The idea is simple: paste any product URL from a supported retailer (https://takemymoney.io/retailers), and it starts monitoring price changes and stock availability when you add it to your watchlist. You're not limited to what's already cataloged - if it's not there, you add it.
The interesting technical challenge was extraction - every retailer structures their pages differently. I started with CSS selectors but they broke constantly. Ended up using Claude's API to extract product details, which has been way more resilient to site changes.
Would love feedback, especially on retailers you'd want supported or features that would make this actually useful to you.