Hello Carsten,

the URL path /PBX0/APPCLIENT/websocket is only intended for myApps client WebSocket connections.

To be able to use RCC API the WebSocket connection must be established to the URL with path /PBX0/APPS/websocket.

Additionally, on this WebSocket connection an AppLogin to an App Object with enabled RCC API must be performed, in order to be able to use RCC API.

More convenient way would be to implement an App Service, that has RCC API enabled on the App Object and provides a custom JsonApi to the clients, which relays the RCC requests, if user is allowed.

Best Regards

Andreas Fink