Service provided by addon

Hi,

I want to develop an addon which would receive a url and then render a page using selenium, do some logic and then call another service. I think it make sense to run this logic dedicated addon (container).

However I can’t find in documentation how to register a service from addon, or call service from addon. From documentation I see that I should use websockets but there is no example how to connect to HA from addon via websockets.

Can you advice me how to run this workload and register a custom service in addon and call service in HA?