# PKCE - invalid\_client

**URL:** <https://devforum.zoom.us/t/pkce-invalid-client/61955>\
**Category:** API and Webhooks\
**Created:** [December 28, 2021, 3:06pm UTC](https://devforum.zoom.us/t/pkce-invalid-client/61955 "2021-12-28T15:06:55Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![vsivasankar](https://avatars.discourse-cdn.com/v4/letter/v/47e85d/32.png) [@vsivasankar](https://devforum.zoom.us/u/vsivasankar)\
**Post date:** [December 28, 2021, 3:06pm UTC](https://devforum.zoom.us/t/pkce-invalid-client/61955/1 "2021-12-28T15:06:55Z")

</div>

## Using this template helps us debug your issues more effectively 🙂

**Description**  
I’m attempting to add PKCE to an OAuth flow that previously worked.  
I am able to get the Authorization code ,with below request

/oauth/authorize?response\_type=code&code\_challenge\_method=S256&client\_id=\<Client\_ID\>&scope=openid profile email accounting.transactions offline\_access&redirect\_uri=[oauth.pstmn.io/v1/callback&state=ABCD&code\_challenge=](http://oauth.pstmn.io/v1/callback&state=ABCD&code_challenge=)\<code\_chalenge\>

but when I pass the code in below URL (Access token request).

URL : /oauth/token  
Method : POST  
Body : {  
grant\_type : authorization\_code  
client\_id:\<Client\_ID\>  
code : \<Authorization\_Code\>  
redirect\_uri: /oauth.pstmn.io/v1/callback  
code\_verifier : \<Code\_Verifier\>

**Error**  
{  
“reason”: “Invalid client\_id or client\_secret”,  
“error”: “invalid\_client”  
}

**Which App Type (OAuth / Chatbot / JWT / Webhook)?**  
OAuth

**Which Endpoint/s?**  
/oauth/authorize  
/oauth/token

**How To Reproduce (If applicable)**  
Steps to reproduce the behavior:

[![](https://us1.discourse-cdn.com/flex016/uploads/zoomdeveloper/original/3X/6/7/679aa66c3b6e52e830f8a16b6a71031daddefc8b.jpeg "PKCE error") ](https://www.youtube.com/watch?v=3bCxP-7bnHU)

**Screenshots (If applicable)**  
If applicable, add screenshots to help explain your problem.

**Additional context**  
Add any other context about the problem here.

---

<div class="post-metadata">

**Author:** ![MaxM](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/maxm/32/42303_2.png) [@MaxM](https://devforum.zoom.us/u/MaxM)\
**Post date:** [January 4, 2022, 11:13pm UTC](https://devforum.zoom.us/t/pkce-invalid-client/61955/2 "2022-01-04T23:13:23Z")

</div>

Hey @vsivasankar,

Thank you for reaching out to the Zoom Developer Forum. I see that you submitted a ticket for this. I make sure to follow up with you there.

Thanks,  
Max

---

<div class="post-metadata">

**Author:** ![MaxM](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/maxm/32/42303_2.png) [@MaxM](https://devforum.zoom.us/u/MaxM)\
**Post date:** [January 4, 2022, 11:13pm UTC](https://devforum.zoom.us/t/pkce-invalid-client/61955/3 "2022-01-04T23:13:28Z")

</div>

Closed on January 4, 2022, 11:13pm UTC