Streaming Response from Route Handler

// app/api/stream/route.ts
export async function GET() {
  const encoder = new TextEncoder();

  const stream = new ReadableStream({
    async start(controller) {
      for (let i = 0; i < 10; i++) {
        const data = JSON.stringify({ count: i, timestamp: Date.now() });
        controller.enqueue(encoder.encode(`data: ${data}\n\n`));
        await new Promise((r) => setTimeout(r, 500));
      }
      controller.enqueue(encoder.encode('data: [DONE]\n\n'));
      controller.close();
    },
  });

  return new Response(stream, {
    headers: {
      'Content-Type': 'text/event-stream',
      'Cache-Control': 'no-cache',
      Connection: 'keep-alive',
    },
  });
}

// Server-Sent Events with dynamic data
// app/api/notifications/route.ts
export async function GET(request: Request) {
  const encoder = new TextEncoder();

  const stream = new ReadableStream({
    async start(controller) {
      const send = (event: string, data: unknown) => {
        controller.enqueue(
          encoder.encode(`event: ${event}\ndata: ${JSON.stringify(data)}\n\n`)
        );
      };

      // Send initial data
      send('connected', { status: 'ok' });

      // Poll for updates
      const interval = setInterval(async () => {
        const notifications = await getNewNotifications();
        if (notifications.length > 0) {
          send('notification', notifications);
        }
      }, 5000);

      // Cleanup on disconnect
      request.signal.addEventListener('abort', () => {
        clearInterval(interval);
        controller.close();
      });
    },
  });

  return new Response(stream, {
    headers: {
      'Content-Type': 'text/event-stream',
      'Cache-Control': 'no-cache',
    },
  });
}