
Discussion on other xmpp.org discussion lists might also be appropriate; see <http://xmpp.org/about/discuss.shtml> for a complete list.
Given that this XMPP Extension Protocol normatively references IETF technologies, discussion on the <email@example.com> list might also be appropriate.
Errata can be sent to <firstname.lastname@example.org>.
The following requirements keywords as used in this document are to be interpreted as described in RFC 2119: "MUST", "SHALL", "REQUIRED"; "MUST NOT", "SHALL NOT"; "SHOULD", "RECOMMENDED"; "SHOULD NOT", "NOT RECOMMENDED"; "MAY", "OPTIONAL".
2. On the difference between IRIs and URIs, see RFC 3987.
4. The XMPP Registrar maintains a list of reserved protocol namespaces as well as registries of parameters used in the context of XMPP extension protocols approved by the XMPP Standards Foundation. For further information, see <https://xmpp.org/registrar/>.
16. The Internet Assigned Numbers Authority (IANA) is the central coordinator for the assignment of unique parameter values for Internet protocols, such as port numbers and URI schemes. For further information, see <http://www.iana.org/>.
Note: Older versions of this specification might be available at http://xmpp.org/extensions/attic/
Removed probe action.
Added actions for roster removal, presence unsubscription, and cancellation of registration; moved querytypes related to XMPP extensions from this document to the relevant XMPP Extension Protocol specifications.
Per a vote of the Jabber Council, advanced to Active.
Added actions for ad-hoc commands and vCard retrieval; clarified some explanatory text.
Updated to reflect draft-saintandre-xmpp-iri-03; modified file transfer query operations to handle both send and receive use cases.
Updated to reflect draft-saintandre-xmpp-iri-01; added file querytype for file transfer.
Updated to reflect draft-saintandre-xmpp-iri-00.
Updated to reflect draft-saintandre-xmpp-uri-08 and subsequent XMPP WG discussion; removed use cases for editing roster items, removing roster items, leaving chatrooms, unsubscribing, and unregistering (these make more sense from within a dedicated client); added use case for simultaneously joining a room and inviting other participants; further specified security considerations.
Updated to reflect draft-saintandre-xmpp-uri-07; specified Service Discovery usage.