Message Archive Management: Trim Command This specification describes how a client can request "trimming" of an archive This XMPP Extension Protocol is copyright © 1999 – 2024 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. ## 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 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. 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). xxxx ProtoXEP Standards Track Standards Council mamtrim Matthew Wild mwild1@gmail.com me@matthewwild.co.uk 0.0.1 2026-03-31 mjw

The XMPP ecosystem has standardized around Message Archive Management (XEP-0313) XEP-0313: Message Archive Management <https://xmpp.org/extensions/xep-0313.html>. for incoming and outgoing message synchronization. Messages are stored in the archive for a period of time, so they can be fetched by all receiving devices. However, the retention of messages is typically controlled purely by the configuration of the server, typically as a fixed period of time.

This specification defines a protocol that allows a client to request "trimming" of an archive’s contents on-demand.

This protocol is designed for on-demand use cases, such as when a user explicitly requests purging all messages from the archive. It is not designed for automated client-side enforcement of a general retention policy (e.g. implementing a user preference that the archive should contain no more than 30 days of messages). Such a feature would be far better implemented with a server-side enforcement approach, which would allow all clients to discover and agree on a policy, and function even when clients are offline.

Servers supporting and allowing this operation MUST advertise the service discovery feature 'urn:xmpp:mamtrim:0'.

If a deployment is configured to disallow trimming (e.g. because of legal or audit requirements to preserve messages), the feature SHOULD NOT be advertised to clients.

If supported by the server, clients may request for an archive to be 'trimmed' - this means immediate removal of all archived stanzas up to, and including, a specified UID. To ensure archive integrity, it is not possible to remove items from the "middle" or end of an archive.

To request trimming, a client sends an <iq/> of type 'set' to the archive, containing a <trim/> element qualified by the 'urn:xmpp:mamtrim:0' namespace.

An empty <trim/> element requests the deletion of all currently-archived stanzas. Alternatively, the element may contain a single <id/> element which, as character data, specifies the archive UID of an item to trim, along with all older items.

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On success, the server returns an empty iq result:

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Alternatively, the server returns an appropriate error.

Servers MUST only allow trimming requests from archive owners. For per-user archives, this means the account owner. For group chat archives, this typically means the owner(s) of the group chat.

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This specification defines the following XML namespace:

  • urn:xmpp:mamtrim:0

Upon advancement of this specification from a status of Experimental to a status of Draft, the XMPP Registrar 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/>. shall add the foregoing namespace to the registry located at <https://xmpp.org/registrar/namespaces.html>, as described in Section 4 of XMPP Registrar Function (XEP-0053) XEP-0053: XMPP Registrar Function <https://xmpp.org/extensions/xep-0053.html>..

There were some options for how to specify the cut-off point for trimming:

Both of these can be inclusive (remove items including any with the specified timestamp or ID) or exclusive (keep the referenced item, but remove earlier items).

The protocol uses IDs, because it is more precise than timestamps, and the trim operation is inclusive of the referenced ID. This is because a common operation is expected to be "trim everything I have received", and this allows a client to pass the latest ID they have received. This prevents a race condition in "delete everything" where an incoming message could arrive after the client sent the request.

TDB.