Organizing Project Files
Colocate by feature when possible. Group by type only for truly shared code.
Standard Layout
src/
├── app/ # Next.js App Router (or pages/)
├── components/
│ ├── ui/ # Reusable primitives (Button, Modal)
│ └── [feature]/ # Feature-specific (auth/, dashboard/)
├── hooks/ # Custom React hooks
├── lib/ # Core utilities, clients, constants
├── services/ # API calls, external integrations
├── stores/ # State management
└── types/ # TypeScript definitions
Placement Quick Reference
| "I need..." | Location |
|---|---|
| A button | components/ui/Button.tsx |
| A login form | components/auth/LoginForm.tsx |
| User data fetching | services/user.ts or hooks/queries/useUser.ts |
| Date formatter | lib/utils.ts |
| Auth state | stores/auth.ts |
| Supabase types | types/supabase.ts (generated) |
| Custom type | types/index.ts or colocate |
Naming
- Components:
PascalCase.tsx - Hooks:
useCamelCase.ts - Utilities:
camelCase.ts - Types:
camelCase.ts
Colocation Pattern
For complex features, keep related files together:
components/auth/
├── LoginForm.tsx
├── LoginForm.test.tsx
├── useLoginForm.ts
└── login-schema.ts
Advanced Patterns
For App Router specifics, barrel files, and monorepo structures, see PATTERNS.md.