signalr

Hub Implementation

```csharp

// Strongly-typed hub with client interface

public class RegisterHub : Hub

{

public async Task SubscribeToRegister(string registerId)

{

await Groups.AddToGroupAsync(Context.ConnectionId, $"register:{registerId}");

}

}

public interface IRegisterHubClient

{

Task RegisterCreated(string registerId, string name);

Task TransactionConfirmed(string registerId, string transactionId);

}

```

Sending from Services

```csharp

public class NotificationService

{

private readonly IHubContext _hubContext;

public async Task NotifyActionConfirmedAsync(ActionNotification notification, CancellationToken ct)

{

await _hubContext.Clients

.Group($"wallet:{notification.WalletAddress}")

.SendAsync("ActionConfirmed", notification, ct);

}

}

```

Client Connection (Testing)

```csharp

var connection = new HubConnectionBuilder()

.WithUrl($"{baseUrl}/actionshub?access_token={jwt}")

.Build();

connection.On("ActionConfirmed", notification => { / handle / });

await connection.StartAsync();

await connection.InvokeAsync("SubscribeToWallet", walletAddress);

```

| Concept | Usage | Example |

|---------|-------|---------|

| Groups | Route messages to subscribers | wallet:{address}, register:{id}, tenant:{id} |

| Typed Hubs | Compile-time safety | Hub |

| IHubContext | Send from services | Inject IHubContext |

| JWT Auth | Query parameter auth | ?access_token={jwt} |

Service Abstraction Over Hub

When: Decoupling business logic from SignalR implementation

```csharp

// Interface in Services/Interfaces/

public interface INotificationService

{

Task NotifyActionAvailableAsync(ActionNotification notification, CancellationToken ct = default);

}

// Register in DI

builder.Services.AddScoped();

```

Hub Registration in Program.cs

```csharp

builder.Services.AddSignalR();

// Map after authentication middleware

app.MapHub("/actionshub");

app.MapHub("/hubs/register");

```

• [patterns](references/patterns.md) - Hub patterns, group routing, typed clients
• [workflows](references/workflows.md) - Testing, scaling, authentication setup

• aspire - Service orchestration and configuration
• jwt - Authentication token setup for hub connections
• redis - Backplane configuration for scaling
• xunit - Integration testing patterns
• fluent-assertions - Test assertions for hub tests

> Fetch latest SignalR documentation with Context7.

How to use Context7:

1. Use mcp__context7__resolve-library-id to search for "signalr aspnetcore"
2. Prefer website documentation (IDs starting with /websites/) over source code
3. Query with mcp__context7__query-docs using the resolved library ID

Library ID: /websites/learn_microsoft_en-us_aspnet_core _(ASP.NET Core docs including SignalR)_

Recommended Queries:

• "SignalR hub groups authentication"
• "SignalR Redis backplane scaling"
• "SignalR strongly typed hubs"