Matterhorn is a terminal client for the MatterMost chat system.

We provide pre-built binary releases for some platforms. Please see the release list to download a binary release for your platform that matches your server version:

https://github.com/matterhorn-chat/matterhorn/releases

To fetch a release and run Matterhorn, you might run the following commands (where VERSION and PLATFORM match your setup):

wget https://github.com/matterhorn-chat/matterhorn/releases/download/<VERSION>/matterhorn-<VERSION>-<PLATFORM>.tar.gz
tar xf matterhorn-<VERSION>-<PLATFORM>.tar.gz
cd matterhorn-<VERSION>-<PLATFORM>
./matterhorn

When you run Matterhorn you'll be prompted for your server information. At present matterhorn supports only username/password authentication.

Note: Version ABBCC.X.Y matches MatterMost server version A.BB.CC. For example, if your MatterMost server version is 3.6.0 then you would download matterhorn version 30600.2.4. See Our Versioning Scheme for details.

For configuration options you have two choices:

• Interactive configuration entered on each program run
• Configuration via stored settings in a config file

The first option is useful when trying out the program because you can get up and running without worrying about making a configuration. Once you're ready to make your settings persistent, they can be added to a configuration file. An example configuration file can be found at sample-config.ini. Any settings omitted from the configuration will be obtained interactively at startup.

When looking for configuration files, matterhorn will prefer config.ini in the current working directory, but will look in the typical XDG configuration directories (you'll probably want to use $HOME/.config/matterhorn/config.ini) and as a last resort look for a globally-accessible /etc/matterhorn/config.ini.

The user interface has three main areas:

• Left: list of channels you're in, and list of users in your team and their statuses (+ means online, - means away, and an absent sigil means offline)
• Right: messages in the current channel
• Bottom: editing area for writing, editing, and replying to messages

You can use built-in keybindings or /cmd-style commands to operate the client. To see available keybindings and commands, use the default binding of F1 or run the /help command.

To join a channel, use the /join command to choose from a list of available channels. To create a channel, use /create-channel. To leave a channel, use /leave-channel.

To see the members in the current channel, use the /members command.

To send a message, type it into the editor and press Enter to send. To send a multi-line message, toggle multi-line mode with the default binding M-e. Markdown syntax is accepted.

To edit your current message in an external editor ($EDITOR), use the default binding of M-k.

To preview the message you're about to send (e.g. to check on how your Markdown syntax will be rendered), toggle preview mode with the default binding M-p.

To change channels, use /focus or one of the default bindings C-n (next channel), C-p (previous channel), C-g (fast channel switch).

To directly message another user, use /focus or C-g.

C-g channel switching mode does a substring match of the input text on the channel and usernames; metacharacters ^ and $ at the beginning or end of input, respectively, anchor the match in case of multiple matches.

To switch to the channel you were in prior to the current channel, use the default binding M-s (swap). The most recent channel is marked in the channel list with a "<" indicator.

To switch to the next channel with unread messages, use the default binding M-a.

To quickly show a list of URLs mentioned in the current channel and then open one in your local browser, use the default binding of C-o and configure the urlOpenCommand configuration setting.

To edit, delete, or reply to a message, select a message with the default binding of C-s. Use the default binding of C-c to cancel these operations.

• Channel creation, deletion, and membership management commands
• Optimized channel-switching modes: M-a, M-s, and C-g
• Message posting, editing, replying, and deletion
• Markdown rendering
• Convenient URL-opening with local browser
• Secure password entry via external command (e.g. OSX keychain)
• Yank verbatim content from messages into the system clipboard
• Preview message rendering before sending
• Optional smart quoting for efficient Markdown entry
• Edit messages with $EDITOR
• Message editor with kill/yank buffer and readline-style keybindings
• Tab-completion of usernames, channel names, and commands

The easiest way to build matterhorn is to use the provided install.sh script, which requires git and an appropriate ghc/cabal installation. It will pull the appropriate repos and build the sandbox in the appropriate way.

If you want to, you can also run the install process manually:

$ cd matterhorn
$ cabal sandbox init
$ cabal install
$ cabal build

Matterhorn version strings will be of the form ABBCC.X.Y where ABBCC corresponds to the MatterMost server version supported by the release. For example, if a release supports MatterMost server version 1.2.3, the ABBCC portion of the matterhorn version will be 10203. The X.Y portion of the version corresponds to our own version namespace for the package. If the server version changes, X.Y SHOULD be 0.0. Otherwise the first component should increment if the package undergoes major code changes or functionality changes. The second component alone should change only if the package undergoes security fixes or other bug fixes.

If you decide to contribute, that's great! Here are some guidelines you should consider to make submitting patches easier for all concerned:

• If you want to take on big things, let's have a design/vision discussion before you start coding. Create a GitHub issue and we can use that as the place to hash things out. We'll be interested to discuss any usability / UI, performance, or compatibility issues.
• Please make changes consistent with the conventions already used in the codebase.

• Q: Does matterhorn support Gitlab authentication?
• A: No. But we would be happy to work with contributors who are interested in investigating what this would take and/or implementing it. See the Contributing section for details.