Building a Real-Time Transcript Viewer for Chat Interactions Using Genesys Cloud WebSockets and a Node.js Client

How-To-Articles
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Building a Real-Time Transcript Viewer for Chat Interactions Using Genesys Cloud WebSockets and a Node.js Client

What You Will Build

A Node.js script that authenticates against Genesys Cloud, opens a persistent WebSocket connection to a messaging conversation, streams transcript events as they occur, and renders formatted agent and customer messages to the console. This tutorial uses the Genesys Cloud REST API for token acquisition, the native WebSocket API for event streaming, and the purecloud-platform-client-v2 SDK combined with the ws library. The code is written in modern JavaScript with async/await patterns and explicit error handling.

Prerequisites

  • OAuth 2.0 Client Credentials grant configured in the Genesys Cloud Developer Portal
  • Required OAuth scope: view:conversation
  • Genesys Cloud API v2
  • Node.js 18.0 or later
  • Dependencies: purecloud-platform-client-v2@^2.0.0, ws@^8.0.0
  • A valid conversation ID from an active or recently active messaging interaction

Authentication Setup

Genesys Cloud requires a valid bearer token for all API and WebSocket connections. The token expires after approximately one hour. Production systems should implement token caching with automatic refresh before expiration. This example uses the Client Credentials flow for simplicity, which is appropriate for server-side integrations.

Install the required packages:

npm install purecloud-platform-client-v2 ws dotenv

Create a .env file with your credentials:

GENESYS_CLIENT_ID=your_client_id
GENESYS_CLIENT_SECRET=your_client_secret
GENESYS_REGION=us-east-1
GENESYS_CONVERSATION_ID=your_conversation_id

The authentication flow uses the purecloud-platform-client-v2 SDK to handle token acquisition. The SDK manages the underlying HTTP POST to /oauth/token and returns a PlatformClient instance with an active session.

import PlatformClient from 'purecloud-platform-client-v2';
import dotenv from 'dotenv';

dotenv.config();

const client = new PlatformClient();

async function initializeClient() {
  try {
    await client.init({
      clientId: process.env.GENESYS_CLIENT_ID,
      clientSecret: process.env.GENESYS_CLIENT_SECRET,
      region: process.env.GENESYS_REGION,
    });
    
    const session = await client.login();
    console.log('OAuth token acquired. Expires at:', session.expiresAt);
    return client;
  } catch (error) {
    if (error.status === 401) {
      console.error('Authentication failed. Verify CLIENT_ID and CLIENT_SECRET.');
      process.exit(1);
    }
    if (error.status === 403) {
      console.error('Forbidden. Ensure the OAuth client has the view:conversation scope.');
      process.exit(1);
    }
    if (error.status === 429) {
      console.error('Rate limited on authentication. Implement exponential backoff.');
      process.exit(1);
    }
    console.error('Authentication error:', error.message);
    process.exit(1);
  }
}

The SDK abstracts the raw HTTP request, but the underlying cycle follows this pattern. The client sends a POST to https://api.{region}.mypurecloud.com/oauth/token with grant_type=client_credentials. The response returns an access_token, token_type, and expires_in value. The SDK caches this token and attaches it to subsequent requests.

Implementation

Step 1: Establish WebSocket Connection with Authentication

Genesys Cloud streams real-time transcript events over a secure WebSocket endpoint. The connection requires the bearer token in the Authorization header. The endpoint follows the pattern wss://api.{region}.mypurecloud.com/api/v2/messaging/conversations/{conversationId}/transcript.

The ws library handles connection lifecycle management. You must pass the token in the headers object during initialization. The region must match the OAuth client configuration.

import WebSocket from 'ws';

const REGION = process.env.GENESYS_REGION || 'us-east-1';
const CONVERSATION_ID = process.env.GENESYS_CONVERSATION_ID;
const BASE_WS_URL = `wss://api.${REGION}.mypurecloud.com`;

function createTranscriptSocket(client) {
  const token = client.session?.accessToken;
  if (!token) {
    throw new Error('No active OAuth token found. Authenticate first.');
  }

  const wsUrl = `${BASE_WS_URL}/api/v2/messaging/conversations/${CONVERSATION_ID}/transcript`;
  
  const ws = new WebSocket(wsUrl, {
    headers: {
      Authorization: `Bearer ${token}`,
      'Content-Type': 'application/json',
    },
  });

  return ws;
}

The server validates the token upon connection. If the token is missing, expired, or lacks the view:conversation scope, the server closes the connection with a 1008 or 1002 error code. The ws library emits a close event with the status code, which you must monitor for reconnection logic.

Step 2: Parse Transcript Events and Render Output

The WebSocket stream delivers JSON-encoded messages. Each message contains an event field, a timestamp, and a payload. The messageAdded event contains the actual transcript data. You must parse each message, filter for relevant events, and format the output.

function parseTranscriptEvent(rawMessage) {
  try {
    const event = JSON.parse(rawMessage);
    return event;
  } catch (error) {
    console.error('Failed to parse WebSocket message:', error.message);
    return null;
  }
}

function formatMessage(payload) {
  const direction = payload.from.id === 'external' ? 'Customer' : 'Agent';
  const sender = payload.from.name || payload.from.id || direction;
  const timestamp = new Date(payload.timestamp).toLocaleTimeString();
  const typeIndicator = payload.type === 'system' ? '[SYSTEM]' : `[${direction}]`;
  
  return `${timestamp} ${typeIndicator} ${sender}: ${payload.text}`;
}

function handleIncomingMessage(ws, data) {
  const event = parseTranscriptEvent(data);
  if (!event) return;

  switch (event.event) {
    case 'messageAdded':
      console.log(formatMessage(event.payload));
      break;
    case 'conversationUpdated':
      console.log(`[UPDATE] Conversation status changed at ${event.timestamp}`);
      break;
    case 'conversationClosed':
      console.log('[CLOSED] Transcript stream ended. Conversation terminated.');
      ws.close(1000, 'Conversation closed');
      break;
    default:
      // Ignore unknown event types gracefully
      break;
  }
}

The messageAdded payload contains nested objects for from and to. The from.id value indicates whether the message originated from an external customer or an internal agent. System messages, such as typing indicators or read receipts, use the system type. The parser filters these out to maintain a clean transcript view.

Step 3: Handle Disconnections and Implement Retry Logic

Network interruptions, token expiration, and server-side resets will terminate the WebSocket connection. You must implement exponential backoff with jitter to prevent thundering herd scenarios during outages. The retry logic also checks for 429 rate limits during reconnection attempts.

function setupReconnectionLogic(ws, client, maxRetries = 5) {
  let retryCount = 0;
  let reconnectTimeout = null;

  ws.on('close', (code, reason) => {
    if (code === 1000 || code === 1001) {
      console.log('WebSocket closed normally.');
      return;
    }

    if (retryCount >= maxRetries) {
      console.error('Max reconnection attempts reached. Exiting.');
      process.exit(1);
    }

    const delay = Math.min(1000 * Math.pow(2, retryCount) + Math.random() * 1000, 30000);
    console.log(`Connection closed with code ${code}. Retrying in ${Math.round(delay)}ms...`);
    
    reconnectTimeout = setTimeout(async () => {
      retryCount++;
      try {
        // Refresh token if expired
        if (client.session?.expiresAt && new Date() >= new Date(client.session.expiresAt)) {
          console.log('Token expired. Refreshing...');
          await client.refreshToken();
        }
        
        const newWs = createTranscriptSocket(client);
        setupReconnectionLogic(newWs, client, maxRetries);
        
        newWs.on('message', (data) => handleIncomingMessage(newWs, data));
        newWs.on('error', (err) => console.error('WebSocket error:', err.message));
      } catch (error) {
        console.error('Reconnection failed:', error.message);
        if (error.status === 429) {
          console.error('Rate limited during reconnection. Backing off longer.');
        }
      }
    }, delay);
  });

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

  return () => {
    if (reconnectTimeout) clearTimeout(reconnectTimeout);
  };
}

The backoff algorithm doubles the delay between attempts and adds random jitter to distribute load across the server. The code checks token expiration before reconnection. If the token has expired, it triggers the SDK refresh method. The 429 status check ensures the client does not overwhelm the authentication endpoint during cascading failures.

Complete Working Example

The following script combines authentication, WebSocket connection, event parsing, and reconnection logic into a single runnable module. Replace the environment variables with your credentials and execute with node transcript-viewer.js.

import PlatformClient from 'purecloud-platform-client-v2';
import WebSocket from 'ws';
import dotenv from 'dotenv';

dotenv.config();

const REGION = process.env.GENESYS_REGION || 'us-east-1';
const CONVERSATION_ID = process.env.GENESYS_CONVERSATION_ID;
const BASE_WS_URL = `wss://api.${REGION}.mypurecloud.com`;

async function initializeClient() {
  const client = new PlatformClient();
  try {
    await client.init({
      clientId: process.env.GENESYS_CLIENT_ID,
      clientSecret: process.env.GENESYS_CLIENT_SECRET,
      region: REGION,
    });
    await client.login();
    return client;
  } catch (error) {
    console.error('Authentication failed:', error.message);
    process.exit(1);
  }
}

function createTranscriptSocket(client) {
  const token = client.session?.accessToken;
  if (!token) throw new Error('No active OAuth token found.');
  
  const wsUrl = `${BASE_WS_URL}/api/v2/messaging/conversations/${CONVERSATION_ID}/transcript`;
  return new WebSocket(wsUrl, {
    headers: {
      Authorization: `Bearer ${token}`,
      'Content-Type': 'application/json',
    },
  });
}

function parseTranscriptEvent(rawMessage) {
  try {
    return JSON.parse(rawMessage);
  } catch (error) {
    return null;
  }
}

function formatMessage(payload) {
  const direction = payload.from.id === 'external' ? 'Customer' : 'Agent';
  const sender = payload.from.name || payload.from.id || direction;
  const timestamp = new Date(payload.timestamp).toLocaleTimeString();
  const typeIndicator = payload.type === 'system' ? '[SYSTEM]' : `[${direction}]`;
  return `${timestamp} ${typeIndicator} ${sender}: ${payload.text}`;
}

function handleIncomingMessage(data) {
  const event = parseTranscriptEvent(data);
  if (!event) return;

  if (event.event === 'messageAdded') {
    console.log(formatMessage(event.payload));
  } else if (event.event === 'conversationClosed') {
    console.log('[CLOSED] Transcript stream ended.');
  } else if (event.event === 'conversationUpdated') {
    console.log(`[UPDATE] Metadata changed at ${event.timestamp}`);
  }
}

function setupReconnectionLogic(ws, client, maxRetries = 5) {
  let retryCount = 0;
  let reconnectTimeout = null;

  ws.on('close', (code) => {
    if (code === 1000 || code === 1001) return;
    if (retryCount >= maxRetries) {
      console.error('Max reconnection attempts reached.');
      process.exit(1);
    }
    
    const delay = Math.min(1000 * Math.pow(2, retryCount) + Math.random() * 1000, 30000);
    console.log(`Connection lost. Retrying in ${Math.round(delay)}ms...`);
    
    reconnectTimeout = setTimeout(async () => {
      retryCount++;
      try {
        if (client.session?.expiresAt && new Date() >= new Date(client.session.expiresAt)) {
          await client.refreshToken();
        }
        const newWs = createTranscriptSocket(client);
        setupReconnectionLogic(newWs, client, maxRetries);
        newWs.on('message', handleIncomingMessage);
        newWs.on('error', (err) => console.error('WS Error:', err.message));
      } catch (error) {
        console.error('Reconnection failed:', error.message);
      }
    }, delay);
  });

  ws.on('error', (err) => console.error('WebSocket error:', err.message));
  return () => { if (reconnectTimeout) clearTimeout(reconnectTimeout); };
}

async function main() {
  console.log('Initializing Genesys Cloud client...');
  const client = await initializeClient();
  
  console.log(`Connecting to conversation ${CONVERSATION_ID}...`);
  const ws = createTranscriptSocket(client);
  
  ws.on('open', () => console.log('WebSocket connected. Streaming transcript...'));
  ws.on('message', handleIncomingMessage);
  
  setupReconnectionLogic(ws, client);
}

main().catch(console.error);

Common Errors & Debugging

Error: 401 Unauthorized on WebSocket Open

The server rejects the connection when the bearer token is missing, malformed, or expired. Verify that the Authorization header contains the exact string Bearer <token>. The ws library does not automatically refresh tokens. You must check client.session.expiresAt before opening a new connection and call client.refreshToken() if the current timestamp exceeds the expiration.

Error: 403 Forbidden on WebSocket Open

The OAuth client lacks the view:conversation scope. Navigate to the Genesys Cloud Developer Portal, locate your OAuth client, and add the scope to the allowed list. Regenerate the token after modifying scopes. The SDK will throw a 403 during login() if the scope is missing, which prevents the WebSocket from opening.

Error: 429 Too Many Requests during Authentication

Genesys Cloud enforces strict rate limits on the /oauth/token endpoint. Rapid reconnection attempts after network failures can trigger cascading 429 responses. Implement exponential backoff with jitter on the authentication retry path. The complete example includes a delay calculation that caps at 30 seconds and adds random variance to prevent synchronized retry storms.

Error: WebSocket Close Code 1006 or 1011

Code 1006 indicates an abnormal closure, typically caused by network interruptions or server-side timeouts. Code 1011 indicates an unexpected condition prevented the request from being fulfilled. The reconnection logic handles both codes by triggering the backoff sequence. Verify that your firewall or proxy does not terminate idle WebSocket connections before the server sends a ping/pong frame.

Error: Malformed JSON in Message Handler

The transcript stream may occasionally deliver binary frames or control messages depending on the client library version. Always wrap JSON.parse() in a try-catch block. The ws library emits strings by default, but you should validate the payload structure before accessing nested properties. The parseTranscriptEvent function returns null on failure to prevent unhandled exceptions from crashing the stream.

Official References