SSE Skill

Expert assistance for implementing Server-Sent Events for real-time streaming.

Capabilities

• Implement SSE endpoints
• Handle streaming responses
• Manage client connections
• Build event-driven updates
• Implement reconnection

Usage

Invoke this skill when you need to:

• Stream updates to clients
• Implement live feeds
• Build notification systems
• One-way real-time communication

Implementation

// Server
app.get('/events', (req, res) => {
  res.setHeader('Content-Type', 'text/event-stream');
  res.setHeader('Cache-Control', 'no-cache');
  res.setHeader('Connection', 'keep-alive');

  const sendEvent = (event: string, data: object) => {
    res.write(`event: ${event}\n`);
    res.write(`data: ${JSON.stringify(data)}\n\n`);
  };

  // Send initial data
  sendEvent('connected', { timestamp: Date.now() });

  // Subscribe to updates
  const unsubscribe = eventEmitter.on('update', (data) => {
    sendEvent('update', data);
  });

  req.on('close', () => {
    unsubscribe();
  });
});

// Client
const eventSource = new EventSource('/events');

eventSource.addEventListener('update', (event) => {
  const data = JSON.parse(event.data);
  console.log('Update:', data);
});

Best Practices

• Handle reconnection
• Use event types for routing
• Implement keep-alive
• Clean up on disconnect

Target Processes

• real-time-updates
• live-feeds
• notification-systems