/node-backend

name: node-backend
description: Node.js backend development patterns for Express, NestJS, Fastify, and Hono. Use when implementing APIs, authentication, middleware, services, and server-side logic with Node.js and TypeScript. Provides project structure, code patterns, and best practices.

Node.js Backend

Patterns and best practices for Node.js backend development with TypeScript.

Framework Selection

| Framework | Best For | Use When | |-----------|----------|----------| | Express | Simple APIs, flexibility | Quick setup, full control needed | | NestJS | Enterprise, structured | Large teams, Angular-like structure | | Fastify | Performance critical | High throughput, schema validation | | Hono | Edge, lightweight | Cloudflare Workers, minimal overhead |

Reference Files

| Topic | Load | Use When | |-------|------|----------| | Project structure | `references/project-structure.md` | Setting up new project or organizing code | | Express patterns | `references/express-patterns.md` | Building with Express | | NestJS patterns | `references/nestjs-patterns.md` | Building with NestJS | | Auth implementation | `references/auth-patterns.md` | Implementing authentication | | Error handling | `references/error-handling.md` | Setting up error handling | | Validation | `references/validation.md` | Input validation patterns |

Quick Start Patterns

Express Basic Setup

import express from 'express';
import cors from 'cors';
import helmet from 'helmet';
import { errorHandler } from './middleware/errorHandler';
import { routes } from './routes';

const app = express();

app.use(helmet());
app.use(cors());
app.use(express.json());

app.use('/api', routes);
app.use(errorHandler);

export { app };

NestJS Module Pattern

@Module({
  imports: [TypeOrmModule.forFeature([User])],
  controllers: [UsersController],
  providers: [UsersService],
  exports: [UsersService],
})
export class UsersModule {}

TypeScript Configuration

{
  "compilerOptions": {
    "target": "ES2022",
    "module": "NodeNext",
    "moduleResolution": "NodeNext",
    "strict": true,
    "esModuleInterop": true,
    "skipLibCheck": true,
    "outDir": "./dist",
    "rootDir": "./src",
    "declaration": true
  }
}

Essential Packages

| Package | Purpose | |---------|---------| | `typescript` | Type safety | | `zod` | Runtime validation | | `bcrypt` | Password hashing | | `jsonwebtoken` | JWT handling | | `helmet` | Security headers | | `cors` | CORS handling | | `winston` / `pino` | Logging | | `prisma` / `drizzle` | Database ORM |

Code Quality Rules

1. **Always use TypeScript** - strict mode enabled 2. **Validate all inputs** - use Zod or class-validator 3. **Handle all errors** - never swallow exceptions 4. **Use async/await** - no callback hell 5. **Environment variables** - use dotenv, never hardcode secrets 6. **Logging** - structured logs with correlation IDs