The folks over at mtgzone.com have a bot that posts links to Magic cards in response to comments that mention them. It’s written in TypeScript, and the source code is here.

I’ve had some ideas about a bot that comments on discussions with links to similar discussions on other instances. It’d use algorithms similar to search indexing, so I might look into a search provider app too, but I think a “related discussion finder” might be a good way to help similar groups find each other across the fediverse and come together. Might help offset some of the downsides of extreme decentralisation.