Real-time streaming: SSE/WebSocket push for breaking news and alerts

[maxwangsongyuan]

Summary

Upgrade from HTTP polling to Server-Sent Events (SSE) for real-time push of breaking news, alerts, and data updates to the browser.

Current State

All browser-to-backend communication uses HTTP polling via SmartPollLoop:

• Telegram Intel: 60s polling
• OREF Alerts: 120s polling
• RSS News: 15min polling
• AIS Vessels: 5min polling (WebSocket upstream exists on Railway relay, but frontend polls HTTP)

Proposed Architecture

Railway relay ──SSE──→ Browser
  - Breaking news alerts (instant push)
  - OREF alerts (instant push)
  - AIS position updates (near real-time)
  - Telegram intel (reduced latency)

Why SSE over WebSocket

• Unidirectional (server→client) is sufficient
• HTTP compatible (works with Vercel Edge)
• Native EventSource API in browsers
• Auto-reconnect built in

Priority

Deferred — current polling intervals are acceptable for MVP. Real-time push becomes important when:

• User count increases (polling doesn't scale)
• Breaking news latency matters (15min RSS delay is too slow)
• AIS tracking needs sub-minute updates

Related

• Design discussion in session 2026-03-07
• SmartPollLoop in src/services/runtime.ts
• Railway relay in scripts/ais-relay.cjs
• Breaking news events: wm:breaking-news CustomEvent pattern already exists