DealPing

DealPing is a full-stack price discovery and alerting application for Amazon UK products. It combines live product data, price history, account management and scheduled notifications in a containerised Next.js application backed by PostgreSQL.

This is a portfolio project built to explore production-style application architecture, third-party API integration, authentication, background processing and container deployment.

Features

• Search Amazon products and retrieve current pricing through Keepa
• Browse hot deals, categories and time-limited offers
• View sampled price-history charts while preserving minimum and maximum points
• Create target-price or any-price-drop alerts
• Send price-drop notifications through Resend
• Register with email/password or sign in with Google
• Manage profile details and invalidate sessions after password changes
• Protect scheduled refresh endpoints with a dedicated cron secret
• Generate affiliate links for supported networks
• Track and reserve Keepa API tokens to control external API usage

Architecture

                         ┌─────────────────────┐
Browser ────────────────►│ Next.js App Router  │
                         │ pages + API routes  │
                         └──────────┬──────────┘
                                    │
              ┌─────────────────────┼─────────────────────┐
              │                     │                     │
              ▼                     ▼                     ▼
       PostgreSQL/Prisma      NextAuth + bcrypt      External services
       users, products,       credentials and        Keepa / Amazon
       prices and alerts      Google OAuth           Awin / Resend
              ▲                                           ▲
              └──────── scheduled refresh jobs ───────────┘

The production Docker image uses a multi-stage build and runs the standalone Next.js server as a non-root user.

Technology

• Application: Next.js 16, React 19 and TypeScript
• Styling: Tailwind CSS
• Database: PostgreSQL with Prisma
• Authentication: NextAuth, Google OAuth and bcrypt
• Data and integrations: Keepa, Amazon Product Advertising API, Awin and Resend
• Visualisation: Recharts
• Deployment: Docker and Docker Compose

Run locally

Requirements

• Node.js 22+
• PostgreSQL database
• Keepa API key for live product data
• Optional Google, Resend, Amazon and Awin credentials for their respective features

Setup

git clone https://github.com/hf5296/dealping.git
cd dealping
npm ci
cp .env.example .env
npx prisma generate
npx prisma db push
npm run dev

Open http://localhost:3000.

The optional seed command creates demonstration products and categories:

npx prisma db seed

Configuration

Copy .env.example to .env and replace only the values required for the features you intend to use.

Variable	Purpose	Required
DATABASE_URL	PostgreSQL connection string	Yes
AUTH_SECRET	Signs authentication tokens	Yes
NEXT_PUBLIC_APP_URL	Public base URL for links and callbacks	Yes
KEEPA_API_KEY	Product search, pricing and history	Yes for live data
GOOGLE_CLIENT_ID, GOOGLE_CLIENT_SECRET	Google sign-in	Optional
RESEND_API_KEY, RESEND_FROM_EMAIL	Password reset and price-alert email	Optional
CRON_SECRET	Protects scheduled refresh endpoints	Yes in production
AMAZON_ACCESS_KEY, AMAZON_SECRET_KEY, AMAZON_PARTNER_TAG	Amazon affiliate integration	Optional
AWIN_API_TOKEN, AWIN_PUBLISHER_ID	Awin affiliate integration	Optional
TRUST_PROXY	Trust proxy-provided client IP headers	Optional

Keepa token-budget variables and maintenance mode are documented in .env.example.

Docker

After creating .env:

docker compose up --build -d
docker compose ps

The Compose stack runs DealPing on port 3000 and persists its file-based API cache in a named volume. PostgreSQL is intentionally external to the stack and must be reachable through DATABASE_URL.

Project structure

src/
├── app/                 # Pages and route handlers
├── components/          # Reusable interface components
├── lib/                 # API clients, caching, email and rate limiting
├── types/               # Shared TypeScript types
└── auth.ts              # NextAuth configuration
prisma/
├── schema.prisma        # PostgreSQL data model
├── migrations/          # Schema migrations
└── seed.ts              # Demonstration data

See PROJECT_GUIDE.md for a deeper walkthrough of the data flows and implementation.

Quality checks

npm run lint
npx tsc --noEmit
npm run build

These checks are intended to become required CI gates as the project is hardened.

Security decisions

• Passwords are hashed with bcrypt.
• Login and API endpoints apply rate limiting.
• Password changes invalidate older sessions.
• Scheduled endpoints require a timing-safe cron-secret check.
• The production container runs as a non-root user.
• Secrets and local databases are excluded from version control.
• Proxy headers are trusted only when explicitly enabled.

Current limitations

• Automated unit and integration tests have not yet been added.
• CI/CD is not configured yet.
• The in-memory rate limiter should be replaced by Redis for multi-instance deployments.
• Live functionality depends on third-party API availability and quotas.
• Dependency and lint findings should be resolved before treating the application as production-ready.