I need a production-ready AI voice agent that answers our clinic’s main phone line 24/7, greets patients naturally, and then guides them through scheduling, rescheduling, or cancelling appointments. The same agent must also reply to moderate-level questions—things like treatment options, chair availability, pricing ranges, and insurance we accept—without passing callers to staff unless the request is complex. Core requirements • Phone–based only: the solution will sit behind our existing number and work with standard SIP/VoIP. • Full, real-time integration: the agent has to read and write appointment data directly in our clinic management system so calendar changes are reflected instantly for both staff and callers. (API docs are available.) • Automated reminders: once an appointment is created or moved, the system should trigger SMS or email reminders using our current messaging gateway. • Conversational quality: natural-sounding voices, accurate intent detection, graceful fall-backs to a human extension if confidence is low. • Security & HIPAA compliance throughout. Deliverables • Deployed voice agent reachable through our phone number. • Middleware or webhook layer that handles real-time updates to our clinic software. • Intent/utterance training set covering all common scenarios we will provide. • Testing script with at least 20 call flows demonstrating successful scheduling, rescheduling, cancellation, and FAQ handling. • Handover package with source, environment notes, and quick-start guide so our tech team can maintain it. Please mention which voice AI stack (Dialogflow CX, Amazon Lex, Twilio Voice, etc.) you would use and any previous medical or dental implementations you have completed.