Building Real-Time Updates with Server-Sent Events (SSE)

For web development, real-time updates are everywhere — think live stock tickers, chat notifications, or server monitoring dashboards. While WebSocket often steals the spotlight for real-time communication, Server-Sent Events (SSE) offers a simpler, HTTP-based alternative for server-to-client streaming. In this article, we’ll explore how to implement SSE using go-zero, a high-performance Go framework, complete with a working example you can try yourself.

Why SSE?

SSE is a lightweight protocol built into HTML5, designed for scenarios where the server needs to push updates to clients over a single, long-lived HTTP connection. Unlike WebSocket’s bidirectional complexity, SSE is unidirectional and leverages standard HTTP, making it easier to set up and debug.

Key benefits:

• Simplicity: Uses plain text/event-stream over HTTP.
• Built-in Reconnection: Browsers automatically retry on disconnects.
• Lightweight: Perfect for one-way data flows like notifications or live feeds.

Today, we’ll use go-zero to build an SSE service that streams server timestamps to connected clients every second. Let’s dive in!

Setting Up the Project

First, ensure you have Go installed (1.16+ recommended). Then, grab the go-zero framework:

go get -u github.com/zeromicro/go-zero