# Project Conventions

## Language
- TypeScript strict mode, no `any` types
- Prefer const over let, never use var
- Use template literals over string concatenation

## Architecture
- Feature-based folder structure under src/features/
- Each feature exports through an index.ts barrel file
- Shared utilities go in src/lib/

## Error Handling
- Use Result<T, E> pattern for expected failures
- Throw only for programmer errors
- Always log errors with structured context

## Testing
- Colocate tests next to source files (*.test.ts)
- Use factories for test data, not fixtures
- Integration tests in __tests__/ directories

---
description: Python backend conventions
globs: "app/**/*.py"
auto_apply: true
---

# Backend Rules

## Stack
- Python 3.12 with FastAPI
- SQLAlchemy 2.0 with async sessions
- Alembic for migrations
- pytest for testing

## Conventions
- Use type hints on all function signatures
- Async endpoints by default
- Pydantic v2 models for request/response schemas
- Repository pattern for database access

## File Structure
- app/api/routes/ — API endpoints
- app/models/ — SQLAlchemy models
- app/schemas/ — Pydantic schemas
- app/services/ — Business logic