Pubsub Social Feed

Pubsub Social Feed This specification defines a way of publishing social content over XMPP. 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). 0472 Experimental Standards Track Standards Council XMPP Core XMPP IM XEP-0060 RFC 4287 XEP-0277 psf Timothée Jaussoin edhelas@movim.eu edhelas@movim.eu https://edhelas.movim.eu 0.2.1 2025-10-13 jp

Clarify text in Reply-To section to show that the XMPP link is mandatory and that the HTTP link is optional.

0.2.0 2023-04-03 tj

Change the pubsub#type to be consistent with other XEPs
Add a Discovery section

0.1.1 2022-12-24 tj

Change the specified pubsub#type profiles to be more consistent
Rephrase some paragraphs
Fix examples formating

0.1.0 2022-12-13 XEP Editor (jsc) Accepted by vote of Council on 2022-10-19. 0.0.1 2022-09-26 tj Initial version.

Social Networking plaftorms are often built around the concept of feeds. XMPP offers, through Publish-Subscribe (XEP-0060) XEP-0060: Publish-Subscribe <https://xmpp.org/extensions/xep-0060.html>., a really generic way of Publishing and Subscribing elements on XMPP nodes. This extension defines a way to publish social content on Pubsub nodes using RFC 4287 RFC 4287: The Atom Syndication Format <http://tools.ietf.org/html/rfc4287>.

Social features in XMPP were historically built on the Microblogging Over XMPP (XEP-0277) XEP-0277: Microblogging over XMPP <https://xmpp.org/extensions/xep-0277.html>. specifications. However, in practice, Microblogging was not clearly defined in more common cases such as on generic Pubsub nodes and it was not easy to differentiate social nodes from the other ones. The current XEP defines a more generic way of handling Social Feeds on XMPP by declaring a secific pubsub#type for those Pubsub nodes and by keeping Microblogging Over XMPP (XEP-0277) XEP-0277: Microblogging over XMPP <https://xmpp.org/extensions/xep-0277.html>. as a subset of it.

Profile: Defined by a specific Pubsub type (pubsub#type) a profile is a Pubsub Social Feed with some constraints. See the Profiles section.

If an entity implements Pubsub Social Feed, it MUST specify the 'urn:xmpp:pubsub-social-feed:1' feature in its service discovery information features as specified in Service Discovery (XEP-0030) XEP-0030: Service Discovery <https://xmpp.org/extensions/xep-0030.html>. and the Entity Capabilities profile specified in Entity Capabilities (XEP-0115) XEP-0115: Entity Capabilities <https://xmpp.org/extensions/xep-0115.html>..

If the entity is also implementing specific profiles, it MUST expose the specific feature defined in the related Pubsub type.

... ... ]]>

A Pubsub Social Feed can be located on any Pubsub node on the XMPP network. Some specific use cases, such as the personal eventing (PEP) node Microblog is defined in the Profiles section.

The publication of a Post consist of a valid RFC 4287 RFC 4287: The Atom Syndication Format <http://tools.ietf.org/html/rfc4287>. entry embeded in a Publish-Subscribe (XEP-0060) XEP-0060: Publish-Subscribe <https://xmpp.org/extensions/xep-0060.html>. item.

The post content itself can be either text (content element without "type" attribute or with "type" attribute with "text" value) or XHTML ("content" element "type" attribute with "xhtml" value). If Romeo publishes XHTML content, his client MUST publish two "content" elements: a text one, and a XHTML one. For XHTML publishing, see Publish-Subscribe (XEP-0060) XEP-0060: Publish-Subscribe <https://xmpp.org/extensions/xep-0060.html>..

hanging out at the Café Napolitano tag:montague.lit,2008-05-08:posts-1cb57d9c-1c46-11dd-838c-001143d5d5db 2008-05-08T18:30:02Z 2008-05-08T18:30:02Z ]]>

Note: The "title" element is required to be included in an "atom:entry" element according to RFC 4287 RFC 4287: The Atom Syndication Format <http://tools.ietf.org/html/rfc4287>.. An implementation MAY provide also "atom:summary" and/or "atom:content" elements too if it needs.

It's possible to insert some rich content in the post. It can be some text formatting, images, etc. Only "xhtml" content type is supported for the moment by this document but possibly it will be extended later.

<div xmlns="http://www.w3.org/1999/xhtml"> <p>hanging out at the <strong>Café Napolitano</strong></p> </div> tag:montague.lit,2008-05-08:posts-1cb57d9c-1c46-11dd-838c-001143d5d5db 2008-05-08T18:30:02Z 2008-05-08T18:30:02Z CapuChat ]]>

Because Juliet is subscribed to some Romeo's family Pubsub service nodes. Romeo's XMPP server will send a Pubsub notification to Juliet. The notification can include an XMPP message body for backwards-compatibility with Jabber clients that are not pubsub-capable (see Message Body ).

hanging out at the Café Napolitano hanging out at the Café Napolitano tag:montague.lit,2008-05-08:posts-1cb57d9c-1c46-11dd-838c-001143d5d5db 2008-05-08T18:30:02Z 2008-05-08T18:30:02Z CapuChat ]]>

Note: these alternate links were not posted by the original client because some clients can't compute them themselves. These things SHOULD be inserted at server side though.

Anyone can publish a post in reply to Romeo's post. Here we assume that a reply comes from Benvolio.

Note: Inclusion of the "thr:in-reply-to" element defined in RFC 4685 RFC 4685: Atom Threading Extensions <http://tools.ietf.org/html/rfc4685>. indicates the post to which the user is replying. This reply MUST have at least one element pointing to the XMPP URI of the post replied to and MAY have a second one pointing to the HTTP URL for the post.

Note: The post can be a reply to more than the only one another.

Benvolio Montague xmpp:romeo@montague.lit @romeo cappuccino this late in the day? tag:montague.lit,2008-05-08:posts-c4145006-1c53-11dd-b2d5-000bcd82471e 2008-05-08T18:31:21Z 2008-05-08T18:31:21Z

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Assuming that Romeo has also subscribed to the same node he will receive the reply that Benvolio sent.

When Benvolio wants to repeat a Romeo's post, his client publishes the same post under a different name. But to be able to track the repeated post original author, Benvolio's client MAY use specific "atom:author" child node, "atom:name" and "atom:uri", containing, respectively, the name of the original post author, and his XMPP URI (JID).

The client SHOULD also put an "atom:link" element with "rel" attribute set to "via" and point it to the original post.

Romeo Montague xmpp:romeo@montague.lit hanging out at the Café Napolitano tag:montague.lit,2008-05-08:posts-1re57d3c-1q46-11dd-748r-024943d2d5rt 2008-05-08T18:30:02Z 2008-05-08T18:32:02Z ]]>

Thus, a different author JID value lets the client know the item has been repeated from another one.

It's also possible for Benvolio to add his own thougths to the repost. To do this he SHOULD wrap the original content in the "xhtml:blockquote" element and after it add his own content. Also, the client MAY post reply without quotation to the original thread to inform users about the repost.

There are two different things that carry a similar sense: the XMPP Pubsub Item ID and the "atom:id" element. This section is devoted to make a separation between them.

The pubsub Item ID MUST be used when linking to an entry with an XMPP channel (i.e. by including it in the URI with the "xmpp" schema). the Atom entry ID MUST be built according to RFC 4287 RFC 4287: The Atom Syndication Format <http://tools.ietf.org/html/rfc4287>. and used in aggregators with the aim of revealing of post duplicates, reposts, mentions, syndications, etc.

Note that the rules of comparing, building and security notes for "atom:id" are listed in the RFC 4287 RFC 4287: The Atom Syndication Format <http://tools.ietf.org/html/rfc4287>..

Depending on service policies and the value of the "pubsub#include_body" node configuration option, Pubsub Social Feed notifications SHOULD include a message "body" element for backwards-compatibility with Jabber clients that are not pubsub-capable. It is RECOMMENDED for the XML character value of the "body" element to be the same as that of the "atom:title" child of the "atom:entry".

Juliet may want to know which places are Romeo's notices related to. That's why Romeo's client MAY geotag microblog entries, using the User Geolocation (XEP-0080) XEP-0080: User Geolocation <https://xmpp.org/extensions/xep-0080.html>. protocol for storing geolocation information.

Romeo's client MUST create a "geoloc" element, with the User Geolocation (XEP-0080) XEP-0080: User Geolocation <https://xmpp.org/extensions/xep-0080.html>. reference namespace: "http://jabber.org/protocol/geoloc".

Romeo Montague xmpp:romeo@montague.lit Is lost in the forest. Need help! tag:montague.lit,2008-05-08:posts-1zr23z8a-3g12-34fh-750b-120867gjc1sqh 2008-05-08T18:43:01Z 2008-05-08T18:43:01Z 48.171761 -3.3667986 France FR Brittany ]]>

Pubsub Social feeds are specified under profiles. Those profiles are constraints applied to nodes and defined by a specific Pubsub type (see Publish-Subscribe (XEP-0060) XEP-0060: Publish-Subscribe <https://xmpp.org/extensions/xep-0060.html>.#registrar-formtypes-metadata)

All the profiles MUST base their default configuration on the Base profile .

This profile is specified by the Pubsub type "urn:xmpp:pubsub-social-feed:1" and define a generic Pubsub Social Feed that can be hosted on any Pubsub service node or Personal Eventing Protocol (XEP-0163) XEP-0163: Personal Eventing Protocol <https://xmpp.org/extensions/xep-0163.html>. node.

Those restrictions MUST be used by all the other profiles defined bellow and in other XEPs based on Pubsub Social Feed.

The "pubsub#notify_retract" MUST be set to "true" to provide clients the ability to track if some items were retracted and reflect such changes in the UI correctly.
The "pubsub#max_items" MUST be set to the "max" value, as defined in the Publish-Subscribe (XEP-0060) XEP-0060: Publish-Subscribe <https://xmpp.org/extensions/xep-0060.html>..
The "pubsub#persist_items" MUST be set to "true".
The "pubsub#send_last_published_item" SHOULD be set to "never".
The "pubsub#deliver_payloads" SHOULD be set to "false". The social content can be quite large so it is advised to let the clients to manually query the content if it is not already cached.

This profile is defined by the Pubsub type "urn:xmpp:microblog:0" as defined in Microblogging Over XMPP (XEP-0277) XEP-0277: Microblogging over XMPP <https://xmpp.org/extensions/xep-0277.html>. and MUST be created and configured under the PEP "urn:xmpp:microblog:0" node.

This profile is defined by the Pubsub type "urn:xmpp:pubsub-social-feed:gallery:1" and can be hosted on any Pubsub service.

All the items published in a gallery node MUST only have at least one attached picture. This picture MUST be of type "enclosure" as specified in RFC 4287 RFC 4287: The Atom Syndication Format <http://tools.ietf.org/html/rfc4287>..

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There are no security features or concerns related to this proposal.

This document requires no interaction with the Internet Assigned Numbers Authority (IANA) 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/>..

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/>. is requested to issue an initial namespace of "urn:xmpp:pubsub-social-feed:1" and "urn:xmpp:pubsub-social-feed:gallery:1".

This specification re-uses the schema for the Atom content format, i.e., the 'http://www.w3.org/2005/Atom' namespace (see RFC 4287 RFC 4287: The Atom Syndication Format <http://tools.ietf.org/html/rfc4287>. ).