NestJS
Progressive Node.js framework inspired by Angular — decorators, dependency injection, and modules for scalable server-side apps.
NestJS brings Angular’s architecture to backend development — modules, controllers, providers, and guards give large teams a consistent structure across a large codebase. It can run on Express or Fastify underneath and supports REST, GraphQL, WebSockets, and microservice transports (Kafka, RabbitMQ, gRPC) out of the box. Its strong opinions about structure make it especially valuable when multiple engineers need to work on the same codebase without stepping on each other.
Quick start
npm i -g @nestjs/cli
nest new my-app
cd my-app
npm run start:dev
// src/posts/post.entity.ts
export class Post {
id: number
title: string
body: string
}
// src/posts/posts.service.ts
import { Injectable, NotFoundException } from '@nestjs/common'
import { Post } from './post.entity'
@Injectable()
export class PostsService {
private posts: Post[] = []
findAll(): Post[] { return this.posts }
findOne(id: number): Post {
const post = this.posts.find(p => p.id === id)
if (!post) throw new NotFoundException(`Post #${id} not found`)
return post
}
create(data: Omit<Post, 'id'>): Post {
const post = { id: this.posts.length + 1, ...data }
this.posts.push(post)
return post
}
}
// src/posts/posts.controller.ts
import { Controller, Get, Post, Body, Param, ParseIntPipe } from '@nestjs/common'
import { PostsService } from './posts.service'
@Controller('posts')
export class PostsController {
constructor(private readonly postsService: PostsService) {}
@Get()
findAll() { return this.postsService.findAll() }
@Get(':id')
findOne(@Param('id', ParseIntPipe) id: number) {
return this.postsService.findOne(id)
}
@Post()
create(@Body() body: { title: string; body: string }) {
return this.postsService.create(body)
}
}
When to use
NestJS is ideal for TypeScript teams building large Node.js backends that need a consistent, opinionated architecture. Its module system and dependency injection shine when multiple developers need clear ownership boundaries. For smaller APIs or teams that prefer flexibility, Express or Fastify without NestJS is simpler. If your frontend is already Angular, NestJS’s shared patterns make the stack feel unified.
// features
- Module/Controller/Provider architecture for a consistent, scalable structure
- Decorators and dependency injection inspired by Angular
- Runs on Express or Fastify — swap the HTTP adapter without rewriting logic
- Built-in support for REST, GraphQL, WebSockets, and microservice transports
- Guards, interceptors, pipes, and filters for cross-cutting concerns
- First-class TypeScript — strict mode by default
- CLI for scaffolding modules, controllers, services, and more
- Extensive documentation and enterprise backing (Trilon)
// installation
npm i -g @nestjs/cli && nest new my-app
npx @nestjs/cli new my-app
// commonly used libraries
Promise-based HTTP client for the browser and Node.js — interceptors, automatic JSON …
TypeScript-first schema declaration and validation — parse untrusted data and infer static …