# Project Rules

## Architecture
- Clean architecture with domain, application, and infrastructure layers
- Domain models must not import from infrastructure
- Use dependency injection for all services

## Code Style
- TypeScript strict mode, no implicit any
- Use Result<T, E> for error handling in domain layer
- Prefer composition over inheritance
- Maximum 3 parameters per function; use options objects for more

## Testing
- Unit tests for domain logic (no mocking frameworks)
- Integration tests for API endpoints
- E2E tests for critical user journeys with Playwright

## Dependencies
- Do not add new dependencies without discussing first
- Prefer standard library over third-party for simple tasks

# Application Guidelines

## Architecture
- This is a monorepo managed with Turborepo
- Apps: web (Next.js), api (Express), mobile (React Native)
- Shared packages: ui, config, types

## Code Standards
- TypeScript strict mode in all packages
- Use barrel exports (index.ts) for public APIs
- No default exports; use named exports everywhere
- Prefer async/await over raw Promises

## API Design
- RESTful endpoints follow /api/v1/{resource} pattern
- All responses use { data, error, meta } envelope
- Validate request bodies with Zod schemas
- Return 4xx for client errors, 5xx for server errors

## Database
- Use Prisma ORM for all database operations
- Migrations checked into source control
- Soft-delete pattern: use deletedAt timestamp, never hard delete
- All timestamps stored as UTC

## Testing
- Jest for unit tests, Playwright for E2E
- Test files colocated: foo.ts -> foo.test.ts
- Mock external services, never call real APIs in tests