Build a Genesys Cloud Presence Event Listener with Python WebSockets

What You Will Build

This tutorial builds a Python service that subscribes to Genesys Cloud agent status changes via the WebSocket API and routes filtered events to an external workforce management webhook. The implementation uses the wss://api.mypurecloud.com/api/v2/websocket endpoint and the websocket-client library. The code covers atomic CONNECT payload construction, subscription schema validation, automatic heartbeat management, latency tracking, and structured audit logging.

Prerequisites

• OAuth 2.0 Client Credentials flow configured in the Genesys Cloud admin console
• Required OAuth scope: presence:view
• Genesys Cloud API version: v2
• Python runtime: 3.9 or higher
• External dependencies: pip install websocket-client requests python-dotenv

Authentication Setup

Genesys Cloud WebSocket connections require a valid OAuth 2.0 access token. The token must include the presence:view scope. The following code retrieves the token and validates the scope before attempting a WebSocket handshake.

import os
import requests
import json
from typing import Dict, Optional

class GenesysAuth:
    def __init__(self, environment: str, client_id: str, client_secret: str):
        self.base_url = f"https://api.{environment}.mypurecloud.com"
        self.client_id = client_id
        self.client_secret = client_secret
        self.token: Optional[str] = None
        self.scopes: list[str] = []

    def fetch_token(self) -> str:
        url = f"{self.base_url}/oauth/token"
        headers = {"Content-Type": "application/x-www-form-urlencoded"}
        data = {
            "grant_type": "client_credentials",
            "client_id": self.client_id,
            "client_secret": self.client_secret,
            "scope": "presence:view"
        }
        
        response = requests.post(url, headers=headers, data=data)
        response.raise_for_status()
        
        token_data = response.json()
        self.token = token_data["access_token"]
        self.scopes = token_data.get("scope", "").split()
        return self.token

    def verify_scope(self, required_scope: str) -> bool:
        return required_scope in self.scopes

# Example usage
# auth = GenesysAuth("us-east-1", os.getenv("GENESYS_CLIENT_ID"), os.getenv("GENESYS_CLIENT_SECRET"))
# token = auth.fetch_token()
# assert auth.verify_scope("presence:view"), "Missing presence:view scope"

The token response contains a scope field. The verification step prevents silent failures when the WebSocket server rejects subscriptions due to insufficient permissions.

Implementation

Step 1: Atomic CONNECT Operation and Payload Construction

The Genesys Cloud WebSocket API requires an immediate CONNECT message after the TCP handshake. This message must contain a unique clientId, a version, and a subscriptions array. The server responds with a status confirmation before any events stream. Sending data before receiving the ACK causes a protocol violation and connection termination.

import websocket
import json
import time
from typing import List, Dict, Any

class ConnectPayloadBuilder:
    @staticmethod
    def build(client_id: str, subscriptions: List[Dict[str, Any]]) -> Dict[str, Any]:
        return {
            "clientId": client_id,
            "version": "1.0.0",
            "subscriptions": subscriptions
        }

def send_connect(ws: websocket.WebSocket, payload: Dict[str, Any]) -> Dict[str, Any]:
    ws.send(json.dumps(payload))
    
    # Wait for ACK with timeout
    ws.settimeout(10.0)
    try:
        ack_raw = ws.recv()
        ack = json.loads(ack_raw)
        
        if ack.get("status") != "success":
            raise ValueError(f"CONNECT rejected: {ack.get('error', 'Unknown error')}")
            
        return ack
    except websocket.WebSocketTimeoutException:
        raise ConnectionError("CONNECT ACK timed out. Server may be overloaded.")

The clientId must be unique per connection. Reusing a clientId while another connection is active forces the server to drop the older session. The subscriptions array defines the change matrix. For agent status, the subscription object is {"type": "presence"}.

Step 2: Subscription Schema Validation and Constraint Checking

Genesys Cloud enforces a maximum of 500 subscriptions per WebSocket connection. Exceeding this limit returns a 400-level protocol error. The validation pipeline checks subscription count, verifies JSON structure, and confirms the OAuth scope before allowing the connection to proceed.

import jsonschema

SUBSCRIPTION_SCHEMA = {
    "type": "array",
    "items": {
        "type": "object",
        "required": ["type"],
        "properties": {
            "type": {"type": "string", "enum": ["presence", "routing:queue", "routing:conversation"]}
        }
    },
    "maxItems": 500
}

def validate_subscriptions(subscriptions: List[Dict[str, Any]], available_scopes: list[str]) -> None:
    # Structural validation
    try:
        jsonschema.validate(instance=subscriptions, schema=SUBSCRIPTION_SCHEMA)
    except jsonschema.exceptions.ValidationError as err:
        raise ValueError(f"Subscription schema violation: {err.message}")

    # Capability and scope verification
    presence_subscribed = any(sub.get("type") == "presence" for sub in subscriptions)
    if presence_subscribed and "presence:view" not in available_scopes:
        raise PermissionError("Subscription requires 'presence:view' OAuth scope")

    print(f"Validation passed. Subscription count: {len(subscriptions)}/500")

This step prevents runtime failures during scaling events when dynamic subscription generation might exceed limits. The jsonschema library ensures the payload matches the server expectation before network transmission.

Step 3: Event Filtering, Deserialization, and Heartbeat Management

The WebSocket stream delivers JSON messages continuously. The server expects a PING message every 20 to 30 seconds. Failure to send PING results in a server-initiated disconnect. The following implementation runs the heartbeat in a background thread, filters presence events by status change, and calculates delivery latency.

import threading
import logging
from datetime import datetime, timezone

logging.basicConfig(level=logging.INFO, format="%(asctime)s [%(levelname)s] %(message)s")

class PresenceListener:
    def __init__(self, ws: websocket.WebSocket, webhook_url: str):
        self.ws = ws
        self.webhook_url = webhook_url
        self.running = False
        self.heartbeat_thread: Optional[threading.Thread] = None
        self.metrics = {"events_received": 0, "webhooks_sent": 0, "latency_sum_ms": 0.0}

    def start_heartbeat(self, interval: int = 25):
        def _ping_loop():
            while self.running:
                try:
                    self.ws.send(json.dumps({"type": "PING"}))
                    # Server responds with PONG automatically handled by library, 
                    # but we wait to avoid flooding
                    time.sleep(interval)
                except Exception as e:
                    logging.error(f"Heartbeat failed: {e}")
                    break
        
        self.heartbeat_thread = threading.Thread(target=_ping_loop, daemon=True)
        self.heartbeat_thread.start()

    def process_stream(self):
        self.running = True
        self.start_heartbeat()
        
        while self.running:
            try:
                raw = self.ws.recv()
                message = json.loads(raw)
                
                # Skip PONG responses
                if message.get("type") == "PONG":
                    continue
                    
                if message.get("eventType") == "presence":
                    self._handle_presence_event(message)
                    
            except websocket.WebSocketConnectionClosedException:
                logging.warning("WebSocket closed by server. Reconnecting in 5s...")
                time.sleep(5)
                break
            except json.JSONDecodeError as e:
                logging.error(f"Invalid JSON from server: {e}")
            except Exception as e:
                logging.error(f"Stream processing error: {e}")
                break

    def _handle_presence_event(self, event: Dict[str, Any]):
        self.metrics["events_received"] += 1
        
        # Calculate latency
        event_ts = datetime.fromisoformat(event["timestamp"].replace("Z", "+00:00"))
        receipt_ts = datetime.now(timezone.utc)
        latency_ms = (receipt_ts - event_ts).total_seconds() * 1000
        self.metrics["latency_sum_ms"] += latency_ms
        
        # Audit log
        logging.info(
            f"AUDIT | userId={event.get('userId')} | "
            f"status={event.get('presenceStatus', {}).get('name')} | "
            f"latency={latency_ms:.2f}ms"
        )
        
        # Sync to external platform
        self._sync_to_webhook(event, latency_ms)

    def _sync_to_webhook(self, event: Dict[str, Any], latency_ms: float):
        payload = {
            "source": "genesys-cloud-presence",
            "userId": event.get("userId"),
            "status": event.get("presenceStatus", {}).get("name"),
            "timestamp": event.get("timestamp"),
            "deliveryLatencyMs": latency_ms
        }
        
        try:
            resp = requests.post(self.webhook_url, json=payload, timeout=5.0)
            resp.raise_for_status()
            self.metrics["webhooks_sent"] += 1
        except requests.RequestException as e:
            logging.error(f"Webhook delivery failed: {e}")

The heartbeat thread runs independently to prevent blocking the main event loop. The latency calculation compares the server-generated timestamp field against local receipt time. The audit log records every status change for governance compliance.

Complete Working Example

import os
import sys
import json
import time
import logging
import requests
import websocket
import threading
from typing import Dict, List, Optional, Any
from datetime import datetime, timezone
import jsonschema

# Configure logging
logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s [%(levelname)s] %(message)s",
    handlers=[logging.StreamHandler(sys.stdout)]
)

class GenesysPresenceClient:
    def __init__(self, environment: str, client_id: str, client_secret: str, webhook_url: str):
        self.environment = environment
        self.client_id = client_id
        self.client_secret = client_secret
        self.webhook_url = webhook_url
        self.ws_url = f"wss://api.{environment}.mypurecloud.com/api/v2/websocket"
        self.access_token: Optional[str] = None
        self.ws: Optional[websocket.WebSocket] = None
        self.running = False
        
        # Validation schemas
        self.subscription_schema = {
            "type": "array",
            "items": {"type": "object", "required": ["type"], "properties": {"type": {"type": "string"}}},
            "maxItems": 500
        }

    def authenticate(self) -> None:
        url = f"https://api.{self.environment}.mypurecloud.com/oauth/token"
        data = {
            "grant_type": "client_credentials",
            "client_id": self.client_id,
            "client_secret": self.client_secret,
            "scope": "presence:view"
        }
        resp = requests.post(url, data=data)
        resp.raise_for_status()
        token_data = resp.json()
        self.access_token = token_data["access_token"]
        scopes = token_data.get("scope", "").split()
        if "presence:view" not in scopes:
            raise PermissionError("Token missing required 'presence:view' scope")
        logging.info("OAuth authentication successful")

    def validate_payload(self, subscriptions: List[Dict[str, Any]]) -> None:
        try:
            jsonschema.validate(instance=subscriptions, schema=self.subscription_schema)
        except jsonschema.exceptions.ValidationError as err:
            raise ValueError(f"Payload validation failed: {err.message}")
        logging.info(f"Payload validated. Subscriptions: {len(subscriptions)}")

    def connect(self) -> None:
        self.authenticate()
        
        # Construct atomic CONNECT directive
        subscriptions = [{"type": "presence"}]
        self.validate_payload(subscriptions)
        
        connect_msg = {
            "clientId": f"presence-listener-{int(time.time())}",
            "version": "1.0.0",
            "subscriptions": subscriptions
        }
        
        logging.info("Establishing WebSocket connection...")
        self.ws = websocket.WebSocket()
        self.ws.connect(self.ws_url)
        
        # Send CONNECT and wait for ACK
        self.ws.send(json.dumps(connect_msg))
        self.ws.settimeout(10.0)
        try:
            ack_raw = self.ws.recv()
            ack = json.loads(ack_raw)
            if ack.get("status") != "success":
                raise RuntimeError(f"CONNECT rejected: {ack.get('error')}")
            logging.info("CONNECT acknowledged by Genesys Cloud")
        except websocket.WebSocketTimeoutException:
            raise ConnectionError("CONNECT ACK timed out")

    def run(self) -> None:
        self.connect()
        self.running = True
        
        # Start heartbeat thread
        def _heartbeat():
            while self.running:
                try:
                    self.ws.send(json.dumps({"type": "PING"}))
                    time.sleep(25)
                except Exception as e:
                    logging.error(f"Heartbeat error: {e}")
                    break
        threading.Thread(target=_heartbeat, daemon=True).start()
        
        # Main event loop
        try:
            while self.running:
                raw = self.ws.recv()
                msg = json.loads(raw)
                
                if msg.get("type") == "PONG":
                    continue
                    
                if msg.get("eventType") == "presence":
                    self._process_event(msg)
        except websocket.WebSocketConnectionClosedException:
            logging.warning("Connection closed. Exiting listener.")
        except Exception as e:
            logging.error(f"Fatal stream error: {e}")
        finally:
            self.stop()

    def _process_event(self, event: Dict[str, Any]) -> None:
        event_ts = datetime.fromisoformat(event["timestamp"].replace("Z", "+00:00"))
        receipt_ts = datetime.now(timezone.utc)
        latency_ms = (receipt_ts - event_ts).total_seconds() * 1000
        
        logging.info(
            f"AUDIT | userId={event.get('userId')} | "
            f"status={event.get('presenceStatus', {}).get('name')} | "
            f"latency={latency_ms:.2f}ms"
        )
        
        webhook_payload = {
            "source": "genesys-cloud",
            "userId": event.get("userId"),
            "status": event.get("presenceStatus", {}).get("name"),
            "timestamp": event.get("timestamp"),
            "latencyMs": latency_ms
        }
        
        try:
            resp = requests.post(self.webhook_url, json=webhook_payload, timeout=5.0)
            resp.raise_for_status()
        except requests.RequestException as e:
            logging.error(f"Webhook sync failed: {e}")

    def stop(self) -> None:
        self.running = False
        if self.ws:
            try:
                self.ws.close()
            except Exception:
                pass
        logging.info("Listener stopped")

if __name__ == "__main__":
    ENV = os.getenv("GENESYS_ENV", "us-east-1")
    CLIENT_ID = os.getenv("GENESYS_CLIENT_ID")
    CLIENT_SECRET = os.getenv("GENESYS_CLIENT_SECRET")
    WEBHOOK_URL = os.getenv("WEBHOOK_URL", "https://httpbin.org/post")
    
    if not all([CLIENT_ID, CLIENT_SECRET]):
        sys.exit("Missing required environment variables: GENESYS_CLIENT_ID, GENESYS_CLIENT_SECRET")
        
    client = GenesysPresenceClient(ENV, CLIENT_ID, CLIENT_SECRET, WEBHOOK_URL)
    try:
        client.run()
    except KeyboardInterrupt:
        client.stop()

Common Errors & Debugging

Error: 401 Unauthorized or WebSocket Handshake Failure

• Cause: Expired OAuth token or missing presence:view scope in the client configuration.
• Fix: Regenerate the token before connecting. Verify the client credentials in the Genesys Cloud admin console. Ensure the scope parameter in the POST request to /oauth/token explicitly includes presence:view.

Error: 400 Bad Request or CONNECT Rejected

• Cause: Malformed clientId, missing version field, or subscription array exceeds 500 items.
• Fix: Validate the CONNECT JSON structure before transmission. Ensure clientId is unique per session. Reduce subscription count if dynamic generation is active. The server returns an error object in the ACK response that specifies the exact violation.

Error: WebSocket Connection Closed by Server

• Cause: Missing or delayed PING heartbeat. The server terminates idle connections after approximately 30 seconds.
• Fix: Implement a background thread sending {"type": "PING"} every 20 to 25 seconds. Do not block the main recv loop with synchronous sleeps. The provided example uses a daemon thread to guarantee heartbeat delivery without interfering with event processing.

Error: 429 Too Many Requests (API Rate Limit)

• Cause: While the WebSocket API itself is not rate-limited in the traditional HTTP sense, rapid reconnection attempts or excessive OAuth token requests trigger rate limiting on the underlying gateway.
• Fix: Implement exponential backoff for reconnection logic. Cache OAuth tokens and refresh only after expiration. The WebSocket connection should remain open for the lifetime of the listener to avoid repeated authentication overhead.

Official References

• Genesys Cloud WebSocket API Documentation
• Genesys Cloud OAuth 2.0 Guide
• Genesys Cloud Presence Data Model
• websocket-client Python Library