...
ws://{url}/ws/rest/WebSocketObjectSubscription/{objectType}/{eventType}/{key}/{token}
The JSON pushed will have the same structure if the one pushed by Webhooks.
It is possible to customize the JSON sent from the Server to the Client using Adjust Number of Fields to be Returned from a Request.
(The JSON fields can be sent through the open Websocket by the Client to the Server)
(To get back to the standard fields list a empty JSON ( {} ) can be sent from the client to the server)