Rails - where in the project to create your own class and how to connect it to the controller?

Question

Ruby on Rails

Good afternoon.
Started learning rails. I master on railstutorial.ru .
But my hands itch, what I want - I want to contact the third class in the controller, which goes to a third-party service.
The question is - where in the Feng Shui rails application should I place this "third" class, in which folder, etc.?

Answer 1

app/services