This is a API written in C# but it can be used in any .NET language. It's a fork from WhatsAPINet, which is based on WhatsAPI. The goal of this fork is to make it all work again and refacter the code, add documentation and write documentation on how Whatsapp works.
- FunXMPP Protocol - https://github.com/mgp25/WhatsAPI-Official/wiki/FunXMPP-Protocol
More info in WhatsAPI Official repo wiki https://github.com/mgp25/WhatsAPI-Official