CXone Webhook 502 errors and implementing a custom retry queue

We are running a high-volume campaign and the CXone webhooks are timing out on our endpoint. The platform returns 200 initially, but our server throws a 502 Bad Gateway after 5 seconds. CXone retries three times, then drops the event. We need a dead letter queue strategy because we can’t afford to lose these contact events.

I’m using Node.js with Express. The current handler looks like this:

app.post('/cxone/webhook', async (req, res) => {
 try {
 await processEvent(req.body);
 res.status(200).send('OK');
 } catch (err) {
 // This is where it fails
 console.error('Webhook error:', err);
 res.status(500).send('Server Error');
 }
});

The problem is processEvent takes too long. I tried setting res.setTimeout(30000) but CXone doesn’t wait that long. It expects a quick acknowledgment.

My plan is to:

1. Acknowledge the webhook immediately with 200.
2. Push the payload to an SQS queue.
3. Have a consumer process the queue.

But I’m worried about duplicate events. CXone retries on 5xx. If I return 200 before the DB commit, I might lose data if the app crashes. If I return 200 after DB commit, I get 502s from CXone.

Is there a way to configure the webhook retry policy in the CXone API? I checked the /api/v2/routing/webhooks endpoint but didn’t see a field for retryCount or deadLetterQueueUrl.

Here is the error log from our side:

[Error: connect ECONNREFUSED 10.0.0.5:443]
 at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1141:16) {
 errno: -111,
 code: 'ECONNREFUSED',
 syscall: 'connect',
 address: '10.0.0.5',
 port: 443
}

Should I be using a message queue like Kafka or just SQS? The volume is about 50k events per hour. I don’t want to build a complex retry mechanism if the platform supports it natively. Any code examples for handling this pattern in Node.js?

Don’t rely on the platform’s built-in retry logic for high-volume campaigns. It’s too aggressive and will hammer your endpoint, likely causing more 502s. You need a buffer.

The pattern I use is a quick ACK followed by async processing. Your Express handler should respond with 200 OK immediately, then push the payload to an internal queue like BullMQ or AWS SQS. This decouples the HTTP request from the heavy lifting.

Here’s how you structure that handler:

const { Worker, Queue } = require('bullmq');
const connection = { host: 'redis.host', port: 6379 };

const webhookQueue = new Queue('cxone-events', { connection });

app.post('/cxone/webhook', async (req, res) => {
 // Acknowledge receipt instantly
 res.status(200).send('OK');

 try {
 // Push to queue for background processing
 await webhookQueue.add('process-event', req.body, {
 attempts: 3,
 backoff: { type: 'exponential', delay: 2000 }
 });
 } catch (err) {
 // Log to DLQ if queue push fails
 console.error('Queue push failed:', err);
 }
});

Once the job is in the queue, a worker processes it. If the worker fails, BullMQ handles retries with exponential backoff. If it fails three times, it moves to the Failed Job Set, which acts as your dead letter queue. You can inspect that set via the BullMQ dashboard or a custom script.

This stops CXone from thinking the delivery failed. It sees a 200 and moves on. Your internal system handles the reliability.

Check your webhook settings in CXone too. Ensure the timeout is set to something reasonable like 3 seconds. Since you’re returning 200 immediately, the platform won’t wait for your actual processing. This keeps the connection open time low and prevents the gateway from timing out.

I’ve seen this pattern save campaigns during peak loads. The key is never doing DB writes or external API calls in the webhook handler itself. Offload everything.

That async ACK pattern is spot on. You don’t want the platform timing out while you’re crunching data. Just make sure your internal queue has proper visibility timeouts configured. If your worker crashes after picking up a job, you don’t want that event lost. BullMQ handles this well with Redis.

The async ACK pattern works, but you’ll hit the 502s again if your worker queue fills up. Just bump the visibility timeout in BullMQ and ensure your endpoint returns 200 before any DB writes.

The docs state: “If the target service returns a 5xx error, Genesys Cloud will retry the webhook delivery.” A 502 triggers this loop. You need to handle the load gracefully. Return 200 OK immediately.