Live

signal.live is HTTP SSE. Expose with .live(signal) on GET (or http.live(signal) for GET /_oke/live/{name}), then subscribe with a callback. for await stays on the server.

For developers streaming shipment status, checkout progress, or live inbox rows into a browser or ops console.

Smallest Example

import { shipmentStatus } from "@/signals/orders";

const stop = api.live(
  shipmentStatus,
  { orderId: "ord_9c2e" },
  {
    onEvent: (event) => {
      // { orderId, status: "packed" | "shipped" | "delivered", eta? }
      updateTrackingCard(event.status, event.eta);
    },
    onError: (err) => {
      showTrackingBanner(err);
    },
    autoResubscribe: false, // default — true reopens after a drop (500ms…30s backoff)
  },
);

stop(); // useEffect cleanup / process exit

Progressive Patterns

const stop = api.live(
  shipmentStatus,
  { orderId: "ord_9c2e" },
  {
    onEvent: (event) => updateTrackingCard(event.status, event.eta),
  },
);
stop();

Live handlers

Exposure matching

The client picks the unique exposure whose matchKey fields are a subset of the input, preferring the largest match ({ orderId } beats firehose). A tie needs via: "unit.flow".

api.live(
  shipmentStatus,
  { orderId: "ord_9c2e" },
  {
    onEvent: updateTrackingCard,
    via: "orders.events",
  },
);

Or call the exposing Flow directly: api.orders.events(input, { onEvent }).

Resume and LiveResumeGap

Reconnects send Last-Event-ID from the last id: the client actually received.

A 410 LiveResumeGap (OKE1210) means that cursor is gone — onError fires, the cursor is dropped, and autoResubscribe replays the remaining tape after backoff.

Server exposure: Signal · Live and HTTP · Live Streams.

Live queries (store.resource({ live: true }))

Every mutate from useLiveQuery generates a client UUID sent as the X-Oke-Mutation-Id header — the server echoes it onto that write's CDC events, so:

• Your own late SSE echoes never double-apply (pending-set dedupe).
• Reconnects replay-guard by event seq (isReplayedEvent).
• Manual refetch() re-runs only the HTTP list read; reconnects always do a full subscribe-protocol cycle (new snapshot + replay).

Consequence: optimistic patches roll back automatically when the Flow returns error !== null. Server CDC / the successful response clear the override so the next upsert is authoritative.

Full React wiring: React.

Troubleshooting

Learn more

• React — useLive, useLiveQuery
• Calling — typed proxy and envelopes
• Signal · Live — tape, resume, OKE1210
• HTTP · Live Streams — server exposure
• Store — live: true on resources

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