You are helping me build the following AI agent workflow.

## Goal
WhatsApp Emergency Notification System: Receives a WhatsApp message, looks up the sender's address in Google Sheets, and alerts the on-duty staff for that specific zone.

## Specification
- What it does: Receive instant WhatsApp alerts when someone contacts you, automatically matched to your zone using a lookup in Google Sheets so you know exactly who needs help immediately. This ensures the right staff member gets notified for every emergency without manual checking.
- Trigger: Triggered by an event (Event · on WhatsApp message)
- Autonomy: Fully hands-off
- Expected setup effort: under an hour
- Tools/services involved:
  - WhatsApp: Trigger and notification delivery
  - Google Sheets: User lookup and address retrieval

## Known pitfalls, handle each one explicitly in your implementation
1. WhatsApp API phone number verification can take time so ensure you have a sandbox environment ready for initial testing before going live.
2. Phone number formatting must be consistent with E.164 standards otherwise the WhatsApp Business API will reject the notification request.
3. Sensitive user data is transmitted in this flow so encrypt all payloads in transit and restrict Google Sheets access via OAuth2 service accounts.

## Reference implementation
https://www.youtube.com/watch?v=GIZzRGYpCbM (workflow template)
Fetch and inspect this before building. If it matches my stack, adapt it;
if not, rebuild the pattern with my tools.

## Process requirements
1. Before building: ask me which of the listed tools I actually use and
   what my platform is (n8n / Make / code / other). Do not assume.
2. Adapt the pattern to my answers; do not force the reference stack.
3. Address every pitfall above; tell me how you handled each.
4. Provide a test plan I can run before letting this touch real data.
5. Ask before any step that sends messages, modifies data, or spends money.

Source: https://usecasesforagents.com/use-case/whatsapp-emergency-notification-system/ via usecasesforagents.com