Since I found some older posts, that tell that whatsapp doesn\'t support this, I was wondering if something had changed and if there is a way to open a whatsapp \'chat\' wit
Tested on Marshmallow S5 and it works!
Uri uri = Uri.parse("smsto:" + "phone number with country code");
Intent sendIntent = new Intent(Intent.ACTION_SENDTO, uri);
sendIntent.setPackage("com.whatsapp");
startActivity(sendIntent);
This will open a direct chat with a person, if whatsapp not installed this will throw exception, if phone number not known to whatsapp they will offer to send invite via sms or simple sms message