WhatsApp Session messages are any messages sent and received in response to a user-initiated message to your application.
A messaging session starts when a user sends your application a message and lasts for 24 hours from the most recently received message. You can wait for users to message your app, or you can send a Template Message to invite the user to respond.
Note: WATI does not charge for incoming session messages.
Our platform only counts outgoing session messages towards billing (also called customer support message)
For more details on our charging model, please refer to this article on Costs for sending messages in WATI