General

Last week, we shared details about ongoing attacks on Matrix. Over the past week or so, we’ve tested some new tooling to help combat abuse on matrix.org.

If you run your own Synapse server and your users are present in the Foundation’s community rooms, you can benefit from this tooling by installing an experimental Synapse module. You can find the code and installation instructions here. We’re deliberately taking the bold step of announcing a tool and also announcing its deprecation in the same post. This is experimental work, and we are iterating quickly. We expect to have an implementation in Synapse shortly, so the module will be discontinued around May 21.

🔗What are policy servers?

Policy servers are an overlapping layer of protection with existing community moderation tools such as Draupnir, Mjolnir and Meowlnir. Rooms can opt-in to this new layer of protection, recommending that servers participating in the room check events with a given policy server before they are sent to their clients. The policy server will pass an opinion on each event, recommending servers in the room to accept the event, or to reject it. For people in the room, this should be effectively invisible. Events which pass the check will be shown as normal, while ones which don’t will never make it through to their clients.

The Foundation intends to offer a policy server to room admins, but we hope that in time other providers will offer alternative policy servers. The Foundation is already running an experimental implementation for some of its public rooms, which we will release once we have confidence in the approach. We also expect that for many rooms, a policy server isn’t necessary, or spends most of the time in a low-power or disabled state. Element and the Foundation are exploring these ideas over the coming weeks.

🔗Get involved

MSC4284 is now open to support this work. Please get involved in the MSC, and help us to improve this addition to safety tooling for the network. We’d especially like to see implementations for non-Synapse servers.

Folks who run communities on Matrix who would like to test our policy server, reach out to us at [email protected], using the subject policy-server-alpha.

After a successful 2024 with a lot to be proud of, and a Matrix Conference that brought our community together to celebrate 10 years of Matrix, we step into 2025 with a light budget and a mighty team poised to make the most of it!

Our priorities remain to make Matrix a safer network, keep growing the ecosystem, make the most of our Governing Board, and drive a fruitful and friendly collaboration across all actors.

However, whether we will manage to get there is not fully a given.

Continue reading…

As of yesterday, Matrix.org is using a curated room directory. We’re paring down the rooms that are visible to a collection of moderated spaces and rooms. This is an intervention against abuse on the network, and a continuation of work that we started in May 2024.

In early 2024 we noticed an uptick in users creating rooms to share harmful content. After a few iterations to identify these rooms and shut them down, we realised we needed to change tack. We landed on first reducing the discoverability and reach of these rooms - after all, no other encrypted messaging platform provides a room directory service, and unfortunately it can clearly serve as a mechanism to amplify abuse. So, in May 2024 we froze the room directory. Matrix.org users were no longer permitted to publish their rooms to the room directory. We also did some manual intervention to reduce the size of the directory as a whole, and remove harmful rooms ahead of blocking them.

This intervention aimed at three targets:

• Lowering the risk of users discovering harmful rooms
• Stopping the amplification of abuse via an under-moderated room directory
• Reducing the risk for Matrix client developers for app store reviews

In truth, the way room discovery works needs some care and attention. Room directories pre-date Spaces, and some of the assumptions don't hold up to real world use. From the freeze, and the months since, we've learned a few things. First, the criteria for appearing in a server's room directory in the first place is way too broad. Also, abuse doesn't happen in a vacuum. Some rooms that were fine at the time of the freeze, are not now. There are a few different causes for that, including room moderators losing interest. We looked for criteria to give us the confidence in removing the freeze, and we hit all the edge cases that make safety work so challenging.

Those lessons led to a realization. One of the values of the Foundation is pragmatism, rather than perfection. We weren't living up to that value, so we decided to change. The plan became simpler: move to a curated list of rooms, with a rough first pass of criteria for inclusion. In parallel, we asked the Governing Board to come up with a process for adding rooms in the future, and to refine the criteria. We've completed the first part of the plan today.

🔗What comes next

There's plenty of scope for refinement here, and we've identified a few places where we can get started:

• The Governing Board will publish criteria for inclusion in the Matrix.org room directory. They'll also tell you how you can suggest rooms and spaces for the directory.
• We're going to recommend safer defaults. Servers should not let users publish rooms unless there are appropriate filtering and moderation tools in place, and people to wield them. For instance, Element have made this change to Synapse in PR18175
• We're exploring discovery as a topic, including removing the room directory API. One promising idea is to use Spaces: servers could publish a default space, with rooms curated by the server admin. Our recent post includes some other projects we have in this area: https://matrix.org/blog/2025/02/building-a-safer-matrix/

🔗FAQs

What criteria did you use for this first pass?
We used a rough rubric: Is the room already in the room directory, and does the Foundation already protect the room with the Matrix.org Mjolnir? From there, we extended to well-moderated rooms and spaces that fit one of the following:

• Matrix client and server implementations (e.g. FluffyChat, Dendrite)
• Matrix community projects (e.g. t2bot.io)
• Matrix homeserver spaces with a solid safety record (e.g. tchncs.de, envs.net)

Why isn't the Office of the Foundation in the directory?
It didn't exist before May 2024, so the Office has never been in the directory. We're going to add it in the next few days, with a couple of other examples that fit our rough rubric.

How do I add my room/space to the list?
At the moment, you can't. The Governing Board will publish the criteria and the flow for getting on the list.

What do I do if I find a harmful room in the current directory?
You shouldn't, but if a room does have harmful content, check out How you can help

N.B. this post is also available in German below.

🔗Introduction

Right now, the world needs secure communication more than ever. Waves of security breaches such as the “Salt Typhoon” compromise of the telephone network’s wiretap system have led the FBI to advise US citizens to switch to end-to-end-encrypted communication. Geopolitical shifts painfully highlight the importance of privacy-preserving communication for vulnerable minorities, in fear of being profiled or targeted. Meanwhile the International Rules-Based Order is at risk like never before.

We built Matrix to provide secure communication for everyone - to be the missing communication layer of the Open Web. This is not hyperbole: Matrix is literally layered on top of the Web - letting organisations run their own servers while communicating in a wider network. As a result, Matrix is “decentralised”: the people who built Matrix do not control those servers; they are controlled by the admins who run them - and just as the Web will outlive Tim Berners-Lee, Matrix will outlive us.

Matrix itself is a protocol (like email), defined as an open standard maintained by The Matrix.org Foundation C.I.C - a UK non-profit incorporated in 2018 to act as the steward of the protocol; to coordinate the protocol’s evolution and to work on keeping the public Matrix network safe. The Foundation is funded by donations from its members (both individuals and organisations), and also organises the Matrix.org homeserver instance used by many as their initial home on the network.

Much like the Web, Matrix is a powerful technology available to the general public, which can be used both for good and evil.

The vast majority of Matrix’s use is constructive: enabling collaboration for open source software communities such as Mozilla, KDE, GNOME, Fedora, Ubuntu, Debian, and thousands of smaller projects; providing a secure space for vulnerable user groups; secure collaboration throughout academia (particularly in DACH); protecting healthcare communication in Germany; protecting national communication in France, Germany, Sweden and Switzerland; and providing secure communication for NATO, the US DoD and Ukraine. You can see the scope and caliber of the Matrix ecosystem from the talks at The Matrix Conference in September.

However, precisely the same capabilities which benefit privacy-sensitive organisations mean that a small proportion of members of the public will try to abuse the system.

We have been painfully aware of the risk of abuse since the outset of the project, and rather than abdicating responsibility in the way that many encrypted messengers do, we’ve worked steadily at addressing it. In the early days, even before we saw significant abuse, this meant speculating on approaches to combat it (e.g. our FOSDEM 2017 talk and subsequent 2020 blog post proposing decentralised reputation; now recognisable in Bluesky’s successful Ozone anti-abuse system and composable moderation). However, these posts were future-facing at the time - and these days we have different, concrete anti-abuse efforts in place.

In this post, we’d like to explain where things are at, and how they will continue to improve in future.

🔗What we do today

The largest use of our funding as a Foundation is spent on our full-time Safety team, and we expanded that commitment at the end of 2024. On a daily basis, the team triage, investigate, identify and remove harmful content from the Matrix.org server, and remove users who share that material. They also build tooling to prevent, detect and remove harmful content, and to protect the people who work on user reports and investigations.

The humans who make up the Foundation Trust & Safety team are dedicated professionals who put their own mental health and happiness in jeopardy every day, reviewing harmful content added by people abusing the service we provide. Their work exposes them to harms including child sexual exploitation and abuse (CSEA), terrorist content, non-consensual intimate imagery (NCII), harassment, hate, deepfakes, fraud, misinformation, illegal pornography, drugs, firearms, spam, suicide, human trafficking and more. It’s a laundry list of the worst that humanity has to offer. The grim reality is that all online services have to deal with these problems, and to balance the work to detect and remove that content with the rights of their users. We’re committed to that work, and to supporting the Trust & Safety team to the best of our ability — we are very grateful for their sacrifice.

Continue reading…

Hi all,

Once again we celebrate the end of another year with the traditional Matrix Holiday Special! (see also 2023, 2022, 2021, 2020, 2019, 2018, 2017, 2016 and 2015 just in case you missed them).

This year, it is an incredible relief to be able to sit down and write an update which is overwhelmingly positive - in stark contrast to the rather mixed bags of 2022 and 2023. This is not to say that things are perfect: most notably, The Matrix.org Foundation has not yet hit its funding goals, and urgently needs more organisations who depend on Matrix to join as members in order to be financially sustainable. However, in terms of progress of Matrix towards outperforming the centralised alternatives; growth of the ecosystem; the success of the first ever Matrix Conference; we couldn’t be happier - and hopefully the more Matrix matures, the more folks will want to join the Foundation to help fund it.

So, precisely why are we feeling so happy right now?

Continue reading…

The Matrix.org Foundation has been made aware that an international investigative operation took down a service called MATRIX which was used by a cybercriminal network, which has no relationship with the Matrix.org Foundation or the Matrix protocol itself.

The takedown site has a Matrix-the-movie branding, which is a probable source of confusion. The app showcased doesn’t look like any of the Matrix clients we’re aware of.

In a statement to the Matrix.org Foundation, Europol confirmed that the MATRIX cybercriminal network and the Matrix protocol are entirely unrelated. Europol states:

The Matrix protocol (matrix.org) is by no means connected to the Matrix secured communication service that was targeted in OTF Continental.

A statement from the Dutch police confirms that this is unrelated: "Matrix is ​​also the name of a company and communications protocol of the same name, which has nothing to do with the crypto communications service Matrix."

Hi all,

Since the outset of Matrix, our aim has always been to provide a protocol that lets you build open, decentralised, secure communication apps which outperform the mainstream centralised alternatives. It’s been a twisty journey - first focusing on making Matrix work at all (back in 2014), and then getting it out of beta with Matrix 1.0 in 2019, and now focusing on making Matrix fast, usable and mainstream-ready with Matrix 2.0.

Meanwhile, the pendulum of decentralisation continues to accelerate in our direction. Our friends at Bluesky have shown that it’s possible to build decentralised social apps which are mainstream friendly enough for Presidents to recommend them; Elon continues to destroy Twitter and showcase the importance of decentralisation to everyone, and even Meta is dabbling in decentralised social media (and decentralised communication!)

So, where does Matrix sit in all this? Well, in order to make the transition to mainstream, we’ve been beavering away to implement four main pillars in Matrix 2.0:

1. Instant login, instant launch, and instant sync (aka Simplified Sliding Sync, MSC4186)
2. Next Generation Auth (aka Native OIDC, MSC3861)
3. Native Matrix Encrypted Multiparty VoIP/Video (aka MatrixRTC, MSC4143)
4. Invisible Encryption (MSC4153 & friends).

Continue reading…

Hi all,

2023 has been a pivotal year for Matrix, with huge changes landing both organisationally and technically to prepare the protocol for future generations. The ecosystem has once again gone from strength to strength, with active users (based on Synapse opt-in phone-home reporting) doubling across the public network, and more projects building on Matrix than we can count (look out for the “This Year in Matrix” community wrap-up blog post) - and more organisations than we can track joining Matrix for all their secure decentralised communication needs.

On the governance side, we are in an incredibly exciting new era with Josh joining the Matrix.org Foundation as its first ever Managing Director (and employee!), with a mandate to cement sustainable funding for Matrix as an independent foundation, governed by the forthcoming elected open Governance Board. Now, Matrix needs funding more than ever - but rather than turning the entirety of this post into a plea for donations, I’m going to let Josh fly the flag in the coming weeks. Meanwhile, if you want Matrix to keep existing (especially if you’re an organisation who builds on Matrix) please join the Foundation and donate.

On the technical side: the theme of the year has been one of focus: extreme, overdue, focus.

Continue reading…

Last week, Element informed the Foundation that it will be forking Synapse and Dendrite. We’re sharing this news with you, along with some background, and our thoughts about this development.

We’ll do our best to answer your questions, address concerns, and find a path forward together.

Continue reading…

TL;DR: If you want to play with a shiny new Matrix 2.0 client, head over to Element X.

Matrix has been going for over 9 years now, providing an open standard for secure, decentralised communication for the open Web - and it’s been quite the journey to get to where we are today. Right now, according to Synapse’s opt-in usage reporting, in total there are 111,873,374 matrix IDs on the public network, spanning 17,289,201 rooms, spread over 64,256 servers. This is just scratching the surface, given we estimate that 66% of servers in the public network don’t report stats, and there are many enormous private networks of servers too. We’ve come a long way from creating Matrix HQ as the first ever room on today’s public network, back on Aug 13th 2014 :)

Meanwhile, the Matrix ecosystem has continued to grow unbelievably - with huge numbers of independent clients, bots and bridges maturing into ecosystems of their own, whole new companies forming around the protocol, and organisations ranging from open source projects to governments, NGOs and Fortune 100 companies adopting Matrix as a way to run their own secure, decentralised, standards-based self-sovereign communication.

The world needs Matrix more than ever. Every day the importance of decentralisation is more painfully obvious, as we concretely see the terrifying risks of centralised Internet services - whether that’s through corporate takeover, state censorship, blanket surveillance, Internet shutdowns, surveillance capitalism, or the spectre of gigantic centralised data breaches. It’s been amazing to see the world pivot in favour of decentralisation over the time we’ve been building Matrix, and our mission has never been more important.

On one hand it feels we’re creeping ever closer to that goal of providing the missing communication layer for the open Web. The European Union’s Digital Markets Act (DMA) is a huge step in that direction - regulation that mandates that if the large centralised messaging providers are to operate in the EU, they must interoperate. We’ve been busy working away to make this a reality, including participating in the IETF for the first time as part of the MIMI working group - demonstrating concretely how (for instance) Android Messages could natively speak Matrix in order to interoperate with other services, while preserving end-to-end encryption.

On the other hand, Matrix has often got stuck in focusing on solving the Hard Problems of decentralisation, decentralised end-to-end encryption, and the logistical complexities of supporting a massive heterogeneous public communication network and its surrounding heterogeneous ecosystem. It’s fair to say that in the early days our focus was on making something that worked at all - and then later, we shifted to focusing on something that worked and scaled correctly… but we hadn’t managed to focus on ensuring that Matrix provides the building blocks necessary to create blazingly fast, hyper-efficient communication apps which has potential to outperform the centralised mainstream messaging services…

…until now!

🔗Matrix 2.0

Back at FOSDEM we announced the idea of Matrix 2.0 - a series of huge step changes in terms of Matrix’s usability and performance, made up of Sliding Sync (instant login/launch/sync), Native OIDC (industry-standard authentication), Native Group VoIP (end-to-end encrypted large-scale voice & video conferencing) and Faster Joins (lazy-loading room state when your server joins a room).

Now, we’re excited to announce that as of today everyone can start playing with these Matrix 2.0 features. There’s still some work to bring them formally into the specification, but we’re putting it out there for folks to experience right now. Developers: watch this space for updates on the spec front.

Practically speaking, this means there are now implementations of the four pillars of Matrix 2.0 available today which you can use to power a daily-driver Matrix 2.0 client. The work here has been driven primarily by Element, using their new Element X client as the test-bed for the new Matrix 2.0 functionality and to prove that the new APIs are informed by real-world usage and can concretely demonstrably create an app which begins to outperform iMessage, WhatsApp and Telegram in terms of usability and performance… all while benefiting from being 100% built on Matrix.

🔗matrix-rust-sdk and Element X

The mission of Matrix 2.0 has been to provide a huge step forwards in real-world performance, usability and stability - and that means using a real client codebase as a guinea pig to ensure the new protocol is fit for purpose. matrix-rust-sdk has been the main vehicle for this, with Element X as the app primarily driving the new features (although other clients built on matrix-rust-sdk such as Fractal 5 can then automatically benefit from the work should they wish).

To see what all the fuss is about, your best bet is probably to head over to the Element X launch blog post and read all about it! But from the Matrix perspective, this is a flag day in terms of the existence of a Matrix client which empirically outperforms the mainstream clients both in terms of usability and performance: it shows that Matrix is indeed viable to power communication for billions of users, should we get the chance.

From a client perspective: this has meant implementing Sliding Sync (MSC3575) in matrix-rust-sdk - and then creating the entirely new matrix-sdk-ui crate in order to expose higher level APIs to help apps efficiently drive their UI, without each app having to keep reinventing the wheel and risking getting it wrong. The new UI crate gives APIs for efficiently managing a lazy-loaded room list, lazy-loaded room timelines (including edits, reactions, aggregations, redactions etc), and even when the app should show a sync spinner or not. As a result, the vast majority of the heavy lifting can be handled in matrix-rust-sdk, ensuring that the app layer can focus on UI rather than Matrix guts - and performance improvements (e.g. roomlist caching and timeline caching) can all be handled in one place to the benefit of all clients using the SDK.

This is a huge breakthrough relative to the old days of Matrix where each client would have no choice but burn significant amounts of time hand-carving its own timeline and encryption glue logic (although of course clients are still very welcome to do so if they wish!) - but for those wanting higher-level building blocks, matrix-rust-sdk now provides an excellent basis for experimenting with Matrix 2.0 clients. It’s worth noting that the library is still evolving fast, though, and many APIs are not long-term stable. Both the Sliding Sync API and the UI crates are still subject to significant change, and while the crypto crate and its underlying vodozemac E2EE implementation is pretty stable, features such as E2EE Backup are still being added to the top-level matrix-rust-sdk (and thence Element X).

In order to hook matrix-rust-sdk up to Element X, the Element team ended up contributing cancellable async bindings to uniffi, Mozilla’s language binding generator, so you can now call matrix-rust-sdk directly from Swift, Kotlin and (in theory) other languages, complete with beautifully simple async/await non-blocking semantics. This looks to be a pretty awesome stack for doing modern cross-platform development - so even if you have a project which isn’t natively in Rust, you should be able to lean on matrix-rust-sdk if you so desire! We hope that other projects will follow the Rust + Swift/Kotlin pattern for their extreme performance needs :)

🔗Sliding Sync

The single biggest change in Matrix 2.0 is the proposal of an entirely new sync API called Sliding Sync (MSC3575). The goal of Sliding Sync is to ensure that the application has the option of loading the absolutely bare essential data required to render its visible user interface - ensuring that operations which have historically been horribly slow in Matrix (login and initial sync, launch and incremental sync) are instant, no matter how many rooms the user is in or how large those rooms are.

While matrix-rust-sdk implements both Sync v2 (the current API in Matrix 1.8) as well as Sliding Sync, Element X deliberately only implements Sliding Sync, in order to focus exclusively on getting the fastest UI possible (and generally to exercise the API). Therefore to use Element X, you need to be running a homeserver with Sliding Sync support, which (for now) means running a sliding-sync proxy which bolts Sliding Sync support on to existing homeservers. You can check out Thib’s excellent tutorial for how to get up and running (or Element Server Suite provides packages from the Element team)

Now, implementing Sliding Sync in matrix-rust-sdk has been a bit of a journey. Since we showed off the very first implementation at FOSDEM, two big problems came to light. For a bit of context: the original design of Sliding Sync was heavily inspired by Discord’s architecture - where the server calculates an ordered list of large numbers of items (your room list, in Matrix’s case); the client says which window into the list it’s currently displaying; and the server sends updates to the client as the view changes. The user then scrolls around that list, sliding the window up and down, and the server sends the appropriate updates - hence the name Sliding Sync.

Sliding Sync was originally driven by our work on Low Bandwidth Matrix - as it makes no sense to have a fancy line protocol which can run over a 2400 baud modem… if the first thing the app tries to do is download a 100MB Sync v2 initial-sync response, or for that matter a 10MB incremental-sync response after having been offline for a few days (10MB takes 9 hours to shift over a 2400 baud modem, for those who missed out on the 80s). Instead, you clearly only want to send the absolute essentials to the client, no matter how big their account is, and that’s what Sliding Sync does.

The first minor flaw in the plan, however, is that the server doesn’t necessarily have all the data it needs to order the room list. Room ordering depends on what the most recent visible events are in a room, and if the room’s end-to-end encrypted, the server has no way of knowing which events are going to be visible for a given client or not. It also doesn’t know which rooms have encrypted mentions inside them, and we don’t want to leak mention metadata to the server, or design out keyword mentions. So, MSC3575 proposed some complicated contortions to let the client tweak the order client-side based on its superior knowledge of the ordering (given most clients would need to sync all the encrypted rooms anyway, in order to index them and search for keyword notifications etc). Meanwhile, the order might be ‘good enough’ even without those tweaks.

The second minor flaw in the plan was that having implemented Sliding Sync in Element X, it turns out that the user experience on mobile of incrementally loading in room list entries from the server as the user scrolls around the list is simply not good enough, especially on bad connectivity - and the last thing we want to do is to design out support for bad connectivity in Matrix. Users have been trained on mobile to expect to be able to swipe rapidly through infinite-scrolling lists of tens of thousands of photos in their photo gallery, or tens of thousands of emails in their mail client, without ever seeing a single placeholder, even for a frame. So if the network roundtrip time to your server is even 100ms, and Sliding Sync is operating infinitely quickly, you’re still going to end up showing a placeholders for a few frames (6 frames, at 60fps, to be precise) if the user starts scrolling rapidly through their room list. And empirically that doesn’t look great - the 2007-vintage iOS team have a lot to answer for in terms of setting user expectations!

So, the obvious way to solve both of these problems is simply to pull in more data in the background, to anticipate the user scrolling around. In fact, it turns out we need to do that anyway, and indeed pull in all the room data so that room-search is instantly responsive; waiting 100ms or more to talk to the server whenever the user tries to search their roomlist is no fun at all, and it transpires that many users navigate their roomlist entirely by search rather than scrolling. As a result, the sliding sync implementation in matrix-rust-sdk has ended up maintaining an ‘all rooms’ list, which starts off syncing the roomlist details for the most recent N rooms, and then in the background expands to sync all the rest. At which point we’re not really sliding a window around any more: instead it’s more of a QoSed incremental sync.

So, to cut a long story short: while the current Sliding Sync implementation in matrix-rust-sdk and Element X empirically works very well, it’s ended up being a bit too complicated and we expect some pretty significant simplifications in the near future based on the best practices figured out with clients using it. Watch this space for updates, although it’s likely that the current form of MSC3575 will prevail in some respect in order to support low-bandwidth environments where roomlist ordering and roomsearch latency is less important than preserving bandwidth. Critically, we want to figure this out before we encourage folks to implement native server implementations - so for now, we’ll be keeping using the sliding-sync proxy as a way to rapidly experiment with the API as it evolves.

🔗Native Matrix Group VoIP

Another pillar of Matrix 2.0 is that we finally have native Matrix Group VoIP calling (MSC3401)! Much like Sliding Sync has been developed using Element X as a testbed, Element Call has been the guinea pig for getting fully end-to-end-encrypted, scalable group voice/video calling implemented on top of Matrix, building on top of matrix-js-sdk. And as of today, Element Call finally has it working, complete with end-to-end encryption (and integrated in Element X, for that matter)!

Much like Sliding Sync, this has also been a bit of a journey. The original implementations of Element Call strictly followed MSC3401, using full mesh conferencing to effectively have every participant place a call to every other participant - thus decentralising the conference and avoiding the need for a conferencing ‘focus’ server… but limiting the conference to 7 or 8 participants given all the duplication of the sent video required. In Element Call Beta 2, end-to-end encryption was enabled; easy, given it’s just a set of 1:1 calls.

Then the real adventure began: to implement a Selective Forwarding Unit (SFU) which can be used to scale up to hundreds of users - or beyond. The unexpected first move came from Sean DuBois, project lead of the awesome Pion WebRTC stack for Golang - who wrote a proof-of-concept called sfu-to-sfu to demonstrate the viability of decentralised heterogenous cascading SFUs, as detailed in MSC3898. This would not only let calls on a single focus scale beyond hundreds of users, but also share the conferencing out across all the participating foci, providing the world’s first heterogeneous decentralised video conferencing. Element took the sfu-to-sfu implementation, hooked it up to Element Call on a branch, and renamed it as waterfall.

However, when Sean first contributed sfu-to-sfu, he mentioned to us that if Matrix is serious about SFUs, we should take a look at LiveKit - an open source startup not dissimilar to Element who were busy building best-in-class SFUs on top of Pion. And while waterfall worked well as a proof of concept, it became increasingly obvious that there’s a lot of work to be done around tuning congestion control, error correction, implementing end-to-end encryption etc which the LiveKit team had already spent years doing. So, Element reached out to the LiveKit team, and started experimenting with what it might take to implement a Matrix-capable SFU on top of the LiveKit engine.

The end result was Element Call Beta 3, which is an interesting hybrid between MSC3401 and LiveKit’s existing signalling: the high-level signalling of the call (its existence, membership, duration etc) is advertised by Matrix - but the actual WebRTC signalling is handled by LiveKit, providing support for hundreds of users per call.

Finally, today marks the release of Element Call Beta 4, which adds back end-to-end encryption via the LiveKit SFU (currently by using a shared static secret, but in the near future will support full Matrix-negotiated end-to-end encryption with sender keys) - and also includes a complete visual refresh. The next steps here include bringing back support for full mesh as well as SFU, for environments without an SFU, and updating all the MSCs to recognise the hybrid signalling model that reality has converged on when using LiveKit. Meanwhile, head over to https://call.element.io to give it a go, or read more about it in the Element X Ignition blog post!

🔗Native Open ID Connect

Finally, last but not least, we’re proud to announce that the project to replace Matrix’s venerable existing authentication APIs with industry-standard Open ID Connect in Matrix 2.0 has taken a huge leap forwards today, with matrix-authentication-service now being available to add Native OIDC support to Synapse, as well as Element X now implementing account registration, login and management via Native OIDC (with legacy support only for login/logout).

This is a critical step forwards in improving the security and maintainability for Matrix’s authentication, and you can read all about it in this dedicated post, explaining the rationale for adopting OpenID Connect for all forms of authentication throughout Matrix, and what you need to know about the transition.

🔗Conclusion

There has been an enormous amount of work that has gone into Matrix 2.0 so far - whether that’s implementing sliding sync in matrix-rust-sdk and sliding-sync proxy, matrix-authentication-service and all the native OIDC infrastructure on servers and clients, the entirety of Element Call and its underpinning matrix-js-sdk and SFU work, or indeed Faster Joins in Synapse, which shipped back in Jan.

It’s been a pretty stressful sprint to pull it all together, and huge thanks go to everyone who’s contributed - both from the team at Element, but also contributors to other projects like matrix-rust-sdk who have got caught in the crossfire :) It’s also been amazing seeing the level of support, high quality testing and excellent feedback from the wider community as folks have got excited about the promise of Matrix 2.0.

On the Foundation side, we’d like to thank the Members whose financial support has been critical in providing bandwidth to enable the progress on Matrix 2.0 - and for those who want to help accelerate Matrix, especially those commercially building on top of Matrix, please consider joining the Foundation as a member! Also, in case you missed it, we’re super excited to welcome Josh Simmons as Managing Director for the Foundation - focusing on running the Foundation membership programme and generally ensuring the growth of the Foundation funding for the benefit of the whole Matrix community. Matthew and Amandine continue to lead the overall project (alongside their day jobs at Element), with the support of the other three independent Guardians - but Josh is working full time exclusively on running the non-profit foundation and gathering funds to support Matrix.

Talking of funding, we should mention that we’ve had to pause work in other places due to lack of Matrix funding - especially while focusing on successfully shipping Matrix 2.0. Major next-generation projects including Third Room, P2P Matrix, and Low Bandwidth Matrix have all been paused unless there’s a major shift in circumstances - so, if you have money and you’re interested in a world where the more experimental next-generation Matrix projects progress with folks working on them as their day job, please get in touch with the Foundation.

🔗What’s next?

While this is the first usable release of Matrix 2.0 implementations, there’s loads of work still to be done - obvious work on Matrix 2.0 includes:

• Getting Native OIDC enabled on matrix.org, and providing migration tools to Native OIDC for existing homeservers in general
• Reworking Sliding Sync based on the lessons learned implementing it in matrix-rust-sdk
• Actually getting the Matrix 2.0 MSCs stabilised and matured to the point they can be approved and merged into the spec
• Adding encrypted backups to matrix-rust-sdk
• Reintroducing full-mesh support for Native Matrix Group VoIP calling
• Having a big Matrix 2.0 launch party once the spec lands!

Outside of Matrix 2.0 work, other big items on the horizon include:

• Adding Rust matrix-sdk-crypto to matrix-js-sdk, at which point all the official Matrix.org client SDKs will (at last!) be using the same stable performant E2EE implementation
• Continuing to contribute Matrix input to the MIMI working group in IETF for Digital Markets Act interoperability
• Working on MLS for next-generation E2EE
• Next generation moderation tooling and capabilities
• Account Portability and Multihomed accounts
• …and much much more.

So: welcome to our brave new Matrix 2.0 world. We hope you’re excited about it as we are - and thanks to everyone for continuing to use Matrix and build on it. Here’s to the beginning of a whole new era!

Matthew, Amandine and the whole Matrix team.