Are posting my ideas/prototypes allowed here?

"Show HN is for something you've made that other people can play with. HN users can try it out, give you feedback, and ask questions in the thread."

I would guess prototypes are fine, but just "ideas" with no artifact are probably not the intended type of post.

I usually like posting about my ideas on social media and trying HN for the first time. Would love to know if idea posting is allowed in the Show category!

The guidelines for Show HN submissions, including what is on- or off-topic, are at https://news.ycombinator.com/showhn.html .