From a design standpoint, implementing all the business logic to be accessible from the terminal makes sense : it separates the presentation layer from the core application : it facilitates developing a command based interface : a command based interface provides a strong foundation for a robust API : it makes it clear what the interface is an interface to.

However, I think there are probably iterations on very minimal browser interfaces that can be used to put the app in front of people very early on to get user feedback about the core functionality and to test out the abstractions...or to put it another way, don't build everything and then see if some people might use it.

Relevant: http://www.themacro.com/articles/2016/01/minimum-viable-prod...

Good luck.