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Support Matrix for Chat


We just switched IRC networks from Freenode to OFTC. This was done quickly because remaining on Freenode was untenable due to recent changes, and the OpenDev community had an existing plan prepared to move to OFTC should such a situation arise.

Now that the immediate issue is addressed, the Zuul community has consulted both internally and externally and would like to host its community chat in Matrix.

Problem Description

Here are some concerns that affect us as a community:

  • Some users like to stay connected all the time so they can read messages from when they are away.

  • Others are only interested in connecting when they have something to say.

  • On Freenode, nick registration was required to join OpenDev related channels in order to mitigate spam. Currently that is not the case with OFTC, but we can’t guarantee that will hold.

  • Some users prefer simple text-based clients.

  • Others prefer rich messaging and browser or mobile clients.

  • Projects rely on the OpenDev bots: gerritbot, meetbot, eavesdrop, and statusbot.

  • OpenDev projects collaborate with each other in various OFTC channels. They also collaborate with folks in other communities in channels.

  • Users must be able to access our chat using Free and Open-Source Software.

  • The software running the chat system itself should be Free and Open-Source as well if possible. Both of these are natural extensions of the Open Infrastructure community’s Four Opens, as well as OpenDev’s mantra that Free Software needs Free Tools.

Benefits Offered by Matrix

  • The Matrix architecture associates a user with a “homeserver”, and that homeserver is responsible for storing messages in all of the rooms the user is present. This means that every Matrix user has the ability to access messages received while their client is disconnected. Users don’t need to set up separate “bouncers”.

  • Authentication happens with the Matrix client and homeserver, rather than through a separate nickserv registration system. This process is familiar to all users of web services, so should reduce barriers to access for new users.

  • Matrix has a wide variety of clients available, including the Element web/desktop/mobile clients, as well as the weechat-matrix plugin. This addresses users of simple text clients and rich media.

  • Bots are relatively simple to implement with Matrix.

  • The Matrix community is dedicated to interoperability. That drives their commitment to open standards, open source software, federation using Matrix itself, and bridging to other communities which themselves operate under open standards. That aligns very well with our four-opens philosophy, and leads directly to the next point:

  • Bridges exist to OFTC,, and, at least for the moment, Freenode. That means that any of our users who have invested in establishing a presence in Matrix can relatively easily interact with communities who call those other networks home.

  • End-to-end encrypted channels for private chats. While clearly the public channels are our main concern, and they will be public and unencrypted, the ability for our community members to have ad-hoc chats about sensitive matters (such as questions which may relate to security) is a benefit. If Matrix becomes more widely used such that employees of companies feel secure having private chats in the same platform as our public community interactions, we all benefit from the increased availability and accessibility of people who no longer need to split their attention between multiple platforms.

  • The Spaces feature allows for easier discovery of available channels for a given community (see

Reasons to Move

Projects could continue to call their channels on OFTC home, and individual users could still use Matrix on their own to obtain most of those benefits by joining the portal room on the OFTC bridge. Some reasons to move to a native Matrix room are:

  • Eliminate a potential failure point. If many/most of us are connected via Matrix and the bridge, then either a Matrix or an OFTC outage would affect us.

  • Eliminate a source of spam. Spammers find IRC networks very easy to attack. Matrix is not immune to this, but it is more difficult.

  • Isolate ourselves from OFTC-related technology or policy changes. For example, if we find we need to require registration to speak in channel, that would take us back to the state where we have to teach new users about nick registration.

  • Elevating the baseline level of functionality expected from our chat platform. By saying that our home is Matrix, we communicate to users that the additional functionality offered by the platform is an expected norm. Rather than tailoring our interactions to the lowest-common-denominator of IRC, we indicate that the additional features available in Matrix are welcomed.

  • Provide a consistent and unconfusing message for new users. Rather than saying “we’re on OFTC, use Matrix to talk to us for a better experience”, we can say simply “use Matrix”.

  • Lead by example. Because of the recent fragmentation in the Free and Open-Source software communities, Matrix is a natural way to frictionlessly participate in a multitude of communities. Let’s show people how that can work.


All of the work to move to OFTC has been done, and for the moment at least, the OFTC bridge is functioning well. OpenDev could decide not to support the Zuul project in their effort to move to Matrix.

OpenDev could also offer limited support by operating bots, but without operating a homeserver.



  • Clark Boylan (Sign up for service on behalf of Foundation)

  • Tristan Cacqueray (Matrix gerritbot replacement)

  • TBD (statusbot replacement/update; corvus is fallback)

  • TBD (eavesdrop replacement/update; corvus is fallback)

  • TBD (meetbot replacement/update)

Gerrit Topic

Use the gerrit topic matrix for changes related to this spec.

Work Items

To support projects that want to use Matrix, OpenDev would do the following:

  • Create a homeserver to host our room and bots. Technically, this is not necessary, but having a homeserver allows us more control over the branding, policy, and technology of our room. It means we are isolated from policy decisions by the admins of, and it fully utilizes the federated nature of the technology.

    The Foundation will subscribe to a hosted server run by Element.

    With Element taking care of maintenance and upgrades, the OpenDev sysadmins have one less potential risk.

    At this stage, we would not host any user accounts on the homeserver; it would only be used for hosting rooms and bot/admin accounts.

    The homeserver will be for; so for example, a room for Zuul would be, and we might expect bot accounts like

  • Ensure that the OpenDev service bots support matrix. Zuul makes use of gerritbot, statusbot, and an eavesdrop service, so with only those implemented, it would be sufficient for the Zuul project to move. A meeting bot could be implemented later for other projects to move.

    Note that any bot that can operate over the Matrix protocol can participate in Matrix or any IRC network, so OpenDev can support projects using Matrix and projects which remain on IRC with the same technology by implementing them using Matrix.

  • Once the homeserver exists, we should create rooms. A declarative git-driven process would be nice, or if we expect only one or a small number of rooms, we could have an admin account manually create them to start.

  • Create instructions to tell users how to use Matrix. These have already been created for the Zuul project. Zuul currently recommends users join the #zuul OFTC channel via the Matrix bridge, so these instructions only need to be updated to change the name of the room.

  • Announce the move, and retire the OFTC channel.

Potential Future Enhancements

Once the OpenDev single-sign-on system is complete, It would be possible for OpenDev and/or the Foundation to add a second homeserver for the purpose of hosting end-user accounts. This might be more comfortable for new users who are joining Matrix at the behest of our community. But it also opens questions about identity and usage (the same questions we would have to answer, for example, if we provided email addresses to project participants), so much further discussion would be needed if this was desired.

It is possible for OpenDev and/or the Foundation to run multiple homeservers in multiple locations in order to aid users who may live in jurisdictions with policy or technical requirements that prohibit their accessing the homeserver.

Because Matrix can interoperate with other messaging systems, it would be possible for OpenDev to use its homeserver to host portal rooms to other communities using other software (with their permission). For example, OpenDev could host a bridge to k8s slack, making it simpler for contributors to communicate with both projects.

All of these, if they come to pass, would be significantly in the future but they do illustrate some of the additional flexibility our communities could obtain by using Matrix.


If OpenDev runs a homeserver, it will be configured in system-config. We may need to modify or write new bots, so gerritbot at least may be affected. We may need new repos for new bots if we write them.


We may run a homeserver; if so, we can probably run it on a 4GB VM to start.

DNS Entries

If we run a homeserver, it will require DNS entries.

Regardless of whether we run one or use an Element-hosted homeserver, we will place a file in the .well-known/ directory on to delegate “” to the homeserver so that Matrix addresses ending with “” are routed there. No DNS entries are required for this.


New user documentation has already been written for Zuul, we can copy that to the infra-manual.


In every respect, Matrix is more secure than IRC. If we run a homeserver ourselves we will be responsible for keeping it up to date, which is not a responsibility we currently have with IRC.


Testing for our bots can be considerably more authentic since we can dynamically spin up a Matrix server in a gate test job.