can it be possible to create both functionality in one app?
Just pass —api or —minimal flag to rails new app command
By default, Rails is a full-stack application simply frontend + backend. When you are planning to develop a backend-only application, you can create it using –api flag.
The way your APIs are exposed will be the same for both the full-stack and API-only rails applications. So if you create a normal(full-stack) application, you can use it both ways.