Qlik Sense expose quite a lot of REST API endpoints for different components (like Proxy service, Repository, Engine service etc).
qlik-rest-api package can be used to communicate with all of them.
The package itself is a generic package. This means that it abstract some of the complexity when calling Qlik's REST endpoints but does not go too "deep".
qlik-rest-api accepts authentication config and exposes base HTTP methods (like GET, POST, PUT etc.) split into few categories.
The package itself is quite light but the trade-off is that all the information should be passed by the developer (like url and body data).
This package is the base for the other packages which are API specific and they are exposing/abstracting the methods in details. Such packages are Qlik Proxy API and Qlik Repo API (both still under development)
Have a look at the package home page for more information!
Have a nice day!