Middleware → Guards → Interceptors (pre) → Pipes → Controller → Interceptors (post) → Exception Filter

@Module({
  imports: [OtherModule],
  controllers: [UserController],
  providers: [UserService],
  exports: [UserService],
})
export class UserModule {}

@Controller('users')
export class UserController {
  constructor(private readonly userService: UserService) {}

  @Get()
  findAll() { return this.userService.findAll(); }

  @Get(':id')
  findOne(@Param('id', ParseIntPipe) id: number) { return this.userService.findOne(id); }

  @Post()
  create(@Body() dto: CreateUserDto) { return this.userService.create(dto); }
}

@Injectable()
export class UserService {
  constructor(@InjectRepository(User) private repo: Repository<User>) {}

  findAll() { return this.repo.find(); }
}

// DTO
export class CreateUserDto {
  @IsString() @MinLength(2) name: string;
  @IsEmail() email: string;
}

// main.ts
app.useGlobalPipes(new ValidationPipe({ whitelist: true, transform: true }));

@Injectable()
export class AuthGuard implements CanActivate {
  canActivate(context: ExecutionContext): boolean {
    const request = context.switchToHttp().getRequest();
    return this.validate(request);
  }
}

nest new project-name       # 새 프로젝트
nest g resource users       # CRUD 리소스
nest g module users         # 모듈
nest g controller users     # 컨트롤러
nest g service users        # 서비스
nest g guard auth           # 가드
nest g pipe validation      # 파이프