A modern web app to track your daily water intake with a 2L daily goal. Features manual logging, NFC device registration for quick taps, and automatic daily reset at 5 AM UTC.

• ✅ Daily Goal Tracking - Visual progress bar towards 2L daily target
• 📱 Quick Add Buttons - Log common amounts (250ml, 500ml, 750ml, 1L) with one tap
• 🎯 Custom Amount - Add any custom amount you drank
• 🏷️ Water Log History - View all today's entries with timestamps
• 📴 NFC Integration - Register NFC devices/tags that auto-log water on tap
• 🔄 Daily Reset - Automatic reset at 5 AM UTC each day
• 🔐 Authentication - Magic link sign-in via Better Auth
• 📊 Stats - Track your water intake over time

├── config/
│   └── constants.ts          # All configuration constants in one place
├── backend/
│   ├── schema.ts             # SQLite schema with water & NFC tables
│   ├── water-utils.ts        # Utility functions for water tracking
│   └── auth.ts               # Better Auth configuration
├── frontend/
│   ├── index.html            # Main HTML template
│   └── index.tsx             # React app with tab-based UI
└── index.ts                  # Hono API server with all endpoints

All constants are defined in config/constants.ts:

export const WATER_CONFIG = {
  DAILY_TARGET_ML: 2000,      // Change daily goal here (in ml)
  RESET_HOUR_UTC: 5,          // Change reset time here (UTC)
  QUICK_ADD_AMOUNTS: [250, 500, 750, 1000],
  MIN_ML_PER_TAP: 100,        // Minimum per NFC tap
  MAX_ML_PER_TAP: 1000,       // Maximum per NFC tap
  DEFAULT_ML_PER_TAP: 500,    // Default amount for new NFC devices
};

• POST /api/water/log - Log water intake

  { "milliliters": 500, "source": "manual" }

• GET /api/water/today - Get today's intake and logs

• GET /api/water/history?days=7 - Get intake history

• DELETE /api/water/:id - Delete a log entry

• POST /api/nfc/register - Start NFC device registration (returns registration URL)
• POST /api/nfc/device - Complete NFC device registration
• GET /api/nfc/devices - Get user's registered NFC devices
• PATCH /api/nfc/device/:id - Update device settings
• DELETE /api/nfc/device/:id - Delete a device
• GET /api/nfc/tap/:token - NFC tap endpoint (logs water automatically)

1. Register Device

   • Click "Start Registration" in NFC Devices tab
   • A QR code is generated with a registration URL
   • Share/scan the QR with your NFC device/app

2. Complete Registration

   • When the device scans the link, you specify the water amount (default 500ml)
   • Device is saved and ready to use

3. Log Water

   • Each tap of the registered NFC device logs water automatically
   • Shows success page with logged amount

• id - Auto-increment primary key
• userId - User who logged the water
• timestamp - When water was logged
• milliliters - Amount of water (in ml)
• source - "manual" or "nfc"
• createdAt - Record creation time

• id - Device UUID
• userId - Owner of the device
• token - Unique tap token
• milliliters - Amount logged per tap
• name - Device name
• createdAt - When registered
• updatedAt - Last update time

• token - Registration token (UUID)
• userId - User registering the device
• createdAt - Token creation time

The app automatically treats the day as starting at 5 AM UTC and ending at the next 5 AM UTC. This is calculated server-side in getTodayStartTime() so it works regardless of user timezone.

To change the reset time, edit RESET_HOUR_UTC in config/constants.ts.

1. Sign in with magic link
2. Click quick-add buttons or enter custom amount
3. Watch your progress bar fill up
4. Optionally register NFC devices for one-tap logging
5. Check history anytime

• Backend: Hono (TypeScript)
• Database: SQLite with Val Town blob storage
• Frontend: React with Twind CSS
• Auth: Better Auth with magic links
• Runtime: Deno on Val Town