I’d like a small system that watches my Google Calendar for new “booking” events and automatically sends a personalised WhatsApp message to the client. Email or SMS could be added later, but WhatsApp is the must-have channel. Here’s the flow I have in mind • A client books a slot on my Google Calendar (or an existing event is updated). • The tool grabs key details—name, date, time, location, notes—and fires off a WhatsApp confirmation right away. • Optional reminders should go out at set offsets (e.g., 24 h and 1 h before). • If I cancel or move the event, an automatic follow-up is sent. I’m flexible on how it’s built: a clean Google Apps Script that runs in the cloud, a lightweight desktop utility, or another online service you recommend. Use any reliable API such as the official WhatsApp Business Cloud API, Twilio, Vonage, etc.—whatever keeps running costs low and integration straightforward. Key needs • Editable message templates (plain text & basic variables) • Support for multiple calendars and future channels (email/SMS) • Simple install / auth steps so I can duplicate it on another Google account • Log of sent messages and error handling Deliverables 1. Fully working script/app with source code 2. Setup guide and quick video or screenshot demo 3. Short hand-off call or chat for final questions Please include past work, a link to a live demo or a concise proposal showing how you’d tackle the WhatsApp API and Google Calendar triggers. If you’ve already built something similar, even better—I’d love to see it in action.