Using the Notification API (WebSockets) to Subscribe to Agent Presence Events

How-To-Articles
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Using the Notification API (WebSockets) to Subscribe to Agent Presence Events

Executive Summary & Architectural Context

When building real-time dashboards, custom wallboards, or WFM integrations, you need to know exactly when an agent goes “On Queue”, “Available”, or “Meal”.

The naive architectural approach is Polling-writing a script that hits the GET /api/v2/users/presence endpoint every 5 seconds. Polling is highly inefficient, introduces artificial latency, and will rapidly exhaust your Genesys Cloud API rate limits (triggering 429 Too Many Requests), taking your dashboard offline.

The enterprise standard is the Notification API. Genesys Cloud provides a robust, real-time WebSocket infrastructure. Instead of asking “Did the status change?”, your application opens a persistent WebSocket connection, subscribes to specific routing and presence topics, and Genesys Cloud actively pushes a JSON payload to your application the exact millisecond an agent’s status changes.

This masterclass details how to architect a resilient WebSocket listener, subscribe to presence topics, and properly handle connection drops and heartbeats.

Prerequisites, Roles & Licensing

  • Licensing: Available on all Genesys Cloud CX tiers.
  • Roles & Permissions:
    • OAuth Client with presence:readonly and routing:readonly scopes.
  • Platform Dependencies:
    • A runtime environment capable of maintaining persistent WebSocket connections (e.g., Node.js with the ws library, or Python with websockets).

The Implementation Deep-Dive

1. Opening the Notification Channel

Before you can subscribe to a topic, you must request a dedicated WebSocket channel from the REST API.

  1. Authenticate via OAuth and obtain your Bearer token.
  2. Execute a POST request to https://api.mypurecloud.com/api/v2/notifications/channels.
  3. The API will respond with a JSON object containing the id (the Channel ID) and the connectUri (the WebSocket URL).
{
  "connectUri": "wss://streaming.mypurecloud.com/channels/channel-id-12345",
  "id": "channel-id-12345",
  "expires": "2026-05-15T12:00:00Z"
}

2. Establishing the WebSocket Connection

Using your language’s WebSocket library, immediately open a connection to the connectUri.

Node.js Example:

const WebSocket = require('ws');
const ws = new WebSocket(channelData.connectUri);

ws.on('open', function open() {
  console.log('WebSocket connection established.');
});

ws.on('message', function incoming(data) {
  const message = JSON.parse(data);
  // Route the event payload to your business logic
  handlePresenceEvent(message); 
});

3. Subscribing to Presence Topics

Opening the socket is not enough; you are currently listening to an empty void. You must tell Genesys Cloud which agents you want to monitor by subscribing to their specific topics via the REST API.

  1. Execute a POST request to https://api.mypurecloud.com/api/v2/notifications/channels/{channel_id}/subscriptions.
  2. The payload is an array of topic strings. For routing status (On Queue vs Off Queue), the topic format is v2.users.{id}.routingStatus. For presence (Available, Meal, Meeting), the format is v2.users.{id}.presence.
[
  { "id": "v2.users.user-id-001.routingStatus" },
  { "id": "v2.users.user-id-001.presence" },
  { "id": "v2.users.user-id-002.presence" }
]

Note: You can subscribe to up to 1,000 topics per channel.

4. Processing the Push Payload

Once subscribed, if user-id-001 clicks “Meal” in their Genesys Cloud interface, your WebSocket will instantly receive a payload:

{
  "topicName": "v2.users.user-id-001.presence",
  "version": "2",
  "eventBody": {
    "source": "PURECLOUD",
    "presenceDefinition": {
      "id": "e08eaf1b-ee47-4fa9-a231-1200e284798f",
      "systemPresence": "Meal"
    },
    "primary": true
  }
}

Your code extracts eventBody.presenceDefinition.systemPresence and updates your custom dashboard UI instantly.

Validation, Edge Cases & Troubleshooting

Edge Case 1: The 24-Hour Expiration Rule

Notification channels are strictly ephemeral. A Genesys Cloud Notification Channel will forcibly close after 24 hours of existence, regardless of activity.

  • The Trap: If you deploy a server script on Friday, it will crash on Saturday when the WebSocket is terminated by the server, and your wallboard will flatline over the weekend.
  • Architectural Solution: You must write reconnect logic. When the ws.on('close') event fires, your code must intercept it, immediately execute a new POST to /notifications/channels, retrieve a new WebSocket URI, establish the connection, and crucially, re-submit all of your subscriptions to the new channel.

Edge Case 2: Handling the Heartbeat (Ping/Pong)

Network load balancers and corporate firewalls will silently kill long-running TCP connections if no data flows across them.

  • Troubleshooting: To prevent dead sockets, Genesys Cloud sends a tiny heartbeat payload {"topicName": "channel.metadata"} every few seconds. Your client must be configured to respond to standard WebSocket Ping/Pong control frames. If your client ignores these, Genesys Cloud will assume your server is dead and severe the connection.

Scaling Limit: The 1,000 Topic Cap

If you have 5,000 agents, you cannot subscribe to all of them on a single channel (the limit is 1,000 topics).

  • Solution: You must shard your connections. Open Channel A and subscribe to agents 1-500. Open Channel B and subscribe to agents 501-1000. Maintain an array of active WebSocket objects in your application state.

Official References