WhatsApp Webhook Auto-Reply Backend

I need a FastAPI service that listens to WhatsApp webhooks, supports several phone numbers at once, and responds automatically.

How it should work:
-Receives inbound WhatsApp messages and files (text, images, PDF, Word, Excel) via webhook
-Stores message metadata + content references in MySQL
-Automatically replies in WhatsApp:
For text: “message received” + copy of the original message
For files: “file received” + filename

Deliverables
1. Source code
2. MySQL schema + seed/migration file.
3. README with setup steps, environment variables and instruction for local deployment.