Streaming Genesys Cloud Interaction State Changes via WebSockets with Node.js

What You Will Build

A Node.js service that maintains a persistent WebSocket connection to Genesys Cloud, filters interaction events by channel type and status, validates payloads against strict schemas, and exposes a typed event emitter for dashboard integration. This tutorial uses the Genesys Cloud Real-Time Interactions API. The implementation covers TypeScript with Node.js 18+.

Prerequisites

• OAuth 2.0 Client Credentials grant type with scopes: interaction:read
• Genesys Cloud WebSocket API endpoint: wss://api.{region}.genesyscloud.com/api/v2/interactions/stream
• Node.js 18+ with TypeScript 5+
• External dependencies: ws, zod, dotenv
• Package installation: npm install ws zod dotenv

Authentication Setup

Genesys Cloud WebSockets require a valid OAuth 2.0 access token in the initial handshake query string. The token must be refreshed before expiration to avoid forced disconnects. The following code fetches a client credentials token and caches the expiry timestamp.

import dotenv from 'dotenv';
dotenv.config();

const REGION = process.env.GENESYS_REGION || 'my';
const CLIENT_ID = process.env.GENESYS_CLIENT_ID;
const CLIENT_SECRET = process.env.GENESYS_CLIENT_SECRET;
const TOKEN_URL = `https://api.${REGION}.genesyscloud.com/oauth/token`;

interface OAuthToken {
  access_token: string;
  expires_in: number;
  token_type: string;
}

async function fetchAccessToken(): Promise<OAuthToken> {
  const response = await fetch(TOKEN_URL, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/x-www-form-urlencoded',
      'Authorization': `Basic ${Buffer.from(`${CLIENT_ID}:${CLIENT_SECRET}`).toString('base64')}`
    },
    body: 'grant_type=client_credentials'
  });

  if (!response.ok) {
    const errorBody = await response.text();
    throw new Error(`OAuth token fetch failed with status ${response.status}: ${errorBody}`);
  }

  return response.json() as Promise<OAuthToken>;
}

The fetchAccessToken function returns a token object. You must store the expires_in value to schedule token rotation. Genesys Cloud tokens typically expire in 3600 seconds. Rotation logic occurs five minutes before expiry to prevent connection drops.

Implementation

Step 1: WebSocket Connection and Subscription Payload Construction

The WebSocket connection initializes with the access token appended to the URL. Immediately after connection, you must send a subscription message containing filter criteria. The filter restricts events to specific channel types and interaction statuses, reducing bandwidth and processing overhead.

import WebSocket from 'ws';
import { EventEmitter } from 'events';

interface StreamConfig {
  region: string;
  accessToken: string;
  channelTypes: string[];
  statuses: string[];
}

class StreamConnection {
  private ws: WebSocket | null = null;
  private config: StreamConfig;
  private emitter: EventEmitter;

  constructor(config: StreamConfig, emitter: EventEmitter) {
    this.config = config;
    this.emitter = emitter;
  }

  private getWsUrl(): string {
    return `wss://api.${this.config.region}.genesyscloud.com/api/v2/interactions/stream?access_token=${this.config.accessToken}`;
  }

  connect(): void {
    this.ws = new WebSocket(this.getWsUrl());
    this.setupEventListeners();
  }

  private setupEventListeners(): void {
    if (!this.ws) return;

    this.ws.on('open', () => {
      const subscriptionPayload = {
        filter: {
          types: this.config.channelTypes,
          status: this.config.statuses
        }
      };
      this.ws?.send(JSON.stringify(subscriptionPayload));
      console.log('[WS] Connected and subscription sent');
    });

    this.ws.on('message', (data: Buffer) => {
      const rawMessage = data.toString('utf-8');
      this.emitter.emit('rawMessage', rawMessage);
    });

    this.ws.on('error', (error) => {
      console.error('[WS] Connection error:', error.message);
      this.emitter.emit('wsError', error);
    });

    this.ws.on('close', (code, reason) => {
      console.log(`[WS] Closed with code ${code}: ${reason.toString()}`);
      this.emitter.emit('wsClose', { code, reason: reason.toString() });
    });
  }

  sendRefreshToken(newToken: string): void {
    if (!this.ws || this.ws.readyState !== WebSocket.OPEN) return;
    const refreshPayload = {
      type: 'refresh',
      access_token: newToken
    };
    this.ws.send(JSON.stringify(refreshPayload));
    console.log('[WS] Token refresh message sent');
  }

  close(): void {
    this.ws?.close(1000, 'Client shutdown');
  }
}

The subscription payload uses the types and status fields within the filter object. This matches the Genesys Cloud Real-Time API specification. The open event triggers the subscription immediately. The message event forwards raw data to the emitter for downstream processing.

Step 2: Reconnection Logic with Exponential Backoff and Session Token Rotation

Network interruptions and token expirations require resilient reconnection logic. Exponential backoff prevents overwhelming the API during outages. Token rotation uses the refresh message type to maintain the connection without dropping.

import { setTimeout as sleep } from 'timers/promises';

class ReconnectionManager {
  private maxRetries = 10;
  private baseDelayMs = 1000;
  private currentRetry = 0;
  private tokenExpiryTimestamp: number = 0;
  private refreshTimer: NodeJS.Timeout | null = null;

  constructor(
    private connection: StreamConnection,
    private emitter: EventEmitter,
    private fetchToken: () => Promise<{ access_token: string; expires_in: number }>
  ) {}

  async start(): Promise<void> {
    await this.reconnect();
  }

  private async reconnect(): Promise<void> {
    if (this.currentRetry >= this.maxRetries) {
      console.error('[RECONN] Max retries reached. Stopping.');
      return;
    }

    const delay = this.baseDelayMs * Math.pow(2, this.currentRetry);
    console.log(`[RECONN] Retrying in ${delay}ms (attempt ${this.currentRetry + 1})`);
    await sleep(delay);

    try {
      const token = await this.fetchToken();
      this.tokenExpiryTimestamp = Date.now() + (token.expires_in * 1000);
      this.scheduleTokenRefresh(token.access_token);

      this.connection.connect();
      this.currentRetry = 0;
    } catch (error) {
      this.currentRetry++;
      await this.reconnect();
    }
  }

  private scheduleTokenRefresh(currentToken: string): void {
    if (this.refreshTimer) clearTimeout(this.refreshTimer);

    const refreshWindowMs = 300000; // 5 minutes before expiry
    const refreshAt = this.tokenExpiryTimestamp - refreshWindowMs;
    const delay = Math.max(refreshAt - Date.now(), 1000);

    this.refreshTimer = setTimeout(async () => {
      try {
        const newToken = await this.fetchToken();
        this.tokenExpiryTimestamp = Date.now() + (newToken.expires_in * 1000);
        this.connection.sendRefreshToken(newToken.access_token);
        this.scheduleTokenRefresh(newToken.access_token);
      } catch (error) {
        console.error('[TOKEN] Refresh failed, triggering reconnect:', error);
        this.emitter.emit('wsClose', { code: 401, reason: 'Token refresh failed' });
      }
    }, delay);
  }

  handleDisconnect(): void {
    if (this.refreshTimer) clearTimeout(this.refreshTimer);
    void this.reconnect();
  }
}

The backoff algorithm doubles the delay on each failure. The token scheduler calculates the refresh window relative to the expiry timestamp. When the window triggers, it fetches a new token and sends the refresh message. If the refresh fails, it emits a close event to trigger the reconnection loop.

Step 3: Message Batching, Deduplication, and Schema Validation

Genesys Cloud streams may contain duplicate messages or out-of-order sequences during network recovery. Sequence number tracking prevents state drift. Schema validation ensures type safety before processing.

import { z } from 'zod';

const InteractionEventSchema = z.object({
  sequence: z.number(),
  id: z.string(),
  type: z.string(),
  status: z.string(),
  channelType: z.string(),
  timestamp: z.string().datetime(),
  attributes: z.record(z.unknown()).optional()
});

type InteractionEvent = z.infer<typeof InteractionEventSchema>;

class MessageProcessor {
  private lastSequence = 0;
  private processedIds = new Set<string>();

  constructor(private emitter: EventEmitter) {}

  process(rawMessage: string): void {
    let parsed: unknown;
    try {
      parsed = JSON.parse(rawMessage);
    } catch {
      console.error('[PROC] Invalid JSON received');
      return;
    }

    const validation = InteractionEventSchema.safeParse(parsed);
    if (!validation.success) {
      console.error('[PROC] Schema validation failed:', validation.error.errors);
      this.emitter.emit('schemaError', validation.error);
      return;
    }

    const event = validation.data;

    if (event.sequence <= this.lastSequence) {
      console.log(`[PROC] Duplicate or outdated sequence ${event.sequence}, skipping`);
      return;
    }

    if (this.processedIds.has(event.id)) {
      console.log(`[PROC] Duplicate interaction ID ${event.id}, skipping`);
      return;
    }

    this.lastSequence = event.sequence;
    this.processedIds.add(event.id);
    this.emitter.emit('validatedEvent', event);
  }
}

The processor parses the raw string, validates against the Zod schema, and checks the sequence number. It maintains a sliding window of processed IDs to catch duplicates that bypass sequence ordering. Validated events emit to the dashboard integration layer.

Step 4: Event-Driven State Machine Transitions and Dashboard Integration

Interactions move through defined statuses. A state machine tracks transitions and emits structured dashboard events. Metrics and audit logs attach to each transition.

interface StateTransition {
  interactionId: string;
  fromStatus: string | null;
  toStatus: string;
  timestamp: string;
  channelType: string;
}

class InteractionStateMachine {
  private currentState = new Map<string, string>();

  constructor(private emitter: EventEmitter) {}

  handleEvent(event: InteractionEvent): void {
    const previousStatus = this.currentState.get(event.id) || null;
    this.currentState.set(event.id, event.status);

    const transition: StateTransition = {
      interactionId: event.id,
      fromStatus: previousStatus,
      toStatus: event.status,
      timestamp: event.timestamp,
      channelType: event.channelType
    };

    this.emitter.emit('stateTransition', transition);
  }
}

class MetricsCollector {
  private messagesReceived = 0;
  private reconnects = 0;
  private startTime = Date.now();

  recordMessage(): void {
    this.messagesReceived++;
  }

  recordReconnect(): void {
    this.reconnects++;
  }

  getThroughputPerSecond(): number {
    const elapsedSeconds = (Date.now() - this.startTime) / 1000;
    return elapsedSeconds > 0 ? this.messagesReceived / elapsedSeconds : 0;
  }

  getReconnectCount(): number {
    return this.reconnects;
  }
}

class AuditLogger {
  private logFile = 'interaction_audit.log';

  log(transition: StateTransition): void {
    const auditEntry = {
      timestamp: new Date().toISOString(),
      type: 'INTERACTION_STATE_CHANGE',
      interactionId: transition.interactionId,
      channelType: transition.channelType,
      previousStatus: transition.fromStatus,
      currentStatus: transition.toStatus,
      eventTimestamp: transition.timestamp
    };
    console.log(JSON.stringify(auditEntry));
  }
}

The state machine maps interaction IDs to their current status. Each valid event triggers a transition emission. The metrics collector calculates throughput and tracks reconnection frequency. The audit logger outputs JSON lines for compliance tracking.

Complete Working Example

import WebSocket from 'ws';
import dotenv from 'dotenv';
import { EventEmitter } from 'events';
import { setTimeout as sleep } from 'timers/promises';
import { z } from 'zod';

dotenv.config();

const REGION = process.env.GENESYS_REGION || 'my';
const CLIENT_ID = process.env.GENESYS_CLIENT_ID;
const CLIENT_SECRET = process.env.GENESYS_CLIENT_SECRET;
const TOKEN_URL = `https://api.${REGION}.genesyscloud.com/oauth/token`;

interface OAuthToken {
  access_token: string;
  expires_in: number;
  token_type: string;
}

async function fetchAccessToken(): Promise<OAuthToken> {
  const response = await fetch(TOKEN_URL, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/x-www-form-urlencoded',
      'Authorization': `Basic ${Buffer.from(`${CLIENT_ID}:${CLIENT_SECRET}`).toString('base64')}`
    },
    body: 'grant_type=client_credentials'
  });

  if (!response.ok) {
    const errorBody = await response.text();
    throw new Error(`OAuth token fetch failed with status ${response.status}: ${errorBody}`);
  }

  return response.json() as Promise<OAuthToken>;
}

const InteractionEventSchema = z.object({
  sequence: z.number(),
  id: z.string(),
  type: z.string(),
  status: z.string(),
  channelType: z.string(),
  timestamp: z.string().datetime(),
  attributes: z.record(z.unknown()).optional()
});

type InteractionEvent = z.infer<typeof InteractionEventSchema>;

interface StateTransition {
  interactionId: string;
  fromStatus: string | null;
  toStatus: string;
  timestamp: string;
  channelType: string;
}

class StreamConnection {
  private ws: WebSocket | null = null;
  private config: { region: string; accessToken: string; channelTypes: string[]; statuses: string[] };
  private emitter: EventEmitter;

  constructor(config: { region: string; accessToken: string; channelTypes: string[]; statuses: string[] }, emitter: EventEmitter) {
    this.config = config;
    this.emitter = emitter;
  }

  private getWsUrl(): string {
    return `wss://api.${this.config.region}.genesyscloud.com/api/v2/interactions/stream?access_token=${this.config.accessToken}`;
  }

  connect(): void {
    this.ws = new WebSocket(this.getWsUrl());
    this.setupEventListeners();
  }

  private setupEventListeners(): void {
    if (!this.ws) return;

    this.ws.on('open', () => {
      const subscriptionPayload = {
        filter: {
          types: this.config.channelTypes,
          status: this.config.statuses
        }
      };
      this.ws?.send(JSON.stringify(subscriptionPayload));
    });

    this.ws.on('message', (data: Buffer) => {
      this.emitter.emit('rawMessage', data.toString('utf-8'));
    });

    this.ws.on('error', (error) => {
      this.emitter.emit('wsError', error);
    });

    this.ws.on('close', (code, reason) => {
      this.emitter.emit('wsClose', { code, reason: reason.toString() });
    });
  }

  sendRefreshToken(newToken: string): void {
    if (!this.ws || this.ws.readyState !== WebSocket.OPEN) return;
    this.ws.send(JSON.stringify({ type: 'refresh', access_token: newToken }));
  }

  close(): void {
    this.ws?.close(1000, 'Client shutdown');
  }
}

class ReconnectionManager {
  private maxRetries = 10;
  private baseDelayMs = 1000;
  private currentRetry = 0;
  private tokenExpiryTimestamp = 0;
  private refreshTimer: NodeJS.Timeout | null = null;

  constructor(
    private connection: StreamConnection,
    private emitter: EventEmitter,
    private fetchToken: () => Promise<{ access_token: string; expires_in: number }>
  ) {}

  async start(): Promise<void> {
    await this.reconnect();
  }

  private async reconnect(): Promise<void> {
    if (this.currentRetry >= this.maxRetries) return;

    const delay = this.baseDelayMs * Math.pow(2, this.currentRetry);
    await sleep(delay);

    try {
      const token = await this.fetchToken();
      this.tokenExpiryTimestamp = Date.now() + (token.expires_in * 1000);
      this.scheduleTokenRefresh(token.access_token);
      this.connection.connect();
      this.currentRetry = 0;
    } catch {
      this.currentRetry++;
      await this.reconnect();
    }
  }

  private scheduleTokenRefresh(currentToken: string): void {
    if (this.refreshTimer) clearTimeout(this.refreshTimer);
    const refreshAt = this.tokenExpiryTimestamp - 300000;
    const delay = Math.max(refreshAt - Date.now(), 1000);

    this.refreshTimer = setTimeout(async () => {
      try {
        const newToken = await this.fetchToken();
        this.tokenExpiryTimestamp = Date.now() + (newToken.expires_in * 1000);
        this.connection.sendRefreshToken(newToken.access_token);
        this.scheduleTokenRefresh(newToken.access_token);
      } catch {
        this.emitter.emit('wsClose', { code: 401, reason: 'Token refresh failed' });
      }
    }, delay);
  }

  handleDisconnect(): void {
    if (this.refreshTimer) clearTimeout(this.refreshTimer);
    void this.reconnect();
  }
}

class MessageProcessor {
  private lastSequence = 0;
  private processedIds = new Set<string>();

  constructor(private emitter: EventEmitter) {}

  process(rawMessage: string): void {
    let parsed: unknown;
    try {
      parsed = JSON.parse(rawMessage);
    } catch {
      return;
    }

    const validation = InteractionEventSchema.safeParse(parsed);
    if (!validation.success) return;

    const event = validation.data;

    if (event.sequence <= this.lastSequence || this.processedIds.has(event.id)) {
      return;
    }

    this.lastSequence = event.sequence;
    this.processedIds.add(event.id);
    this.emitter.emit('validatedEvent', event);
  }
}

class InteractionStateMachine {
  private currentState = new Map<string, string>();

  constructor(private emitter: EventEmitter) {}

  handleEvent(event: InteractionEvent): void {
    const previousStatus = this.currentState.get(event.id) || null;
    this.currentState.set(event.id, event.status);

    const transition: StateTransition = {
      interactionId: event.id,
      fromStatus: previousStatus,
      toStatus: event.status,
      timestamp: event.timestamp,
      channelType: event.channelType
    };

    this.emitter.emit('stateTransition', transition);
  }
}

class MetricsCollector {
  private messagesReceived = 0;
  private reconnects = 0;
  private startTime = Date.now();

  recordMessage(): void { this.messagesReceived++; }
  recordReconnect(): void { this.reconnects++; }

  getThroughputPerSecond(): number {
    const elapsed = (Date.now() - this.startTime) / 1000;
    return elapsed > 0 ? this.messagesReceived / elapsed : 0;
  }
  getReconnectCount(): number { return this.reconnects; }
}

class AuditLogger {
  log(transition: StateTransition): void {
    console.log(JSON.stringify({
      timestamp: new Date().toISOString(),
      type: 'INTERACTION_STATE_CHANGE',
      interactionId: transition.interactionId,
      channelType: transition.channelType,
      previousStatus: transition.fromStatus,
      currentStatus: transition.toStatus,
      eventTimestamp: transition.timestamp
    }));
  }
}

class InteractionStreamProcessor extends EventEmitter {
  private connection: StreamConnection;
  private reconnectionManager: ReconnectionManager;
  private processor: MessageProcessor;
  private stateMachine: InteractionStateMachine;
  private metrics: MetricsCollector;
  private audit: AuditLogger;

  constructor() {
    super();
    this.connection = new StreamConnection(
      {
        region: REGION,
        accessToken: '',
        channelTypes: ['voice', 'chat', 'email'],
        statuses: ['queued', 'ringing', 'connected', 'completed']
      },
      this
    );
    this.reconnectionManager = new ReconnectionManager(this.connection, this, fetchAccessToken);
    this.processor = new MessageProcessor(this);
    this.stateMachine = new InteractionStateMachine(this);
    this.metrics = new MetricsCollector();
    this.audit = new AuditLogger();
    this.bindEvents();
  }

  private bindEvents(): void {
    this.on('rawMessage', (msg: string) => {
      this.metrics.recordMessage();
      this.processor.process(msg);
    });

    this.on('validatedEvent', (event: InteractionEvent) => {
      this.stateMachine.handleEvent(event);
    });

    this.on('stateTransition', (transition: StateTransition) => {
      this.audit.log(transition);
      this.emit('dashboardUpdate', transition);
    });

    this.on('wsClose', () => {
      this.metrics.recordReconnect();
      this.reconnectionManager.handleDisconnect();
    });
  }

  start(): void {
    console.log('[STREAM] Starting interaction stream processor');
    this.reconnectionManager.start();
  }

  getMetrics(): { throughput: number; reconnects: number } {
    return {
      throughput: this.metrics.getThroughputPerSecond(),
      reconnects: this.metrics.getReconnectCount()
    };
  }
}

const processor = new InteractionStreamProcessor();
processor.on('dashboardUpdate', (update: StateTransition) => {
  console.log('[DASHBOARD] State change:', update);
});

processor.start();

Common Errors & Debugging

Error: WebSocket close code 4001

• What causes it: The access token provided in the handshake query string is expired or invalid.
• How to fix it: Verify the OAuth client credentials and ensure the token fetch returns a valid JWT. Check that the grant_type=client_credentials payload matches your client configuration.
• Code showing the fix: The ReconnectionManager automatically catches 401 closes and triggers reconnect(), which fetches a fresh token and reinitializes the WebSocket.

Error: Schema validation failed: Invalid datetime

• What causes it: The timestamp field in the interaction payload does not match ISO 8601 format. This occurs during regional API inconsistencies or mock data injection.
• How to fix it: Adjust the Zod schema to accept flexible datetime formats or coerce the string before validation.
• Code showing the fix: Replace z.string().datetime() with z.string().datetime().or(z.string()) to tolerate non-standard formats while maintaining type safety.

Error: Sequence number regression detected

• What causes it: Network partitions cause the server to resend older events. The deduplication logic blocks them, which is correct behavior.
• How to fix it: No code change required. The lastSequence check prevents state drift. If you require historical replay, implement a separate REST-based catch-up mechanism using the /api/v2/analytics/conversations/details/query endpoint.
• Code showing the fix: The MessageProcessor already implements if (event.sequence <= this.lastSequence) return;.

Error: Filter criteria rejected by server

• What causes it: The subscription payload contains unsupported channel types or status values for your organization.
• How to fix it: Query the supported interaction types via the REST API first. Update the channelTypes and statuses arrays in the constructor configuration.
• Code showing the fix: Modify the StreamConnection config object to match your environment: channelTypes: ['voice'] and statuses: ['queued', 'connected'].

Official References

• Genesys Cloud Real-Time Interactions API Documentation
• Genesys Cloud OAuth 2.0 Authentication Guide
• Node.js WebSocket (ws) Package Documentation
• Zod Schema Validation Library