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Realtime Overview

@mountsqli/realtime adds live behavior on top of your data: a Hub of Channels, PresenceChannel for who’s online, and LiveQuery for query results that update as data changes.

Pieces

Section titled “Pieces”
Class Role
Hub owns channels, presence rooms, live queries
Channel pub/sub by name
PresenceChannel tracks members in a room
LiveQuery re-runs a query on change and pushes diffs

How it fits

Section titled “How it fits”
graph TD
  H[Hub] --> C[Channel: publish/subscribe]
  H --> P[PresenceChannel: who is here]
  H --> L[LiveQuery: query + diffs]

Why in-process pub/sub?

Section titled “Why in-process pub/sub?”

The Hub is an in-process message bus — fast, no network. The mountsqli dev server exposes it over SSE (/live/<channel>) so browsers can subscribe.

Best practices

Section titled “Best practices”
  • Use LiveQuery for dashboards that must reflect writes immediately.
  • Use PresenceChannel for “who’s online” without polling.
  • Unsubscribe (Unsubscribe) when a client disconnects.

Common mistakes

Section titled “Common mistakes”
  • Assuming the Hub spans processes — it’s in-process; use an external bus for multi-instance.
  • Forgetting to unsubscribe — leaks subscribers.
Section titled “Related”