WhatsApp Flow Hospital Booking System

A comprehensive WhatsApp Flow endpoint for managing hospital appointment bookings with encrypted interactions, featuring patient registration, appointment scheduling, and secure communication.

Features

• Patient Registration: Support for new and existing patients
• Appointment Booking: Doctor and time slot selection
• Payment Method Selection: Private or insurance options
• Secure Communication: End-to-end encryption with WhatsApp Flow
• Multiple Clinics: Support for various medical specialties
• Environment-based Configuration: Secure credential management

Prerequisites

• Node.js (v16.0.0 or higher)
• npm or yarn package manager
• WhatsApp Business API access
• RSA key pair for encryption

Installation

1. Clone the repository:

git clone <repository-url>
cd whatsapp-flow-tools

2. Install dependencies:

npm install

3. Set up environment variables:

cp .env.example .env

4. Configure your .env file with actual values (see Configuration section below)

Configuration

Environment Variables

Create a .env file based on .env.example and configure the following variables:

Required Variables

Variable	Description	Example
RSA_PASSPHRASE	Passphrase for RSA private key	your_secure_passphrase
RSA_PRIVATE_KEY	RSA private key for decryption	-----BEGIN RSA PRIVATE KEY----- ...
API_BASE_URL	Base URL for webhook endpoints	https://your-n8n-instance.domain.com
API_SIGNUP_ENDPOINT	Signup webhook path	/webhook/signup
API_SIGNIN_ENDPOINT	Sign-in webhook path	/webhook/sign_in
API_BOOKING_ENDPOINT	Booking submission webhook path	/webhook/submitbooking

Optional Variables

Variable	Description	Default
NODE_ENV	Environment mode	development

RSA Key Setup

1. Generate RSA Key Pair (if you don't have one):

# Generate private key
openssl genrsa -des3 -out private.pem 2048

# Generate public key  
openssl rsa -in private.pem -outform PEM -pubout -out public.pem

2. Configure WhatsApp Flow:
   • Upload the public key to WhatsApp Business Manager
   • Add the private key content to RSA_PRIVATE_KEY in your .env file
   • Set the passphrase in RSA_PASSPHRASE

API Endpoints Setup

Configure your n8n or webhook service with the following endpoints:

• Signup: Handles new patient registration
• Sign-in: Authenticates existing patients
• Booking: Processes appointment submissions

Usage

Development

npm run dev

Production

npm start

Flow Structure

The booking flow follows this sequence:

1. ADMISSION - Clinic, doctor, date, time, patient type, and payment selection
2. REGISTRATION (new patients) - Personal information form
3. PASIEN (existing patients) - Sign-in with name/phone and birth date
4. KONFIRMASI - Booking confirmation
5. COMPLETE - Success screen with booking details

Security

• All communication is encrypted using RSA + AES-128-GCM
• Environment variables store sensitive credentials
• Private keys are never exposed in code
• The .env file is automatically gitignored
• Environment validation ensures all required variables are present

File Structure

whatsapp-flow-tools/
├── hospital booking/
│   └── booking.js          # Main flow endpoint
├── .env                    # Environment variables (gitignored)
├── .env.example           # Environment template
├── .gitignore             # Git ignore rules
├── package.json           # Node.js dependencies
└── README.md             # This file

Environment Variable Validation

The application automatically validates that all required environment variables are present on startup. If any are missing, it will throw a clear error message indicating which variables need to be configured.

Troubleshooting

Common Issues

1. Decryption Errors:

   • Verify RSA private key format
   • Check passphrase accuracy
   • Ensure key matches WhatsApp public key

2. API Connectivity:

   • Verify webhook URLs are accessible
   • Check network connectivity
   • Validate API endpoint responses

3. Environment Variables:

   • Ensure .env file exists in project root
   • Check for typos in variable names
   • Verify no trailing whitespace in values

Debug Mode

Set NODE_ENV=development to enable detailed logging:

NODE_ENV=development npm start

Original WhatsApp Flow Payload Processor

This project extends the original WhatsApp Flow payload processor concept with hospital booking functionality.

Core Functions

• parseIncoming(body): Detects if body contains messages, statuses, or flow action
• normalizeMessages(entries): Flattens to uniform internal message objects
• buildFlowResponse({ type, data }): Returns object to JSON.stringify for Meta reply
• buildAck(): Minimal 200 OK payload

Example Integration

// inside an express /webhook POST handler
app.post('/webhook', (req, res) => {
  const responsePayload = processWebhookBody(req.body);
  res.status(200).json(responsePayload);
});

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Test thoroughly
5. Submit a pull request

License

MIT License - see LICENSE file for details