When the service hosting a Multi-User Chat (XEP-0045) [1] room shuts down, e.g., for a software upgrade, it informs XMPP clients by sending them an "unavailable" presence with a dedicated status code (332). It is then up to the client to attempt to re-join the room, either periodically, or via a user-triggered action.
This specification describes a mechanism for the MUC service to inform XMPP clients that the MUC service is now operational again, and that rooms are ready to be re-joined. This removes the need for periodic re-tries, reducing client-generated traffic. It also prevents situations where a user expects to still "be in a room" and receive its live messages when their client actually expects a manual action from them.
When a MUC service wants to inform that it is back online, it sends XMPP clients a Direct MUC Invitations (XEP-0249) [2] with a dedicated "ready" element in the message stanza.
<message from='rooms.example.org'
to='user@example2.org'>
<x xmlns='jabber:x:conference'
jid='room@rooms.example.org'
reason='The MUC service is back up and you are a member of this room. Please join!'/>
<ready xmlns='urn:xmpp:muc-ready:0' />
</message>
Supporting clients should attempt re-joining the MUC at this stage. Non-supporting XMPP clients treat this like any other invitation, so this automatically acts a fallback for them.
MUC services supporting this feature SHOULD advertise 'urn:xmpp:muc-ready:0' in the disco#features of their rooms. Clients can tweak or disable their periodic rejoin attempt behaviour based on this feature's availability for a given room or MUC service.
Clients supporting this feature SHOULD NOT display such invitations in their user interface.
This specification is not intended to replace MUC Self-Ping (Schrödinger's Chat) (XEP-0410) [3]; it solves a different practical issue encountered in deployments of Multi-User Chat (XEP-0045) [1].
The protocol described in this document is not necessary for local users of MUC services tightly coupled to their "host" XMPP server. Under such circumstances, the issue addressed by this specification can be tackled in a custom and possibly more efficient way, eg, by persisting occupants across restarts and not informing clients at all.
None.
None.
This specification could be abused to trap clients into joining rooms that the user does not intend to be an occupant of.
After receiving a ready payload, clients MUST ensure that being an occupant of the room is compatible the user's intent, i.e., that the user had previously intended to join this room and did not explicitly left it since.
None.
This specification defines a new namespace: 'urn:xmpp:muc-ready'
<?xml version='1.0' encoding='UTF-8'?>
<xs:schema
xmlns:xs='http://www.w3.org/2001/XMLSchema'
targetNamespace='urn:xmpp:muc-ready:0'
xmlns='urn:xmpp:muc-ready:0'
elementFormDefault='qualified'>
<xs:annotation>
<xs:documentation>
This schema defines the 'ready' element used to signal that a MUC
service is operational and rooms are ready to be rejoined.
</xs:documentation>
</xs:annotation>
<xs:element name='ready' />
</xs:schema>
This document in other formats: XML PDF
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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 <standards@xmpp.org> discussion list.
Discussion on other xmpp.org discussion lists might also be appropriate; see <https://xmpp.org/community/> for a complete list.
Errata can be sent to <editor@xmpp.org>.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.
1. XEP-0045: Multi-User Chat <https://xmpp.org/extensions/xep-0045.html>.
2. XEP-0249: Direct MUC Invitations <https://xmpp.org/extensions/xep-0249.html>.
3. XEP-0410: MUC Self-Ping (Schrödinger's Chat) <https://xmpp.org/extensions/xep-0410.html>.
Note: Older versions of this specification might be available at https://xmpp.org/extensions/attic/
First draft.
@report{cedilnik2026xepxxxx,
title = {MUC is ready},
author = {Cedilnik, Nicolas},
type = {XEP},
number = {xxxx},
version = {0.0.1},
institution = {XMPP Standards Foundation},
url = {https://xmpp.org/extensions/xep-xxxx.html},
date = {2026-09-29/2026-09-29},
}END