Building a shift management automation tool that changes agent statuses in bulk at the start and end of shifts. The tool calls the Presence API to set all agents to “On Queue” at 09:00 and “Off Queue” at 18:00.
The API calls succeed individually, but when we fire 50+ status changes within a 10-second window, our real-time monitoring dashboard (which subscribes to presence notifications via WebSocket) goes haywire. Agents briefly show as “On Queue” then snap back to “Available” then back to “On Queue” in rapid succession.
The monitoring dashboard subscribes to v2.users.{userId}.presence for each agent. During the bulk status change, we receive 3-5 presence events per agent instead of the expected single event. The events arrive out of order - we see the final state, then a stale state, then the final state again.
The API calls themselves are straightforward:
PATCH /api/v2/users/{userId}/presences/PURECLOUD
{
"presenceDefinition": { "id": "on-queue-presence-id" }
}
Is there a recommended pattern for bulk presence changes that avoids flooding the notification channel with out-of-order events?
The out-of-order events are caused by the presence system’s event fan-out architecture. When you change a user’s presence via the API, the change propagates through multiple internal services (routing engine, notification bus, analytics pipeline). Each service emits its own presence change event, and these events can arrive at your WebSocket subscription in any order.
The standard fix is to implement a debounce buffer on your notification handler. Do not process presence events immediately. Buffer them for 2 seconds, then only apply the most recent event per user:
const presenceBuffer = {};
ws.onmessage = (event) => {
const data = JSON.parse(event.data);
const userId = data.eventBody.id;
presenceBuffer[userId] = data.eventBody;
clearTimeout(presenceBuffer[userId + '_timer']);
presenceBuffer[userId + '_timer'] = setTimeout(() => {
applyPresenceUpdate(userId, presenceBuffer[userId]);
delete presenceBuffer[userId];
}, 2000);
};
For the bulk API calls themselves, add a 200ms delay between each PATCH request. The rate limit on the Presence API is 10 requests per second per org, not per user. Firing 50 requests in 10 seconds is within the limit but creates a thundering herd on the notification bus.
The debounce approach is the correct client-side fix. I want to add a server-side optimization that dramatically reduces the event noise for bulk operations.
Instead of calling the individual user presence endpoint 50 times, use the bulk presence update endpoint:
PATCH /api/v2/users/presences/bulk
{
"entities": [
{ "id": "user1-id", "presenceDefinition": { "id": "on-queue-id" } },
{ "id": "user2-id", "presenceDefinition": { "id": "on-queue-id" } }
]
}
The bulk endpoint processes all changes as a single atomic operation, which results in exactly one presence notification event per user rather than the 3-5 duplicate events you see with individual API calls. The internal event fan-out is batched, so the routing engine and notification bus receive a single consolidated update.
The bulk endpoint accepts up to 100 users per request. For our healthcare contact center with 200 agents, we make 2 bulk calls at shift change and the notification channel stays clean.
One important caveat: the bulk endpoint requires the users:write OAuth scope rather than the presence:write scope used by the individual endpoint. Make sure your OAuth client has the correct permissions.