Lead-AI-US/lead-ai-whatsapp-agent — reverse-engineered prompt

Build me the first working version of this WhatsApp AI lead agent from the existing repo docs.

I want a simple backend that can receive WhatsApp messages through Twilio, verify the webhook, send the message into an AI workflow, answer basic FAQs, ask a few lead qualification questions, detect when someone wants to book an appointment, respect business hours, and flag conversations that should go to a human. Store leads and conversation history in a CRM friendly way using either Firebase or PostgreSQL, whichever is easiest to make clean for now.

Please include clear environment variables, safe handling for secrets, basic validation, and avoid logging private customer info. Add a small admin or business user view if practical so a business can see new leads, their status, summaries, scores, and escalation notes.

Keep it prototype quality but actually runnable locally. Update the README with install, run, test, and setup steps. Look up current Twilio, FastAPI, and OpenAI docs online if you need to.