dev.ly — Backend

The core URL shortener API for dev.ly. Handles user authentication, URL creation/management, short-code redirects, and pushes click events to the analytics pipeline via BullMQ. Built with Express 5 and PostgreSQL.

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Features

• JWT Authentication — Secure register/login with bcrypt password hashing
• URL Shortening — Base62-encoded short codes with custom expiry
• Redirect Engine — GET /:shortCode → 302 redirect with async click logging
• Redis URL Cache — Sub-millisecond redirects via cached URL lookups
• BullMQ Click Queue — Fire-and-forget click events with guaranteed delivery to the analytics worker
• Rate Limiting — Redis-backed rate limiting on auth & API endpoints (redirects are never blocked)
• Database Migrations — Auto-run SQL migrations on startup

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Tech Stack

Technology	Purpose
Express 5	HTTP framework
PostgreSQL 15	Primary database
Redis 7	URL caching & rate limiting
BullMQ	Job queue for click events
JSON Web Tokens	Auth tokens
bcrypt	Password hashing
Axios	Internal HTTP calls

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Project Structure

backend/
├── index.js                         # Entry point
├── Dockerfile                       # Docker build
├── package.json
└── src/
    ├── config/
    │   ├── db.js                    # PostgreSQL pool
    │   └── redis.js                 # Redis/IORedis client
    ├── controllers/
    │   ├── authController.js        # Register, Login, Profile
    │   └── urlController.js         # Create, List, Delete, Redirect
    ├── db/
    │   ├── migrate.js               # Auto-migration runner
    │   └── migrations/
    │       ├── 001_initial_schema.sql
    │       ├── 002_increase_short_code_length.sql
    │       ├── 003_add_analytics_columns.sql
    │       └── 004_add_utm_and_unique.sql
    ├── middlewares/
    │   ├── authMiddleware.js         # JWT verification
    │   └── rateLimiter.js            # Redis-backed rate limiter
    ├── queues/
    │   └── clickQueue.js             # BullMQ producer
    ├── routes/
    │   ├── authRoutes.js             # /api/auth/*
    │   └── urlRoutes.js              # /api/url/*
    └── utils/
        └── base62.js                 # Short code encoding

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API Endpoints

Method	Endpoint	Auth	Description
POST	/api/auth/register	✗	Register a new user
POST	/api/auth/login	✗	Login, returns JWT
GET	/api/auth/profile	✓	Get current user profile
POST	/api/url	✓	Create a short URL
GET	/api/url	✓	List user's URLs
DELETE	/api/url/:id	✓	Delete a URL
GET	/:shortCode	✗	Redirect → original URL

Rate Limits

Endpoint	Limit	Behavior
POST /api/auth/*	10 req/min	Returns 429
POST /api/url	30 req/min	Returns 429
GET /:shortCode	No limit	Always redirects

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Getting Started

Prerequisites

• Node.js 18+
• PostgreSQL 15+
• Redis 7+

Install & Run

npm install
node index.js

The server starts on port 5001 (default).

Database Migrations

Migrations run automatically on startup. To run manually:

npm run migrate

Environment Variables

Create a .env file:

PORT=5001
DB_USER=postgres
DB_PASSWORD=postgres
DB_HOST=localhost
DB_NAME=devly
DB_PORT=5432
JWT_SECRET=supersecretkey_change_me_in_prod
ANALYTICS_URL=http://localhost:5002
REDIS_URL=redis://localhost:6379

Docker: Use DB_HOST=db, ANALYTICS_URL=http://analytics:5002, REDIS_URL=redis://redis:6379

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🔗 Related Repos

Repo	Description
dev.ly	Main repo (system design & orchestration)
dev.ly-frontend	Next.js dashboard
dev.ly-analytics	Analytics microservice