Help with Zoho CRM API Integration in C# WinForms (Token Generation Issue)

Help with Zoho CRM API Integration in C# WinForms (Token Generation Issue)

Hi everyone,

I need your help with integrating the Zoho CRM API into a C# desktop application.

My goal is to build a WinForms app in Visual Studio that does the following:

  • Fetch the full list of client projects (module: Deals) and display them in a searchable dropdown list.

  • When a project is selected, fetch related info: the contact name (Contact_Name) and account name (Account_Name).

  • Then, based on the contact, retrieve their details: name, phone, address, etc.

  • Eventually, I will use this data to pre-fill a .ordx file (but that part comes later).

My current issue is: I can't generate access tokens for my app.

Here's what I've tried so far:

  1. I went to the Zoho API Console and created a Self Client application.

  2. I received a Client ID and Client Secret.

  3. I selected the scope ZohoCRM.modules.ALL.

  4. Then, I tried using the following URL in my browser to get a device code:


  1. https://accounts.zoho.com/oauth/v3/device/code?grant_type=device_request&client_id=MY.CLIENT-ID&scope=ZohoCRM.modules.READ&access_type=offline&prompt=consent

(of course replacing MY.CLIENT-ID with the actual one)

But it doesn’t work — I get no usable token or code.

Could someone point me to a complete working example or video tutorial on how to set up Zoho CRM API access from a WinForms application?

Thanks a lot in advance for your help!