open API with restful aspects. A conversational AI bot should be able to call the API to obtain 2 or 3 future open time slots for a meeting with the human salesperson. If the conversational AI says to the human "I have Tuesday, July 2nd at 11:00 am or Wednesday, July 3rd at 1:30 pm" the human can confirm which time is best and the API would then schedule a call at that selected time.

If the human says, "I am on vacation that week, can we look at the following week?", the bot should be able to query via API for availabilities on the week of July 8th.

An API like this will allow massive bookings using a scalable conversational bot making hundreds of simultaneous phone calls to prospects who previously expressed interest in a product or service.

We use Air.ai and Intelepeer.ai, but it could be Thought.ly or any tech.

I suppose the same might apply for SMS systems. Instead of sending an SMS with a link to a booking page, the SMS can offer "press A or Tuesday to book a call on Tuesday or B or Wednesday to book a call Wed...." each time the SMS via AI is guiding the customer to the booking. This way, they know a meeting was or was not booked when the conversation ends.