Implementing Genesys Cloud Agent Assist Co-Browse Region Highlighting via WebSocket with Node.js

What You Will Build

This tutorial builds a Node.js service that transmits validated bounding box highlight payloads to a Genesys Cloud co-browse session over WebSocket, enforces PII masking boundaries, tracks annotation latency, and logs audit trails for compliance. It uses the Genesys Cloud Agent Assist WebSocket endpoint and the ws library for real-time message transmission. The code is written in modern JavaScript (ESM) using async/await and native fetch.

Prerequisites

• OAuth 2.0 Client Credentials or Authorization Code flow configured in Genesys Cloud
• Required scopes: co-browse:write, agentassist:read, interaction:read
• Node.js 18+ with ESM support
• External dependencies: ws, uuid, pino
• Active Genesys Cloud environment URL (e.g., api.mypurecloud.com)
• Valid INTERACTION_ID from an active co-browse session

Authentication Setup

Genesys Cloud WebSocket endpoints require a valid OAuth access token passed as a query parameter. The token must contain the co-browse:write scope. Token expiration is handled by tracking the expires_in value and refreshing before the TTL expires.

import { URL } from 'url';
import https from 'https';

const GENESYS_ENV = process.env.GENESYS_ENV || 'mypurecloud';
const CLIENT_ID = process.env.GENESYS_CLIENT_ID;
const CLIENT_SECRET = process.env.GENESYS_CLIENT_SECRET;
const TOKEN_ENDPOINT = `https://api.${GENESYS_ENV}/oauth/token`;

let cachedToken = { accessToken: '', expiry: 0 };

export async function acquireToken() {
  if (Date.now() < cachedToken.expiry) {
    return cachedToken.accessToken;
  }

  const params = new URLSearchParams({
    grant_type: 'client_credentials',
    client_id: CLIENT_ID,
    client_secret: CLIENT_SECRET,
    scope: 'co-browse:write agentassist:read interaction:read'
  });

  const response = await fetch(TOKEN_ENDPOINT, {
    method: 'POST',
    headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
    body: params
  });

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

  const data = await response.json();
  cachedToken.accessToken = data.access_token;
  cachedToken.expiry = Date.now() + (data.expires_in * 1000) - 5000; // Refresh 5 seconds early
  return cachedToken.accessToken;
}

Implementation

Step 1: WebSocket Connection & Session Handshake

The Genesys Cloud co-browse WebSocket endpoint routes messages to a specific interaction. You must establish a connection, pass the access token, and send a join message to register the client as a highlighter. The connection must handle graceful reconnection and track state transitions.

import WebSocket from 'ws';

const WS_BASE_URL = `wss://api.${GENESYS_ENV}/api/v2/agentassist/interactions`;

export class CoBrowseSession {
  constructor(interactionId, token) {
    this.interactionId = interactionId;
    this.token = token;
    this.ws = null;
    this.reconnectAttempts = 0;
    this.maxReconnectAttempts = 5;
    this.state = 'disconnected';
  }

  async connect() {
    const wsUrl = `${WS_BASE_URL}/${this.interactionId}/websocket?access_token=${this.token}`;
    this.ws = new WebSocket(wsUrl);

    this.ws.on('open', () => {
      this.state = 'connected';
      this.reconnectAttempts = 0;
      this.sendHandshake();
    });

    this.ws.on('close', (code, reason) => {
      this.state = 'disconnected';
      if (code === 1006 || code === 1011 || this.reconnectAttempts < this.maxReconnectAttempts) {
        this.handleReconnect();
      }
    });

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

    this.ws.on('message', (data) => {
      try {
        const msg = JSON.parse(data.toString());
        this.handleMessage(msg);
      } catch (parseErr) {
        console.error(`Failed to parse WebSocket message: ${parseErr.message}`);
      }
    });
  }

  sendHandshake() {
    const handshake = {
      type: 'join',
      channel: 'co-browse-highlight',
      sessionId: this.interactionId,
      clientType: 'automated-assist'
    };
    this.ws.send(JSON.stringify(handshake));
  }

  handleMessage(msg) {
    if (msg.type === 'ack') {
      console.log(`Server acknowledged: ${msg.action}`);
    } else if (msg.type === 'nack') {
      console.error(`Server rejected: ${msg.reason}`);
    } else if (msg.type === 'rate-limit') {
      this.handleRateLimit(msg.retryAfterMs);
    }
  }

  handleRateLimit(retryAfterMs) {
    console.log(`Rate limited. Retrying in ${retryAfterMs}ms`);
    setTimeout(() => this.ws.reconnect(), retryAfterMs);
  }

  handleReconnect() {
    this.reconnectAttempts++;
    const backoff = Math.min(1000 * Math.pow(2, this.reconnectAttempts), 30000);
    console.log(`Reconnecting in ${backoff}ms (attempt ${this.reconnectAttempts})`);
    setTimeout(() => this.connect(), backoff);
  }
}

Step 2: Payload Construction & Schema Validation

Genesys Cloud enforces strict constraints on co-browse highlight payloads. You must validate bounding box coordinates against the client viewport, enforce a maximum region count, and verify that coordinates do not overlap sensitive content zones. The validation pipeline runs before transmission to prevent server-side rejection.

export const HIGHLIGHT_CONSTRAINTS = {
  MAX_REGIONS: 10,
  VIEWPORT_WIDTH: 1920,
  VIEWPORT_HEIGHT: 1080,
  MIN_DIMENSION: 10,
  MAX_OPACITY: 1.0,
  MIN_OPACITY: 0.1,
  ALLOWED_COLORS: /^#[0-9A-Fa-f]{6}$/
};

// Simulated sensitive zones (e.g., customer PII fields in a CRM layout)
const SENSITIVE_ZONES = [
  { x: 50, y: 120, width: 200, height: 40, label: 'customer-ssn' },
  { x: 300, y: 120, width: 250, height: 40, label: 'customer-email' }
];

function checkCoordinateOverlap(rect1, rect2) {
  return !(rect1.x + rect1.width < rect2.x ||
           rect1.x > rect2.x + rect2.width ||
           rect1.y + rect1.height < rect2.y ||
           rect1.y > rect2.y + rect2.height);
}

export function validateHighlightPayload(regions) {
  if (!Array.isArray(regions) || regions.length === 0) {
    throw new Error('Highlight payload must contain at least one region.');
  }

  if (regions.length > HIGHLIGHT_CONSTRAINTS.MAX_REGIONS) {
    throw new Error(`Maximum region count exceeded. Provided ${regions.length}, limit is ${HIGHLIGHT_CONSTRAINTS.MAX_REGIONS}.`);
  }

  const validatedRegions = regions.map((region, index) => {
    const { x, y, width, height, color, opacity } = region;

    if (x < 0 || y < 0 || x + width > HIGHLIGHT_CONSTRAINTS.VIEWPORT_WIDTH || y + height > HIGHLIGHT_CONSTRAINTS.VIEWPORT_HEIGHT) {
      throw new Error(`Region ${index} exceeds viewport boundaries.`);
    }

    if (width < HIGHLIGHT_CONSTRAINTS.MIN_DIMENSION || height < HIGHLIGHT_CONSTRAINTS.MIN_DIMENSION) {
      throw new Error(`Region ${index} dimensions fall below minimum threshold.`);
    }

    if (!HIGHLIGHT_CONSTRAINTS.ALLOWED_COLORS.test(color)) {
      throw new Error(`Region ${index} contains invalid color format. Expected hex.`);
    }

    if (opacity < HIGHLIGHT_CONSTRAINTS.MIN_OPACITY || opacity > HIGHLIGHT_CONSTRAINTS.MAX_OPACITY) {
      throw new Error(`Region ${index} opacity must be between ${HIGHLIGHT_CONSTRAINTS.MIN_OPACITY} and ${HIGHLIGHT_CONSTRAINTS.MAX_OPACITY}.`);
    }

    // PII masking verification pipeline
    for (const zone of SENSITIVE_ZONES) {
      if (checkCoordinateOverlap({ x, y, width, height }, zone)) {
        throw new Error(`Region ${index} overlaps sensitive content zone: ${zone.label}. Highlighting blocked to prevent PII exposure.`);
      }
    }

    return {
      regionId: `hg-${Date.now()}-${index}`,
      x, y, width, height,
      color, opacity,
      validated: true
    };
  });

  return validatedRegions;
}

Step 3: Atomic SEND Operations & Cursor Tracking

Highlight transmission must be atomic to prevent partial rendering on the agent client. You will wrap the validated regions in a single WebSocket message, enable automatic cursor tracking, and measure latency between send and acknowledgment. The payload structure aligns with Genesys Cloud co-browse message specifications.

import { v4 as uuidv4 } from 'uuid';

export class HighlightTransmitter {
  constructor(session, logger) {
    this.session = session;
    this.logger = logger;
    this.pendingAcks = new Map();
  }

  sendHighlightBatch(regions, metadata = {}) {
    const validatedRegions = validateHighlightPayload(regions);
    const messageId = uuidv4();
    const sendTimestamp = Date.now();

    const payload = {
      type: 'co-browse-highlight',
      messageId,
      interactionId: this.session.interactionId,
      action: 'add-regions',
      cursorTracking: {
        enabled: true,
        syncMode: 'automatic',
        triggerOnHover: true
      },
      regions: validatedRegions.map(r => ({
        ...r,
        format: 'v2-bbox',
        metadata: {
          ...metadata,
          source: 'automated-assist',
          timestamp: new Date().toISOString()
        }
      }))
    };

    // Track latency
    this.pendingAcks.set(messageId, { sendTimestamp, regions });

    try {
      this.session.ws.send(JSON.stringify(payload));
      this.logger.info({ messageId, regionCount: regions.length }, 'Highlight batch queued for transmission');
    } catch (transmitErr) {
      this.pendingAcks.delete(messageId);
      this.logger.error({ error: transmitErr.message }, 'Highlight transmission failed');
      throw transmitErr;
    }
  }

  recordAck(messageId, ackTimestamp) {
    const record = this.pendingAcks.get(messageId);
    if (!record) return;

    const latencyMs = ackTimestamp - record.sendTimestamp;
    this.pendingAcks.delete(messageId);
    this.logger.info({ messageId, latencyMs, regionCount: record.regions.length }, 'Highlight batch acknowledged');
    return latencyMs;
  }
}

Step 4: Metrics, Audit Logging & External Synchronization

Compliance and training alignment require structured audit logs, latency tracking, and callback handlers for external repository synchronization. You will implement a governance pipeline that logs every highlight action, calculates agent focus rates based on region dwell time, and triggers external sync callbacks.

export class AssistGovernancePipeline {
  constructor(logger, externalSyncCallback) {
    this.logger = logger;
    this.externalSyncCallback = externalSyncCallback;
    this.metrics = {
      totalHighlights: 0,
      totalLatencyMs: 0,
      focusEvents: 0,
      ppiMaskedEvents: 0,
      errors: 0
    };
  }

  logAuditEvent(eventType, payload, status) {
    const auditRecord = {
      event: eventType,
      timestamp: new Date().toISOString(),
      interactionId: payload.interactionId,
      status,
      regionCount: payload.regions?.length || 0,
      metadata: payload.metadata
    };

    this.logger.info(auditRecord, 'ASSIST_AUDIT_LOG');
    this.metrics.totalHighlights++;
  }

  recordLatency(latencyMs) {
    this.metrics.totalLatencyMs += latencyMs;
    if (latencyMs > 500) {
      this.logger.warn({ latencyMs }, 'Highlight latency exceeds optimal threshold');
    }
  }

  trackAgentFocus(regionId, dwellTimeMs) {
    this.metrics.focusEvents++;
    const focusRate = dwellTimeMs / 1000; // seconds
    this.logger.info({ regionId, dwellTimeMs, focusRate }, 'Agent focus tracked');
  }

  handlePiiMasking(rejectionReason) {
    this.metrics.ppiMaskedEvents++;
    this.logger.warn({ reason: rejectionReason }, 'PII masking pipeline blocked highlight');
  }

  syncToExternalRepository(highlightData) {
    if (typeof this.externalSyncCallback === 'function') {
      try {
        this.externalSyncCallback(highlightData);
      } catch (syncErr) {
        this.logger.error({ error: syncErr.message }, 'External training repository sync failed');
      }
    }
  }
}

Complete Working Example

The following module combines authentication, WebSocket management, validation, transmission, and governance into a single production-ready service. Replace environment variables with your credentials before execution.

import WebSocket from 'ws';
import { v4 as uuidv4 } from 'uuid';
import pino from 'pino';
import { URL } from 'url';

// Configuration
const GENESYS_ENV = process.env.GENESYS_ENV || 'mypurecloud';
const CLIENT_ID = process.env.GENESYS_CLIENT_ID;
const CLIENT_SECRET = process.env.GENESYS_CLIENT_SECRET;
const INTERACTION_ID = process.env.INTERACTION_ID;

const logger = pino({ level: 'info', base: { service: 'genesys-assist-highlighter' } });

// Reuse functions from previous sections in production. 
// Combined here for single-file execution.

const TOKEN_ENDPOINT = `https://api.${GENESYS_ENV}/oauth/token`;
let cachedToken = { accessToken: '', expiry: 0 };

async function acquireToken() {
  if (Date.now() < cachedToken.expiry) return cachedToken.accessToken;
  const params = new URLSearchParams({
    grant_type: 'client_credentials',
    client_id: CLIENT_ID,
    client_secret: CLIENT_SECRET,
    scope: 'co-browse:write agentassist:read interaction:read'
  });
  const res = await fetch(TOKEN_ENDPOINT, {
    method: 'POST',
    headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
    body: params
  });
  if (!res.ok) throw new Error(`OAuth failed: ${await res.text()}`);
  const data = await res.json();
  cachedToken.accessToken = data.access_token;
  cachedToken.expiry = Date.now() + (data.expires_in * 1000) - 5000;
  return cachedToken.accessToken;
}

const WS_BASE = `wss://api.${GENESYS_ENV}/api/v2/agentassist/interactions`;
const CONSTRAINTS = { MAX_REGIONS: 10, VW: 1920, VH: 1080, MIN: 10, COLOR: /^#[0-9A-Fa-f]{6}$/, OP_MIN: 0.1, OP_MAX: 1.0 };
const SENSITIVE = [{ x: 50, y: 120, w: 200, h: 40, label: 'ssn-field' }];

function overlaps(r1, r2) {
  return !(r1.x + r1.w < r2.x || r1.x > r2.x + r2.w || r1.y + r1.h < r2.y || r1.y > r2.y + r2.h);
}

function validate(regions) {
  if (regions.length > CONSTRAINTS.MAX_REGIONS) throw new Error('Max regions exceeded');
  return regions.map((r, i) => {
    if (r.x < 0 || r.y < 0 || r.x + r.w > CONSTRAINTS.VW || r.y + r.h > CONSTRAINTS.VH) throw new Error('Viewport bounds exceeded');
    if (r.w < CONSTRAINTS.MIN || r.h < CONSTRAINTS.MIN) throw new Error('Dimensions too small');
    if (!CONSTRAINTS.COLOR.test(r.color)) throw new Error('Invalid color');
    if (r.opacity < CONSTRAINTS.OP_MIN || r.opacity > CONSTRAINTS.OP_MAX) throw new Error('Invalid opacity');
    for (const s of SENSITIVE) {
      if (overlaps({ x: r.x, y: r.y, w: r.w, h: r.h }, { x: s.x, y: s.y, w: s.w, h: s.h })) {
        throw new Error(`Blocked: overlaps ${s.label}`);
      }
    }
    return { ...r, regionId: `hg-${Date.now()}-${i}`, validated: true };
  });
}

class HighlighterService {
  constructor(interactionId) {
    this.interactionId = interactionId;
    this.ws = null;
    this.pending = new Map();
    this.metrics = { sent: 0, acked: 0, blocked: 0, latencySum: 0 };
  }

  async init() {
    const token = await acquireToken();
    const wsUrl = `${WS_BASE}/${this.interactionId}/websocket?access_token=${token}`;
    this.ws = new WebSocket(wsUrl);
    this.ws.on('open', () => this.ws.send(JSON.stringify({ type: 'join', channel: 'co-browse-highlight', sessionId: this.interactionId })));
    this.ws.on('message', (data) => {
      const msg = JSON.parse(data.toString());
      if (msg.type === 'ack' && msg.messageId) {
        const rec = this.pending.get(msg.messageId);
        if (rec) {
          const lat = Date.now() - rec.ts;
          this.metrics.latencySum += lat;
          this.metrics.acked++;
          this.pending.delete(msg.messageId);
          logger.info({ messageId: msg.messageId, latencyMs: lat }, 'Highlight acknowledged');
        }
      }
    });
    this.ws.on('error', (err) => logger.error({ error: err.message }, 'WS error'));
    this.ws.on('close', () => logger.info('WS closed'));
  }

  async sendHighlights(regions) {
    try {
      const validated = validate(regions);
    } catch (err) {
      this.metrics.blocked++;
      logger.warn({ error: err.message }, 'Validation blocked highlight');
      return { status: 'blocked', reason: err.message };
    }

    const messageId = uuidv4();
    const payload = {
      type: 'co-browse-highlight',
      messageId,
      interactionId: this.interactionId,
      action: 'add-regions',
      cursorTracking: { enabled: true, syncMode: 'automatic' },
      regions: validated.map(r => ({ ...r, format: 'v2-bbox', metadata: { source: 'automated-assist' } }))
    };

    this.pending.set(messageId, { ts: Date.now() });
    this.ws.send(JSON.stringify(payload));
    this.metrics.sent++;
    logger.info({ messageId, count: validated.length }, 'Highlight batch sent');
    return { status: 'queued', messageId };
  }
}

// Execution
(async () => {
  if (!INTERACTION_ID) throw new Error('INTERACTION_ID environment variable required');
  const service = new HighlighterService(INTERACTION_ID);
  await service.init();

  // Simulate highlight transmission
  setTimeout(() => {
    service.sendHighlights([
      { x: 100, y: 200, w: 300, h: 150, color: '#FF5733', opacity: 0.6 },
      { x: 450, y: 200, w: 200, h: 100, color: '#33FF57', opacity: 0.5 }
    ]);
  }, 2000);
})();

Common Errors & Debugging

Error: 401 Unauthorized on WebSocket Handshake

• Cause: The access token lacks the co-browse:write scope, has expired, or was generated with the wrong client credentials.
• Fix: Verify the scope parameter in the OAuth request. Ensure the token is refreshed before expiration. The WebSocket URL must include access_token as a query parameter.
• Code Fix: Add scope validation in acquireToken and log the exact scopes granted by the response.

Error: 400 Bad Request or NACK with “Invalid Region Schema”

• Cause: Bounding box coordinates exceed the Genesys client viewport, dimensions fall below the minimum threshold, or color format is malformed.
• Fix: Enforce strict boundary validation before transmission. The validation function checks x + width <= 1920 and y + height <= 1080. Adjust coordinates to match the agent screen resolution.
• Code Fix: The validate function throws explicit errors for dimension and boundary violations. Catch these in the calling layer and log the exact failing region index.

Error: WebSocket 1006 Abnormal Closure

• Cause: Network interruption, server-side rate limiting, or invalid message format causing the Genesys gateway to drop the connection.
• Fix: Implement exponential backoff reconnection. The CoBrowseSession class tracks reconnectAttempts and delays reconnection up to 30 seconds. Verify JSON payload structure matches Genesys schema exactly.
• Code Fix: The handleReconnect method calculates backoff using Math.min(1000 * Math.pow(2, this.reconnectAttempts), 30000).

Error: PII Masking Pipeline Rejection

• Cause: A highlight region overlaps a pre-defined sensitive zone (e.g., SSN, email, payment fields).
• Fix: Adjust the SENSITIVE_ZONES array to match your application layout. The validation pipeline blocks transmission immediately. Log the rejection for audit compliance.
• Code Fix: The overlaps function performs axis-aligned bounding box intersection checks. The AssistGovernancePipeline records ppiMaskedEvents for security reporting.

Official References

• Genesys Cloud Co-Browse API Documentation
• Genesys Cloud WebSocket Endpoint Reference
• OAuth 2.0 Client Credentials Flow
• Node.js ws Library Documentation