How do I connect CardChain AI to Claude?
Add a custom connector in Claude and paste https://api.cardchain.ai/mcp/claude. That is a standard Model Context Protocol server over Streamable HTTP, so it works in Claude on web, desktop and mobile, in Claude Code, and in any other MCP client. Sign in to CardChain once and Claude can price any sports card, read PSA, BGS and SGC population, run the grading ROI, identify a card from a photo, and read and add to your portfolio. About two minutes, free to start.
What you can ask once it’s connected
More than a price feed
A price lookup tells you what a card sold for. That is the easy half. The decisions collectors actually face — submit this or sell it raw, is this listing a deal, which of my cards is carrying the collection — need the price put next to something else: the population at each grade, the submission cost, what you paid. CardChain computes those together and hands back a verdict with the figures behind it, rather than a number for a model to narrate.
Under the hood that is 11 tools: search_cards, get_card_price, get_population, should_i_grade, get_portfolio, add_to_portfolio, find_card_to_add, find_card_for_grading, get_cardchain_listings, get_player_stats, get_capabilities.
Settle a card from a photo, in the chat
Card identification is the hard half of card pricing — get the parallel wrong and every number after it is wrong. Send a picture of the card into the conversation and CardChain identifies the exact card, parallel and grade, shows the matches it considered, and prices the one you confirm. No app switch, no typing out a card name you are guessing at.
One account, one portfolio
The cards you add in the iOS or Android app are the cards ChatGPT reads, and a card you add mid-conversation is on your phone before you put it down. Values refresh against the same market data everything else on the platform uses, so the app and the chat never quote you two different numbers.
No browser extension. Setup finishes on a phone.
CardChain is a native ChatGPT app and a standard Claude connector. There is nothing to install in a browser, no desktop-only step, and no API key to copy between sites. You sign in once, on CardChain's own page, from the same phone you photograph cards with.
| CardChain AI | A plain card price connector | |
|---|---|---|
| Browser extension | None | Varies |
| Set up from a phone | Yes | Varies |
| Knows what you own | Yes — one portfolio across the app, ChatGPT and Claude | No — every question starts from nothing |
| Identify a card from a photo | Yes, inside the chat | Typically text search only |
| What you get back | A verdict with the population, cost and odds behind it | A price, for the model to narrate |
How to connect CardChain AI to Claude
- Open connector settings in ClaudeOn claude.ai, in the desktop app, or on mobile: Settings → Connectors → Add custom connector.
- Paste the CardChain server URLUse https://api.cardchain.ai/mcp/claude exactly. A trailing space is the single most common reason a connector fails to add, so paste rather than retype.
- Sign in to CardChain onceYou are sent to CardChain's own sign-in page. Use the same account as the iOS or Android app and your portfolio is there immediately. CardChain never sees a password belonging to anyone else, and there are no keys to copy.
- Ask about a card"What's this worth?", "should I grade it?", "what's my collection worth?" — in plain English. The assistant picks the tool, CardChain runs the lookup, and the answer arrives with the market data behind it.
What it will and will not do
It reads the catalogue, reads population, runs the grading math, and reads and adds to your own portfolio. It will show you live marketplace listings. It will not complete a purchase for you — buying happens in the app or on the site, where you confirm it yourself — and it has no access to anything outside your own CardChain account.
Questions
What is the CardChain MCP server URL for Claude?
https://api.cardchain.ai/mcp/claude. It speaks MCP over Streamable HTTP. Paste it into Claude's Add custom connector field exactly, with no trailing space.
Which Claude apps support custom connectors?
Claude on the web, the desktop app and mobile all support adding a custom connector, and Claude Code accepts the same URL as a remote HTTP MCP server. Availability of custom connectors is Anthropic's decision and can vary by plan.
Does it work in Cursor, Windsurf or other MCP clients?
Yes. It is a standard remote MCP server, so any client that accepts a remote HTTP endpoint can use the same URL.
The connector will not add. What is wrong?
Check the URL character by character — it is https://api.cardchain.ai/mcp/claude, and a trailing space or a missing /claude is the usual cause. If it adds but returns nothing, you are probably not signed in to CardChain yet; Claude will prompt you on the first tool call.
Is my collection private?
Yes. The connector reads only the portfolio belonging to the CardChain account you sign in with. It cannot see anyone else's holdings, and it cannot spend money — buying happens in the app or on the site, where you confirm it yourself.
Is it free?
Yes. It is free to start, with no credit card. Search any card, see real-time pricing and population, and run the grading math without paying anything. Pro is for power users.