# Multiple Participant Left events received

**URL:** <https://devforum.zoom.us/t/multiple-participant-left-events-received/7785>\
**Category:** API and Webhooks\
**Created:** [January 30, 2020, 4:36am UTC](https://devforum.zoom.us/t/multiple-participant-left-events-received/7785 "2020-01-30T04:36:54Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![tommy](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/tommy/32/72769_2.png) [@tommy](https://devforum.zoom.us/u/tommy)\
**Post date:** [January 30, 2020, 4:40pm UTC](https://devforum.zoom.us/t/multiple-participant-left-events-received/7785/2 "2020-01-30T16:40:57Z")

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Hey @heidi.zh.n,

This is most likely happening because you are not [sending a 200 OK response back](https://marketplace.zoom.us/docs/api-reference/webhook-reference#notification-delivery).

If Zoom does not get a 200 OK response after sending a Webhook, it assumes it failed, and will retry a few times.

Related post:

> [@Recording.completed event fired twice](https://devforum.zoom.us/t/recording-completed-event-fired-twice/5205/10):
>
> To fix this, try sending a 200 response back within a few seconds (1 second if possible). If Zoom does not get the 200 response, it initiates retry logic after 5 mins. Here is an example of how to send a 200 response after receiving a webhook event in Node.js / Express app.post('/webhook', async function (req, res) { // need to respond within 1 second with a 200 or else Zoom thinks webhook did not work and will retry. res.status(200) res.send() // your app logic here }) [https://derick…](https://derickbailey.com/2016/03/14/properly-handling-webhooks-with-node-and-express/)

Thanks,  
Tommy

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