A campus and community alert app built with React Native (Expo) and Supabase. View and create location-based alerts (safety, food, events, lost & found, and more) on a map and in a feed.

• Map view – See alerts as pins on a map with category-based colors
• Alerts feed – Browse, filter, and refresh alerts with pull-to-refresh
• Create alerts – Add title, description, category, optional photo, expiry time, and location (with campus boundary check)
• Categories – Food, Safety, Social, Academic, Sports, Lost & Found, Events
• Auth – Sign up, sign in, and sign out with Supabase Auth
• Profile & settings – User profile and app settings
• Real-time – Alerts can update in real time via Supabase Realtime

• Frontend: React Native (Expo SDK 54), React Navigation, NativeWind (Tailwind), React Native Maps
• Backend / data: Supabase (Auth, PostgreSQL, Storage, Realtime)
• Optional backend: Python (FastAPI, Supabase client) – see backend/requirements.txt

• Node.js 18+
• npm or yarn
• Expo Go on your phone (or iOS Simulator / Android Emulator)
• A Supabase project

git clone https://github.com/mm-xo/Nitrogen.git
cd Nitrogen/frontend
npm install

1. Create a project at app.supabase.com.
2. In the dashboard: Settings → API.
3. Copy Project URL and the anon public key (long JWT).

In the frontend folder, create a .env file (it is gitignored):

EXPO_PUBLIC_SUPABASE_URL=https://your-project-ref.supabase.co
EXPO_PUBLIC_SUPABASE_ANON_KEY=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...

Replace with your Supabase Project URL and anon public key.

Your Supabase project needs:

• Tables: e.g. an alerts table with columns such as id, title, description, category, created_at, expires_at, user_id, photo_url, latitude, longitude, and Row Level Security (RLS) policies as needed.
• Storage: A bucket for alert images (e.g. alert-photos) with policies allowing authenticated uploads and public (or signed) read access.

Exact schema should match what the app uses in CreateAlertScreen.js, AlterPins.js, and related code.

From the frontend directory:

cd frontend
npx expo start

Then:

• Press i for iOS Simulator or a for Android Emulator, or
• Scan the QR code with Expo Go on your device (same Wi‑Fi as your machine).

Restart the dev server after changing .env.

Nitrogen/
├── frontend/                 # Expo / React Native app
│   ├── App.js
│   ├── lib/
│   │   └── supabase.js       # Supabase client and auth storage
│   ├── src/
│   │   ├── components/
│   │   ├── constants/        # categories, campus, etc.
│   │   ├── context/          # AuthContext, Locationcontext
│   │   ├── map/              # MapView, AlterPins (fetch pins)
│   │   ├── navigation/       # AppNavigator, tabs + stack
│   │   ├── screens/          # Login, Signup, Map, Alerts, CreateAlert, Profile, Settings
│   │   ├── themes/
│   │   └── utils/
│   └── .env                  # EXPO_PUBLIC_SUPABASE_* (create locally, do not commit)
├── backend/                  # Optional Python backend
│   └── requirements.txt
└── README.md