Nespresso Expert machine has the Bluetooth ability which officially can be used only by Nespresso mobile app and it does not offer any API for 3rd party applications and services. Moreover, the Bluetooth services and characteristics are not documented and easy to use by the other Bluetooth libraries plus there is no documentation for the Bluetooth packets payload that need to be sent or received.
However, after searching a lot and sniffing the packets for a couple of days, I've been able to hack the machine and write the small nodejs application using noble and express to control and monitor the machine with Rest API exposed by express through Bluetooth connection. As I did this application for my ex-company and they are still using it for their demo I cannot share the code but I'm going to explain how it works.
_Thanks to this