Whatsapp Sender / API

Hi, I'm needing for a Whatsapp API (much like WhatsAPI), in order to be able to do the following: - Send Whatsapp by calling this api from a PHP site. - Send Whatsapp messages to a list of my clients, located on a database source (mysql or even a text file). This is not a spam tool, since my clients agreed with this notification service. I've tried all apis around (python, PHP) but none of them are ready to be used as bulk messaging system, which is what i'm needing, so this version should be ready, optimized and focused on this requirement: be able to send a standard or customized message to a list of phone numbers. I dont need any particular coding language, as long as it works and can also be called using php and can work on a linux hosting environment. Thanks a lot.