nestjs

NestJS Skill

A progressive Node.js framework for building efficient, reliable and scalable server-side applications.

Ecosystem Graph

graph LR
  nestjs["NestJS"]
  nestjs -- "extended by" --> express
  nestjs -- "deploys to" --> docker
  nestjs -- "deploys to" --> kubernetes

Quick Start

NestJS forces an Angular-like architecture (Modules, Controllers, Providers) onto Node.js. Under the hood, it uses Express by default but can be swapped to Fastify.

npm i -g @nestjs/cli
nest new project-name

Production Patterns

Dependency Injection

Never instantiate classes with new. Use the @Injectable() decorator and let the Nest IoC (Inversion of Control) container manage singletons. This makes mocking services during testing exceptionally easy.

Architecture & Scaling

Microservices

Nest natively supports microservice architectures. Instead of HTTP, you can easily configure a controller to listen to Kafka, NATS, or Redis Pub/Sub using the @MessagePattern() decorator without changing your business logic.

Error Recovery

Use custom Exception Filters (@Catch()) to map domain-specific errors (like database connection failures) to standard HTTP responses globally.

Security Notes

Utilize NestJS Guards (@Injectable() implements CanActivate) to handle Authorization (e.g., verifying JWTs or Role-Based Access Control). Guards execute before interceptors and pipes.

Relationships

Deploys To: docker, kubernetes

References

• NestJS Docs

Why use this skill

Use this when your agent works with nestjs — structured patterns beat pasted docs and prevent common hallucinations.

AI pitfalls

• Using outdated SDK or API versions from training data
• Inventing environment variable names
• Omitting error handling and retry logic

Production checklist

• Secrets in environment variables, not source code
• Error handling and logging in place
• Rate limits and timeouts configured