# Validating webhooks: ASP.NET MVC Application

**URL:** <https://devforum.zoom.us/t/validating-webhooks-asp-net-mvc-application/85109>\
**Category:** API and Webhooks\
**Created:** [March 22, 2023, 2:34am UTC](https://devforum.zoom.us/t/validating-webhooks-asp-net-mvc-application/85109 "2023-03-22T02:34:04Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![rich1](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/rich1/32/1265_2.png) [@rich1](https://devforum.zoom.us/u/rich1)\
**Post date:** [March 22, 2023, 2:34am UTC](https://devforum.zoom.us/t/validating-webhooks-asp-net-mvc-application/85109/1 "2023-03-22T02:34:04Z")

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**API Endpoint(s) and/or Zoom API Event(s)**  
Zoom API Webhooks

**Description**  
I’m attempting to re-implement our Webhooks endpoint using the new challenge/response framework. However, while I see the webhook fire, I don’t seem to have a response body that I can parse to get the plainToken from the payload. The JSON representation that is being sent is empty and is set to -1.

**Error?**  
No error message, just no payload to parse.

**How To Reproduce**  
I have my Webhook endpoint, which is within an [ASP.NET](http://ASP.NET) web service, set up like this:

```
    <AllowAnonymous>
    <HttpPost>
    Async Function Post() As Threading.Tasks.Task(Of HttpResponseMessage)
        Dim json As String = Await Request.Content.ReadAsStringAsync

```

At this point in the code, my json variable is empty. I can’t further deserialize it to get at the plainToken value and respond to the Webhook appropriately.

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**Author:** ![freelancer.nak](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/freelancer.nak/32/40968_2.png) [@freelancer.nak](https://devforum.zoom.us/u/freelancer.nak)\
**Post date:** [March 22, 2023, 1:39pm UTC](https://devforum.zoom.us/t/validating-webhooks-asp-net-mvc-application/85109/2 "2023-03-22T13:39:07Z")

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@rich1 Hope you will be fine.

Webhook Validation using C# is already resolved here.

> [@Can't validate event notification endpoint URL](https://devforum.zoom.us/t/cant-validate-event-notification-endpoint-url/80380/9):
>
> @sales4 @sfaraclas @littlelaureates Here is C# working code point_down [HttpPost(Name = "events")] public ActionResult Events(ValidateUrlEvent notification) { var encoding = new System.Text.ASCIIEncoding(); var sha256 = new System.Security.Cryptography.HMACSHA256(); sha256.Key = encoding.GetBytes("Your Event Secret Token"); var hash = sha256.ComputeHash(encoding.GetBytes(notification.payload.plainToken)); var hashed=ToHex(hash,false); …

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex016/uploads/zoomdeveloper/original/3X/6/1/614bdd549b610bbaa46ff934617683a02bdaa03c.png) [@system](https://devforum.zoom.us/u/system)\
**Post date:** [March 25, 2024, 5:15am UTC](https://devforum.zoom.us/t/validating-webhooks-asp-net-mvc-application/85109/3 "2024-03-25T05:15:18Z")

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