shortlink-api

A small but production-minded URL shortener API. It turns a long URL into a short code, redirects visitors to the original, and tracks click analytics along the way. I built it to practice clean REST design, input validation, persistence, rate limiting, and tests, not to reinvent bit.ly.

Features

• Shorten any http or https URL to a compact code
• Optional custom aliases (for example /launch) with duplicate protection
• Optional expiry, after which a link returns 410 Gone
• Click analytics: total clicks plus the ten most recent, with referrer and user agent
• Rate limiting on the create endpoint to discourage abuse
• SQLite persistence behind an injectable database, so tests run fully in memory
• A test suite covering the main paths

Tech

Node.js and Express, with Node's built-in SQLite (node:sqlite), so there is no native module to compile. Rate limiting uses express-rate-limit, and the tests run on the built-in node --test runner with supertest.

Getting started

npm install
npm start
# server on http://localhost:3000

Examples

Create a short link:

curl -X POST http://localhost:3000/api/shorten \
  -H "Content-Type: application/json" \
  -d '{"url":"https://example.com/a/very/long/path","expiresInDays":30}'

{ "code": "Xa3b9Z", "shortUrl": "http://localhost:3000/Xa3b9Z", "expiresAt": 1788900000000 }

Follow it, then read its stats:

curl -i http://localhost:3000/Xa3b9Z      # 302 redirect to the original URL
curl http://localhost:3000/api/stats/Xa3b9Z

API

Method	Path	Description
POST	/api/shorten	Create a short link
GET	/:code	Redirect to the original URL
GET	/api/stats/:code	Click analytics for a link
GET	/api/health	Health check

The full contract lives in openapi.yaml.

Tests

npm test

License

MIT