It's possible, but the word "coexistence" does a lot of heavy lifting here. Think of it like running two engines on the same chassis-you can do it, but you need to be deliberate about which one's in control at any given moment.
WhatsApp's own coexistence feature lets you keep the Business app for day-to-day manual replies while a Cloud API integration handles the automated flows-templates, notifications, maybe customer queries that match certain keywords. The trick is the phone number. Both need access to the same number, so you're essentially sharing the line. WhatsApp allows this, but only if the API instance is the primary and the Business app is secondary. That means the API sees everything, while the app only sees what the API hasn't claimed.
For a CRM to track messages cleanly, you'd want the API as the single source of truth. The Business app becomes more of a fallback for human intervention when the automation hits a wall. Just keep an eye on message limits-once you flip the switch to an API, the Business app's free tier caps and moderation rules shift.
Works well in practice if you've got a clear handoff logic. If you're trying to have both simultaneously without rules, you'll end up with duplicates and confused customers.
