# OpenAI Codex Prompt

Write a clean and robust service module to send WhatsApp messages using VexaHost WA Gateway.
API URL: https://wa.vexahostcloud.my.id/api/v1/messages/text
Method: POST
Headers:
  X-Api-Key: process.env.WA_API_KEY
  Content-Type: application/json
Body:
  { "to": recipient_phone, "message": text_message }
Requirements:
- Validate phone number input (supports 08... or 628...)
- Parse JSON response and log queue message ID
- Add exponential retry on 5xx server errors