WhatsApp web api

I'm trying to create a node js web version of WhatsApp web version. I tried this last year but. I'm getting all the response but its encrypted i didn't able to decrypt that here is what i did 1). Create an initial websocket connection with WhatsApp web server and generate QR code 2). Print the QR in terminal and scan it with phone 3). Connection successful 4). I started getting callback in websocket on data but its encrypted. I tried reverse engineering of their code but i didn't get picture about encryption. Anybody know how it works it will​be really helpful