Will it be possible to create collections and fields using the API in the near future?
Good question! That would be nice... don't remember where but I read recently that the crew is thinking about it but there's no timeline for implementation. For now, you have to use the Designer UI. Though I'd settle just for "auto-publish" of added items, since right now they just queue for publishing when you add them via API...
What is the use case for this?
Creating the same set of collections and fields on multiple sites without having to set it up manually each time. Another option would be some way of copying the CMS structure from one site to another.
^ Mainly this. Right now I have a new project "template" with dummy style guide, basic style reset, icons, etc., that I just duplicate every time I start a new project. And while it's true that it will duplicate all the collections + fields as well, being able to create new ones from the command line would be aces 🂡
+1 for this feature!