FolderStructure.dev

NestJS REST API Project Structure

Full REST API with validation, OpenAPI documentation, TypeORM database, and proper module separation.

#nestjs #typescript #nodejs #api #rest #swagger #typeorm
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Project Directory

myproject/
src/
Application source
main.ts
Swagger setup, validation
app.module.ts
Root module
config/
Configuration
configuration.ts
Typed config
database.config.ts
swagger.config.ts
common/
Shared utilities
decorators/
public.decorator.ts
filters/
http-exception.filter.ts
Global error handling
interceptors/
transform.interceptor.ts
Response wrapping
guards/
auth.guard.ts
dto/
pagination.dto.ts
modules/
Feature modules
users/
users.module.ts
users.controller.ts
users.service.ts
dto/
create-user.dto.ts
class-validator
update-user.dto.ts
entities/
user.entity.ts
TypeORM entity
auth/
auth.module.ts
auth.controller.ts
auth.service.ts
strategies/
jwt.strategy.ts
local.strategy.ts
database/
TypeORM setup
database.module.ts
migrations/
TypeORM migrations
.gitkeep
test/
app.e2e-spec.ts
jest-e2e.json
nest-cli.json
tsconfig.json
tsconfig.build.json
package.json
.env.example
.eslintrc.js
.prettierrc
.gitignore
README.md

Why This Structure?

This structure separates concerns with feature modules in modules/, shared code in common/, and configuration in config/. Swagger provides auto-generated API docs, class-validator ensures type-safe validation, and TypeORM handles database operations.

Key Directories

  • src/modules/-Feature modules (users, auth, etc.) with their own DTOs and entities
  • src/common/-Shared guards, filters, interceptors, decorators
  • src/config/-Typed configuration using @nestjs/config
  • src/database/-TypeORM connection and migrations

Getting Started

  1. npm install
  2. cp .env.example .env (set DATABASE_URL)
  3. npm run migration:run
  4. npm run start:dev
  5. Visit http://localhost:3000/api for Swagger UI

Module Anatomy

  • *.module.ts-Module definition, imports providers
  • *.controller.ts-HTTP routes, uses decorators
  • *.service.ts-Business logic, injects repository
  • dto/-Data Transfer Objects with validation
  • entities/-TypeORM database entities

When To Use This

  • Production APIs requiring documentation
  • Projects with database persistence needs
  • Team-based development
  • APIs needing authentication/authorization
  • Microservices with well-defined contracts

Trade-offs

  • More boilerplate-Each feature needs module, controller, service, DTOs
  • Learning curve-NestJS decorators and DI take time to master
  • TypeORM sync-Use migrations in production, never synchronize: true