A Chrome extension. On any Amazon product page, hit Track price, set a target, and Pricewatch checks the price once a day. The day it drops below your target you get a Chrome notification (always) and an email (if configured). The popup shows every tracked product with its price history sparkline and where the price looks to be heading.
Built on the same design system and architecture as Decoder (the AI Dictionary extension): Manifest V3, vanilla JS, no build step, off-white + slate-blue UI, in-place popover UX.
Amazon PDP ──content.js──> "Track price" chip → popover → set target
│ (message)
▼
background.js ←── daily chrome.alarms
│ fetches each tracked PDP, parses price
│ records one history point per day
│ price ≤ target? → notification + email/webhook
│
store.js (chrome.storage.local — all data on-device)
│
popup.html/js — list, sparklines, trends, targets
| File | Role |
|---|---|
extension/background.js |
Service worker: daily alarm, price checks, alerts, message router |
extension/store.js |
Data layer over chrome.storage.local |
extension/parser.js |
Product/price extraction — DOM mode (content script) + HTML-regex mode (worker) |
extension/predictor.js |
Phase 2: trend + 7-day forecast from history (linear regression) |
extension/mailer.js |
Email (EmailJS) + webhook alert delivery |
extension/content.js |
PDP chip + in-place tracking popover |
extension/popup.* |
Tracked-products dashboard |
extension/config.js |
Email/webhook keys + daily check hour |
- Phase 1 (done): track from PDP, daily check, threshold alerts via notification + optional email.
- Phase 2 (done, needs data): per-product sparkline of price history and a trend read ("falling toward $X, could hit your target in ~N days"). Trends appear after ~5 daily points.
See SETUP.md. Short version: chrome://extensions → Developer mode → Load unpacked →
pick the extension/ folder. Email is optional; notifications work with zero setup.
Contact: sumitd0704@gmail.com