I’d be interested in a feature like this. I’m planning to have a Discourse instance be the backbone of a plugin repository; each plugin would have a topic in a certain category with a field that can be set. An external frontend would then query the API for information from Discourse such as download link, version, and author.
Edit: I found this but it’s not clear how to use this. I’ve also been studying the tagging plugin but I have no idea how that works, I just want to be able to add a custom field to the json output of the topic.