FIXED-SOURCE RECORD

Event Relay

Event relay: one shared SSE channel pushing host-side events to subscribed browser surfaces. Frames carry an optional JSON payload — some plugins use it as a pure change signal (doorbell style, refetching their own truth), others consume the payload directly (notifications, kanban updates). Client opens the stream with the union of subscribed topic prefixes (server-side filtering) and signals reconnects via __relay/open.