Three Custom Mattermost Plugins

As I mentioned last post, I love Mattermost, self hosting its open source Teams Edition for myself and friends as a private replacement for Slack or Discord. Like Slack, it is extensible with plugins, so with the time saving aid of Claude Code (without which these just wouldn't exist, due to that aforementioned time, which is quite a constrained resource), I've made some custom plugins to fill some gaps in functionality in the out of the box Mattermost experience.

The Social Preview Plugin provides rich link previews for all the major social media platforms that Mattermost just leaves as a url, and improves on the layout of the previews Mattermost does provide. This makes sharing links much more pleasant, and makes it unnecessary to click through to a browser just to see what it is.

My Reply In Channel Plugin provides the functionality to reply to a thread, but also share that reply in the parent channel, mimicking the functionality Slack has to "Also send to channel" checkbox in a thread reply.

And finally the Scheduled Posts Plugin brings the ability to schedule posts for the future, to the Teams Edition. Mattermost does have scheduling functionality, but it is gated behind their paid licensed versions. This is fair enough, but since their plugin platform exposes all the required plumbings, it was simple to provide it myself.

As I think of more useful Mattermost plugins where there's a gap, I'll be sure to let it be known here.