How to call rest API and subscribe for notification/event from custom widget

[Stefan_Witschel]

Hi @sudarshan.karande

there is not REST API over MQTT just the REST API which you might use in your widget.

I would urge you to read either the documentation or the following knowledge base articles:
https://cumulocity.com/guides/web/libraries/#client

Cumulocity IoT Web Development Tutorial - Part 3: Query data from Cumulocity IoT

Cumulocity IoT Web Development Tutorial - Part 1: Start your journey Cumulocity IoT Web Development Tutorial - Part 2: Create your first component Cumulocity IoT Web Development Tutorial - Part 3: Query data from Cumulocity IoT Cumulocity IoT Web Development Tutorial - Part 4: Convert component into a widget Cumulocity IoT Web Development Tutorial - Part 5: Provide widget as a UI Plugin Part 3 has finally arrived! [about-time] In the last part you have implemented your first componen…

http://resources.cumulocity.com/documentation/websdk/client/classes/alarmservice.html
http://resources.cumulocity.com/documentation/websdk/client/classes/eventservice.html

It is pretty simple to use the @c8y/client to read alarms (even on real-time) and visualize them in any widget / ui component.