Hey Sven 
I would recommend M10074 Novulo API Calls and responses. This component depends on M7899 Novulo Basic Calls and responses.
It allows you to configure and debug call templates and group them in call template collections. This is an example call template:
You can execute test calls, create dynamic URLs, bodies and import the response and map it onto Novulo records, if you want.
Furthermore, each call is logged and the response that has been received.
Once your calls are working, you might want to use M10388 Novulo Call template processes. It allows you to configure the execution of Novulo processes before/after building/processing.
Let me know if it works out or if you get stuck, I am happy to help