Hello.
I have been testing the new Whatsapp Cloud API service, and it works perfectly from WINDEV.
For now I have only tried to send and receive simple messages.

Attached two projects:

The first project is a a windows application for sending messages, consisting of a button with 3 lines of code, and a short explanation.

The second one is a WebService consisting of two entry points, one GET and one POST, with three lines of code each.
Which serves as a webhook to receive whatsapp messages.

Note: For the correct functioning of the webhook it is necessary to install an ssl certificate, so that the website is secure (https).
Note: I could not deploy my WD24 WebService into my WAS27 to test it. So I upload the same project made with WD28, that is the version that I initally used and tested. (i tried to make it in version 24, for those people that didn't update to the last version)