Dto — Real-time with SignalR

Real-time push with [SignalRHub]

Add [SignalRHub] to an entity to generate a strongly-typed SignalR hub and client interface. When paired with [CrudApi], the generated POST/PATCH/DELETE endpoints automatically inject IHubContext and push notifications to connected clients after each store operation.

Standalone usage

[SignalRHub]
public class Order
{
    public int Id { get; set; }
    public required string Product { get; set; }
    public decimal Total { get; set; }
}

This generates:

// Generated hub + client interface
public interface IOrderHubClient
{
    Task OnCreated(OrderResponse item);
    Task OnUpdated(OrderResponse item);
    Task OnDeleted(int id);
}

public class OrderHub : Hub<IOrderHubClient> { }

Paired with [CrudApi]

When both attributes are present, the generated CRUD endpoints inject IHubContext<OrderHub, IOrderHubClient> and push automatically:

[CrudApi]
[SignalRHub]
public class Order
{
    [DtoIgnore(DtoTarget.Create | DtoTarget.Update | DtoTarget.Query)]
    public int Id { get; set; }
    public required string Product { get; set; }
    public decimal Total { get; set; }
    public OrderStatus Status { get; set; }
}

The generated endpoints behave as:

Endpoint	Store operation	SignalR push
POST /api/orders	Create	Clients.All.OnCreated(response)
PATCH /api/orders/{id}	Update	Clients.All.OnUpdated(response)
DELETE /api/orders/{id}	Delete	Clients.All.OnDeleted(id)

Setup

Map the generated hub in Program.cs:

builder.Services.AddSignalR();

var app = builder.Build();

app.MapOrderEndpoints();                    // CRUD endpoints (generated)
app.MapHub<OrderHub>("/api/orders/hub");    // SignalR hub

Client interface shape

The generated IOrderHubClient always follows the same pattern:

public interface I{Entity}HubClient
{
    Task OnCreated({Entity}Response item);
    Task OnUpdated({Entity}Response item);
    Task OnDeleted(int id);            // key type matches the entity's primary key
}

Frontend connection (TypeScript)

Connect from a JavaScript/TypeScript client using the @microsoft/signalr package:

import { HubConnectionBuilder } from "@microsoft/signalr";

const connection = new HubConnectionBuilder()
  .withUrl("/api/orders/hub")
  .withAutomaticReconnect()
  .build();

connection.on("OnCreated", (order) => {
  console.log("New order:", order);
});

connection.on("OnUpdated", (order) => {
  console.log("Updated order:", order);
});

connection.on("OnDeleted", (id) => {
  console.log("Deleted order:", id);
});

await connection.start();

Notes

• [SignalRHub] without [CrudApi] only generates the hub and interface — you call IHubContext yourself in custom endpoints or services.
• The hub class is partial, so you can add OnConnectedAsync/OnDisconnectedAsync overrides in a separate file.
• Group-based broadcasting (e.g. per-tenant) is not generated — use the partial hub to add group logic when needed.