LinkGate

Because even a URL deserves privacy.

LinkGate is a multi-role, access-controlled URL shortener built with NestJS, Prisma, and PostgreSQL.
It supports public, private, and group-scoped links with fine-grained authorization enforced at the data layer.

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💡 Motivation

LinkGate is built as a learning-driven backend project, focusing on:

• real authorization problems
• correct data modeling
• type safety without over-engineering
• pragmatic NestJS + Prisma usage
• Not a toy CRUD. Not a tutorial clone.

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🚀 Features

• 🔗 URL shortening with collision-safe identifiers
• 🔐 Access control per URL:
  • PUBLIC – accessible by anyone
  • PRIVATE – accessible only by the owner
  • GROUP – accessible by members of a specific group
• 👥 Group system with roles and membership status
  • Owner / Admin / Member
  • Pending / Accepted / Rejected membership
• 🧠 Authorization enforced via Prisma queries (not post-filters)
• 📦 Clean service-oriented architecture (NestJS)
• 🗄️ PostgreSQL with Prisma ORM
• ✅ DTO validation using class-validator

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🏗️ Tech Stack

• Backend: NestJS (TypeScript)
• ORM: Prisma
• Database: PostgreSQL
• Validation: class-validator
• Auth (planned): JWT
• Runtime: Node.js

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📐 Architecture Overview

src/
├── prisma/ # PrismaService, database access
├── user/ # User module
├── group/ # Group & membership logic
├── url/ # URL shortening & access control
├── utils/ # Shared utilities (hashing, ID generation)
└── generated/ # Prisma generated client

Key design decisions:

• Authorization logic is pushed into Prisma queries
• Services return explicitly shaped data, not raw models
• No global “god” services; dependencies are explicit

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🧩 Data Model (High Level)

• User
• Group
• GroupMembers
  • role: OWNER | ADMIN | MEMBER
  • status: PENDING | ACCEPTED | REJECTED
• Url
  • access: PUBLIC | PRIVATE | GROUP
  • ownerId
  • optional groupId

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⚙️ Setup & Development

Prerequisites

• Node.js ≥ 18
• PostgreSQL
• npm / pnpm / yarn

Install dependencies

npm install

Environment variables

Create a .env file:

DATABASE_URL=postgresql://user:password@localhost:5432/linkgate

Database setup

npx prisma migrate dev
npx prisma generate

Run the app

npm run start:dev