XEP-0256: Last Activity in Presence

NOTICE: This document is currently within Last Call or under consideration by the XMPP Council for advancement to the next stage in the XSF standards process.

Table of Contents

1. Use Case

Last Activity [1] defines a method for determining the last time that an XMPP entity was active. This document specifies that an online client MAY include last activity information when sending presence updates. The prototypical use case is including the idle time when automatically setting the user's <show/> value to "away" or "xa" (extended away). For example, consider a user who has configured her client to automatically change her presence to "away" after 10 minutes of inactivity. The client could include an iq:last flag to specify how long the user has been idle.

Example 1. Last Indication in Auto-Away

<presence from='juliet@capulet.com/balcony'>
  <show>away</show>
  <query xmlns='jabber:iq:last' seconds='600'/>
</presence>
  

If one of the user's contacts receives that presence notification with delayed delivery (see Delayed Delivery [2]) on login in response to a presence probe as described in XMPP IM [3], the contact will then know how long the user has been idle (i.e., the number of seconds since the delayed delivery timestamp, plus the iq:last seconds). Thus the contact does not need to send an iq:last query.

Example 2. Last Indication in Auto-Away With Delayed Delivery

<presence from='juliet@capulet.com/balcony' to='romeo@montague.net'>
  <show>away</show>
  <query xmlns='jabber:iq:last' seconds='600'/>
  <delay xmlns='urn:xmpp:delay'
     from='capulet.com'
     stamp='2002-09-10T23:41:07Z'/>
</presence>
  

2. Security Considerations

Including a last activity notation in presence notifications can enable those who receive such notifications to determine exactly when a user has stopped interacting with his or her XMPP client, but this information is in essence already available if the user publishes timely presence updates. Therefore, this specification introduces no new vulnerabilities.

3. IANA Considerations

This document requires no interaction with the Internet Assigned Numbers Authority (IANA) [4].

4. XMPP Registrar Considerations

This document requires no interaction with the XMPP Registrar [5].

Appendices

Appendix A: Document Information

Series: XEP
Number: 0256
Publisher: XMPP Standards Foundation
Status: Proposed
Type: Standards Track
Version: 0.1
Last Updated: 2008-11-26
Approving Body: XMPP Council
Dependencies: XMPP Core, XMPP IM, XEP-0012
Supersedes: None
Superseded By: None
Short Name: N/A
Source Control: HTML  RSS

Appendix B: Author Information

Appendix C: Legal Notices

Appendix D: Relation to XMPP

The Extensible Messaging and Presence Protocol (XMPP) is defined in the XMPP Core (RFC 3920) and XMPP IM (RFC 3921) 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

Appendix H: Revision History

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