ManyChat’s API does not currently allow checking if a WhatsApp number or WhatsApp ID exists as a subscriber. This is a basic requirement for any serious integration.

A direct endpoint is needed to avoid:

• Errors when creating already existing subscribers

• Unnecessary API calls

• Data duplication and inconsistencies

It should return whether the number is linked to a subscriber Id or not.

Without this, it's not possible to validate data before operating.
Hope this gets added soon.