Price Hunter App Blueprint
A complete architecture for a price tracking app — monitor competitor prices, compare across retailers, get alerts when prices drop, and visualize historical price trends. 12 nodes, ready to export to Cursor or Claude Code.
What this app does
Price Hunter is for dropshippers, e-commerce sellers, and bargain hunters who need to track product prices across multiple retailers. Instead of manually checking Amazon, eBay, and competitor stores every day, the app scrapes prices on a schedule, stores historical data for trend analysis, compares prices across sources, and sends alerts when a price drops below a threshold or a competitor undercuts you.
This blueprint maps out 12 nodes across frontend pages, backend APIs, AI analysis, schedulers, a database, and an alert system. It's designed for a solo seller or small e-commerce team tracking 50-500 products.
Architecture diagram
Node breakdown
Frontend pages
- Product Dashboard — list of all tracked products with current price, lowest price, price trend (up/down/stable), and source. Click a product to see historical price chart. Sort by biggest price drop or biggest price increase.
- Price Alert Settings — configure alerts per product: "notify me when price drops below X" or "notify me when competitor price is lower than mine by Y%." Choose email or push notification. Set quiet hours.
- Add Product — paste a product URL from Amazon, eBay, or a competitor store. The scraper extracts the product name, current price, and image. Assign to a category and set an alert threshold.
Backend APIs
- Products API —
GET /api/products(list with current price and trend),POST /api/products(add from URL),GET /api/products/:id/prices(historical price data for charts),DELETE /api/products/:id. - Prices API —
GET /api/prices/latest(latest prices across all products and sources),POST /api/prices(internal: scraper writes new price data),GET /api/prices/compare/:productId(price comparison across sources for a product). - Alerts API —
GET /api/alerts(list user's alert configurations),POST /api/alerts(create alert rule),PATCH /api/alerts/:id(edit threshold or notification preference),GET /api/alerts/triggered(recently triggered alerts).
AI prompt
- Price Comparison AI — input: product name, prices from multiple sources, user's selling price; task: analyze which source is cheapest, calculate price differences as percentages, flag significant changes (>5% drop or increase); output: structured comparison with cheapest source, price gap, and trend recommendation ("buy now" or "wait — price trending down").
Database & services
- Price DB (PostgreSQL) — tables: products (id, user_id, name, url, image_url, category, user_selling_price, created_at), price_history (id, product_id, source, price, currency, scraped_at), alerts (id, product_id, type, threshold, notification_method, is_active, last_triggered), users (id, email, created_at).
- Price Scraper (Cron) — runs hourly. For each tracked product, fetches the product page from each source, extracts the current price, and writes to price_history. Handles anti-bot measures with rotating user agents. Retries failed scrapes with exponential backoff.
- Alert Checker (Cron) — runs every 15 minutes. Compares latest prices against alert thresholds. If a price crosses a threshold, triggers the alert and sends notification via the configured channel (email or push).
How it works end-to-end
- User opens Add Product and pastes an Amazon product URL
- The Price Scraper extracts product name, current price, and image
- Product appears on the Product Dashboard with its first price data point
- User opens Price Alert Settings and sets: "Alert me when price drops below $25"
- Every hour, the Price Scraper fetches the product page and stores the new price in Price DB
- Every 15 minutes, the Alert Checker compares latest prices against thresholds
- When price drops below $25, the Alert Checker triggers the alert and sends an email
- User opens the Product Dashboard, sees the price drop on the historical chart
- The Price Comparison AI analyzes prices across sources and recommends "buy now" or "wait"
- Alert appears in the triggered alerts list on the dashboard
The Price Scraper must respect robots.txt and rate limits. Aggressive scraping will get you blocked. This blueprint uses rotating user agents and exponential backoff, but you should also respect each retailer's terms of service and consider using official APIs where available (Amazon Product Advertising API, eBay Browse API).
Bluemoonkey input prompt
This is what you paste into Bluemoonkey's canvas — a plain-language description of what the app should do. Bluemoonkey's AI advisor reads this and generates the full node architecture (pages, APIs, database, AI prompt, and schedulers) shown above. You don't need to write anything technical here — just describe what you want in your own words.
A price tracking app for dropshippers and e-commerce sellers who need to monitor product prices across Amazon, eBay, and competitor stores.
I need an Add Product page where I paste a product URL and the app pulls in the name, price, and image automatically.
A Product Dashboard showing all tracked products with current price, lowest price ever, price trend, and a historical price chart when I click into one.
A Price Alert Settings page where I set rules like "notify me when price drops below X" or "alert me when a competitor is cheaper than me by Y%." I want to choose email or push notifications and set quiet hours.
The app should check prices automatically every hour and store the history so I can see trends over time.
Every 15 minutes, check if any price crossed my alert threshold and send the notification if it did.
Also include an AI feature that compares prices across sources and tells me whether to buy now or wait, based on the trend.After Bluemoonkey generates the blueprint, review each node — adjust wording, check the scraper's schedule, and confirm the architecture matches what you need. From there, Bluemoonkey's canvas gives you a build-ready prompt for Cursor or Claude Code with one click — no manual prompt writing required.
New to planning? Read how to plan an app before coding.
Fork this blueprint
Open the free canvas, import this architecture, and customize it for your price tracking workflow.
Open Canvas — Free →FAQ
What is a price tracking app?
A price tracking app monitors product prices across retailers, stores historical price data, compares competitors, and sends alerts when prices drop or competitors change their pricing. It helps dropshippers and e-commerce sellers stay competitive without manually checking prices.
Can I export this blueprint to Claude Code?
Yes. Paste the Bluemoonkey input prompt above into the free canvas, let the AI advisor build out the blueprint, then click Export. Bluemoonkey generates a structured, Claude Code-ready prompt for you automatically — no manual prompt writing needed.
Do I need to write the Cursor prompt myself?
No. You only write the short, plain-language prompt above and paste it into Bluemoonkey's canvas. Bluemoonkey's AI advisor turns it into the full node architecture, and when you click Export, it generates the structured, technical prompt for Cursor or Claude Code automatically.
How does the price scraper work?
The scraper runs as a cron job every hour. It fetches each tracked product's page, extracts the current price using CSS selectors or regex patterns, and writes the data to the price_history table. It uses rotating user agents and exponential backoff to avoid getting blocked.
Is web scraping legal?
Web scraping is legal in many jurisdictions but must respect robots.txt, terms of service, and rate limits. This blueprint includes rate limiting and backoff, but you should review each retailer's terms and consider using official APIs (Amazon Product Advertising API, eBay Browse API) where available.