Sending WhatsApp messages without confirmation

There are similar questions, but they do not touch on the nuance of the smartwatch from Pebble, which I mentioned below.

I am developing an Android application that has the ability to send a text message via WhatsApp. As far as I know, there is no way to do this other than from starting an intent and confirming sending messages through WhatsApp itself, as WhatsApp doesn't seem to provide a way to send a message directly from other apps, omitting the confirmation step.

However, as I have already shown, it is possible to send messages using a pebble smart watch without any intermediate steps.

What is the reason for this and can I somehow get around the need to launch WhatsApp to send a message?