speckit.event-realtimelisted

## 🎯 Mission Design and implement ultra-reliable real-time communications and event-driven distributed architectures. Ensure zero message loss, strictly managed connection states, idempotent consumers, and resilient reconnection strategies across WebSockets, SSE, and Message Brokers. ## 📥 Required Inputs - `.agents/specs/[feature]/spec.md`, `plan.md`, and `tasks.md` - Target transport (WebSocket, Server-Sent Events, Webhooks, Message Broker) - Event schemas, ordering guarantees, and throughput requirements ## 📋 Protocol ### 1. WebSocket Architecture (Multi-Node Scaling) - **Stateless Server Nodes**: Distribute WebSocket connections across multiple server instances using Redis Pub/Sub, Redis Streams, or RabbitMQ as the central message bus backplane. - **Connection Heartbeat**: Implement ping/pong heartbeat every 30 seconds. Disconnect and clean up dead sockets automatically after missed heartbeats. - **Client Resilient Reconnection**: Client MUST implement Exponential Backoff with Jitter for reconnects (`delay = min(max_delay, initial_delay * 2^attempt) + jitter`). - **Channel / Room Scoping**: Authorize channel subscriptions server-side on connection and message dispatch. ### 2. Server-Sent Events (SSE) for Unidirectional Streams - **Use Cases**: Live LLM token streaming, notification feeds, progress dashboards. - **Headers**: Set `Content-Type: text/event-stream`, `Cache-Control: no-cache`, `Connection: keep-alive`, `X-Accel-Buffering: no` (for Nginx proxy). - **Eve