Evolution API
CautionSelf-hosted open-source WhatsApp API (unofficial, ban risk).
Green API
CautionWhatsApp Web-based API (unofficial).
Whapi.Cloud
CautionUnofficial WhatsApp API, quick to integrate.
WPPConnect
CautionOpen-source WhatsApp Web automation (unofficial).
whatsapp-web.js
CautionNode.js WhatsApp Web library (unofficial).
Baileys
CautionWhatsApp multi-device protocol library (unofficial).