# Zoom API using HttpClient not working over TLS 1.3

**URL:** <https://devforum.zoom.us/t/zoom-api-using-httpclient-not-working-over-tls-1-3/75558>\
**Category:** API and Webhooks\
**Created:** [September 7, 2022, 4:44pm UTC](https://devforum.zoom.us/t/zoom-api-using-httpclient-not-working-over-tls-1-3/75558 "2022-09-07T16:44:07Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![yli](https://avatars.discourse-cdn.com/v4/letter/y/bbe5ce/32.png) [@yli](https://devforum.zoom.us/u/yli)\
**Post date:** [September 7, 2022, 4:44pm UTC](https://devforum.zoom.us/t/zoom-api-using-httpclient-not-working-over-tls-1-3/75558/1 "2022-09-07T16:44:07Z")

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**API Endpoint(s) and/or Zoom API Event(s)**  
“[https://api.zoom.us/v2/users?page\_size=300](https://api.zoom.us/v2/users?page_size=300)”

**Description**  
We wrote a .net 5.0 Console program to call Zoom api using HttpClient connection.  
When TLS 1.2 is enabled on the workstation/server, the program works properly to retrieve Zoom users.

However when our system admin team disabled TLS 1.0, 1.1, 1.2 protocols on the server. But kept TLS 1.3 enabled. The program stopped working and got the follow error message.

**Error?**  
“The SSL connection could not be established, see inner exception.”

**How To Reproduce**  
_Steps to reproduce the behavior:_  
_1. Use HttpClient to connect_  
\*2. JWT authentication  
HttpClient client = new HttpClient();  
client.BaseAddress = new Uri(“[https://api.zoom.us/v2/](https://api.zoom.us/v2/)”);  
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue(“application/json”));  
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue(“Bearer”, jwt);

HttpResponseMessage response = await client.GetAsync(“users?page\_size=300”)

_3. Any errors_  
“The SSL connection could not be established, see inner exception.”

_Questions_  
Does Zoom API is supported on TLS 1.3?

We have some Web API calls with some other vendors and most of them work properly with TLS 1.3 enabled (TLS 1.2 disabled).

Any help or clue would be greatly appreciated!

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<div class="post-metadata">

**Author:** ![gianni.zoom](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/gianni.zoom/32/32523_2.png) [@gianni.zoom](https://devforum.zoom.us/u/gianni.zoom)\
**Post date:** [September 13, 2022, 1:11am UTC](https://devforum.zoom.us/t/zoom-api-using-httpclient-not-working-over-tls-1-3/75558/2 "2022-09-13T01:11:17Z")

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Hi @yli ,

I’ll check internally to see what information we can share about our TLS protocols with respect to this. Thanks for brining this to our attention!

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**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:** [September 16, 2023, 4:48pm UTC](https://devforum.zoom.us/t/zoom-api-using-httpclient-not-working-over-tls-1-3/75558/3 "2023-09-16T16:48:09Z")

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Closed on September 16, 2023, 4:48pm UTC

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