Galois releases Matterhorn, an open source Terminal Client for Mattermost

Screenshot_4Jonathan Daugherty is a staff engineer at Galois, Inc. ( where he works on a variety of projects in Haskell and C and leads the Matterhorn project.

I’m pleased to announce the release of Matterhorn, a terminal client for Mattermost. My colleagues at Galois, Inc. and I have been building this client and using it at Galois since August 2016.

It’s now available in binary and source form on our GitHub project page:

You can also get binary releases for OS X, Fedora, and Ubuntu from the releases page:

Please note: Matterhorn versions are tied to Mattermost server versions. We support Mattermost 3.10, the latest release, but if you’re running an older version then be sure to get the Matterhorn version that goes with your server version. For example, a Matterhorn version string like “30802.X.Y” goes with server version 3.8.2.


Matterhorn is a terminal client for the Mattermost platform. Interact with team members across channels with full Markdown support.

Matterhorn aims to provide a keyboard- and terminal-optimized user experience while still providing access to features that Mattermost web client users will expect. For example, we provide keyboard shortcuts to switch to the next channel with unread messages and the previous channel viewed. We also provide a keyboard interface for downloading attachments and opening URLs using your system’s local browser. For message rendering, we support full Markdown syntax and even provide a “preview mode” for message editing so you can see how your message will be formatted.

Check here for a full feature list and also take a look at the feature walk-through here.

Matterhorn is ready to use today and provides a rich terminal-based client for Matterhorn, although we still have more features we are working on and we’re always paying attention to Mattermost release notes to see what Matterhorn needs to be brought up to date. If you find something that’s missing, please let us know by opening a ticket on our GitHub project!

We wrote Matterhorn in the Haskell programming language, a compiled, strongly-typed functional programming language. People familiar with Haskell might enjoy our more detailed blog post on our experience building Matterhorn on our blog here:

We also developed an API bindings package, mattermost-api, as part of our work. Haskell programmers can use this package to write their own Mattermost integrations:

Matterhorn is open source but is developed primarily with funding from Galois, Inc. Please stop by the project page to report bugs, request features, or submit patches!


The Matterhorn development team on GitHub: @jtdaugherty, @dagit, @aisamanra, and @kquick!





Let us know what you think!

What do you think of Matterhorn? Please share your feedback in the comments below, or via GitHub:

More about Galois

Galois specializes in the research and development of new technologies that solve the most difficult problems in computer science. We are passionate about the trustworthiness of critical systems, and work to ensure that the systems you depend on work as intended, and only as intended. Our team works closely with clients to achieve a balance between the privacy/cost/speed challenges involved in making systems more trustworthy.

Galois is a privately held U.S.-owned and -operated company established in 1999 in Portland, Oregon. We were founded on core principles that are central to how we function. We believe that we can and should derive joy from our work, be authentic and trustworthy in all of our interactions, and cherish the opportunity to develop and steward new technology.



Jason Blais is a Lead Product Manager at Mattermost, Inc. Prior to joining Mattermost, Jason served as a product manager and analytics manager for SpinPunch, a Y Combinator-backed online gaming startup. Jason has also provided statistical consultation at Stanford University. He is a University of Waterloo alumnus.