Direct WhatsApp Cloud API Integration

My jewellery SaaS already runs on Next.js for the frontend and Node.js for the backend. What I now need is a seamless, first-party WhatsApp Business integration—no third-party BSPs such as MSG91 or AiSensy—using Meta’s own Cloud API.

Scope
• Set up the WhatsApp Cloud API under my Meta Business account, including the proper phone number verification and webhook configuration.
• Register and get approved two categories of message templates: utility (for bills/invoices) and marketing (for promotions). All template copy and designs are ready; you only handle their submission and approval.
• Build the Node.js endpoints that my existing backend will call:
– /api/whatsapp/sendInvoice
– /api/whatsapp/sendPromotion
Each should accept a payload with the customer’s WhatsApp number, template variables, and an optional media URL, then send the message through the Cloud API and return the delivery status.
• Add minimal authentication so these endpoints are secure for my internal services.
• Provide concise README or inline comments showing how to rotate tokens, add new templates, and monitor delivery reports.

Acceptance criteria
1. Invoices and promotions arrive on a live WhatsApp number using the approved templates with variable substitution working.
2. The endpoints return Meta’s message ID plus a clear success/error flag.
3. Setup instructions allow me to re-deploy or migrate without additional support.

If you have recent experience wiring Node.js backends to the WhatsApp Cloud API and can demonstrate at least one live implementation, let’s talk.