Ah. The thing that I'm using is running some kind of headless Chrome that runs the WhatsApp Web: https://github.com/pedroslopez/whatsapp-web.js

From what I understand this might get killed by Facebook at some point as they never approved this method.

What was the issue with the official API? https://developers.facebook.com/docs/whatsapp/

It's not available for personal use and requires business verification if I understand correctly: https://developers.facebook.com/docs/whatsapp/overview#terms...

No idea, didn't write it, but it Just Works.

Only wimps use APIs.