Server-Sent Events

@sse(cPath)

Register SSE endpoint for clients to subscribe.

@sse("/events")

$bolt.sseFilterParams(cPath)

Enable param-based event filtering for an SSE route. When enabled, subscribers will only receive events whose params are a superset of their own route params. Must be called after @sse.

@sse("/channel/:name")
sseFilterParams("/channel/:name")

With filtering enabled, a subscriber on /channel/sports will only receive broadcasts where the params include name: "sports". Without filtering, all subscribers on the channel receive all events.

$bolt.sseMaxSubscribers(nMax)

Set the maximum concurrent SSE subscribers per route. When the limit is reached, new subscribers receive a 503 response with a Retry-After header. Default: 1000.

sseMaxSubscribers(500)

$bolt.sseBroadcast(cPath, cData)

Send data event to all subscribers.

$bolt.sseBroadcast("/events", "New notification!")

$bolt.sseBroadcastEvent(cPath, cEventName, cData)

Send named event to all subscribers.

$bolt.sseBroadcastEvent("/events", "update", "v2 released")

$bolt.sseBroadcastParams(cPath, cData, aParams)

Send data event to subscribers matching a params filter. Only subscribers whose route params contain all the specified key-value pairs will receive the event.

$bolt.sseBroadcastParams("/sse/channel/:name", "goal!", [:name = "sports"])

Subscribers on /sse/channel/sports receive the event; subscribers on /sse/channel/tech do not.

$bolt.sseBroadcastEventParams(cPath, cEventName, cData, aParams)

Send named event to subscribers matching a params filter.

$bolt.sseBroadcastEventParams("/sse/channel/:name", "breaking", "headline", [:name = "news"])

Client-side:

const es = new EventSource('/events');
es.onmessage = (e) => console.log(e.data);
es.addEventListener('update', (e) => console.log(e.data));