Jul 15 – 21, 2023
University of Macedonia (UoM)
Europe/Athens timezone

Matrix and ActivityPub for everything

Jul 16, 2023, 12:25 PM
room 2

room 2

Conference Talk Frameworks and Toolkits


Alexey Rusakov (Matrix.org) Carl Schwan (KDE) Tobias Fella


In this talk, we will explore the Matrix and ActivityPub standards and how they can be used outside of their primary purpose, by powering everything from comment systems to calendar invitations, coordinating itineraries, and synchronizing data.


Matrix and ActivityPub are protocols intended mainly for Real-Time Messaging and Social-Network applications. Both work in a federated way, giving users the ability to choose the instance they use while being able to communicate with anyone on a different instance.

While both of these protcols are widely used today (matrix in the form of various clients and ActivityPub mostly by powering Mastodon), they can be useful for many more use-cases.

Any system that could benefit from synchronizing information between different users (or different devices of a single user!) could profit from integrating with either of them.

In this talk, we want to give a broad overview over the functionality provided by Matrix and ActivityPub, where they are now, and what we can expect from them in the future. We then want to explore some possible use-cases for them outside of what exists today.

In the KDE ecosystem, we have a NeoChat, a Matrix client built on libQuotient, and Tokodon, a Mastodon client.
By using either libQuotient, or parts of Tokodon's backend, more applications could quickly develop integration with these ecosystems. We want to use this talk as an introduction to a BoF where we want to explore this further.


Alexey is the maintainer of libQuotient, a library for building matrix applications built using Qt, and Quaternion, a Matrix client built on top of it. He is also a member of the Matrix Spec Core Team, the body governing the development of the Matrix specification.

Carl is a KDE developer, working, among others, on NeoChat, KDE's Matrix Client, and Tokodon, KDE's mastodon client.

Tobias is a KDE developer working mostly on NeoChat and libQuotient, where he is currently implementing end-to-end encryption.

Primary authors

Presentation materials