go-fiber-sse-user-channel

A clean and minimal Go Fiber v3 project that demonstrates how to use Server-Sent Events (SSE) to send real-time messages to clients based on user IDs.

This project is ideal as a reusable module or reference for integrating user-targeted SSE messaging in your own applications.

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🚀 Features

• 🔄 Server-Sent Events (SSE) over HTTP
• 👤 Multiple sessions per user (userID)
• 📡 Broadcast messages to all sessions of a given user
• ✅ Graceful shutdown support
• 📊 System and runtime monitoring (/metrics/system endpoint)
• ⚙️ Built with Go Fiber v3

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📦 Requirements

• Go 1.20+
• Fiber v3
• gopsutil (for system metrics)

Install dependencies:

go get github.com/gofiber/fiber/v3
go get github.com/shirou/gopsutil/v3

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🛠 Installation

git clone https://github.com/your-username/go-fiber-sse-user-channel.git
cd go-fiber-sse-user-channel
go run main.go

Server will run on http://localhost:8080

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📘 API Endpoints

1. GET /sse?userID=123

Establishes an SSE connection for the given user ID.

Example cURL:

curl -N http://localhost:8080/sse?userID=123

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2. POST /send-to-user

Broadcasts a message to all active sessions of a given user.

Request Body:

{
  "userID": "123",
  "value": {
    "message": "Hello world!"
  }
}

Response:

{
  "sent": 2
}

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3. GET /health

Basic health check endpoint.

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4. GET /connections

Returns the number of open HTTP connections and active sessions.

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5. GET /metrics/system

Returns detailed system and Go runtime metrics including:

• CPU usage %
• RAM usage (used / total)
• Go memory stats
• GC cycles
• Active goroutines
• Timestamp

Useful for observability and debugging.

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🧪 Example Client (HTML)

You can test the SSE functionality using the included example HTML file:

open examples/sse-client.html

Make sure the Go server is running on http://localhost:8080, then open the file in your browser and enter a user ID to start receiving real-time messages.

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🧼 Graceful Shutdown

When you press Ctrl+C or terminate the process:

• All active SSE connections are closed
• Channels are cleaned up
• The server exits cleanly within a 5-second timeout

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💡 Use Cases

• Real-time user notifications (e.g. order status updates)
• One-way messaging without full WebSocket complexity
• Live dashboards or system updates per user

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🤝 Contributing

Feel free to fork this repo or open an issue / PR if you have suggestions or improvements.

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📄 License

MIT — see LICENSE for details.