Routing Genesys Cloud EventBridge Voice Events to AWS SQS with Node.js

What You Will Build

• An asynchronous Express listener that receives Genesys Cloud EventBridge voice events, validates cryptographic signatures, and forwards structured data to an AWS SQS queue.
• This integration uses the Genesys Cloud EventBridge webhook delivery mechanism and the AWS SDK v3 SQSClient for message publishing.
• The implementation is written in Node.js 18+ using modern async/await syntax, Express for routing, and native crypto for signature verification.

Prerequisites

• Genesys Cloud EventBridge webhook secret (configured via the EventBridge integration settings)
• AWS Access Key ID and Secret Access Key with sqs:SendMessage, sqs:SendMessageBatch, and sqs:SendMessage permissions
• Node.js 18+ runtime environment
• External dependencies: express, @aws-sdk/client-sqs, crypto, dotenv, uuid
• Install dependencies with: npm install express @aws-sdk/client-sqs uuid dotenv

Authentication Setup

Inbound EventBridge webhooks do not use OAuth 2.0 token flows. Genesys Cloud signs each HTTP POST request with a shared secret using HMAC-SHA256. The signature arrives in the X-Genesys-Signature header. Your listener must reconstruct the hash using the raw request body and the stored secret. If the computed hash matches the header value, the request originates from Genesys Cloud.

OAuth Scope: N/A (Inbound EventBridge webhooks use HMAC-SHA256 signature validation instead of OAuth 2.0)

The following code demonstrates the exact validation routine. It reads the raw body, computes the hash, and performs a constant-time comparison to prevent timing attacks.

import crypto from 'crypto';

const GENEYS_WEBHOOK_SECRET = process.env.GENESYS_WEBHOOK_SECRET;

export function validateGenesysSignature(body, signatureHeader) {
  if (!GENEYS_WEBHOOK_SECRET || !signatureHeader) {
    throw new Error('Missing webhook secret or signature header');
  }

  const computedHash = crypto
    .createHmac('sha256', GENEYS_WEBHOOK_SECRET)
    .update(body)
    .digest('hex');

  // Constant-time comparison to prevent timing attacks
  const isValid = crypto.timingSafeEqual(
    Buffer.from(computedHash, 'utf8'),
    Buffer.from(signatureHeader, 'utf8')
  );

  if (!isValid) {
    throw new Error('Invalid HMAC-SHA256 signature. Request rejected.');
  }

  return true;
}

This function must execute before any payload parsing. A failed validation triggers an immediate 401 response, preventing malicious actors from injecting spoofed events into your message queue.

Implementation

Step 1: Initialize Server and Health Check Endpoint

Infrastructure monitoring tools require a lightweight endpoint to verify service availability. The health check endpoint returns HTTP 200 with a JSON payload containing the service status and timestamp. It does not process business logic, ensuring it never blocks event ingestion.

import express from 'express';

const app = express();
const PORT = process.env.PORT || 3000;

// Health check endpoint for infrastructure monitoring
app.get('/health', (req, res) => {
  res.status(200).json({
    status: 'healthy',
    timestamp: new Date().toISOString(),
    service: 'genesys-eventbridge-sqs-listener'
  });
});

app.listen(PORT, () => {
  console.log(`EventBridge listener running on port ${PORT}`);
});

This endpoint allows load balancers and container orchestrators to perform liveness probes. The response contains no sensitive data and executes synchronously to guarantee sub-millisecond latency.

Step 2: Validate Webhook Signatures Using HMAC-SHA256

Express must parse the raw body without JSON transformation to preserve the exact byte sequence used for signature validation. The express.raw() middleware captures the payload as a Buffer. The route handler extracts the X-Genesys-Signature header, passes the buffer to the validation function, and throws a 401 error on mismatch.

import express from 'express';
import { validateGenesysSignature } from './auth.js';

const router = express.Router();

// Use raw body parser to preserve exact bytes for HMAC validation
router.use(express.raw({ type: 'application/json', limit: '1mb' }));

router.post('/webhook/genesys', async (req, res) => {
  try {
    const signature = req.headers['x-genesys-signature'];
    validateGenesysSignature(req.body, signature);
    
    // Parse JSON only after successful validation
    const payload = JSON.parse(req.body.toString());
    
    // Forward to event processor
    const result = await processVoiceEvent(payload);
    
    res.status(200).json({ received: true, eventId: payload.id });
  } catch (error) {
    if (error.message.includes('Invalid HMAC')) {
      return res.status(401).json({ error: 'Invalid signature' });
    }
    console.error('Webhook processing failed:', error);
    return res.status(500).json({ error: 'Internal processing error' });
  }
});

export default router;

The route returns 200 immediately after successful validation to acknowledge receipt. Genesys Cloud EventBridge expects an HTTP 2xx response within 30 seconds. Delayed responses trigger retry mechanisms that increase queue pressure. The actual SQS publishing occurs asynchronously after the 200 response is sent.

Step 3: Parse EventBridge Payloads and Filter Voice Event Types

Genesys Cloud EventBridge delivers events with a standardized envelope. The type field indicates the specific event. Voice routing events use prefixes like routing:conversation:voice. The listener must filter these types before transformation. Other event types (chat, callback, workitem) bypass processing to prevent unnecessary queue traffic.

const ALLOWED_VOICE_EVENT_TYPES = [
  'routing:conversation:voice:created',
  'routing:conversation:voice:updated',
  'routing:conversation:voice:terminated'
];

export async function processVoiceEvent(payload) {
  const eventType = payload.type;
  
  if (!ALLOWED_VOICE_EVENT_TYPES.includes(eventType)) {
    console.log(`Ignoring non-voice event type: ${eventType}`);
    return { skipped: true, eventType };
  }

  return { processed: true, eventType, data: payload };
}

This filtering step reduces downstream processing costs. EventBridge delivers high-volume streams during peak hours. Filtering at the ingress point prevents non-relevant payloads from consuming SQS throughput quotas.

Step 4: Transform Payloads to SQS Message Attributes

SQS message attributes enable downstream consumers to filter messages without reading the full body. The transformation extracts critical voice metadata and maps it to string-typed attributes. The raw payload remains in the message body for consumers that require full context.

export function transformToSqsAttributes(eventData) {
  const attributes = {
    'eventType': {
      DataType: 'String',
      StringValue: eventData.type
    },
    'conversationId': {
      DataType: 'String',
      StringValue: eventData.data?.conversationId || 'unknown'
    },
    'direction': {
      DataType: 'String',
      StringValue: eventData.data?.direction || 'unknown'
    },
    'queueName': {
      DataType: 'String',
      StringValue: eventData.data?.queueName || 'unknown'
    },
    'timestamp': {
      DataType: 'String',
      StringValue: eventData.timestamp || new Date().toISOString()
    }
  };

  return attributes;
}

SQS message attributes have a 10 KB limit per message. The transformation excludes large fields like transcript or recordingUrl from attributes. Those fields remain in the JSON body. This design balances filtering capability with attribute size constraints.

Step 5: Send to SQS with Deduplication and DLQ Routing

The final step publishes the message to a FIFO SQS queue. FIFO queues guarantee exactly-once processing and preserve order. The MessageDeduplicationId prevents duplicate processing when Genesys Cloud retries delivery. The implementation includes explicit retry logic for 429 Throttling exceptions and routes poison messages to a Dead-Letter Queue when retries exhaust.

import { SQSClient, SendMessageCommand, ThrottlingException } from '@aws-sdk/client-sqs';
import { v4 as uuidv4 } from 'uuid';

const sqsClient = new SQSClient({ region: process.env.AWS_REGION });
const MAIN_QUEUE_URL = process.env.SQS_MAIN_QUEUE_URL;
const DLQ_URL = process.env.SQS_DLQ_URL;

const MAX_RETRIES = 3;
const BASE_DELAY = 1000; // 1 second

export async function publishToSqs(payload, attributes) {
  const dedupId = payload.id || uuidv4();
  
  const command = new SendMessageCommand({
    QueueUrl: MAIN_QUEUE_URL,
    MessageBody: JSON.stringify(payload),
    MessageAttributes: attributes,
    MessageDeduplicationId: dedupId,
    MessageGroupId: 'voice-events' // Required for FIFO queues
  });

  for (let attempt = 1; attempt <= MAX_RETRIES; attempt++) {
    try {
      const response = await sqsClient.send(command);
      console.log(`Message published successfully: ${response.MessageId}`);
      return response;
    } catch (error) {
      if (error instanceof ThrottlingException && attempt < MAX_RETRIES) {
        const delay = BASE_DELAY * Math.pow(2, attempt - 1);
        console.warn(`429 ThrottlingException. Retrying in ${delay}ms (attempt ${attempt}/${MAX_RETRIES})`);
        await new Promise(resolve => setTimeout(resolve, delay));
        continue;
      }
      
      // Route poison messages to DLQ after exhausting retries or on fatal errors
      console.error(`Fatal SQS error after ${attempt} attempts. Routing to DLQ.`, error);
      await routeToDlq(payload, attributes, error);
      throw error;
    }
  }
}

async function routeToDlq(payload, attributes, originalError) {
  const dlqPayload = {
    originalPayload: payload,
    error: originalError.message,
    timestamp: new Date().toISOString(),
    retryAttempts: MAX_RETRIES
  };

  const dlqCommand = new SendMessageCommand({
    QueueUrl: DLQ_URL,
    MessageBody: JSON.stringify(dlqPayload),
    MessageAttributes: {
      ...attributes,
      'dlqReason': {
        DataType: 'String',
        StringValue: originalError.name || 'UnknownError'
      }
    }
  });

  try {
    await sqsClient.send(dlqCommand);
    console.log('Poison message successfully routed to DLQ');
  } catch (dlqError) {
    console.error('Failed to route to DLQ:', dlqError);
  }
}

The retry loop implements exponential backoff for 429 responses. SQS enforces per-second throughput limits. Backoff prevents cascading throttling across your application instances. The DLQ routing captures the original payload alongside the error context, enabling developers to replay or inspect failed messages without losing data.

Complete Working Example

The following script combines all components into a single runnable application. It initializes the Express server, registers the health check and webhook routes, and starts listening. Replace environment variables with your credentials before execution.

import express from 'express';
import dotenv from 'dotenv';
import { validateGenesysSignature } from './auth.js';
import { processVoiceEvent, transformToSqsAttributes } from './transform.js';
import { publishToSqs } from './sqs.js';

dotenv.config();

const app = express();
const PORT = process.env.PORT || 3000;

// Health check endpoint
app.get('/health', (req, res) => {
  res.status(200).json({
    status: 'healthy',
    timestamp: new Date().toISOString(),
    service: 'genesys-eventbridge-sqs-listener'
  });
});

// Webhook ingestion endpoint
app.post('/webhook/genesys', express.raw({ type: 'application/json', limit: '1mb' }), async (req, res) => {
  try {
    const signature = req.headers['x-genesys-signature'];
    validateGenesysSignature(req.body, signature);
    
    const payload = JSON.parse(req.body.toString());
    const validation = await processVoiceEvent(payload);
    
    if (validation.skipped) {
      return res.status(200).json({ received: true, action: 'skipped', eventType: validation.eventType });
    }

    const attributes = transformToSqsAttributes(payload);
    await publishToSqs(payload, attributes);
    
    res.status(200).json({ received: true, eventId: payload.id });
  } catch (error) {
    if (error.message.includes('Invalid HMAC')) {
      return res.status(401).json({ error: 'Invalid signature' });
    }
    console.error('Webhook processing failed:', error);
    return res.status(500).json({ error: 'Internal processing error' });
  }
});

app.listen(PORT, () => {
  console.log(`EventBridge listener running on port ${PORT}`);
});

Run the application with node index.js. The server binds to port 3000 and accepts POST requests at /webhook/genesys. The health check responds at /health. All configuration values load from a .env file containing GENESYS_WEBHOOK_SECRET, AWS_REGION, SQS_MAIN_QUEUE_URL, and SQS_DLQ_URL.

Common Errors and Debugging

Error: 401 Invalid signature

• What causes it: The X-Genesys-Signature header does not match the computed HMAC-SHA256 hash. This occurs when the webhook secret in your environment variables differs from the secret configured in Genesys Cloud, or when the request body is modified before hashing.
• How to fix it: Verify that express.raw() parses the body before any middleware modifies it. Ensure GENESYS_WEBHOOK_SECRET matches the exact string from the EventBridge configuration. Do not URL-encode or trim the secret.
• Code showing the fix: The validation function in Step 2 uses crypto.timingSafeEqual to prevent timing attacks and rejects mismatched hashes immediately.

Error: 429 ThrottlingException

• What causes it: The AWS SQS queue has reached its per-second message rate limit. FIFO queues default to 300 messages per second. High-volume Genesys Cloud voice events can exceed this threshold during peak hours.
• How to fix it: The retry logic in Step 5 implements exponential backoff. Increase the BASE_DELAY or MAX_RETRIES if your queue consistently throttles. Alternatively, increase the FIFO queue throughput limit in the AWS console.
• Code showing the fix: The publishToSqs function catches ThrottlingException, calculates delay = BASE_DELAY * Math.pow(2, attempt - 1), and pauses before retrying.

Error: 400 MessageDeduplicationId too long

• What causes it: SQS FIFO queues require MessageDeduplicationId to be 128 characters or fewer. Genesys Cloud event IDs can exceed this length if they contain full UUIDs with prefixes.
• How to fix it: Hash the event ID or truncate it before assignment. Use crypto.createHash('sha256').update(payload.id).digest('hex').substring(0, 128) if IDs are unpredictable.
• Code showing the fix: Replace const dedupId = payload.id || uuidv4(); with a hashed version when dealing with long identifiers.

Error: 500 Internal processing error with DLQ routing failure

• What causes it: The primary SQS queue rejects the message due to malformed attributes, and the DLQ also rejects the fallback message. This typically indicates missing IAM permissions or incorrect queue URLs.
• How to fix it: Verify that the AWS credentials have sqs:SendMessage permissions on both the main queue and the DLQ. Ensure the queue URLs use the correct AWS region. Check CloudWatch Logs for the exact AWS error code.
• Code showing the fix: The routeToDlq function wraps the DLQ send in a try/catch block and logs failures explicitly, preventing silent drops.

Official References

• Genesys Cloud EventBridge Webhook Configuration
• AWS SQS SendMessage API Documentation
• Node.js Crypto Module Reference
• Genesys Cloud EventBridge Payload Schema