The basics
Understanding WhatsApp number coexistence
WhatsApp number coexistence lets one number run on the WhatsApp Business App and the WhatsApp Business Platform at the same time. It is WhatsApp Business API coexistence built directly by Meta, so businesses do not have to choose between the app they already trust and the automation an API unlocks, or give up the number their customers already have saved. This is true WhatsApp Business app and API coexistence, not a workaround.
Before coexistence, connecting a number to the WhatsApp API meant migrating away from the app entirely. Embedded Signup changed that. The same number WhatsApp API and app now share one WhatsApp Business Account (WABA), with a Meta Business Solution Provider (BSP) like TeamInbox handling the connection and keeping WhatsApp app chat history migration synced in both directions.