We are using Intercom's direct integration with whatsapp. Earlier we were using a service called octopod which used to set the phone number and we used that and some intercom apis to add our custom attributes to intercom contacts.

Hey @shashank k​ 👋

Have you tried using webhooks to see if that is included in the webhook payload? That might be worth a try if you haven't already. These are the webhook topics here: https://developers.intercom.com/intercom-api-reference/reference/webhook-models-1

You could select one that suits your needs and run a test to see if it includes the Whatsapp number.

That being said, a phone attribute should be included in the contact object as shown here https://developers.intercom.com/intercom-api-reference/reference/contacts-model

Hope this helps 🙌