TypeScript Backend Starter with PostgreSQL, Express, and Node.js

A powerful and flexible TypeScript backend boilerplate built on top of Express and PostgreSQL, designed with a NestJS-inspired modular architecture — offering both structure and freedom.

This starter brings the best of both worlds:

• NestJS-style project structure (with guards, filters, decorators, dto, repositories, etc.)
• Express-level flexibility
• Class-based architecture with Dependency Injection (DI) for easy scalability and plugin-based extensibility.

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✨ Features

• ⚙️ TypeScript — Strong typing for reliability and better DX.
• 🚀 Express — Lightweight, unopinionated, and extremely flexible.
• 🧩 NestJS-inspired architecture — Organized modules with controllers, services, guards, filters, and more.
• 🧠 Dependency Injection (DI) — Loosely coupled components for easier testing and plugin integration.
• 🗄️ PostgreSQL + Prisma ORM — Powerful schema management and migrations.
• 🔐 Guards, Filters, Decorators — Extendable request handling and validation patterns.
• 📦 DTOs and Validators (Zod) — Type-safe input validation.
• 🐳 Docker Support — Instantly spin up PostgreSQL locally.
• 🧰 Utility-first design — Clean structure for middlewares, repositories, and helpers.
• 📜 OpenAPI/Swagger — Auto-generated API documentation.

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📁 Project Structure

backend/
├── dist/
├── node_modules/
├── prisma/
├── src/
│   ├── configs/
│   ├── controllers/
│   ├── decorators/
│   ├── dto/
│   ├── errors/
│   ├── filters/
│   ├── guards/
│   ├── interfaces/
│   ├── middlewares/
│   ├── repositories/
│   ├── routes/
│   ├── services/
│   ├── types/
│   ├── utils/
│   ├── validators/
│   ├── container.ts          # Dependency Injection container
│   ├── index.ts              # Application entry point
│   └── openApiSpec.ts        # Swagger/OpenAPI definition
├── .env
├── .env.example
├── package.json
├── tsconfig.json
└── README.md

This structure follows the NestJS philosophy of modular separation, but keeps Express’s unopinionated nature, giving you full control over middleware and routing.

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⚡ Getting Started

1. Clone the Repository

git clone https://github.com/MeerUzairWasHere/TypePEN.git
cd TypePEN

2. Install Dependencies

cd backend && npm install

3. Set Up the Database

Use either a remote PostgreSQL provider (Neon, Supabase, ElephantSQL) or local Docker setup.

Option A: Remote Database

Rename .env.example → .env and add your connection string:

DATABASE_URL=your-postgresql-url

Option B: Local Docker Database

npm run db

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4. Run Migrations

npm run dev:migrate

5. Start the Server

npm run dev

Server will start on http://localhost:3000

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🧩 Dependency Injection and Extensibility

This boilerplate uses a class-based architecture with a DI container (container.ts), enabling clean dependency management between services, repositories, and controllers.

Example:

// user.service.ts
export class UserService {
  constructor(private userRepository: UserRepository) {}

  async findAll() {
    return this.userRepository.findMany();
  }
}

This design allows future plugins or modules (e.g., EmailService, CacheService) to be added seamlessly.

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🧱 Framework Philosophy

• NestJS-like modularity for organization.
• Express-like flexibility for freedom.
• Class-based design for scalability.
• DI-first approach for maintainability.

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🧾 License

Licensed under the MIT License.

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