Server-Sent Events(SSE)

Github Source: https://github.com/gogf/examples/tree/main/httpserver/sse

Description

This example demonstrates how to implement Server-Sent Events (SSE) using GoFrame. Server-Sent Events is a technology that allows a server to push updates to a client via HTTP connection. Unlike WebSocket, SSE is unidirectional - only the server can send data to the client.

The example implements a simple SSE server that streams responses character by character, simulating a real-time typing effect commonly seen in modern AI chat applications.

Requirements

• Go 1.22 or higher
• Git
• GoFrame

Structure

- go.mod: The Go module file.
- main.go: The main application entry point with SSE implementation.

Features

• Server-Sent Events implementation
• Character-by-character streaming response for simulated AI chat
• Proper HTTP headers for SSE

Setup

1. Clone the repository:

   git clone https://github.com/gogf/examples.git
   cd examples/httpserver/sse

2. Install the dependencies:

   go mod tidy

3. Run the application:

   go run main.go

Usage

1. Run the example:

   go run main.go

2. The server will start at: http://127.0.0.1:8000

3. Access the SSE endpoint:

   • In a browser, navigate to: http://127.0.0.1:8000/ai/chat
   • You should see words appearing one by one with a typing effect

Implementation Details

The SSE implementation includes:

• Setting the correct HTTP headers for SSE:

  • Content-Type: text/event-stream
  • Cache-Control: no-cache
  • Connection: keep-alive

• Streaming response with proper flushing

• Simulated typing delay using time.Sleep

• Simple HTTP routing with GoFrame's router

Notes

• SSE connections remain open until explicitly closed by the client
• The server must flush the response buffer after each message
• For production use, consider implementing reconnection logic and event IDs
• SSE works over regular HTTP/HTTPS and supports automatic reconnection in browsers