ShopScout

ShopScout is an AI-powered Chrome extension that analyzes any Amazon or eBay product in seconds, giving you a clear Buy Score, live price comparison, and strategic bidding advice.

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ShopScout - Your AI Shopping Co-Pilot

Inspiration

Online shopping has become overwhelming. Prices fluctuate, reviews are unreliable, and it’s hard to tell if something is actually a good deal. Everyone has experienced buyer’s remorse after hours of comparing listings and reading reviews. ShopScout was created to eliminate that frustration by providing instant, evidence-backed insights into whether a product is worth buying.

What it does

ShopScout is a Chrome extension that enhances online shopping on Amazon and eBay with AI-powered product analysis.

Smart Analysis Engine

  • DealSense Score (0–10): A composite score that evaluates price fairness, review sentiment, seller reliability, and product specifications.
  • Live Price Comparison: Scrapes real-time listings and visualizes where the current price sits in the market range.
  • AI Review Analysis: Summarizes hundreds of reviews into concise pros and cons using Claude 4.5.

Context-Aware Intelligence

ShopScout automatically adapts its analysis to the product type:

  • Electronics Mode: Verifies specs and value.
  • Fashion Mode: Focuses on fit and sizing insights.
  • Beauty Mode: Evaluates ingredients and skin-type compatibility.
  • Collectibles Mode: Uses sold listing data instead of active listings.
  • Generic Mode: Default analysis for general items.

DealSense: Your Deal Maker

DealSense represents the overall judgment of whether a product is worth buying. It powers both the Buy Score and the price fairness insights across all marketplaces, not just eBay. On eBay, it also provides specialized bidding and negotiation insights:

  • Snipe Bid Calculator: Recommends optimal bid strategies (Conservative, Balanced, Aggressive).
  • Best Offer Strategy: Suggests tiered offers with estimated acceptance rates.
  • Negotiation Templates: Generates messages to send to sellers.
  • Timing Insights: Identifies auctions with hidden deal potential.

Safety Features

  • Detects out-of-stock items, invalid price ranges, and incomplete variations.
  • Blocks recommendations when listings appear suspicious or lack sufficient data.

How it was built

Architecture

ShopScout uses a modular Manifest V3 Chrome Extension structure:

  • Content Scripts: Extract data such as title, price, seller, and reviews from product pages.
  • Background Service Worker: Handles logic, analysis orchestration, API calls, and scoring.
  • Sidepanel UI: Renders adaptive results and visualizations in real time.

Key Technologies

  • Claude 4.5: Acts as an agent that autonomously chains scraping, reasoning, and analysis steps.
  • Regex and DOM Parsing: Extracts structured data from Amazon and eBay HTML.
  • Price Comparison Engine: Cross-fetches marketplace data for real-time comparisons.
  • Weighted Scoring System: Combines normalized sub-scores into the overall DealSense score.

Smart Features

  • Caching system with TTL to avoid redundant API calls.
  • Mode-switching logic for category-specific analysis.
  • Review highlighting that links directly to source reviews.

Challenges

  1. Cross-Site Scraping:
    Bypassing CORS and handling dynamic content required carefully constructed URLs and manual HTML parsing.

  2. Product Variations:
    Range prices (for example, "$19.99–$29.99") caused parsing errors. Stop conditions were added to prompt users to select specific variants.

  3. Auction vs. Fixed-Price Handling:
    Mixed formats distorted averages, so detection logic was added to treat them separately.

  4. Category Detection Accuracy:
    Early misclassifications, such as sneakers tagged as electronics, led to refining keyword-based logic.

  5. Performance Optimization:
    Initial runs took over 15 seconds. Optimization of API batching and caching reduced this to under 5 seconds.

  6. UI State Management:
    Managing state across scripts and tabs required a coordinated message-passing and caching system.

Accomplishments

  • Sub-5-second Analysis: Maintains accuracy without interrupting user flow.
  • Adaptive AI: Claude intelligently routes different products to the right analysis mode.
  • DealSense Scoring: Provides consistent, explainable deal evaluations across all products.
  • Clean, Minimal UI: Simple yet information-dense presentation of insights.
  • Transparent Price Visualization: The price number line helps users instantly gauge fairness.
  • Privacy First: No backend. Users use their own Claude key, keeping data local.

Lessons Learned

Technical Lessons

  • Web scraping requires resilient fallback logic.
  • Managing API costs and caching is critical for scalable extensions.
  • Understanding Chrome’s extension architecture (service workers, content scripts, UI) is essential.

Product Lessons

  • Category-specific logic dramatically improves relevance.
  • Responsiveness matters more than perfect accuracy.
  • Transparency builds user trust in AI recommendations.

AI Lessons

  • Agentic AI workflows save time by letting the model decide what data to fetch and weigh.
  • Retrieval-Augmented Generation (RAG) reduces hallucinations when properly constrained.
  • Streaming responses improve perceived speed.
  • Tool use and function calling enable complex reasoning chains in-browser.

Struggles

Too much time was spent building a custom search infrastructure for the tool. Configuring the RAG system and managing search pipelines took valuable development time that should have gone toward core features. It would have been far more efficient to outsource search and pay the premium upfront rather than debugging and maintaining a homegrown solution.

What’s next for ShopScout

Short Term

  • Re-enable optimized spec analysis for electronics.
  • Add product Q&A capabilities for follow-up questions.
  • Support multiple currencies and exchange rates.
  • Extend compatibility to Firefox and Edge.

Medium Term

  • Integrate price history tracking and trend predictions.
  • Add Walmart and Target support.
  • Allow users to save and monitor tracked items.
  • Introduce anonymized crowd-based DealSense averages.

Long Term

  • Launch a mobile companion app.
  • Publish to Chrome Web Store and Mozilla Add-ons.
  • Expand into a conversational multi-product shopping assistant.

Dream Feature:
A public “ShopScout Score” database, an index of product credibility and deal quality across the web, serving as a universal trust layer for e-commerce.

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