---
title: Webhook event delivery
slug: content-marketing-platform/api/W0i3-webhook-event-delivery
docTags: 
createdAt: 2026-06-24T17:30:22.336Z
---

## Acknowledgement

When you receive an event, acknowledge the delivery by returning an HTTP `200` or `202` status code. Any status other than `200` or `202` is considered a delivery failure.

## Delivery sequence

Optimizely Content Marketing Platform (CMP) does not guarantee the delivery of events in the sequence in which they are generated. You can use the CMP Open API to fetch the latest data.

## Duplicate events

In rare cases, callback endpoints might receive the same event more than once. Make your event processing idempotent to guard against duplicated events.

## Retry

In case of delivery failure, Optimizely CMP tries to deliver the event again, for up to three days, with an exponential backoff.

## Timeout

It is expected that the callback endpoint will respond within **30 seconds** of receiving the webhook event. If it takes more than 30 seconds, the connection is terminated and will be considered a delivery failure.