Build Appointment Reminder App with WhatsApp

What you're building: Appointment scheduler that sends automatic WhatsApp reminders

Tech stack: React + NestJS + PostgreSQL + Twilio WhatsApp

Step 1: Tell Cocoding.ai What to Build

Copy/paste this prompt:

Build a full-stack appointment reminder app using React, NestJS,
PostgreSQL, and TypeORM with WhatsApp integration.

Features:
- Create appointments (client name, phone, date/time, notes)
- View/delete appointments
- Send WhatsApp reminders automatically at appointment time
- Use GMT+6 Dhaka timezone

Cocoding.ai creates everything automatically — backend, frontend, database, deployment.

Step 2: Get Twilio Credentials

📸 Screenshot placeholder: Twilio dashboard showing Account SID and Auth Token location

2.1 Create Free Account

1. Go to [twilio.com/try-twilio](https://www.twilio.com/try-twilio)
2. Sign up + verify phone

2.2 Copy Your Keys

From Twilio dashboard copy:

• Account SID (starts with AC)
• Auth Token (click Show)

📸 Screenshot placeholder: Twilio WhatsApp sandbox setup page with join instructions

2.3 Enable WhatsApp Sandbox

1. In Twilio: Messaging → Try it out → Send a WhatsApp message
2. On your phone, send the join message to the Twilio number
3. Copy sandbox number: whatsapp:+14155238886

Step 3: Add Credentials to App

📸 Screenshot placeholder: .env file open in editor showing where to paste Twilio credentials

Open backend/.env and replace the Twilio values:

TWILIO_ACCOUNT_SID=your_account_sid_here
TWILIO_AUTH_TOKEN=your_auth_token_here
TWILIO_WHATSAPP_FROM=whatsapp:+14155238886

Step 4: Test It

1. Open your app (Cocoding.ai provides URL)
2. Create appointment:

- Phone: +8801234567890 (must include + and country code)

- Time: 2 minutes from now

1. Wait for WhatsApp message at appointment time

📸 Screenshot placeholder: App interface showing appointment creation form

📸 Screenshot placeholder: App showing list of appointments

📸 Screenshot placeholder: WhatsApp reminder message received on phone

Phone Format Tips

Must include: + and country code

Troubleshooting

WhatsApp not sending?

• Did you join the sandbox on your phone?
• Are credentials correct in .env?
• Phone number format correct (with +)?
• Restart backend after updating .env

Wrong timezone? Tell Cocoding.ai: "Change timezone to GMT+X [your timezone]"

Backend errors? Tell Cocoding.ai: "Backend not working, fix it"

Go Production (Optional)

Sandbox is free but has limits. For production:

1. Twilio Console → Messaging → WhatsApp → Senders
2. Request your Twilio number
3. Complete Facebook verification (1-2 weeks)
4. Update .env with your number

Cost: ~$0.005 per message

Customize Your App

Tell Cocoding.ai what you want:

• "Send reminders 1 hour before instead of at appointment time"
• "Add email notifications"
• "Add calendar view"
• "Let clients confirm/cancel by replying on WhatsApp"