📡 Real-Time Communication with SignalR in ASP.NET Core Complete Setup Guide

Want to build a real-time chat app or push live notifications? In this blog, I’ll walk you through setting up SignalR from scratch using ASP.NET Core and a .NET console client. Perfect for beginners or those revisiting SignalR.

🔧 Step 1: Create the SignalR Server Project

Create an ASP.NET Core Web API project and add package

dotnet add package Microsoft.AspNetCore.SignalR

🧠 Step 2: Create a SignalR Hub

Create a new class ChatHub.cs inside the project:

using Microsoft.AspNetCore.SignalR;

public class ChatHub : Hub
{
    public async Task SendMessage(string user, string message)
    {
        await Clients.All.SendAsync("ReceiveMessage", user, message);
    }
}

🌐 Step 3: Configure the SignalR Hub in Program.cs

Update Program.cs to register the SignalR service and endpoint:

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddSignalR();
builder.Services.AddControllers();
var app = builder.Build();

app.UseHttpsRedirection();
app.UseAuthorization();
app.MapControllers();

// Add this line to map the hub
app.MapHub<ChatHub>("/chatHub");

app.Run();

🧪 Step 4: Run the Server

dotnet run

📥 Step 5: Create a .NET Console Client

Create a new console app and add SignalR client package

dotnet add package Microsoft.AspNetCore.SignalR.Client

🧑‍💻 Step 6: Build the Client Logic

Replace Program.cs content with:

using Microsoft.AspNetCore.SignalR.Client;

var connection = new HubConnectionBuilder()
    .WithUrl("https://<your localhost>/chatHub") your server
    .WithAutomaticReconnect()
    .Build();

// Receive messages
connection.On<string, string>("ReceiveMessage", (user, message) =>
{
    Console.WriteLine($"{user}: {message}");
});

try
{
    await connection.StartAsync();
    Console.WriteLine("Connected to SignalR Hub.");
}
catch (Exception ex)
{
    Console.WriteLine($"Connection failed: {ex.Message}");
    return;
}

// Sending messages
while (true)
{
    Console.Write("Enter your name: ");
    var user = Console.ReadLine();

    Console.Write("Enter your message: ");
    var message = Console.ReadLine();

    try
    {
        await connection.InvokeAsync("SendMessage", user, message);
    }
    catch (Exception ex)
    {
        Console.WriteLine($"Error sending message: {ex.Message}");
    }
}

✅ Step 7: Test the Communication

• Run the server project:

cd ../SignalRServer
dotnet run

• Run the client project in a new terminal:

cd ../SignalRClient
dotnet run

Type your name and message in the console. If everything is set up correctly, you’ll see the message echoed back from the hub.

🧪 Test Multiple Clients

Open two terminals and run the client in each. You’ll see real-time communication between both.