Thanks for reply.
There are some point which i want to understand.
1) How to check, the list of services available in a widget.
2) How i can invoke any of the services available in widget.
3) Pushing JSON data to a service.
4) Getting JSON response return by service.
Basically, i am creating more than one widget where output of one widget can be used as input to other.
It will be helpful if you can share "Thingworx extension guide".
Here are some documents I found through our support/documentation site support.ptc.com