---
title: Webhooks FAQ
slug: apis/faq/webhooks-cos
description: Discover essential insights in our comprehensive FAQ document on webhooks, covering event types, delivery statuses, resource limits, and IP addresses for sandbox and production environments.
docTags: 
createdAt: 2025-11-19T09:08:00.356Z
---

## Webhooks – Frequently Asked Questions

This section answers common questions about Webhooks.

**What webhook events are available?                                                                                                     **Please refer to [COS webhooks](docId\:BN5XtgkJogBe-CtwomCbS)  

**Why is my webhook status *****Suspended*****?                                                                              ***Suspended* status means that we could not successfully deliver an event to one of your registrations. 

**What is the retention period of webhooks?                                                                             **Currently there is no limitation to the retention period. However, webhooks expire after 7 days and cannot be redelivered.

**What is the maximum number of resources included in a single webhook event?            **50k for events received in basic format                                                                                      1k for events in extended format.

**How are webhook failures handled?                                                                                                                               **After a delivery failure, COS will retry 3 additional times after approximately 30 - 60 seconds before your registration updates to a *Suspended* status. If we still can't deliver the event after several retries, its registration status changes to *Suspended* and we start to queue all your events for your registration. No further attempts are made to deliver previous or future events until your registration returns to an *Active* status.

**What is the IP address from which COS webhooks are sent?                                                      **For sandbox it is 66.206.202.40 and for production it is 66.206.202.41.