%ents; ]>
Message Archive Management Preferences This document defines a protocol to control a user's archiving preferences. &LEGALNOTICE; 0441 Experimental Standards Track Standards Council XMPP Core XEP-0030 XEP-0313 mamprefs &mwild; &ksmith; 0.2.0 2020-08-25 XEP Editor (jsc) Accepted by vote of Council on 2020-08-19. 0.1 2020-04-03 mw

Split from XEP-0313, no protocol changes

This specification describes a protocol for a server to allow a client to configure a user's message archiving preferences. It is intended to be used in conjunction with &xep0313;.

After observing XEP-0313 usage in the wild, it became apparent that preferences were not often used, and can interfere with clients that use the archive for synchronization of messages received by the user while disconnected. Therefore it is not actively encouraged for an implementation/deployment to offer this functionality.

Depending on implementation and deployment policies, a server MAY allow the user to have control over the server's archiving behaviour. This specification defines a basic protocol for this, and also allows a server to offer more advanced configuration to a user.

If the server supports and allows configuration of the preferences described below then it SHOULD implement the protocol defined in this section. This allows the user to retrieve and configure the following preferences:

  • A list of JIDs that should always have messages to/from archived in the user's store.
  • A list of JIDs that should never have messages to/from archived in the user's store.
  • The default archiving behaviour (for JIDs in neither of the above lists).
]]>

The server replies with the user's current archiving preferences. The <prefs> element MUST be present and contain the current default archiving policy. The <always> and <never> MUST also be present (even if empty), and contain a list of JIDs enclosed in <jid> elements.

]]>

It is also possible that the server may respond with a stanza error, for example the standard 'feature-not-implemented' (server does not support MAM configuration) defined in &rfc6120;.

]]>

To update the preferences, the client can simply send an iq stanza with a type of 'set':

romeo@montague.lit montague@montague.lit ]]>

The server then replies with the applied preferences (note that due to server policies these MAY be different to the preferences sent by the client):

romeo@montague.lit montague@montague.lit ]]>

It is also possible for the server to respond with an error, for example (but not limited to) the standard 'feature-not-implemented' (the server does not support configuration of preferences), 'forbidden' (the user is not authorized to change their preferences) or 'not-allowed' (the server generally does not allow changing of configuration preferences).

If a JID is in neither the 'always archive' nor the 'never archive' list then whether it is archived depends on this setting, the default.

The 'default' attribute of the 'prefs' element MUST be one of the following values:

  • 'always' - all messages are archived by default.
  • 'never' - messages are never archived by default.
  • 'roster' - messages are archived only if the contact's bare JID is in the user's roster.

The <prefs/> element MAY contain an <always/> child element. If present, it contains a list of <jid/> elements, each containing a single JID. The server SHOULD archive any messages to/from this JID (see 'JID matching').

If missing from the preferences, <always/> SHOULD be assumed by the server to be an empty list.

The <prefs/> element MAY contain an <never/> child element. If present, it contains a list of <jid/> elements, each containing a single JID. The server SHOULD NOT archive any messages to/from this JID (see 'JID matching').

If missing from the preferences, <never/> SHOULD be assumed by the server to be an empty list.

In addition to this protocol, a server MAY offer more advanced configuration to the user through &xep0050;. Such an interface might, for example, allow the user to configure what types of messages to store, or set a limit on how long messages should remain in the archive.

If supported, such a configuration command SHOULD be presented on the well-defined command node of "urn:xmpp:mam#configure".

When comparing the message target JID against the user's roster (ie. when the user has set default='roster') the comparison MUST use the bare target JID (that is, stripped of any resource).

For matching against entries in either the 'allow' or 'never' lists, for each listed JID:

  • If the listed JID contains a resource, compare against the target JID as-is.
  • If the listed JID has no resource (it is a bare JID) then first strip any resource from the target JID prior to comparison.

For outgoing messages, the server MUST use the value of the 'to' attribute as the target JID.

For incoming messages, the server MUST use the value of the 'from' attribute as the target JID.