Events & subscriptions

Subscribe to live data with @sixb/client/hooks. Subscriptions use your browser session, or a native client's session, and receive only events permitted by your grants.

For a normal action button, use useActionRunMutation. It already waits for the action and refreshes changed data.

Subscribe to changes

Use a typed event builder with useEvents:

import { events, useEvents } from "@sixb/client/hooks"
import { Invoice } from "../ontology/invoice"

function InvoiceActivity({ invoiceId }: { invoiceId: string }) {
  const state = useEvents(events.object(Invoice).byId(invoiceId).updated(), (event) => {
    console.log("Invoice changed", event.payload.properties)
  })

  return <span>{state.connected ? "Live" : "Offline"}</span>
}

The hook manages subscription cleanup and reconnects. For a standalone browser app, complete client setup first.

Filter events

Use topic builders such as events.datasets(), events.rules(), and events.schedules() for broader subscriptions. events.all() selects all visible events.

Read live telemetry

useLatest keeps the latest received value for each telemetry property:

import { events, useLatest } from "@sixb/client/hooks"
import { Device } from "../ontology/device"

function Temperature({ deviceId }: { deviceId: string }) {
  const { values } = useLatest(events.object(Device).byId(deviceId).telemetry())
  const value = values[Device.p.temperature.id]?.value
  return <span>{value == null ? "No reading" : String(value)}</span>
}

Use useLatestByObject for several objects; its byObject result groups values by object ID. Both hooks reset accumulated values when the subscription scope changes. They track received events; use a telemetry query when you also need stored readings.

Refresh queries

Use useInvalidateOnEvent to refresh cached queries after matching changes:

import { events, objectQueryKeys, useInvalidateOnEvent } from "@sixb/client/hooks"
import { Invoice } from "../ontology/invoice"
import { openInvoices } from "../queries/invoices"

useInvalidateOnEvent(
  events.object(Invoice).upserted(),
  () => [objectQueryKeys.list(openInvoices.limit(50))],
  { debounceMs: 50 }
)

Subscription options

useEvents accepts an optional third argument:

For protocol messages and replay behavior, see WebSockets. Event-triggered backend work belongs in Schedules.