# I Built an AI Research Assistant for Finding Pokemon Cards on eBay **TL;DR:** I wanted to learn how to build AI agent applications, so I made a tool that helps me find and evaluate Pokemon cards on eBay. It searches listings, analyzes photos with AI, and predicts what PSA grade a card might get. Sharing in case it helps others. --- ## Why I Built This Two reasons: **1. I wanted to learn AI agents.** Everyone's talking about them, but I learn best by building something real. I needed a project with actual complexity - multiple AI models working together, real-time data, user feedback loops. **2. I needed this for my hobby.** I collect Pokemon cards and got tired of the manual research process: searching eBay, opening 50 tabs, squinting at photos trying to spot corner whitening, checking prices across sites. I wanted a research assistant that does the tedious parts. ## What It Does **Mintachu** is basically a research assistant for eBay card shopping: - **Search** - Find Pokemon card listings on eBay - **Analyze** - AI looks at the listing photos and spots condition issues - **Grade** - Predicts what PSA grade the card might receive - **Price** - Shows market values so you know if it's a good deal Think of it like having a knowledgeable friend look over your shoulder while you shop. ## The AI Agent Part (What I Learned) The interesting technical challenge was building a multi-agent system. Instead of one AI doing everything, I have 4 specialized agents: | Agent | Role | |-------|------| | **Front Analyzer** | Examines the front of the card | | **Back Analyzer** | Examines the back of the card | | **Grader** | Combines findings into a grade prediction | | **Auditor** | Reviews and adjusts the final grade | Each agent has a specific job and passes its findings to the next one. You can watch them work in real-time - seeing their "thinking" as they analyze the card. Building this taught me a lot about: - Prompt engineering for vision models - Streaming responses to keep the UI responsive - Coordinating multiple AI calls without timeouts - Making AI outputs actually useful (not just impressive demos) ## Honest Limitations - Photo quality from eBay listings varies wildly - It's a research tool, not a guarantee - Vintage cards are harder to analyze - The AI can miss things a human would catch I use it as a first-pass filter, not a replacement for careful inspection. ## Try It 🔗 **[mintachu.com](https://mintachu.com)** Free, no account needed. Would love feedback if you find it useful (or if you don't). --- *If you're interested in the technical side - it's Next.js, Gemini Vision API, deployed on Vercel. Happy to chat about the implementation.*

Mintachu

AI-assisted Pokémon TCG grading

AI-assisted Pokémon TCG grading