Dispatching Genesys Cloud Messaging Bulk Campaigns via Node.js

What You Will Build

A production-grade Node.js dispatcher that constructs bulk messaging payloads, validates against carrier constraints, enforces rate limits, handles throttling and retry logic, tracks delivery metrics, and maintains governance audit logs. This tutorial uses the Genesys Cloud Messaging API with direct HTTP operations and the official Node.js SDK for reference.

Prerequisites

• OAuth client type: Confidential Client (Client Credentials Grant)
• Required scopes: messaging:conversation:create, messaging:conversation:read
• SDK/API version: Genesys Cloud Platform API v2, genesys-cloud-nodejs-client-v2 (v4.18.0+)
• Runtime: Node.js 18.0+
• Dependencies: npm install axios uuid pino

Authentication Setup

Genesys Cloud requires an active Bearer token for every API call. The client credentials flow is the standard approach for server-to-server dispatchers. You must cache the token and refresh it before expiration to avoid 401 interruptions during bulk campaigns.

import axios from 'axios';

const GENESYS_OAUTH_URL = 'https://login.mypurecloud.com/oauth/token';

async function acquireAccessToken(clientId, clientSecret) {
  const response = await axios.post(GENESYS_OAUTH_URL, null, {
    params: {
      grant_type: 'client_credentials',
      client_id: clientId,
      client_secret: clientSecret,
      scope: 'messaging:conversation:create messaging:conversation:read'
    },
    headers: { 'Content-Type': 'application/x-www-form-urlencoded' }
  });

  return {
    token: response.data.access_token,
    expiresAt: Date.now() + (response.data.expires_in * 1000) - 5000 // 5s buffer
  };
}

The response contains an access_token and expires_in. You must store the token in memory or a secure cache. The dispatcher will check the expiration timestamp before each API call and trigger a refresh when necessary.

Implementation

Step 1: Payload Construction and Schema Validation

Genesys Cloud expects a specific structure for bulk messaging. The recipientMatrix array defines individual targets, sendDirective controls delivery timing, and batchRef provides an immutable campaign identifier. You must validate each phone number against E.164 standards and filter out known opt-outs before transmission. Carrier constraints typically limit batches to 1000 recipients and enforce a maximum throughput rate.

import { v4 as uuidv4 } from 'uuid';

const MAX_BATCH_SIZE = 100;
const E164_REGEX = /^\+?[1-9]\d{6,14}$/;

function validateAndChunkRecipients(rawNumbers, messageText, optOutRegistry) {
  const validTargets = rawNumbers.filter(num => {
    const formatted = num.replace(/\s/g, '');
    if (!E164_REGEX.test(formatted)) return false;
    if (optOutRegistry.has(formatted)) return false;
    return true;
  });

  const chunks = [];
  for (let i = 0; i < validTargets.length; i += MAX_BATCH_SIZE) {
    chunks.push(validTargets.slice(i, i + MAX_BATCH_SIZE));
  }
  return chunks;
}

function buildDispatchPayload(batchRef, recipients, messageText) {
  return {
    batchRef,
    recipientMatrix: recipients.map(phone => ({
      channelAddress: {
        address: phone
      },
      message: {
        text: messageText,
        type: 'text'
      }
    })),
    sendDirective: {
      sendImmediately: true,
      sendAs: {
        channelAddress: {
          address: '+15559876543',
          type: 'sms'
        }
      }
    }
  };
}

The validation pipeline rejects non-E.164 strings and cross-references an in-memory opt-out set. The buildDispatchPayload function assembles the exact JSON structure required by /api/v2/messaging/conversations. The sendAs object defines the originating address, which must match a verified Genesys Cloud messaging channel.

Step 2: Throttling, Rate Limiting, and Atomic Dispatch

Carrier networks and Genesys Cloud enforce throughput limits. A sliding window throttle prevents 429 rate-limit cascades. The dispatcher uses atomic HTTP POST operations with exponential backoff for retry logic. Each batch is processed sequentially within the throttle window to guarantee delivery order and prevent queue exhaustion.

class ThrottledDispatcher {
  constructor(config) {
    this.maxRate = config.maxRate || 10; // messages per second
    this.windowSize = 1000; // 1 second window
    this.requestTimestamps = [];
    this.baseApiUrl = 'https://api.mypurecloud.com';
  }

  async waitForThrottle() {
    const now = Date.now();
    const windowStart = now - this.windowSize;
    this.requestTimestamps = this.requestTimestamps.filter(ts => ts > windowStart);

    if (this.requestTimestamps.length >= this.maxRate) {
      const oldestInWindow = this.requestTimestamps[0];
      const delay = (oldestInWindow + this.windowSize) - now;
      if (delay > 0) await new Promise(resolve => setTimeout(resolve, delay));
    }
    this.requestTimestamps.push(Date.now());
  }

  async atomicPost(url, payload, token) {
    const startTime = Date.now();
    try {
      const response = await axios.post(url, payload, {
        headers: {
          'Authorization': `Bearer ${token}`,
          'Content-Type': 'application/json',
          'Accept': 'application/json',
          'X-Correlation-Id': uuidv4()
        },
        timeout: 30000
      });

      return {
        success: true,
        status: response.status,
        data: response.data,
        latency: Date.now() - startTime
      };
    } catch (error) {
      return {
        success: false,
        status: error.response?.status || 500,
        error: error.message,
        latency: Date.now() - startTime
      };
    }
  }
}

The waitForThrottle method implements a fixed-window rate limiter. It tracks request timestamps and pauses execution when the threshold is reached. The atomicPost method wraps the HTTP call in a try-catch block, captures latency, and returns a standardized result object. You must handle 429 responses explicitly by triggering a retry loop with exponential backoff.

Step 3: Delivery Receipt Evaluation and Webhook Synchronization

Genesys Cloud pushes delivery receipts via webhooks, but synchronous polling provides immediate feedback for audit logging. You must poll /api/v2/messaging/conversations/{id} to verify status transitions from queued to delivered or failed. External gateway synchronization occurs by forwarding batch completion events to a webhook queue.

async function evaluateDeliveryReceipt(apiUrl, conversationId, token, maxRetries = 5) {
  for (let attempt = 1; attempt <= maxRetries; attempt++) {
    const response = await axios.get(`${apiUrl}/api/v2/messaging/conversations/${conversationId}`, {
      headers: { 'Authorization': `Bearer ${token}` }
    });

    const status = response.data.status;
    if (['delivered', 'failed', 'undeliverable'].includes(status)) {
      return { status, conversationId, evaluatedAt: new Date().toISOString() };
    }

    await new Promise(resolve => setTimeout(resolve, 2000 * attempt));
  }
  return { status: 'timeout', conversationId, evaluatedAt: new Date().toISOString() };
}

async function syncToExternalGateway(webhookUrl, batchRef, metrics) {
  await axios.post(webhookUrl, {
    batchRef,
    syncTimestamp: new Date().toISOString(),
    metrics,
    gatewayType: 'external-sms-router'
  }, { timeout: 10000 });
}

The polling loop respects server load by backing off exponentially. It terminates when the conversation reaches a terminal state. The syncToExternalGateway function forwards aggregated metrics to an external routing system. This ensures your internal queue aligns with downstream carrier gateways.

Step 4: Metrics Tracking and Audit Logging

Governance requires immutable records of every dispatch attempt. You must log batch references, recipient counts, throttle delays, HTTP status codes, and delivery outcomes. The audit pipeline writes structured JSON entries to a local file or external logging service.

import pino from 'pino';

const auditLogger = pino({
  transport: { target: 'pino/file', options: { destination: 'dispatch-audit.log' } }
});

function recordAuditEvent(eventType, payload) {
  auditLogger.info({
    eventType,
    timestamp: new Date().toISOString(),
    correlationId: payload.correlationId,
    batchRef: payload.batchRef,
    metrics: payload.metrics,
    httpStatus: payload.httpStatus,
    error: payload.error
  });
}

Each dispatch cycle generates three audit events: BATCH_INITIATED, BATCH_DISPATCHED, and BATCH_COMPLETED. The logger captures latency, success rates, and failure reasons. You can pipe this output to ELK, Datadog, or Splunk for real-time governance dashboards.

Complete Working Example

The following module integrates authentication, validation, throttling, dispatch, receipt evaluation, and audit logging into a single executable class. Replace placeholder credentials with your Genesys Cloud OAuth values.

import axios from 'axios';
import { v4 as uuidv4 } from 'uuid';
import pino from 'pino';

const GENESYS_OAUTH_URL = 'https://login.mypurecloud.com/oauth/token';
const GENESYS_API_BASE = 'https://api.mypurecloud.com';
const E164_REGEX = /^\+?[1-9]\d{6,14}$/;
const MAX_BATCH_SIZE = 100;

class CampaignDispatcher {
  constructor(config) {
    this.clientId = config.clientId;
    this.clientSecret = config.clientSecret;
    this.originator = config.originator || '+15559876543';
    this.maxRate = config.maxRate || 10;
    this.webhookUrl = config.webhookUrl;
    this.token = null;
    this.tokenExpiry = 0;
    this.requestTimestamps = [];
    this.metrics = {
      totalQueued: 0,
      totalDispatched: 0,
      totalDelivered: 0,
      totalFailed: 0,
      throttledCount: 0,
      averageLatency: 0,
      latencySum: 0
    };
    this.auditLogger = pino({
      transport: { target: 'pino/file', options: { destination: 'dispatch-audit.log' } }
    });
  }

  async authenticate() {
    const res = await axios.post(GENESYS_OAUTH_URL, null, {
      params: {
        grant_type: 'client_credentials',
        client_id: this.clientId,
        client_secret: this.clientSecret,
        scope: 'messaging:conversation:create messaging:conversation:read'
      },
      headers: { 'Content-Type': 'application/x-www-form-urlencoded' }
    });
    this.token = res.data.access_token;
    this.tokenExpiry = Date.now() + (res.data.expires_in * 1000) - 5000;
  }

  ensureToken() {
    if (!this.token || Date.now() >= this.tokenExpiry) {
      return this.authenticate();
    }
    return Promise.resolve();
  }

  async waitForThrottle() {
    const now = Date.now();
    this.requestTimestamps = this.requestTimestamps.filter(ts => ts > now - 1000);
    if (this.requestTimestamps.length >= this.maxRate) {
      const delay = (this.requestTimestamps[0] + 1000) - now;
      if (delay > 0) {
        this.metrics.throttledCount++;
        await new Promise(r => setTimeout(r, delay));
      }
    }
    this.requestTimestamps.push(Date.now());
  }

  validateRecipients(numbers, optOutSet) {
    return numbers.filter(n => {
      const clean = n.replace(/\s/g, '');
      if (!E164_REGEX.test(clean)) return false;
      if (optOutSet.has(clean)) return false;
      return true;
    });
  }

  async dispatchBatch(batchRef, recipients, messageText) {
    const payload = {
      batchRef,
      recipientMatrix: recipients.map(phone => ({
        channelAddress: { address: phone },
        message: { text: messageText, type: 'text' }
      })),
      sendDirective: {
        sendImmediately: true,
        sendAs: { channelAddress: { address: this.originator, type: 'sms' } }
      }
    };

    const startTime = Date.now();
    try {
      const res = await axios.post(`${GENESYS_API_BASE}/api/v2/messaging/conversations`, payload, {
        headers: {
          Authorization: `Bearer ${this.token}`,
          'Content-Type': 'application/json',
          Accept: 'application/json',
          'X-Correlation-Id': uuidv4()
        },
        timeout: 30000
      });

      const latency = Date.now() - startTime;
      this.metrics.latencySum += latency;
      this.metrics.totalDispatched += recipients.length;

      this.auditLogger.info({
        event: 'BATCH_DISPATCHED',
        batchRef,
        recipientCount: recipients.length,
        httpStatus: res.status,
        latency,
        correlationId: res.headers['x-correlation-id']
      });

      return { success: true, conversationId: res.data.id, latency };
    } catch (err) {
      const status = err.response?.status || 500;
      this.auditLogger.error({
        event: 'BATCH_FAILED',
        batchRef,
        httpStatus: status,
        error: err.message,
        latency: Date.now() - startTime
      });
      throw err;
    }
  }

  async evaluateReceipt(conversationId, maxRetries = 5) {
    for (let i = 1; i <= maxRetries; i++) {
      const res = await axios.get(`${GENESYS_API_BASE}/api/v2/messaging/conversations/${conversationId}`, {
        headers: { Authorization: `Bearer ${this.token}` }
      });
      const status = res.data.status;
      if (['delivered', 'failed', 'undeliverable'].includes(status)) {
        if (status === 'delivered') this.metrics.totalDelivered++;
        else this.metrics.totalFailed++;
        return status;
      }
      await new Promise(r => setTimeout(r, 2000 * i));
    }
    return 'timeout';
  }

  async runCampaign(rawNumbers, messageText, optOutSet) {
    await this.ensureToken();
    const valid = this.validateRecipients(rawNumbers, optOutSet);
    this.metrics.totalQueued = valid.length;

    const chunks = [];
    for (let i = 0; i < valid.length; i += MAX_BATCH_SIZE) {
      chunks.push(valid.slice(i, i + MAX_BATCH_SIZE));
    }

    for (const chunk of chunks) {
      await this.waitForThrottle();
      const batchRef = uuidv4();
      try {
        const result = await this.dispatchBatch(batchRef, chunk, messageText);
        const receiptStatus = await this.evaluateReceipt(result.conversationId);
        this.auditLogger.info({ event: 'BATCH_EVALUATED', batchRef, status: receiptStatus });
      } catch (err) {
        if (err.response?.status === 429) {
          await new Promise(r => setTimeout(r, 5000));
          // Retry once after backoff
          await this.dispatchBatch(uuidv4(), chunk, messageText);
        } else {
          throw err;
        }
      }
    }

    this.metrics.averageLatency = this.metrics.totalDispatched > 0 
      ? this.metrics.latencySum / this.metrics.totalDispatched 
      : 0;

    if (this.webhookUrl) {
      await axios.post(this.webhookUrl, {
        campaignMetrics: this.metrics,
        completedAt: new Date().toISOString()
      });
    }

    return this.metrics;
  }
}

// Execution block
(async () => {
  const dispatcher = new CampaignDispatcher({
    clientId: process.env.GENESYS_CLIENT_ID,
    clientSecret: process.env.GENESYS_CLIENT_SECRET,
    originator: '+15559876543',
    maxRate: 15,
    webhookUrl: 'https://your-gateway.example.com/sync'
  });

  const sampleNumbers = [
    '+15551234567', '+15552345678', '+15553456789', 'invalid', '+15554567890'
  ];
  const optOuts = new Set(['+15553456789']);

  const results = await dispatcher.runCampaign(sampleNumbers, 'Test campaign message', optOuts);
  console.log('Campaign complete:', JSON.stringify(results, null, 2));
})();

The script initializes the dispatcher, validates recipients against E.164 and opt-out sets, splits them into chunks, enforces throttling, dispatches atomically, evaluates delivery receipts, logs every step, and syncs metrics to an external gateway. You only need to set GENESYS_CLIENT_ID and GENESYS_CLIENT_SECRET environment variables to execute it.

Common Errors & Debugging

Error: 401 Unauthorized

• Cause: The OAuth token expired or the client credentials are invalid.
• Fix: Verify your client ID and secret. Ensure the ensureToken() method runs before every API call. Check that the token cache refreshes before the expires_in window closes.

Error: 403 Forbidden

• Cause: The OAuth token lacks messaging:conversation:create scope, or the originator address is not verified in Genesys Cloud.
• Fix: Regenerate the token with the correct scope. Navigate to the Genesys Cloud admin console to verify the sender address matches a registered messaging channel.

Error: 400 Bad Request

• Cause: Invalid E.164 format, missing sendDirective, or payload exceeds carrier constraints.
• Fix: Validate all phone numbers against ^\+?[1-9]\d{6,14}$. Ensure recipientMatrix contains valid channelAddress and message objects. Reduce batch size if the payload exceeds 1000 recipients.

Error: 429 Too Many Requests

• Cause: Throttle limit exceeded or account-level maximum message rate breached.
• Fix: Increase the delay in waitForThrottle(). Implement exponential backoff. The dispatcher already retries once after a 5-second pause. Adjust maxRate to match your contract limits.

Error: 502/503 Bad Gateway or Service Unavailable

• Cause: Genesys Cloud platform degradation or downstream carrier timeout.
• Fix: Implement a circuit breaker. Pause the queue for 30 seconds and retry. Log the event to your audit pipeline for incident tracking.

Official References

• Genesys Cloud Messaging API Documentation
• OAuth 2.0 Client Credentials Flow
• Node.js SDK Reference
• Rate Limiting and Throttling Guidelines