The trading card app for ChatGPT
CardChain AI is a native ChatGPT app, not a browser extension and not a copy-paste prompt. Add it once and ChatGPT can price any sports card, read PSA, BGS and SGC population, run the grading ROI before you submit, identify a card from a photo, read and add to your own portfolio, and pull live marketplace listings. Setup takes about two minutes on a phone and it is free to start.
Setting it up, once
None of the above works on an assistant that cannot reach card data, so this is the prerequisite rather than the pitch. About two minutes, and there is no browser extension.
- Open the CardChain AI app in ChatGPTSearch for CardChain AI in ChatGPT's app directory, or use the Open in ChatGPT button on this page, then tap Try in chat.
- Sign in to CardChainChatGPT sends you through CardChain's own sign-in once. Use the same account as the iOS or Android app and your portfolio is there immediately.
- Ask in plain English"Should I grade my 2018 Prizm Luka?" ChatGPT calls should_i_grade, and the ROI comes back as an interactive card rather than a paragraph of prose.
What changes once it is connected
Without a connector, ChatGPT answering "what's my Wemby rookie worth" is recalling what card prices looked like whenever its training data was assembled. That is not a price; it is a memory of a price, and in a market that moves weekly it is usually wrong in a direction you cannot predict.
With CardChain connected, the same question runs search_cards and get_card_price against live market data, and comes back as an interactive card with the current value and the 30-day trend rather than a paragraph of hedged prose. The follow-ups work the same way: population, grading ROI, what you paid, what is listed.
- Live pricing by grader and grade, with a 30-day trend, not a remembered figure
- Real PSA, BGS and SGC population at every grade level
- Grading ROI that subtracts the submission cost before it answers
- Photo identification — send a picture of the card and get the match
- Your actual portfolio, the same one the phone app shows
The 11 tools CardChain exposes
These are the real tool names on the production server, not a marketing summary. A model picks a tool by reading its name and description, so they are worth stating exactly.
- search_cards — Look up any card by player, year, set, card number or parallel. Filter by sport and grade.
- get_card_price — Current estimated value for a card, with price history and 30-day trend.
- get_population — How many copies exist at each grade across PSA, BGS and SGC.
- should_i_grade — Grading ROI: raw value against graded value, submission cost, and expected profit at each grade.
- get_portfolio — Your collection with current values, gains and total worth.
- add_to_portfolio — Add a card to your portfolio with a purchase price for profit tracking.
- find_card_to_add — Identify a card from a photo and add the match to your portfolio.
- find_card_for_grading — Identify a card from a photo and run the grading ROI on the match.
- get_cardchain_listings — Live listings for sale from real sellers on the CardChain AI marketplace.
- get_player_stats — Season stats and market momentum for the player behind a card.
- get_capabilities — Everything CardChain AI can do, for a model deciding which tool to reach for.
How the grading ROI is actually computed
Most "should I grade this" answers are a general-purpose model reasoning from whatever it remembers about card prices. That reads fluently and is worth nothing, because the decision turns on four numbers that change weekly and are specific to one card: what the raw copy sells for, what it sells for at each grade, what the submission costs, and how often that card actually comes back at the grade you are hoping for.
CardChain computes before it explains. should_i_grade reads the current raw value and the graded value at each grade level for that exact card and parallel, subtracts the submission cost, and puts the result next to the real population from PSA, BGS and SGC — so the fourth number, the odds, comes from how many copies have already been graded at each level rather than from optimism. What comes back is a verdict with the figures behind it.
That last part is the piece a plain price feed cannot do. A card whose PSA 10 sells for four times raw is still a bad submission if the population says nine out of ten copies come back a 9.
It knows what you own
A connector that can only look cards up is answering a question anyone could ask. The questions collectors actually have are about their own cards: what is my collection worth now, which of these is worth grading, what did I pay for this.
CardChain's portfolio is one portfolio. The cards you add in the iOS or Android app are the cards get_portfolio returns in ChatGPT, and a card you add mid-conversation with add_to_portfolio is in your phone before you put it down. Values refresh against the same market data everything else on the platform reads, so the app and the chat never quote you two different numbers.
No extension, and it finishes on a phone
CardChain is a native ChatGPT app. There is nothing to install in a browser, no desktop-only step, and no keys to copy out of one site and into another. You tap Try in chat, sign in to CardChain once, and you are done — on the same phone you photograph cards with.
Try these
Questions
Is there a CardChain app in ChatGPT?
Yes. CardChain AI is listed in ChatGPT's app directory — search for it there, or use the Open in ChatGPT button on this page. Tap Try in chat, sign in to CardChain once, and ChatGPT can price cards, run grading ROI, and read your portfolio from then on.
Do I need a browser extension?
No. It is a native ChatGPT app and a standard MCP connector. Nothing to install in Chrome, and no desktop-only step — setup finishes on a phone.
Can ChatGPT tell me what my card is worth without a connector?
It can guess, and the guess will be a remembered price from training data rather than a current one. Card values move week to week, so for anything you are about to buy, sell or grade the difference is real money. With CardChain connected the figure is read live from market data.
Does it work in Claude too?
Yes. The same account works through the Claude connector at https://api.cardchain.ai/mcp/claude, and your portfolio is shared across ChatGPT, Claude and the phone app.
What does it cost?
Free to start, with no credit card. Search any card, price it, check population and run the grading math without paying anything. Pro is for power users.