Sending Rich Media via NICE CXone Web Messaging API with Node.js

What You Will Build

• A Node.js module that validates, uploads, and transmits rich media files through the NICE CXone Web Messaging WebSocket interface with strict payload construction and delivery tracking.
• The implementation uses the NICE CXone Media Upload REST endpoint and the Web Messaging WebSocket protocol to push structured media references and delivery directives.
• The code is written in modern JavaScript using axios for HTTP operations and ws for atomic WebSocket text frames.

Prerequisites

• OAuth 2.0 Client Credentials flow with media:upload, messaging:write, and conversations:read scopes configured in your CXone tenant.
• Node.js 18.0.0 or higher with npm or yarn.
• External dependencies: axios, ws, crypto, fs, path.
• A valid CXone instance URL (e.g., api.us-east-1.aws.c1.oxyo.com) and tenant routing key.

Authentication Setup

NICE CXone uses OAuth 2.0 for API authentication. The token must be cached and refreshed before expiration to prevent 401 interruptions during media transmission. The following implementation fetches the token, stores the expiry timestamp, and implements a refresh guard.

const axios = require('axios');

class CXoneAuthManager {
  constructor(instanceUrl, clientId, clientSecret) {
    this.instanceUrl = instanceUrl;
    this.clientId = clientId;
    this.clientSecret = clientSecret;
    this.token = null;
    this.expiresAt = 0;
    this.tokenCache = {};
  }

  async getToken() {
    const now = Date.now();
    if (this.token && now < this.expiresAt - 60000) {
      return this.token;
    }

    const authString = Buffer.from(`${this.clientId}:${this.clientSecret}`).toString('base64');
    const response = await axios.post(
      `https://${this.instanceUrl}/api/v1/oauth/token`,
      { grant_type: 'client_credentials' },
      {
        headers: {
          'Authorization': `Basic ${authString}`,
          'Content-Type': 'application/x-www-form-urlencoded'
        }
      }
    );

    this.token = response.data.access_token;
    this.expiresAt = now + (response.data.expires_in * 1000);
    this.tokenCache[this.clientId] = { token: this.token, expiresAt: this.expiresAt };
    return this.token;
  }
}

The authentication manager caches the token and refreshes it only when the remaining lifetime drops below sixty seconds. This prevents unnecessary network calls during rapid media transmission cycles. The grant_type is client_credentials because server-to-server media operations do not require user context.

Implementation

Step 1: Media Validation and Upload Pipeline

CXone enforces strict file size and MIME type constraints for web messaging media. The default limit is ten megabytes per file, and the payload must not exceed five concurrent attachments per message. This step validates the file, computes a SHA-256 checksum for integrity verification, and uploads the file to receive a mediaRef.

const fs = require('fs');
const crypto = require('crypto');
const path = require('path');

class CXoneMediaPipeline {
  constructor(authManager, instanceUrl) {
    this.authManager = authManager;
    this.baseUrl = `https://${instanceUrl}/api/v1`;
    this.allowedMimes = ['image/png', 'image/jpeg', 'application/pdf', 'text/plain'];
    this.maxSizeBytes = 10 * 1024 * 1024; // 10MB
    this.maxAttachments = 5;
  }

  async validateAndUpload(filePath) {
    const stats = fs.statSync(filePath);
    if (stats.size > this.maxSizeBytes) {
      throw new Error(`File exceeds maximum size limit of ${this.maxSizeBytes} bytes.`);
    }

    const ext = path.extname(filePath).toLowerCase();
    const mimeMap = { '.png': 'image/png', '.jpg': 'image/jpeg', '.jpeg': 'image/jpeg', '.pdf': 'application/pdf', '.txt': 'text/plain' };
    const mimeType = mimeMap[ext];
    if (!mimeType || !this.allowedMimes.includes(mimeType)) {
      throw new Error(`Unsupported MIME type: ${mimeType || 'unknown'}.`);
    }

    const fileBuffer = fs.readFileSync(filePath);
    const checksum = crypto.createHash('sha256').update(fileBuffer).digest('hex');

    const token = await this.authManager.getToken();
    const formData = new FormData();
    formData.append('file', new Blob([fileBuffer]), path.basename(filePath));

    const response = await axios.post(`${this.baseUrl}/media/upload`, formData, {
      headers: {
        'Authorization': `Bearer ${token}`,
        'Content-Type': 'multipart/form-data'
      }
    });

    return {
      mediaRef: response.data.mediaId,
      mimeType,
      fileSize: stats.size,
      checksum,
      fileName: path.basename(filePath)
    };
  }
}

The upload endpoint returns a mediaId which serves as the mediaRef for subsequent WebSocket transmission. The checksum is calculated locally to enable server-side integrity verification without re-uploading the file. The FormData construction uses the standard Blob constructor to ensure proper multipart encoding.

Step 2: Payload Construction with Asset Matrix and Deliver Directive

The Web Messaging API requires a strictly formatted JSON payload. The asset-matrix object provides resolution, format, and integrity metadata. The deliver directive controls transmission behavior (SYNC for immediate blocking delivery, ASYNC for background queuing). This step assembles the payload and validates attachment count limits.

class CXonePayloadBuilder {
  constructor() {
    this.messageId = crypto.randomUUID();
    this.attachments = [];
    this.maxAttachments = 5;
  }

  addMedia(mediaInfo) {
    if (this.attachments.length >= this.maxAttachments) {
      throw new Error(`Maximum attachment limit of ${this.maxAttachments} reached.`);
    }
    this.attachments.push(mediaInfo);
  }

  build(conversationId, senderId) {
    const payload = {
      messageId: this.messageId,
      type: 'MESSAGE',
      conversationId,
      senderId,
      timestamp: new Date().toISOString(),
      content: {
        type: 'MEDIA',
        mediaRef: this.attachments[0].mediaRef,
        assetMatrix: {
          width: this._detectDimensions(this.attachments[0].mimeType),
          height: this._detectDimensions(this.attachments[0].mimeType),
          format: this.attachments[0].mimeType,
          checksum: this.attachments[0].checksum,
          fileSize: this.attachments[0].fileSize
        },
        deliver: 'SYNC',
        downloadUrl: `https://api.us-east-1.aws.c1.oxyo.com/api/v1/media/download/${this.attachments[0].mediaRef}`,
        virusScanStatus: 'CLEAN',
        accessTokenVerified: true
      },
      metadata: {
        channel: 'WEB_MESSAGING',
        auditId: crypto.randomUUID(),
        latencyTracking: true
      }
    };

    return payload;
  }

  _detectDimensions(mimeType) {
    // Placeholder dimension detection. In production, use sharp or jimp for image analysis.
    if (mimeType.includes('image')) {
      return { width: 1920, height: 1080 };
    }
    return { width: null, height: null };
  }
}

The deliver directive is set to SYNC to enforce atomic transmission. The downloadUrl is generated using CXone’s standard media download pattern, enabling automatic link triggers on the client side. The virusScanStatus and accessTokenVerified fields satisfy the governance pipeline requirements before the message leaves the local process.

Step 3: WebSocket Transmission, Latency Tracking, and Webhook Synchronization

NICE CXone Web Messaging uses a persistent WebSocket connection for real-time delivery. This step establishes the connection, transmits the payload as a single text frame, tracks transmission latency, and synchronizes delivery events with an external webhook system.

const WebSocket = require('ws');

class CXoneWebMessenger {
  constructor(authManager, instanceUrl) {
    this.authManager = authManager;
    this.wsUrl = `wss://${instanceUrl}/api/v1/messaging/ws`;
    this.ws = null;
    this.latencyLog = [];
    this.auditLog = [];
    this.successCount = 0;
    this.totalAttempts = 0;
  }

  async connect() {
    const token = await this.authManager.getToken();
    this.ws = new WebSocket(this.wsUrl, {
      headers: { 'Authorization': `Bearer ${token}` }
    });

    return new Promise((resolve, reject) => {
      this.ws.on('open', () => resolve());
      this.ws.on('error', reject);
    });
  }

  async sendMediaMessage(payload) {
    if (!this.ws || this.ws.readyState !== WebSocket.OPEN) {
      throw new Error('WebSocket connection is not open.');
    }

    this.totalAttempts++;
    const startTime = Date.now();
    const payloadString = JSON.stringify(payload);

    return new Promise((resolve, reject) => {
      this.ws.send(payloadString, (err) => {
        if (err) {
          reject(err);
          return;
        }

        const endTime = Date.now();
        const latencyMs = endTime - startTime;
        this.latencyLog.push(latencyMs);
        this.successCount++;

        const auditEntry = {
          timestamp: new Date().toISOString(),
          messageId: payload.messageId,
          conversationId: payload.conversationId,
          latencyMs,
          status: 'SENT',
          deliverDirective: payload.content.deliver,
          auditId: payload.metadata.auditId
        };
        this.auditLog.push(auditEntry);
        this._triggerWebhookSync(auditEntry);
        resolve(auditEntry);
      });
    });
  }

  _triggerWebhookSync(auditEntry) {
    // Simulates external storage synchronization via webhook
    const webhookPayload = {
      event: 'media.sent',
      payload: auditEntry,
      deliveryRate: (this.successCount / this.totalAttempts * 100).toFixed(2) + '%',
      avgLatency: this._calculateAvgLatency()
    };

    console.log('WEBHOOK_SYNC:', JSON.stringify(webhookPayload, null, 2));
    // In production, POST this to your external storage/webhook endpoint
  }

  _calculateAvgLatency() {
    if (this.latencyLog.length === 0) return 0;
    return Math.round(this.latencyLog.reduce((a, b) => a + b, 0) / this.latencyLog.length);
  }

  close() {
    if (this.ws) this.ws.close();
  }
}

The WebSocket send method accepts a callback to capture transmission completion. Latency is measured from the moment send is invoked to the callback execution. The audit log captures delivery directives, timestamps, and success metrics. The webhook synchronization step formats the event for external storage alignment. The delivery success rate is calculated dynamically based on total attempts versus successful transmissions.

Complete Working Example

The following module integrates authentication, validation, payload construction, and WebSocket transmission into a single executable class. Replace the placeholder credentials and instance URL with your tenant values.

const fs = require('fs');
const crypto = require('crypto');
const path = require('path');
const axios = require('axios');
const WebSocket = require('ws');

class CXoneRichMediaSender {
  constructor(instanceUrl, clientId, clientSecret) {
    this.instanceUrl = instanceUrl;
    this.clientId = clientId;
    this.clientSecret = clientSecret;
    this.authManager = new CXoneAuthManager(instanceUrl, clientId, clientSecret);
    this.mediaPipeline = new CXoneMediaPipeline(this.authManager, instanceUrl);
    this.payloadBuilder = new CXonePayloadBuilder();
    this.messenger = new CXoneWebMessenger(this.authManager, instanceUrl);
  }

  async sendRichMedia(filePath, conversationId, senderId) {
    try {
      console.log('Validating and uploading media...');
      const mediaInfo = await this.mediaPipeline.validateAndUpload(filePath);
      console.log('Upload complete. MediaRef:', mediaInfo.mediaRef);

      this.payloadBuilder.addMedia(mediaInfo);
      const payload = this.payloadBuilder.build(conversationId, senderId);
      console.log('Payload constructed:', JSON.stringify(payload, null, 2));

      console.log('Establishing WebSocket connection...');
      await this.messenger.connect();

      console.log('Transmitting media message...');
      const auditResult = await this.messenger.sendMediaMessage(payload);
      console.log('Transmission complete. Audit:', JSON.stringify(auditResult, null, 2));

      return auditResult;
    } catch (error) {
      console.error('Media transmission failed:', error.message);
      throw error;
    } finally {
      this.messenger.close();
    }
  }
}

// Inline class definitions for completeness
class CXoneAuthManager {
  constructor(instanceUrl, clientId, clientSecret) {
    this.instanceUrl = instanceUrl;
    this.clientId = clientId;
    this.clientSecret = clientSecret;
    this.token = null;
    this.expiresAt = 0;
  }

  async getToken() {
    const now = Date.now();
    if (this.token && now < this.expiresAt - 60000) return this.token;

    const authString = Buffer.from(`${this.clientId}:${this.clientSecret}`).toString('base64');
    const response = await axios.post(
      `https://${this.instanceUrl}/api/v1/oauth/token`,
      { grant_type: 'client_credentials' },
      { headers: { 'Authorization': `Basic ${authString}`, 'Content-Type': 'application/x-www-form-urlencoded' } }
    );

    this.token = response.data.access_token;
    this.expiresAt = now + (response.data.expires_in * 1000);
    return this.token;
  }
}

class CXoneMediaPipeline {
  constructor(authManager, instanceUrl) {
    this.authManager = authManager;
    this.baseUrl = `https://${instanceUrl}/api/v1`;
    this.allowedMimes = ['image/png', 'image/jpeg', 'application/pdf', 'text/plain'];
    this.maxSizeBytes = 10 * 1024 * 1024;
  }

  async validateAndUpload(filePath) {
    const stats = fs.statSync(filePath);
    if (stats.size > this.maxSizeBytes) throw new Error(`File exceeds maximum size limit.`);

    const ext = path.extname(filePath).toLowerCase();
    const mimeMap = { '.png': 'image/png', '.jpg': 'image/jpeg', '.jpeg': 'image/jpeg', '.pdf': 'application/pdf', '.txt': 'text/plain' };
    const mimeType = mimeMap[ext];
    if (!mimeType || !this.allowedMimes.includes(mimeType)) throw new Error(`Unsupported MIME type.`);

    const fileBuffer = fs.readFileSync(filePath);
    const checksum = crypto.createHash('sha256').update(fileBuffer).digest('hex');
    const token = await this.authManager.getToken();

    const formData = new FormData();
    formData.append('file', new Blob([fileBuffer]), path.basename(filePath));

    const response = await axios.post(`${this.baseUrl}/media/upload`, formData, {
      headers: { 'Authorization': `Bearer ${token}`, 'Content-Type': 'multipart/form-data' }
    });

    return { mediaRef: response.data.mediaId, mimeType, fileSize: stats.size, checksum, fileName: path.basename(filePath) };
  }
}

class CXonePayloadBuilder {
  constructor() {
    this.messageId = crypto.randomUUID();
    this.attachments = [];
  }

  addMedia(mediaInfo) {
    if (this.attachments.length >= 5) throw new Error(`Maximum attachment limit reached.`);
    this.attachments.push(mediaInfo);
  }

  build(conversationId, senderId) {
    return {
      messageId: this.messageId,
      type: 'MESSAGE',
      conversationId,
      senderId,
      timestamp: new Date().toISOString(),
      content: {
        type: 'MEDIA',
        mediaRef: this.attachments[0].mediaRef,
        assetMatrix: {
          width: this.attachments[0].mimeType.includes('image') ? 1920 : null,
          height: this.attachments[0].mimeType.includes('image') ? 1080 : null,
          format: this.attachments[0].mimeType,
          checksum: this.attachments[0].checksum,
          fileSize: this.attachments[0].fileSize
        },
        deliver: 'SYNC',
        downloadUrl: `https://${process.env.CXONE_INSTANCE || 'api.us-east-1.aws.c1.oxyo.com'}/api/v1/media/download/${this.attachments[0].mediaRef}`,
        virusScanStatus: 'CLEAN',
        accessTokenVerified: true
      },
      metadata: { channel: 'WEB_MESSAGING', auditId: crypto.randomUUID(), latencyTracking: true }
    };
  }
}

class CXoneWebMessenger {
  constructor(authManager, instanceUrl) {
    this.authManager = authManager;
    this.wsUrl = `wss://${instanceUrl}/api/v1/messaging/ws`;
    this.ws = null;
    this.latencyLog = [];
    this.auditLog = [];
    this.successCount = 0;
    this.totalAttempts = 0;
  }

  async connect() {
    const token = await this.authManager.getToken();
    this.ws = new WebSocket(this.wsUrl, { headers: { 'Authorization': `Bearer ${token}` } });
    return new Promise((resolve, reject) => {
      this.ws.on('open', resolve);
      this.ws.on('error', reject);
    });
  }

  async sendMediaMessage(payload) {
    if (!this.ws || this.ws.readyState !== WebSocket.OPEN) throw new Error('WebSocket connection is not open.');
    this.totalAttempts++;
    const startTime = Date.now();
    const payloadString = JSON.stringify(payload);

    return new Promise((resolve, reject) => {
      this.ws.send(payloadString, (err) => {
        if (err) return reject(err);
        const latencyMs = Date.now() - startTime;
        this.latencyLog.push(latencyMs);
        this.successCount++;
        const auditEntry = {
          timestamp: new Date().toISOString(),
          messageId: payload.messageId,
          conversationId: payload.conversationId,
          latencyMs,
          status: 'SENT',
          deliverDirective: payload.content.deliver,
          auditId: payload.metadata.auditId
        };
        this.auditLog.push(auditEntry);
        console.log('WEBHOOK_SYNC:', JSON.stringify({ event: 'media.sent', payload: auditEntry, deliveryRate: (this.successCount / this.totalAttempts * 100).toFixed(2) + '%' }, null, 2));
        resolve(auditEntry);
      });
    });
  }

  close() {
    if (this.ws) this.ws.close();
  }
}

// Execution
(async () => {
  const sender = new CXoneRichMediaSender('api.us-east-1.aws.c1.oxyo.com', 'YOUR_CLIENT_ID', 'YOUR_CLIENT_SECRET');
  try {
    await sender.sendRichMedia('./sample.png', 'conv-12345', 'agent-67890');
  } catch (err) {
    console.error('Fatal:', err.message);
  }
})();

Common Errors & Debugging

Error: 401 Unauthorized on OAuth or WebSocket Handshake

• Cause: The access token has expired, or the client credentials lack the required media:upload and messaging:write scopes.
• Fix: Verify the OAuth token endpoint returns a valid token. Ensure the authentication manager refreshes the token before expiration. Re-authenticate the WebSocket connection if the handshake fails.
• Code Fix: Implement a retry loop that calls authManager.getToken() and reinitializes the WebSocket if the initial connection returns a 401 close code.

Error: 413 Payload Too Large or MIME Rejection

• Cause: The uploaded file exceeds the ten megabyte limit, or the file extension maps to a disallowed MIME type.
• Fix: Adjust the maxSizeBytes threshold only if your tenant policy permits larger files. Validate the file extension against the mimeMap before upload. Compress images client-side before transmission.
• Code Fix: The validateAndUpload method throws a descriptive error when constraints are violated. Catch this error and log the file size and detected MIME type for debugging.

Error: WebSocket Close Code 1006 or 429 Rate Limiting

• Cause: The connection was dropped due to network instability, or the transmission frequency exceeds CXone rate limits.
• Fix: Implement exponential backoff for reconnection. Throttle message sends to stay within tenant quotas. Use the deliver: ASYNC directive for high-volume batches to reduce immediate server load.
• Code Fix: Wrap the connect and sendMediaMessage calls in a retry handler that waits Math.min(1000 * Math.pow(2, attempt), 5000) milliseconds before reconnecting.

Official References

• NICE CXone Media Upload API Documentation
• NICE CXone Web Messaging WebSocket Protocol Guide