nestjs-best-practices

Original：🇺🇸 English

Translated

NestJS 11+ best practices for enterprise Node.js applications with TypeScript. Use when writing, reviewing, or refactoring NestJS controllers, services, modules, or APIs. Triggers on: NestJS modules, controllers, providers, dependency injection, @Injectable, @Controller, @Module, middleware, guards, interceptors, pipes, exception filters, ValidationPipe, class-validator, class-transformer, DTOs, JWT authentication, Passport strategies, @nestjs/passport, TypeORM entities, Prisma client, Drizzle ORM, repository pattern, circular dependencies, forwardRef, @nestjs/swagger, OpenAPI decorators, GraphQL resolvers, @nestjs/graphql, microservices, TCP transport, Redis transport, NATS, Kafka, NestJS 11 breaking changes, Express v5 migration, custom decorators, ConfigService, @nestjs/config, health checks, or NestJS testing patterns.

1installs

Sourceejirocodes/agent-skills

Added on2026-02-10

NPX Install

npx skill4agent add ejirocodes/agent-skills nestjs-best-practices

SKILL.md Content

View Translation Comparison →

NestJS 11 Best Practices

Quick Reference

Topic	When to Use	Reference
Core Architecture	Modules, Providers, DI, forwardRef, custom decorators	core-architecture.md
Request Lifecycle	Middleware, Guards, Interceptors, Pipes, Filters	request-lifecycle.md
Validation & Pipes	DTOs, class-validator, ValidationPipe, transforms	validation-pipes.md
Authentication	JWT, Passport, Guards, Local/OAuth strategies, RBAC	authentication.md
Database	TypeORM, Prisma, Drizzle ORM, repository patterns	database-integration.md
Testing	Unit tests, E2E tests, mocking providers	testing.md
OpenAPI & GraphQL	Swagger decorators, resolvers, subscriptions	openapi-graphql.md
Microservices	TCP, Redis, NATS, Kafka patterns	microservices.md

Essential Patterns

Module with Providers

typescript

@Module({
  imports: [DatabaseModule],
  controllers: [UsersController],
  providers: [UsersService],
  exports: [UsersService], // Export for other modules
})
export class UsersModule {}

Controller with Validation

typescript

@Controller('users')
export class UsersController {
  constructor(private readonly usersService: UsersService) {}

  @Post()
  create(@Body() createUserDto: CreateUserDto) {
    return this.usersService.create(createUserDto);
  }

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

DTO with Validation

typescript

import { IsEmail, IsString, MinLength, IsOptional } from 'class-validator';

export class CreateUserDto {
  @IsEmail()
  email: string;

  @IsString()
  @MinLength(8)
  password: string;

  @IsOptional()
  @IsString()
  name?: string;
}

Exception Filter

typescript

@Catch(HttpException)
export class HttpExceptionFilter implements ExceptionFilter {
  catch(exception: HttpException, host: ArgumentsHost) {
    const ctx = host.switchToHttp();
    const response = ctx.getResponse<Response>();
    const status = exception.getStatus();

    response.status(status).json({
      statusCode: status,
      message: exception.message,
      timestamp: new Date().toISOString(),
    });
  }
}

Guard with JWT

typescript

@Injectable()
export class JwtAuthGuard extends AuthGuard('jwt') {
  canActivate(context: ExecutionContext) {
    return super.canActivate(context);
  }
}

NestJS 11 Breaking Changes

Express v5: Wildcards must be named (e.g.,
```
*splat
```
), optional params use braces
```
/:file{.:ext}
```
Node.js 20+: Minimum required version
Fastify v5: Updated adapter for Fastify users
Dynamic Modules: Same module with identical config imported multiple times = separate instances

Common Mistakes

Not using
forwardRef()
for circular deps - Causes "cannot resolve dependency" errors; wrap in
```
forwardRef(() => ModuleName)
```
Throwing plain errors instead of HttpException - Loses status codes, breaks exception filters; use
```
throw new BadRequestException('message')
```
Missing
@Injectable()
decorator - Provider won't be injectable; always decorate services
Global ValidationPipe without
whitelist: true
- Allows unexpected properties; set
```
whitelist: true, forbidNonWhitelisted: true
```
Importing modules instead of exporting providers - Use
```
exports
```
array to share providers across modules
Async config without
ConfigModule.forRoot()
- ConfigService undefined; import ConfigModule in AppModule
Testing without
overrideProvider()
- Uses real services in unit tests; mock dependencies with
```
overrideProvider(Service).useValue(mock)
```
E2E tests sharing database state - No isolation between tests; use transactions or truncate tables in beforeEach

nestjs-best-practices

NPX Install

Tags

SKILL.md Content

NestJS 11 Best Practices

Quick Reference

Essential Patterns

Module with Providers

Controller with Validation

DTO with Validation

Exception Filter

Guard with JWT

NestJS 11 Breaking Changes

Common Mistakes