How to use SignalR on Flutter?
I just created a Flutter client for SignalR (ASP.NET Core). You can find it at Pub
If flutter plugins are not available for Signalr, you can always use native libraries available for signalr and use flutter's platform channels to use those native features in your flutter code.
Here are some helpful resource that might help
How to use signalr in Android?
https://github.com/Gurgen/SignalR-.net-core-android-client
Flutter platform channels