XEP-0423: XMPP Compliance Suites 2020

This document defines XMPP application categories for different use cases (Core, Web, IM, and Mobile), and specifies the required XEPs that client and server software needs to implement for compliance with the use cases.
Georg Lukas
© 1999 – 2020 XMPP Standards Foundation. SEE LEGAL NOTICES.


NOTICE: The protocol defined herein is a Draft Standard of the XMPP Standards Foundation. Implementations are encouraged and the protocol is appropriate for deployment in production systems, but some changes to the protocol are possible before it becomes a Final Standard.
Standards Track
1.0.0 (2019-11-07)
Document Lifecycle
  1. Experimental
  2. Proposed
  3. Draft
  4. Final

1. Introduction

There is a growing number of XMPP Extension Protocols (XEPs) that provide different building blocks for XMPP-based applications. XMPP software developers are confronted with the challenge of finding the right combination of XEPs for a given application profile. Users need a way to compare applications without resorting to comparing for individual XEP numbers.

This document defines XMPP application Categories based on typical use cases (Core, Web, IM, Mobile) and Levels (Core, Advanced) based on functionality in the respective category. For each combination of those, the required XEPs are referenced. As the protocol landscape changes over time, this document is updated roughly once a year.

For developers, this document provides guidance on which specifications they need to consider when implementing an application of a certain kind. By completing a compliance test or performing a self-assessment, they can advertise their implementation as compliant with a given Category and Level.

For users, this provides an easy way to compare implementations based on their respective advertised compliance levels and year.

Unless explicitly noted, support for the listed specifications is REQUIRED for compliance purposes. A feature is considered supported if all comma separated feature providers listed in the "Providers" column are implemented (unless otherwise noted).

1.1 Changes since 2019

The following changes were made to the Compliance Suites since XMPP Compliance Suites 2019 (XEP-0412) [15]:

2. Compliance Categories

2.1 Core Compliance Suite

Table 1: XMPP Core Compliance Levels
Feature Core Server Core Client Advanced Server Advanced Client Providers
Core features RFC 6120 [16] [17]
TLS RFC 7590 [19]
Direct TLS ✓ [20] SRV records for XMPP over TLS (XEP-0368) [21]
Feature discovery Service Discovery (XEP-0030) [22]
Feature broadcasts Entity Capabilities (XEP-0115) [23]
Server Extensibility N/A N/A Jabber Component Protocol (XEP-0114) [24]
Event publishing ✓ [25] Personal Eventing Protocol (XEP-0163) [26]

2.2 Web Compliance Suite

To be considered XMPP web compliant, all features from the core compliance category must be met, as well as all features in this suite.

Table 2: XMPP Web Compliance Levels
Feature Core Server Core Client Advanced Server Advanced Client Providers
Web Connection Mechanisms ✓ [27] ✓ [28] ✓ [27] ✓ [28] RFC 7395 [29], XMPP Over BOSH (XEP-0206) [30] (See also: BOSH (XEP-0124) [31])
Connection Mechanism Discovery N/A Discovering Alternative XMPP Connection Methods (XEP-0156) [7]

2.3 IM Compliance Suite

To be considered XMPP IM compliant, all features from the core compliance category must be met, as well as all features in this suite.

Table 3: XMPP IM Compliance Levels
Feature Core Server Core Client Advanced Server Advanced Client Providers
Core features RFC 6121 [32]
The /me Command N/A N/A The /me Command (XEP-0245) [10]
User Avatars N/A N/A ✓ [33] User Avatar (XEP-0084) [34]
User Avatar Compatibility ✓ [33] User Avatar to vCard-Based Avatars Conversion (XEP-0398) [35], vCard-Based Avatars (XEP-0153) [36]
vcard-temp vcard-temp (XEP-0054) [37]
Outbound Message Synchronization Message Carbons (XEP-0280) [38]
User Blocking Blocking Command (XEP-0191) [39]
Group Chat ✓ [27] ✓ [40] ✓ [27] ✓ [40] Multi-User Chat (XEP-0045) [41] [42], Direct MUC Invitations (XEP-0249) [44]
Advanced Group Chat ✓ [27] Bookmark Storage (XEP-0048) [45], Message Archive Management (XEP-0313) [46] [47], MUC Self-Ping (Schrödinger's Chat) (XEP-0410) [48], Bookmarks Conversion (XEP-0411) [14]
Persistent Storage of Private Data via PubSub ✓ [27] Best Practices for Persistent Storage of Private Data via Publish-Subscribe (XEP-0223) [49]
Private XML Storage ✓ [27] Private XML Storage (XEP-0049) [50] (only recommended for legacy bookmarks support)
Stream Management Stream Management (XEP-0198) [51]
Message Acknowledgements N/A N/A Message Delivery Receipts (XEP-0184) [52]
History Storage / Retrieval Message Archive Management (XEP-0313) [46]
Chat States N/A N/A Chat State Notifications (XEP-0085) [53]
Message Correction N/A N/A Last Message Correction (XEP-0308) [54]
File Upload ✓ [27] ✓ [27] HTTP File Upload (XEP-0363) [11]
Direct File Transfer N/A N/A Jingle File Transfer (XEP-0234) [12], Jingle In-Band Bytestreams Transport Method (XEP-0261) [13]

Further specifications of note, which are not required for compliance:

2.4 Mobile Compliance Suite

To be considered XMPP mobile compliant, all features from the core compliance category must be met, as well as all features in this suite.

Table 4: XMPP Mobile Compliance Levels
Feature Core Server Core Client Advanced Server Advanced Client Providers
Stream Management Stream Management (XEP-0198) [51]
Client State Indication Client State Indication (XEP-0352) [55]
Third Party Push Notifications ✓ [27] ✓ [56] Push Notifications (XEP-0357) [57]

Further specifications of note, which are not required for compliance:

3. Future Development

This section outlines the protocol specifications that are relevant for developers, but are not ready yet to be required for Compliance. Developers are encouraged to implement those and to share their experience and feedback.

4. Implementation Notes

Some of the protocol specifications referenced herein have their own dependencies; developers need to consult the relevant specifications for further information.

5. Security Considerations

This document introduces no additional security considerations above and beyond those defined in the documents on which it depends.

6. IANA Considerations

This document requires no interaction with the Internet Assigned Numbers Authority (IANA) [68].

7. XMPP Registrar Considerations

This document requires no interaction with the XMPP Registrar [69].

8. Acknowledgements

The author would like to thank Guus der Kinderen, Dele Olajide, Marc Laporte, Dave Cridland, Daniel Gultsch, Florian Schmaus, Tobias Markmann, and Jonas Schäfer for their suggestions.


Appendix A: Document Information

XMPP Standards Foundation
Standards Track
Last Updated
Approving Body
XMPP Council
RFC 6120, RFC 6121, RFC 7395, RFC 7590, RFC 7622, XEP-0030, XEP-0045, XEP-0048, XEP-0049, XEP-0084, XEP-0085, XEP-0114, XEP-0115, XEP-0124, XEP-0163, XEP-0191, XEP-0198, XEP-0206, XEP-0223, XEP-0249, XEP-0280, XEP-0313, XEP-0352, XEP-0368
Superseded By
Short Name
Source Control

This document in other formats: XML  PDF

Appendix B: Author Information

Georg Lukas


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.

Disclaimer of Warranty

## 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. ##

Limitation of Liability

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.

IPR Conformance

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).

Visual Presentation

The HTML representation (you are looking at) is maintained by the XSF. It is based on the YAML CSS Framework, which is licensed under the terms of the CC-BY-SA 2.0 license.

Appendix D: Relation to XMPP

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.

Appendix E: Discussion Venue

The primary venue for discussion of XMPP Extension Protocols is the <standards@xmpp.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 <xsf-ietf@xmpp.org> list might also be appropriate.

Errata can be sent to <editor@xmpp.org>.

Appendix F: Requirements Conformance

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".

Appendix G: Notes

1. XEP-0066: Out of Band Data <https://xmpp.org/extensions/xep-0066.html>.

2. XEP-0385: Stateless Inline Media Sharing (SIMS) <https://xmpp.org/extensions/xep-0385.html>.

3. XEP-0392: Consistent Color Generation <https://xmpp.org/extensions/xep-0392.html>.

4. XEP-0077: In-Band Registration <https://xmpp.org/extensions/xep-0077.html>.

5. XEP-0157: Contact Addresses for XMPP Services <https://xmpp.org/extensions/xep-0157.html>.

6. XEP-0286: Mobile Considerations on LTE Networks <https://xmpp.org/extensions/xep-0286.html>.

7. XEP-0156: Discovering Alternative XMPP Connection Methods <https://xmpp.org/extensions/xep-0156.html>.

8. XEP-0333: Chat Markers <https://xmpp.org/extensions/xep-0333.html>.

9. XEP-0420: Stanza Content Encryption <https://xmpp.org/extensions/xep-0420.html>.

10. XEP-0245: The /me Command <https://xmpp.org/extensions/xep-0245.html>.

11. XEP-0363: HTTP File Upload <https://xmpp.org/extensions/xep-0363.html>.

12. XEP-0234: Jingle File Transfer <https://xmpp.org/extensions/xep-0234.html>.

13. XEP-0261: Jingle In-Band Bytestreams Transport Method <https://xmpp.org/extensions/xep-0261.html>.

14. XEP-0411: Bookmarks Conversion <https://xmpp.org/extensions/xep-0411.html>.

15. XEP-0412: XMPP Compliance Suites 2019 <https://xmpp.org/extensions/xep-0412.html>.

16. RFC 6120: Extensible Messaging and Presence Protocol (XMPP): Core <http://tools.ietf.org/html/rfc6120>.

17. RFC 7622 [18] is not listed due to the unclear interoperability impact of using PRECIS and Stringprep in the same ecosystem.

18. RFC 7622: Extensible Messaging and Presence Protocol (XMPP): Address Format <http://tools.ietf.org/html/rfc7622>.

19. RFC 7590: Use of Transport Layer Security (TLS) in the Extensible Messaging and Presence Protocol (XMPP) <http://tools.ietf.org/html/rfc7590>.

20. Server support of XEP-0368 means having the ability to accept direct TLS connections.

21. XEP-0368: SRV records for XMPP over TLS <https://xmpp.org/extensions/xep-0368.html>.

22. XEP-0030: Service Discovery <https://xmpp.org/extensions/xep-0030.html>.

23. XEP-0115: Entity Capabilities <https://xmpp.org/extensions/xep-0115.html>.

24. XEP-0114: Jabber Component Protocol <https://xmpp.org/extensions/xep-0114.html>.

25. While 'Personal Eventing Protocol' does not require all the features of 'Publish-Subscribe' to be available on the users' JIDs, and nor does this suite, it is desirable for this to be the case and it is expected that this will a requirement of future Compliance Suites.

26. XEP-0163: Personal Eventing Protocol <https://xmpp.org/extensions/xep-0163.html>.

27. Support can be enabled via an external component or an internal server module/plugin. If claiming compliance using such an addition, the necessary components/modules/plugins MUST be detailed.

28. Only one of the recommended providers must be implemented for compliance.

29. RFC 7395: An Extensible Messaging and Presence Protocol (XMPP) Subprotocol for WebSocket <http://tools.ietf.org/html/rfc7395>.

30. XEP-0206: XMPP Over BOSH <https://xmpp.org/extensions/xep-0206.html>.

31. XEP-0124: Bidirectional-streams Over Synchronous HTTP <https://xmpp.org/extensions/xep-0124.html>.

32. RFC 6121: Extensible Messaging and Presence Protocol (XMPP): Instant Messaging and Presence <http://tools.ietf.org/html/rfc6121>.

33. Not required for command line or terminal based interfaces.

34. XEP-0084: User Avatar <https://xmpp.org/extensions/xep-0084.html>.

35. XEP-0398: User Avatar to vCard-Based Avatars Conversion <https://xmpp.org/extensions/xep-0398.html>.

36. XEP-0153: vCard-Based Avatars <https://xmpp.org/extensions/xep-0153.html>.

37. XEP-0054: vcard-temp <https://xmpp.org/extensions/xep-0054.html>.

38. XEP-0280: Message Carbons <https://xmpp.org/extensions/xep-0280.html>.

39. XEP-0191: Blocking Command <https://xmpp.org/extensions/xep-0191.html>.

40. Support for the Entity Use Cases and Occupant Use Cases is REQUIRED; support for the remaining use cases is RECOMMENDED.

41. XEP-0045: Multi-User Chat <https://xmpp.org/extensions/xep-0045.html>.

42. Implementations should take note that future versions of these compliance suites may rely on Mediated Information eXchange (MIX) (XEP-0369) [43] instead.

43. XEP-0369: Mediated Information eXchange (MIX) <https://xmpp.org/extensions/xep-0369.html>.

44. XEP-0249: Direct MUC Invitations <https://xmpp.org/extensions/xep-0249.html>.

45. XEP-0048: Bookmark Storage <https://xmpp.org/extensions/xep-0048.html>.

46. XEP-0313: Message Archive Management <https://xmpp.org/extensions/xep-0313.html>.

47. Support for requesting history from a MUC archive as opposed to from the user's account.

48. XEP-0410: MUC Self-Ping (Schrödinger's Chat) <https://xmpp.org/extensions/xep-0410.html>.

49. XEP-0223: Best Practices for Persistent Storage of Private Data via Publish-Subscribe <https://xmpp.org/extensions/xep-0223.html>.

50. XEP-0049: Private XML Storage <https://xmpp.org/extensions/xep-0049.html>.

51. XEP-0198: Stream Management <https://xmpp.org/extensions/xep-0198.html>.

52. XEP-0184: Message Delivery Receipts <https://xmpp.org/extensions/xep-0184.html>.

53. XEP-0085: Chat State Notifications <https://xmpp.org/extensions/xep-0085.html>.

54. XEP-0308: Last Message Correction <https://xmpp.org/extensions/xep-0308.html>.

55. XEP-0352: Client State Indication <https://xmpp.org/extensions/xep-0352.html>.

56. Only on platforms that disallow long-lasting background connections.

57. XEP-0357: Push Notifications <https://xmpp.org/extensions/xep-0357.html>.

58. XEP-0386: Bind 2.0 <https://xmpp.org/extensions/xep-0386.html>.

59. XEP-0409: IM Routing-NG <https://xmpp.org/extensions/xep-0409.html>.

60. XEP-0397: Instant Stream Resumption <https://xmpp.org/extensions/xep-0397.html>.

61. XEP-0380: Explicit Message Encryption <https://xmpp.org/extensions/xep-0380.html>.

62. XEP-0384: OMEMO Encryption <https://xmpp.org/extensions/xep-0384.html>.

63. XEP-0396: Jingle Encrypted Transports - OMEMO <https://xmpp.org/extensions/xep-0396.html>.

64. XEP-0374: OpenPGP for XMPP Instant Messaging <https://xmpp.org/extensions/xep-0374.html>.

65. XEP-0402: PEP Native Bookmarks <https://xmpp.org/extensions/xep-0402.html>.

66. XEP-0225: Component Connections <https://xmpp.org/extensions/xep-0225.html>.

67. XEP-0390: Entity Capabilities 2.0 <https://xmpp.org/extensions/xep-0390.html>.

68. 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/>.

69. 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/>.

Appendix H: Revision History

Note: Older versions of this specification might be available at http://xmpp.org/extensions/attic/

  1. Version 1.0.0 (2019-11-07)

    Update to Draft as per council vote on 2019/11/07.

  2. Version 0.3.0 (2019-11-06)

    Update with LC feedback

  3. Version 0.2.0 (2019-10-15)

    Update before LC:

  4. Version 0.1.0 (2019-09-11)
    Accepted by vote of Council on 2019-09-11.
    XEP Editor (jsc)
  5. Version 0.0.1 (2018-12-08)

    First draft based on XEP-0412. Non-editorial Changes:


Appendix I: Bib(La)TeX Entry

  title = {XMPP Compliance Suites 2020},
  author = {Lukas, Georg},
  type = {XEP},
  number = {0423},
  version = {1.0.0},
  institution = {XMPP Standards Foundation},
  url = {https://xmpp.org/extensions/xep-0423.html},
  date = {2018-12-08/2019-11-07},