Is a “headless” CMS what I’m looking for ?

Hi there

I'm looking for some kind of stack, SDK, etc. that would help me bootstrap a project real quick.

That project is a backend system that allows for JSON content delivery to our custom applications (made with Unity). It will use .NET Core 5.

I need something that:

• Allows me to create custom models ("tables" and "columns" if you will) with lots of column types and possibly create custom ones
• Have an interface to edit the content based on those custom models (if that interface is customizable, great!)
• Events logs of what content been edited, when, by who, etc. (At least, have to the tools so we can easily code that logging logic)
• Security: I need it to be customizable and flexible. We have this concept of "project" and the projects hold content and different users will have different access to different "projects"

Is there anything out there that would fill those requirements ?

Thanks.