Nestjs Best Practices

What it does

When your agent uses it

• Designing NestJS modules
• Implementing providers
• Creating exception filters
• Validating DTOs

Example prompts

• “Use the nestjs-best-practices skill to provide comprehensive NestJS best practices including modular architecture, dependency injection scoping…”
• “/nestjs-best-practices”

Requirements

• Node.js
• Pre-approved tools (allowed-tools): Read, Write, Edit, Glob, Grep, Bash

Workflow steps

6 steps, taken from the step headings in SKILL.md.

1. 1Modular Architecture
2. 2Dependency Injection
3. 3Request Lifecycle
4. 4Error Handling
5. 5Validation
6. 6Database Patterns (Drizzle ORM)

What it can do on your machine

Read from SKILL.md and the folder at commit fe73fb3. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves these tools, so the agent can use them without asking each time:

  • Read
  • Write
  • Edit
  • Glob
  • Grep
  • Bash

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Ships script files (TypeScript), which the agent can run.

  Shell commands in SKILL.md call:

  • npx

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Links to these hosts (documentation or services it may open):

  • docs.nestjs.com

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Nestjs Best Practices loads about 1.8k tokens when it runs, and up to ~8.2k if it reads all its reference files. Until then it costs about 93 tokens; SKILL.md has 598 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~93

When it runs · the whole SKILL.md, loaded when a task matches

~1.8k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~8.2k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

• NotePre-approves every shell command (allowed-tools: Bash)SKILL.md

  allowed-tools: Read, Write, Edit, Glob, Grep, Bash

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from giuseppe-trisciuoglio/developer-kit at commit fe73fb3, republished under its MIT licence (© giuseppe-trisciuoglio). 598 words, ~1,832 tokens.

name

nestjs-best-practices

description

Provides comprehensive NestJS best practices including modular architecture, dependency injection scoping, exception filters, DTO validation with class-validator, and Drizzle ORM integration. Use when designing NestJS modules, implementing providers, creating exception filters, validating DTOs, or integrating Drizzle ORM within NestJS applications.

allowed-tools

Read, Write, Edit, Glob, Grep, Bash

Middleware → Guards → Interceptors (before) → Pipes → Route Handler → Interceptors (after) → Exception Filters

// product/product.module.ts
@Module({
  imports: [DatabaseModule],
  controllers: [ProductController],
  providers: [ProductService, ProductRepository],
  exports: [ProductService], // Only export what others need
})
export class ProductModule {}

// product/dto/create-product.dto.ts
import { IsString, IsNumber, IsPositive, MaxLength } from 'class-validator';

export class CreateProductDto {
  @IsString() @MaxLength(255) readonly name: string;
  @IsNumber() @IsPositive() readonly price: number;
}

@Injectable()
export class ProductService {
  constructor(private readonly productRepository: ProductRepository) {}

  async findById(id: string): Promise<Product> {
    const product = await this.productRepository.findById(id);
    if (!product) throw new ProductNotFoundException(id);
    return product;
  }
}

# Check module is imported in AppModule
grep -r "ProductModule" src/app.module.ts

# Run e2e to confirm exports work
npx jest --testPathPattern="product"

© giuseppe-trisciuoglio, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 9 other files (references, assets) in plugins/developer-kit-typescript/skills/nestjs-best-practices of giuseppe-trisciuoglio/developer-kit.

• SKILL.md
• assets/templates/controller-template.ts
• assets/templates/module-template.ts
• assets/templates/service-template.ts
• references/api-validation-dto.md
• references/arch-module-boundaries.md
• references/architecture.md
• references/db-drizzle-patterns.md
• references/di-provider-scoping.md
• references/error-exception-filters.md

Open the folder on GitHubat commit fe73fb3