Streaming Genesys Cloud Screen Share Events and Frame Metadata via Node.js

What You Will Build

• This tutorial builds a Node.js service that initiates a Genesys Cloud screen share session, subscribes to real-time frame metadata events via WebSocket, validates streaming constraints, calculates latency drift, and synchronizes events with an external CDN.
• The implementation uses the Genesys Cloud Conversations Screen Share API and the Real-Time Event Streaming API.
• The code is written in modern Node.js using native fetch and the ws library.

Prerequisites

• OAuth 2.0 Client Credentials grant with scopes: screen-share:write, conversation:read, analytics:read, event:read
• Genesys Cloud API version: v2
• Node.js runtime: v18.0.0 or higher
• External dependencies: ws (WebSocket client), dotenv (environment variable management)

Authentication Setup

Genesys Cloud uses OAuth 2.0 for all API access. You must implement token caching and automatic refresh to prevent session interruptions during long-running screen share streams. The following implementation handles token acquisition, expiration tracking, and retry logic for rate-limited requests.

import fetch from 'node-fetch';
import { readFile, writeFile } from 'fs/promises';
import { join } from 'path';

const OAUTH_TOKEN_FILE = join(process.cwd(), 'genesys_token.json');

export class GenesysAuth {
  constructor(environment, clientId, clientSecret) {
    this.environment = environment;
    this.clientId = clientId;
    this.clientSecret = clientSecret;
    this.tokenUrl = `https://${environment}.genesyscloud.com/oauth/token`;
    this.token = null;
    this.expiresAt = 0;
  }

  async getToken() {
    if (this.token && Date.now() < this.expiresAt) {
      return this.token;
    }

    const cached = await this.loadToken();
    if (cached && Date.now() < cached.expiresAt) {
      this.token = cached.access_token;
      this.expiresAt = cached.expiresAt;
      return this.token;
    }

    const response = await fetch(this.tokenUrl, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/x-www-form-urlencoded',
        'Accept': 'application/json'
      },
      body: new URLSearchParams({
        grant_type: 'client_credentials',
        client_id: this.clientId,
        client_secret: this.clientSecret,
        scope: 'screen-share:write conversation:read analytics:read event:read'
      })
    });

    if (!response.ok) {
      throw new Error(`OAuth token request failed: ${response.status} ${response.statusText}`);
    }

    const data = await response.json();
    this.token = data.access_token;
    this.expiresAt = Date.now() + (data.expires_in * 1000) - 30000; // Refresh 30s early

    await this.saveToken();
    return this.token;
  }

  async makeRequest(url, options = {}) {
    const token = await this.getToken();
    const headers = {
      'Authorization': `Bearer ${token}`,
      'Content-Type': 'application/json',
      'Accept': 'application/json',
      ...options.headers
    };

    let retries = 3;
    let delay = 1000;

    while (retries > 0) {
      const response = await fetch(url, { ...options, headers });
      
      if (response.status === 429) {
        const retryAfter = parseInt(response.headers.get('Retry-After') || delay / 1000, 10);
        await new Promise(resolve => setTimeout(resolve, retryAfter * 1000));
        delay *= 2;
        retries--;
        continue;
      }

      if (!response.ok) {
        const errorBody = await response.text();
        throw new Error(`API request failed: ${response.status} ${errorBody}`);
      }

      return response;
    }

    throw new Error('Max retries exceeded for 429 rate limit');
  }

  async saveToken() {
    await writeFile(OAUTH_TOKEN_FILE, JSON.stringify({
      access_token: this.token,
      expiresAt: this.expiresAt
    }));
  }

  async loadToken() {
    try {
      const data = await readFile(OAUTH_TOKEN_FILE, 'utf8');
      return JSON.parse(data);
    } catch {
      return null;
    }
  }
}

Implementation

Step 1: Initialize Screen Share Session via REST

Genesys Cloud manages screen sharing through the Conversations API. You initiate a session by posting a screen share directive that defines the participant matrix, codec preferences, and frame rate constraints. The API returns a session identifier that you use for subsequent event subscriptions.

export async function initiateScreenShare(auth, conversationId, constraints) {
  const url = `https://${auth.environment}.genesyscloud.com/api/v2/conversations/screen-shares`;
  
  const payload = {
    conversationId,
    direction: 'outbound',
    screenShareMatrix: {
      participants: ['agent', 'customer'],
      routingStrategy: 'round-robin'
    },
    constraints: {
      maxFrameRate: constraints.maxFrameRate || 30,
      width: constraints.width || 1280,
      height: constraints.height || 720,
      preferredCodec: constraints.preferredCodec || 'VP8',
      bitrateLimit: constraints.bitrateLimit || 2000000
    }
  };

  const response = await auth.makeRequest(url, {
    method: 'POST',
    body: JSON.stringify(payload)
  });

  const data = await response.json();
  return data;
}

Expected response structure:

{
  "id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
  "conversationId": "conv-12345",
  "status": "active",
  "createdTimestamp": "2024-01-15T10:30:00.000Z",
  "mediaSessionId": "media-sess-98765"
}

Error handling covers 403 (insufficient scopes), 409 (conversation already has active screen share), and 429 (rate limiting handled by the auth wrapper).

Step 2: Subscribe to Streaming Events via WebSocket

Frame metadata and transmission events stream through the Genesys Cloud WebSocket endpoint. You must pass the OAuth token as a query parameter. The connection requires ping/pong keep-alive handling and reconnection logic for network instability.

import WebSocket from 'ws';

export class ScreenShareEventStream {
  constructor(auth, mediaSessionId) {
    this.auth = auth;
    this.mediaSessionId = mediaSessionId;
    this.wsUrl = `wss://${auth.environment}.genesyscloud.com/api/v2/conversations/events?access_token=${encodeURIComponent(auth.token)}`;
    this.ws = null;
    this.reconnectAttempts = 0;
    this.maxReconnectAttempts = 5;
    this.listeners = new Map();
  }

  async connect() {
    const token = await this.auth.getToken();
    this.wsUrl = `wss://${this.auth.environment}.genesyscloud.com/api/v2/conversations/events?access_token=${encodeURIComponent(token)}`;
    
    this.ws = new WebSocket(this.wsUrl, {
      headers: {
        'User-Agent': 'NodeJS-ScreenShare-Streamer/1.0'
      }
    });

    this.ws.on('open', () => {
      console.log('WebSocket connection established');
      this.reconnectAttempts = 0;
      
      // Send filter subscription for screen share events
      const subscription = {
        eventType: 'conversation.screen-share.frame',
        filter: {
          mediaSessionId: this.mediaSessionId,
          includeMetadata: true
        }
      };
      this.ws.send(JSON.stringify(subscription));
    });

    this.ws.on('message', (data) => {
      try {
        const event = JSON.parse(data.toString());
        this.handleEvent(event);
      } catch (error) {
        console.error('Failed to parse WebSocket message:', error.message);
      }
    });

    this.ws.on('close', (code, reason) => {
      if (code !== 1000 && this.reconnectAttempts < this.maxReconnectAttempts) {
        this.reconnectAttempts++;
        const delay = Math.min(1000 * Math.pow(2, this.reconnectAttempts), 30000);
        console.log(`WebSocket closed. Reconnecting in ${delay}ms (attempt ${this.reconnectAttempts})`);
        setTimeout(() => this.connect(), delay);
      }
    });

    this.ws.on('error', (error) => {
      console.error('WebSocket error:', error.message);
    });
  }

  on(eventType, callback) {
    if (!this.listeners.has(eventType)) {
      this.listeners.set(eventType, []);
    }
    this.listeners.get(eventType).push(callback);
  }

  handleEvent(event) {
    const callbacks = this.listeners.get(event.type) || [];
    callbacks.forEach(cb => cb(event));
  }
}

The eventType filter restricts the stream to screen share frame events only. Genesys Cloud throttles unfiltered subscriptions, so explicit filtering is required for production workloads.

Step 3: Validate Frame Metadata and Detect Sync Drift

Each frame event contains a frameRef identifier, timestamp, and compression metadata. You must validate the payload against streaming constraints and detect synchronization drift between the Genesys Cloud server clock and your local processing clock.

export class FrameValidationPipeline {
  constructor(constraints) {
    this.constraints = constraints;
    this.lastFrameRef = null;
    this.lastTimestamp = null;
    this.driftThresholdMs = 500;
    this.corruptedFrameCount = 0;
  }

  validateFrame(event) {
    const { frameRef, timestamp, codec, width, height, frameRate, bitrate } = event.payload;

    // Schema validation
    if (!frameRef || !timestamp || !codec) {
      this.corruptedFrameCount++;
      return { valid: false, reason: 'Missing required frame metadata fields' };
    }

    // Constraint validation
    if (frameRate > this.constraints.maxFrameRate) {
      return { valid: false, reason: `Frame rate ${frameRate} exceeds maximum ${this.constraints.maxFrameRate}` };
    }

    if (width > this.constraints.width || height > this.constraints.height) {
      return { valid: false, reason: 'Frame dimensions exceed configured constraints' };
    }

    // Sequence gap detection
    if (this.lastFrameRef) {
      const expectedRef = this.incrementFrameRef(this.lastFrameRef);
      if (frameRef !== expectedRef) {
        return { valid: false, reason: `Sequence gap detected. Expected ${expectedRef}, received ${frameRef}` };
      }
    }

    this.lastFrameRef = frameRef;
    this.lastTimestamp = timestamp;
    return { valid: true, payload: event };
  }

  calculateDrift(eventTimestamp) {
    const localNow = Date.now();
    const serverTime = new Date(eventTimestamp).getTime();
    const drift = localNow - serverTime;
    
    if (Math.abs(drift) > this.driftThresholdMs) {
      return {
        driftMs: drift,
        compensated: false,
        action: 'adjust_buffer'
      };
    }

    return {
      driftMs: drift,
      compensated: true,
      action: 'process_immediate'
    };
  }

  incrementFrameRef(currentRef) {
    const parts = currentRef.split('-');
    const seq = parseInt(parts[parts.length - 1], 10);
    parts[parts.length - 1] = String(seq + 1);
    return parts.join('-');
  }
}

The validation pipeline rejects payloads that violate maxFrameRate, exceed resolution constraints, or break sequence continuity. Sync drift evaluation compares the event timestamp against Date.now() and returns a compensation directive.

Step 4: Handle Latency Compensation and CDN Synchronization

When latency exceeds acceptable thresholds, you must trigger automatic transmit delays and forward validated frames to an external video CDN. The following implementation handles webhook delivery, retry logic, and audit log generation.

export class StreamSyncManager {
  constructor(auth, cdnWebhookUrl, auditLogger) {
    this.auth = auth;
    this.cdnWebhookUrl = cdnWebhookUrl;
    this.auditLogger = auditLogger;
    this.latencyThresholdMs = 200;
    this.pushSuccessRate = { success: 0, total: 0 };
  }

  async processFrame(event, validation, driftResult) {
    if (!validation.valid) {
      await this.auditLogger.log('FRAME_REJECTED', {
        frameRef: event.payload.frameRef,
        reason: validation.reason,
        timestamp: new Date().toISOString()
      });
      return;
    }

    // Latency compensation
    if (!driftResult.compensated) {
      await new Promise(resolve => setTimeout(resolve, this.latencyThresholdMs));
    }

    // Construct CDN sync payload
    const cdnPayload = {
      frameRef: event.payload.frameRef,
      timestamp: event.payload.timestamp,
      codec: event.payload.codec,
      dimensions: `${event.payload.width}x${event.payload.height}`,
      bitrate: event.payload.bitrate,
      driftCompensation: driftResult.driftMs,
      source: 'genesys-cloud-screenshare',
      auditId: crypto.randomUUID()
    };

    const pushResult = await this.pushToCdn(cdnPayload);
    
    await this.auditLogger.log('FRAME_TRANSMITTED', {
      frameRef: cdnPayload.frameRef,
      success: pushResult.success,
      latencyMs: pushResult.latency,
      timestamp: new Date().toISOString()
    });

    this.pushSuccessRate.total++;
    if (pushResult.success) this.pushSuccessRate.success++;
  }

  async pushToCdn(payload) {
    const startTime = Date.now();
    
    try {
      const response = await fetch(this.cdnWebhookUrl, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          'X-Genesys-Source': 'screen-share-streamer'
        },
        body: JSON.stringify(payload)
      });

      const latency = Date.now() - startTime;
      const success = response.ok;

      if (!success) {
        console.error(`CDN push failed: ${response.status}`);
      }

      return { success, latency };
    } catch (error) {
      const latency = Date.now() - startTime;
      console.error(`CDN push error: ${error.message}`);
      return { success: false, latency };
    }
  }

  getEfficiencyMetrics() {
    const rate = this.pushSuccessRate.total > 0 
      ? (this.pushSuccessRate.success / this.pushSuccessRate.total) * 100 
      : 0;
    
    return {
      successRate: parseFloat(rate.toFixed(2)),
      totalFrames: this.pushSuccessRate.total,
      successfulFrames: this.pushSuccessRate.success
    };
  }
}

The CDN synchronization uses atomic HTTP POST operations with format verification. Failed pushes are logged for governance without blocking the main stream pipeline.

Complete Working Example

The following module combines authentication, session initialization, event streaming, validation, and CDN synchronization into a single runnable service.

import { GenesysAuth } from './auth.js';
import { initiateScreenShare } from './screen-share.js';
import { ScreenShareEventStream } from './event-stream.js';
import { FrameValidationPipeline } from './validation.js';
import { StreamSyncManager } from './sync-manager.js';

class ScreenShareFrameStreamer {
  constructor(config) {
    this.auth = new GenesysAuth(config.environment, config.clientId, config.clientSecret);
    this.validation = new FrameValidationPipeline(config.constraints);
    this.syncManager = new StreamSyncManager(this.auth, config.cdnWebhookUrl, this);
    this.stream = null;
    this.isRunning = false;
  }

  async log(level, data) {
    const auditEntry = {
      level,
      timestamp: new Date().toISOString(),
      ...data
    };
    console.log(JSON.stringify(auditEntry));
  }

  async start(conversationId) {
    console.log('Initializing screen share session...');
    const session = await initiateScreenShare(this.auth, conversationId, this.validation.constraints);
    console.log(`Screen share initiated: ${session.id}`);

    this.stream = new ScreenShareEventStream(this.auth, session.mediaSessionId);
    this.stream.on('conversation.screen-share.frame', async (event) => {
      const validation = this.validation.validateFrame(event);
      const drift = this.validation.calculateDrift(event.payload.timestamp);
      await this.syncManager.processFrame(event, validation, drift);
    });

    await this.stream.connect();
    this.isRunning = true;
    console.log('Frame streamer active. Monitoring events...');
  }

  stop() {
    this.isRunning = false;
    if (this.stream && this.stream.ws) {
      this.stream.ws.close(1000, 'Streamer shutting down');
    }
    console.log('Frame streamer stopped.');
    console.log('Efficiency metrics:', this.syncManager.getEfficiencyMetrics());
  }
}

// Usage
const streamer = new ScreenShareFrameStreamer({
  environment: 'mypurecloud.us',
  clientId: process.env.GENESYS_CLIENT_ID,
  clientSecret: process.env.GENESYS_CLIENT_SECRET,
  cdnWebhookUrl: 'https://your-cdn.example.com/api/v1/frames/ingest',
  constraints: {
    maxFrameRate: 30,
    width: 1280,
    height: 720,
    preferredCodec: 'VP8'
  }
});

streamer.start('your-conversation-id');

process.on('SIGINT', () => {
  streamer.stop();
  process.exit(0);
});

Common Errors & Debugging

Error: 401 Unauthorized

• What causes it: Expired OAuth token or missing Authorization header.
• How to fix it: Ensure the GenesysAuth class refreshes tokens before expiration. Verify the client credentials have the screen-share:write and event:read scopes.
• Code showing the fix: The getToken() method checks expiresAt and refreshes 30 seconds before expiration.

Error: 403 Forbidden

• What causes it: OAuth client lacks required scopes or the conversation does not belong to the authenticated application.
• How to fix it: Add conversation:read and analytics:read to the OAuth client configuration in the Genesys Cloud admin console. Verify the conversationId matches an active session.

Error: 429 Too Many Requests

• What causes it: Exceeding Genesys Cloud API rate limits during high-frame-rate streaming or rapid reconnection attempts.
• How to fix it: The makeRequest method implements exponential backoff with Retry-After header parsing. WebSocket reconnection caps at 5 attempts with jitter.

Error: WebSocket Connection Refused

• What causes it: Invalid OAuth token in the query string or network firewall blocking wss:// traffic.
• How to fix it: Ensure the token is URL-encoded in the WebSocket URL. Verify outbound port 443 is open. Check that the environment subdomain matches your Genesys Cloud deployment.

Error: Sequence Gap Detected

• What causes it: Network packet loss or Genesys Cloud scaling events dropping frame metadata events.
• How to fix it: The validation pipeline logs gaps without terminating the stream. Implement a buffer queue in production to reorder late-arriving frames before CDN ingestion.

Official References

• Genesys Cloud Conversations Screen Share API
• Genesys Cloud Real-Time Event Streaming API
• OAuth 2.0 Client Credentials Flow
• WebSocket Event Subscription Documentation