How to send a PDF file to a WhatsApp user in C# (.NET) using Visual Studio 2022

Using the WhatsMate WhatsApp Gateway REST API

This article shows you how to send a document (e.g. a PDF file, an MP4 file, a WAV file, etc.) to a registered WhatsApp user in Microsoft’s .NET language: C#.

If you are using Visual Studio 2019, please read this tutorial instead.

Before the recipient can receive your WhatsApp message, she MUST register with the WhatsMate WA Gateway. Instructions are available on the official site. Unregistered users will never receive messages from the Gateway.

To send a WhatsApp message containing a PDF document in C#, do this:

  1. First, learn how to send a simple text message on the official site.
  2. With the above knowledge, you can now download our sample code.
  3. Locate the file cs_vs2022/send-pdf-individual.cs.
  4. Study the C# source code and customize the TODO/FIXME lines.
    • Among other things, put down YOUR OWN number as the recipient. You can’t send messages to strangers because we are against SPAMMERS.
  5. Run the C# program in Visual Studio to send yourself the first PDF file!

Happy coding :)