Compare Prices

Search for a product across retailers in parallel using a hidden window, save pricing data incrementally to disk, and deliver a clean HTML comparison report with direct links to every product page.

When to Apply

Activate when the user asks to compare prices for a product, find the cheapest option, check if a price is good, or shop across multiple stores.

Workflow

Phase 1 — Clarify

Confirm with the user before searching:

Product name — exact model, variant, size, or color if applicable
Retailer preferences — any stores to include or exclude
Region / currency — defaults to user's locale

Phase 2 — Set Up & Search

| Step | Tool | Detail | |------|------|--------| | Create output directory | evaluate_script | Create compare-<product-slug>/ in your working directory with a raw/ subfolder | | Open hidden window | create_hidden_window | Dedicated workspace — keeps the user's browsing undisturbed | | Open parallel tabs | new_hidden_page | Open up to 10 tabs concurrently, one per retailer/search |

Default search targets (adjust based on product type and user's region):

| Tab | Target | |-----|--------| | 1 | Google Shopping — https://www.google.com/search?tbm=shop&q=<product> | | 2 | Amazon — https://www.amazon.com/s?k=<product> | | 3 | Walmart — https://www.walmart.com/search?q=<product> | | 4 | Best Buy — https://www.bestbuy.com/site/searchpage.jsp?st=<product> | | 5 | Target — https://www.target.com/s?searchTerm=<product> | | 6 | eBay — https://www.ebay.com/sch/i.html?_nkw=<product> | | 7–10 | Additional retailers relevant to the product category (Newegg for tech, Home Depot for tools, etc.) |

Phase 3 — Extract & Save

For each tab, extract pricing data and save immediately:

| Step | Tool | Detail | |------|------|--------| | Navigate | navigate_page | Go to the search URL | | Read results | get_page_content | Extract the search results page as markdown | | Find best match | navigate_page | Click through to the most relevant product listing | | Extract pricing | get_page_content | Pull the product page content — price, availability, shipping, seller | | Save raw data | evaluate_script | Write to raw/<retailer>.json with all extracted fields (see format below) | | Close tab | close_page | Free the tab after saving |

Never hold all retailer data in memory. Save each retailer's data to its own file immediately after extraction.

Raw Data Format (`raw/<retailer>.json`)

{
  "retailer": "Amazon",
  "product_name": "Product Title as Listed",
  "product_url": "https://www.amazon.com/dp/...",
  "price": 299.99,
  "original_price": 349.99,
  "currency": "USD",
  "shipping": "Free",
  "availability": "In Stock",
  "seller": "Amazon.com",
  "condition": "New",
  "rating": "4.5/5",
  "notes": "Prime eligible",
  "extracted_at": "2025-03-11T10:30:00Z"
}

Phase 4 — HTML Report

After all retailers are processed, read the saved raw/*.json files and generate a self-contained report.html:

| Requirement | Detail | |-------------|--------| | Theme | Light background (#ffffff), clean sans-serif typography, generous whitespace | | Header | Product name, search date, number of retailers checked | | Best Deal banner | Highlighted card at the top showing the lowest total price with a direct link to the product page | | Comparison table | All retailers sorted by total price (lowest first) with columns: Retailer, Price, Shipping, Total, Stock, Seller, Rating, Link | | Product links | Every retailer name and a "View Deal" button must be a clickable <a href> linking to the actual product page URL | | Price highlights | Lowest price in green, highest in muted gray. Show discount percentage if original price differs. | | Self-contained | All styles in a <style> block — no external CSS or JS | | Responsive | Readable on desktop and mobile | | Footer | "Generated by BrowserOS Compare Prices" with date |

Use evaluate_script to write report.html to the output directory.

Phase 5 — Open & Notify

| Step | Tool | Detail | |------|------|--------| | Close hidden window | close_window | Clean up the research workspace | | Open report | new_page | Open file://<path>/report.html in the user's active window | | Notify user | — | Tell the user the comparison is complete, highlight the best deal, and provide the report path |

Tool Reference

| Category | Tools Used | |----------|-----------| | Window management | create_hidden_window, close_window | | Tab management | new_hidden_page, close_page, new_page | | Navigation | navigate_page | | Content extraction | get_page_content | | Data & file I/O | evaluate_script |

Tips

Always compare total price (product + shipping), not just the listed price.
Note the seller — marketplace third-party sellers may have different return policies than the retailer itself.
Mention membership discounts (Prime, Walmart+) as a note, not as the default price.
If the product has variants (sizes, colors), ensure every retailer is quoting the same variant.
If a retailer blocks scraping or returns no results, skip it and note the gap in the report.
For used/refurbished listings, separate them from new-condition results.