XEP-xxxx: MAM Subscriptions

Allow entities to subscribe to MAM (XEP-0313) archives in order to keep updated and engaged in a converstation.
Florian Schmaus
© 1999 – 2020 XMPP Standards Foundation. SEE LEGAL NOTICES.


WARNING: This document has not yet been accepted for consideration or approved in any official manner by the XMPP Standards Foundation, and this document is not yet an XMPP Extension Protocol (XEP). If this document is accepted as a XEP by the XMPP Council, it will be published at <http://xmpp.org/extensions/> and announced on the <standards@xmpp.org> mailing list.
Standards Track
0.0.1 (2015-05-14)
Document Lifecycle
  1. Experimental
  2. Proposed
  3. Draft
  4. Final

1. Introduction

This extension of Message Archive Management (XEP-0313) [1] allows XMPP clients to subscribe to MAM archives and to carbon copy/fork messages to all connected resources of the receiving XMPP entity, removing the need for Message Carbons (XEP-0280) [2]. After a client is subscribed to an archive, it will receive notifications when a new <message/> was added to the archive, which include the added <message/>.

2. Discovering Support

An entity advertises support for this protocol by including the 'urn:xmpp:mam:sub:0' feature in its service discovery information features as specified in Service Discovery (XEP-0030) [3].

Example 1. Client requests information about its own server
<iq xmlns='jabber:client'
  <query xmlns='http://jabber.org/protocol/disco#info'/>
Example 2. Server responds with "MAM subscritions" feature
  <iq xmlns='jabber:client'
  <query xmlns='http://jabber.org/protocol/disco#info'>
    <feature var='urn:xmpp:mam:sub:0'/>

3. Subscription Management

3.1 Subscribing

When a client wants to receive notifications about messages being added to a MAM archive, it does subscripe to the archive by sending an <iq/> of type 'set' containing a child element <subscribe/> qualified by the 'urn:xmpp:mam:sub:0' namespace.

Example 3. Client subscribes to the MAM archive
<iq xmlns='jabber:client'
  <subscribe xmlns='urn:xmpp:mam:sub:0'/>

The server will respond with an <iq/>-result when the client was successfully subscribed to the archive.

Example 4. Server acknowledges subscription
<iq xmlns='jabber:client'

3.2 Unsubscribing

At any point, clients can unsubscribe from the MAM archive by sending an <iq/> of type 'set' containing a child element <unsubscribe/> qualified by the 'urn:xmpp:mam:sub:0' namespace.

Example 5. Client unsubscribes from the MAM archive
<iq xmlns='jabber:client'
  <unsubscribe xmlns='urn:xmpp:mam:sub:0'/>

The server will respond with an <iq/>-result when the client was successfully unsubscribed from the archive.

Example 6. Server acknowledges subscription removal
<iq xmlns='jabber:client'

4. Receiving MAM notifications

Every time a message is added to the MAM archive, a MAM notification MUST be sent to entities subscribed to the archive, regardless of the message type or content. Note that this implies that clients, which are subscribed to the MAM archive and are also the final recipient of a <message/>, will receive such a <message/> twice: In the first place because of the stanza routing rules defined in RFC 6120 [4] and RFC 6121 [5], and also as content of the resulting MAM archive notification.

Each notification is send as <message/> of type 'normal' from the clients bare JID containing a <mamsub/> extension, which SHOULD contain the a <message-id/> element as defined in XEP-MID (TODO XEP number) and MUST contain exaclty one <forwarded> element as defined in Stanza Forwarding (XEP-0297) [6] containing the original message.

The value of the 'id' attribute found in the <message-id/> element is the unique and stable ID of the message, which unambigously identifies the message withing the MAM archive.

Example 7. Server sends MAM notification
<message xmlns='jabber:client'
  <mamsub xmlns='urn:xmpp:mam:sub:0'>
    <messsage-id xmlns='urn:xmpp:mid:0' id='de305d54-75b4-431b-adb2-eb6b9e546013'/>
    <forwarded xmlns='urn:xmpp:forward:0'>
      <message xmlns='jabber:client'
        <body>What man art thou that, thus bescreen'd in night, so stumblest on my counsel?</body>

5. Security Considerations

As the notifications defined in this document contain full <message/> stanzas, it is important for implementations to take care that the receiving entities of such notifications are allowed to see that information. This usually means they receiving entities share the same bare JID with the intended receiver. (TODO wording)

6. IANA Considerations

This document requires no interaction with the Internet Assigned Numbers Authority (IANA) [7].

7. XMPP Registrar Considerations

7.1 Protocol Namespaces

The XMPP Registrar [8] includes 'urn:xmpp:mam:sub:0' in its registry of protocol namespaces (see <https://xmpp.org/registrar/namespaces.html>).

7.2 Protocol Versioning

If the protocol defined in this specification undergoes a revision that is not fully backwards-compatible with an older version, the XMPP Registrar shall increment the protocol version number found at the end of the XML namespaces defined herein, as described in Section 4 of XEP-0053.

8. XML Schema

REQUIRED for protocol specifications.


Appendix A: Document Information

XMPP Standards Foundation
Standards Track
Last Updated
Approving Body
XMPP Council
XMPP Core, XEP-0030, XEP-0297, XEP-0313, XEP-MID (TODO)
Superseded By
Short Name
NOT_YET_ASSIGNED (suggested: 'mamsub')

This document in other formats: XML  PDF

Appendix B: Author Information

Florian Schmaus


This XMPP Extension Protocol is copyright (c) 1999 - 2014 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. In no event shall the XMPP Standards Foundation or the authors of this Specification be liable for any claim, damages, or other liability, whether in an action of contract, tort, or otherwise, arising from, out of, or in connection with the Specification or the implementation, deployment, or other use of the Specification. ##

Limitation of Liability

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IPR Conformance

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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.

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

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

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

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

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

6. XEP-0297: Stanza Forwarding <https://xmpp.org/extensions/xep-0297.html>.

7. 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/>.

8. 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 0.0.1 (2015-05-14)

    First draft.