# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Project Overview

Prism is a real-time messenger built with Expo (React Native) frontend and NestJS backend using GraphQL and PostgreSQL. The project is structured as a monorepo with separate frontend and backend directories.

## Development Commands

### Backend (NestJS)
```bash
cd backend
npm run start:dev    # Development server with hot reload
npm run build        # Build for production
npm run test         # Run unit tests
npm run test:e2e     # Run end-to-end tests
npm run lint         # ESLint with auto-fix
npm run format       # Prettier formatting
```

### Frontend (Expo/React Native)
```bash
cd frontend
npx expo start       # Start Expo development server
npx expo start --ios # Start with iOS simulator
npx expo start --android # Start with Android emulator
```

## Architecture

### Backend Architecture
- **Framework**: NestJS with TypeScript
- **API**: GraphQL using code-first approach with auto-generated schema
- **Database**: PostgreSQL with TypeORM (synchronize enabled in development)
- **Authentication**: JWT with Passport strategy
- **Real-time**: GraphQL Subscriptions for live updates
- **Module Structure**:
  - `auth/` - JWT authentication and guards
  - `users/` - User management and profiles
  - `conversations/` - Chat/conversation management
  - `messages/` - Message handling and real-time updates

### Frontend Architecture
- **Framework**: Expo with React Native and TypeScript
- **State Management**: Apollo Client for GraphQL state management
- **UI Framework**: React Native Paper with custom theming
- **Navigation**: React Navigation with stack and tab navigators
- **Storage**: AsyncStorage for token persistence
- **Key Contexts**: AuthContext for authentication state

### Data Flow
- Frontend communicates with backend exclusively through GraphQL
- Real-time updates via GraphQL subscriptions
- JWT tokens stored in AsyncStorage and included in GraphQL requests via authLink
- Apollo Client handles caching with cache-and-network fetch policy

## Database Configuration

The project supports both remote and local PostgreSQL:
- Remote database is the default (configured in backend .env)
- Local database can be enabled by uncommenting postgres service in docker-compose.yml
- TypeORM synchronize is enabled in development (automatic schema updates)

## Environment Configuration

### Backend Environment Variables
Required in `backend/.env`:
```
DATABASE_HOST=
DATABASE_PORT=5432
DATABASE_USERNAME=
DATABASE_PASSWORD=
DATABASE_NAME=prism_messenger
JWT_SECRET=
JWT_EXPIRATION=7d
```

### Frontend API Configuration
Update `frontend/src/config/api.ts` based on development environment:
- iOS simulator: http://localhost:3000/graphql
- Android emulator: http://10.0.2.2:3000/graphql
- Physical device: http://YOUR_IP:3000/graphql

## Key Implementation Details

- GraphQL schema is auto-generated at `backend/src/schema.gql`
- All GraphQL queries, mutations, and subscriptions are centralized in `frontend/src/graphql/`
- Authentication uses JWT with bearer token authorization
- Real-time features implemented via GraphQL subscriptions with graphql-ws
- Frontend theme system supports both light and dark modes
- Message features include send, edit, delete with real-time updates