The Card API — MCP Server

Real sold prices for trading cards, directly inside your AI.

Connect Claude, Cursor, Windsurf, ChatGPT, or any MCP-compatible client to millions of true sold prices across eBay, Goldin, Heritage, Fanatics, and more — including Best Offer prices (the actual negotiated amount, which most data providers never show).

One URL. No setup beyond your API key. Data updated daily.

Get a free API key →

Quickstart

Claude Code

claude mcp add thecardapi \
  --transport http \
  --url https://thecardapi.com/api/mcp \
  --header "Authorization: Bearer YOUR_API_KEY"

Claude Desktop (~/Library/Application Support/Claude/claude_desktop_config.json)

{
  "mcpServers": {
    "thecardapi": {
      "command": "npx",
      "args": [
        "mcp-remote",
        "https://thecardapi.com/api/mcp",
        "--header",
        "Authorization: Bearer YOUR_API_KEY"
      ]
    }
  }
}

Cursor (~/.cursor/mcp.json)

{
  "mcpServers": {
    "thecardapi": {
      "url": "https://thecardapi.com/api/mcp",
      "headers": { "Authorization": "Bearer YOUR_API_KEY" }
    }
  }
}

Windsurf (~/.codeium/windsurf/mcp_settings.json)

{
  "mcpServers": {
    "thecardapi": {
      "serverUrl": "https://thecardapi.com/api/mcp",
      "headers": { "Authorization": "Bearer YOUR_API_KEY" }
    }
  }
}

LangChain (Python)

from langchain_mcp_adapters.client import MultiServerMCPClient

client = MultiServerMCPClient({
    "thecardapi": {
        "url": "https://thecardapi.com/api/mcp",
        "transport": "streamable_http",
        "headers": {"Authorization": "Bearer YOUR_API_KEY"},
    }
})

Tools

Market Data

| Tool | What it does | |---|---| | search_cards | Search millions of real sold prices. Filter by card name, platform, grader, grade, listing type, date range, and price. Returns true Best Offer prices — the actual negotiated amount, not the list price. | | grade_impact_analysis | Full PSA/BGS/SGC/CGC price ladder for any card — avg, median, and sale count per grade. Identifies the best-value grade: where the jump to the next grade up is steepest. | | grader_comparison | PSA vs BGS vs SGC vs CGC for the same card and grade. Shows which grader commands the highest premium and by how much. | | grading_value_calculator | Should you grade this card? Real cost math — all PSA/BGS/SGC/CGC tiers including bulk rates and shipping — vs actual market comps. Shows expected profit or loss at each grade. | | price_momentum | Is this card trending up or down? Compares two equal time windows back-to-back and returns price change %, volume change %, and a momentum signal. | | seller_lookup | Full profile on any seller: total sales, average price, feedback score, last active date, which grades they specialize in, and a trust signal. | | slab_lookup | Enter a PSA/BGS/SGC/CGC serial number and see every time that specific physical card has sold, and how its price changed over time. Carfax for cards. |

Want List

| Tool | What it does | |---|---| | search_catalog | Search a catalog of 9.7M+ cards by natural language. Returns ranked candidates with images. | | add_to_want_list | Add a specific card to your want list with optional condition, grader, grade, and max price preferences. | | view_want_list | View all cards currently on your want list. | | remove_from_want_list | Remove a card from your want list. |

Example prompts

What are PSA 10 Luka Doncic 2018 Prizm Silver rookies actually selling for
right now — true Best Offer prices, not just auctions?

I paid $6,500 for a raw 1986 Fleer Jordan. Is PSA grading it worth it,
and what grade do I need to break even?

For a grade 9 Wembanyama Prizm Silver, does PSA, CGC, or BGS command
the highest average sale price?

Pull the full transaction history for PSA cert 84566824 — every sale,
every price, has it appreciated?

Has the market for Charizard Base Set Holo PSA 10 been rising or falling
over the past two weeks — include volume.

Full seller profile on pwcc_auctions: total sales, average price,
what grades do they typically move.

Why Best Offer prices matter

eBay hides the final accepted price on Best Offer listings. Most price trackers either skip these entirely or show the original list price — both of which distort the true market. The Card API captures the actual negotiated amount at time of sale, giving you a complete picture of what cards are really trading for.

Data coverage

• Platforms: eBay (Auction, Fixed Price, Best Offer), Goldin, Heritage, Fanatics Vault, Pristine, REA, Alt, Sotheby's
• Categories: Baseball, basketball, football, hockey, soccer, Pokémon, Magic: The Gathering, Yu-Gi-Oh, and 30+ more
• Graders: PSA, BGS (Beckett), SGC, CGC
• Updated: Daily

Authentication

All tools use the same API key as the REST API. Pass it as a Bearer token:

Authorization: Bearer tca_your_key_here

Your tier's rate limits apply automatically. The free tier is enough to explore all 11 tools.

Get your free key at thecardapi.com →

Full documentation

REST API reference, response schemas, CSV export, and webhook docs: thecardapi.com/docs

MCP-specific setup for all clients: thecardapi.com/mcp