Glad to see new faces coming up with ideas on how to extend the capabilities of the fediverse honestly. The narrow subset of communications that Mastodon provides for is such a small fraction of what could be!
If you’re new-ish you’ve probably heard that the primary protocol that makes the fediverse happen is ActivityPub (an oversimplification but enough for this toot).
You may not have discovered that ActivityPub leans heavily on ActivityStreams for its vocabulary - take a look at some of the combinations of "actions", "actors", and "objects" that AS codifies out of the box (and it too can be extended!)