create an API

I’m by no means a wordpress expert, so maybe there is a way already.

I have a lot of books that i manage in another software package.
Currently I have to manually add / edit books on my website.

It would be awesome if I could build some kind of integration with an API that would let me automate the synchronisation of these 2 systems.

Is it possible to create some kind of api endpoint where my software could talk to to GET/PUT/POST books?
Preferably in a way that also works with the images that are referenced.