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!

    • Sticky Posts

    • Kaizen #197: Frequently Asked Questions on GraphQL APIs

      🎊 Nearing 200th Kaizen Post – We want to hear from you! Do you have any questions, suggestions, or topics you would like us to cover in future posts? Your insights and suggestions help us shape future content and make this series better for everyone.
    • Kaizen #198: Using Client Script for Custom Validation in Blueprint

      Nearing 200th Kaizen Post – 1 More to the Big Two-Oh-Oh! Do you have any questions, suggestions, or topics you would like us to cover in future posts? Your insights and suggestions help us shape future content and make this series better for everyone.
    • Celebrating 200 posts of Kaizen! Share your ideas for the milestone post

      Hello Developers, We launched the Kaizen series in 2019 to share helpful content to support your Zoho CRM development journey. Staying true to its spirit—Kaizen Series: Continuous Improvement for Developer Experience—we've shared everything from FAQs
    • Kaizen #193: Creating different fields in Zoho CRM through API

      🎊 Nearing 200th Kaizen Post – We want to hear from you! Do you have any questions, suggestions, or topics you would like us to cover in future posts? Your insights and suggestions help us shape future content and make this series better for everyone.
    • Client Script | Update - Introducing Commands in Client Script!

      Have you ever wished you could trigger Client Script from contexts other than just the supported pages and events? Have you ever wanted to leverage the advantage of Client Script at your finger tip? Discover the power of Client Script - Commands! Commands