UltraWS

Simple, easy to use WebSocket server, similar to SignalR.

The key difference is that SignalR operates on WebSocket connections, while this implementation uses concept of client, which can be single connection (then it works like SignalR), or the authenticated entity, and then WebSocket messages are synchronized over all client connections.

Sample usage:

Program.cs

services.AddUltraWs()
    .AddWsHub<ChatHub>(new WsHubOptions<ChatHub>
    {
    });

...

app.UseWebSockets();
app.MapUltraWs<ChatHub>("");

The MapUltraWs() method is Minimal API builder, so you can add authentication, authorization, filters etc. easily.

Hub

Like SignalR, this implementation relies on concept of Hub. You create it by inheriting from WsHub<Thub>, like it:

public class ChatHub : WsHub<ChatHub>
{
    public override async Task HandleAsync(WsHubInvocationMessage message, CancellationToken cancellationToken = default)
    {
        switch (message.MethodName)
        {
            case nameof(SendPrivateMessage):
                await SendPrivateMessage(message.Args[0] as SendPrivateMessageDto);
                break;
        }
    }

    public override Task OnConnectedAsync()
    {
        return base.OnConnectedAsync();
    }

    public override Task OnDisconnectedAsync()
    {
        return base.OnDisconnectedAsync();
    }

    public async Task SendPrivateMessage(SendPrivateMessageDto dto)
    {
        var id = Context.ClientId;
        await Clients.SendAsync(id, new WsHubInvocationMessage
        {
            MethodName = "ReceivePrivateMessage",
            Args = new object[]
            {
                dto
            }
        });
    }
}

The key difference is that you have to implement HandleAsync() method as shown in the code above. You need to switch by message.MethodName and invoke appropriate method. It's done this way to avoid too much reflection.