WebSocket & Real-time

You can broadcast real-time updates to multiple frontend clients by emitting WebSocket events immediately after backend data mutations. This approach pushes changes directly to connected UIs, ensuring instant synchronization without manual polling.

The best way to handle SSE reconnections without losing events is by utilizing an event_buffer. This mechanism stores events temporarily, ensuring that clients receive any missed event data automatically upon successfully reconnecting to the server.

WebSocket broadcast operates under a single-worker constraint by relying on in-memory distribution to route events to connected clients. This architectural choice ensures reliable message delivery within a single process before requiring external scaling solutions.

You need Redis Pub/Sub to scale WebSocket broadcasting across multi-worker deployments. The in-memory distribution works for a single worker, but Redis is required to synchronize events and broadcast messages reliably across multiple server instances.

You integrate frontend applications by connecting a dedicated client, such as budgetWSClient.js, to standardize event handling. This script manages WebSocket connections and SSE polling, ensuring your UI receives and processes real-time updates consistently.

You should consider SSE for scenarios requiring reliable event streaming with built-in reconnection buffering, while WebSocket is better suited for bidirectional communication. This Skill supports both, allowing you to push changes via WebSockets and buffer SSE events.