Hi Dojo,
I'm creating a flow in Power Automate that when a maintenance window is scheduled it will send a Teams message to every person that is logged in on my system.
For this I'll make us of Webhooks to retrieve a JSON list of logged in persons. But which call can I use to have the persons that are currently logged in?
Hi Jens,
I don't think the DataMiner Web API's expose an API call to retrieve the active connections. We could add this as a new software feature.
As a workaround, you could create a protocol or script that retrieves this information through an SLNet call and stores it in a parameter, which you can fetch through the Web APIs.
The following SLNet request will return the information you want.
var activeUsers = engine.SendSLNetMessage(new GetInfoMessage(InfoType.ClientList)).OfType<LoginInfoResponseMessage>();
We were recently asked to provide something similar and a workable solution would be to use the information events. Every time a user logs in/out of DataMiner an associated information event is logged.
Depending on the application (Cube, HTML5 Apps) used you could see various messages (e.g., New Client Registered). You can then write a simple automation that retrieves the clients that have logged in but not logged out yet and notify those. 
Hope it helps.
There is also the API Deployment feature (currently still in softlaunch) that you can use to directly access an automation script from a REST API