Hub Setup

The HARRR class is the SignalARRR hub base class. It extends ASP.NET Core's Hub with typed method dispatch, authorization, client context tracking, and streaming support.

Create a hub

Every SignalARRR application needs at least one hub. The hub itself can be empty — actual method implementations go into ServerMethods classes.

public class AppHub : HARRR
{
    public AppHub(IServiceProvider sp) : base(sp) { }
}

Register and map

In Program.cs, register SignalARRR services and map the hub endpoint:

builder.Services.AddSignalR();
builder.Services.AddSignalARRR(options => options
    .AddServerMethodsFrom(typeof(Program).Assembly));

var app = builder.Build();

app.UseRouting();
app.MapHARRRController<AppHub>("/apphub");

MessagePack support

For better performance with many clients, add MessagePack alongside JSON:

builder.Services.AddSignalR()
    .AddMessagePackProtocol();  // clients can choose JSON or MessagePack

Both protocols run simultaneously — JSON clients and MessagePack clients connect to the same hub.

AddServerMethodsFrom() scans the assembly for all ServerMethods<T> classes and registers them in DI.

MapHARRRController<T>() maps the hub at the specified path and also registers a download endpoint at {path}/download/{id} for file stream references.

Multiple hubs

You can have multiple hubs in the same application:

public class ChatHub : HARRR
{
    public ChatHub(IServiceProvider sp) : base(sp) { }
}

public class AdminHub : HARRR
{
    public AdminHub(IServiceProvider sp) : base(sp) { }
}

app.MapHARRRController<ChatHub>("/chathub");
app.MapHARRRController<AdminHub>("/adminhub");

ServerMethods classes are scoped to a specific hub type via the generic parameter:

public class ChatMethods : ServerMethods<ChatHub>, IChatHub { ... }   // only on ChatHub
public class AdminMethods : ServerMethods<AdminHub>, IAdminHub { ... } // only on AdminHub

Connection options

MapHARRRController accepts SignalR's HttpConnectionDispatcherOptions for configuring transports, buffer sizes, and authorization:

app.MapHARRRController<AppHub>("/apphub", options =>
{
    options.Transports = HttpTransportType.WebSockets;
    options.ApplicationMaxBufferSize = 64 * 1024;
});

Hub lifecycle

HARRR provides the standard SignalR lifecycle hooks. Override them to run logic when clients connect or disconnect:

public class AppHub : HARRR
{
    public AppHub(IServiceProvider sp) : base(sp) { }

    public override async Task OnConnectedAsync()
    {
        await base.OnConnectedAsync();  // registers client in ClientManager
        Logger?.LogInformation("Client {Id} connected", Context.ConnectionId);
    }

    public override async Task OnDisconnectedAsync(Exception? exception)
    {
        Logger?.LogInformation("Client {Id} disconnected", Context.ConnectionId);
        await base.OnDisconnectedAsync(exception);  // unregisters client
    }
}

WARNING

Always call base.OnConnectedAsync() and base.OnDisconnectedAsync() — they manage the client registration in ClientManager.

Hub properties

Property	Type	Description
ServiceProvider	IServiceProvider	DI container for the current request
Logger	ILogger?	Logger instance (resolved from DI)
ClientContext	ClientContext	Enhanced context for the calling client
Context	HubCallerContext	Standard SignalR caller context
Clients	IHubCallerClients	Access to client connections
Groups	IGroupManager	Group management

Next steps

• Server Methods — split hub logic across classes
• Authorization — protect methods with [Authorize]
• Client Manager — call clients from outside the hub