Lumen.SSE 1.0.4

🔌Lumen — SSE for ASP.NET Core

A lightweight, configurable Server-Sent Events (SSE) library for ASP.NET Core.
Easily add real-time, uni-directional server-to-client messaging without WebSockets.

✨ Features

• ✅ Simple integration with minimal APIs
• 🧩 Middleware-based connection handling
• 🧠 Supports multiple clients & devices per user
• 🔄 Built-in ping/keep-alive
• 🔧 Fully configurable endpoints and connection logic
• 📦 .NET 6/7/8 compatible

📦 Installation

Install via NuGet:

dotnet add package Lumen.SSE

🚀 Usage

1. Configure services

To customize global SSE behavior (ping interval, connection limits, etc.), see
👉 AddSse Configuration Options

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddSse();

2. Configure middleware

To customize middleware-level behavior such as connection path, user/device IDs, etc., see
👉 UseSse Configuration Options

var app = builder.Build();
app.UseSse();

3. Send events

To send events in different ways and configure middleware part, see 👉 Sending Events with ISsePublisher

app.MapPost("/send-message", async (
    Message message,
    ISsePublisher sse)
    => await sse.New()
        .SetEvent("new_message")
        .SetData(message)
        .SendToAllClientsAsync());

📡 Client-Side (JavaScript)

const sseUrl = `https://localhost:7287/sse/connection`;
const eventSource = new EventSource(sseUrl);

eventSource.onopen = () => {
    console.log("✅ Connected to SSE server");
};

eventSource.addEventListener("new_message", (event) => {
    const parsedData = JSON.parse(event.data);
    console.log("📨 New Message:", parsedData);
});

eventSource.onerror = (err) => {
    console.error("🚨 SSE connection error:", err);
};

🔍 SSE vs WebSockets

🟢 Use SSE when:

• You only need server-to-client updates
• You want a simple, scalable, and HTTP-friendly solution

🟡 Use WebSockets when:

• You need real-time two-way communication
• The client should also be able to push events to the server

💡 Why choose Lumen (SSE)?

• Zero dependencies
• High performance for broadcasting updates
• Great for lightweight, read-only real-time applications

💬 Questions? Feedback?

Feel free to open an issue or contact the maintainer.