Promo Code API

A simple REST API for managing and activating promo codes. Built with Node.js, Express, TypeScript, and PostgreSQL.

What it does

• Create and manage promo codes with a discount, activation limit, and expiry date
• Activate a promo code with an email address
• Prevents duplicate activations — each email can activate a promo code only once
• Prevents activation if the code is expired or has reached its limit

Requirements

• Node.js 18+
• PostgreSQL

Getting started

1. Clone the repo

git clone https://github.com/Musaye99/promo-api
cd promo-api

2. Install dependencies

npm install

3. Setup environment

Create a .env file in the root:

DATABASE_URL="postgresql://user:password@localhost:5432/promodb"

4. Run database migrations

npx prisma migrate dev

5. Start the server

npm run dev

Server runs on http://localhost:3000

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API Endpoints

Create a promo code

POST /promo-codes

{
  "code": "SAVE20",
  "discount": 20,
  "limit": 5,
  "expiresAt": "2026-12-31"
}

Get all promo codes

GET /promo-codes

Get a single promo code

GET /promo-codes/:code

Activate a promo code

POST /promo-codes/:code/activate

{
  "email": "user@example.com"
}

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Error responses

Status	Meaning
400	Missing fields, code expired, or limit reached
404	Promo code not found
409	Code already exists or email already activated
500	Server error

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Tech stack

• Node.js + TypeScript
• Express
• Prisma
• PostgreSQL