Birko.Communication.SSE

Server-Sent Events (SSE) client and server library for the Birko Framework, implementing the W3C SSE specification for real-time one-way server push.

Features

• SSE client for receiving event streams from HTTP endpoints
• SSE server for pushing real-time events to connected clients
• W3C-compliant event format (Id, Event, Data, Retry)
• Middleware pipeline (authentication, rate limiting, CORS, logging)
• Client connection tracking and management
• Event-driven architecture with typed events
• Custom header support for authentication

Installation

This is a shared project (.projitems). Reference it from your main project:

<Import Project="..\Birko.Communication.SSE\Birko.Communication.SSE.projitems"
        Label="Shared" />

Dependencies

• Birko.Communication - Base communication interfaces
• System.Net.Http - HTTP client for SSE connections
• System.Text.Json - JSON serialization for event data

Usage

SSE Client

using Birko.Communication.SSE;

var client = new SseClient("https://api.example.com/events");

client.OnConnected += (sender, e) => Console.WriteLine("Connected");
client.OnMessage += (sender, message) => Console.WriteLine($"Message: {message}");
client.OnEvent += (sender, sseEvent) =>
{
    Console.WriteLine($"Event: {sseEvent.Event}, Data: {sseEvent.Data}, ID: {sseEvent.Id}");
};

await client.ConnectAsync();

SSE Server

using Birko.Communication.SSE;

var server = new SseServer();
server.OnClientConnected += (sender, connection) =>
{
    Console.WriteLine("Client connected");
};

// Broadcast an event to all connected clients
var evt = new SseEvent
{
    Event = "update",
    Data = "{\"status\": \"active\"}",
    Id = "1"
};
await server.BroadcastAsync(evt);

Middleware Pipeline

using Birko.Communication.SSE.Middleware;

var config = new SseAuthenticationConfiguration { /* ... */ };
var authService = new SseAuthenticationService(config);

// Rate limiting, CORS, and logging middleware are also available

API Reference

Classes

Class	Description
SseClient	Client for receiving SSE streams, implements IDisposable
SseServer	Server for pushing events to clients, implements IDisposable
SseEvent	W3C SSE event model (Id, Event, Data, Retry)
SseMiddleware	Base middleware pipeline (SseContext, SseRequestDelegate)
SseAuthenticationMiddleware	Authentication middleware
SseRateLimitMiddleware	Rate limiting middleware
SseCorsMiddleware	CORS middleware
SseLoggingMiddleware	Request/response logging middleware
SseAuthenticationService	Authentication logic
SseAuthenticationConfiguration	Authentication settings

Namespaces

• Birko.Communication.SSE - Client, server, and event model
• Birko.Communication.SSE.Middleware - Middleware pipeline components

Related Projects

• Birko.Communication - Base communication abstractions
• Birko.Communication.WebSocket - Full-duplex WebSocket communication
• Birko.Communication.REST - REST API client/server

License

Part of the Birko Framework.