Polymarket MCP Server: Connect Claude, Cursor and ChatGPT to Live Smart-Money Data (2026)

A Model Context Protocol (MCP) server is how an AI client — Claude, Cursor, ChatGPT or an agent you wrote — gets tools it can call. A Polymarket MCP server hands it the prediction market: which markets are live, what they are pricing, and, on this one, who is on each side of the trade.

Two kinds of Polymarket MCP server

Most Polymarket MCP servers on GitHub and npm are thin wrappers over Polymarket's public Gamma and CLOB APIs. They are free, you run them yourself, and they return what the exchange publishes: markets, prices, order books, sometimes order placement with your own key. For raw prices they are the right choice.

The Polymarket MCP server from Polynyx is the other kind: hosted at one URL, read-only, and built on an analytics layer the public APIs do not carry — the smart money on each market, a leaderboard of 200,000+ ranked wallets rebuilt from on-chain fills, every wallet's track record, conviction clusters and model signals. Ask it who is on the other side of a trade and it answers with names, entry prices and win rates.

Connect it to Claude Code

claude mcp add --transport http polynyx https://polynyx.com/mcp \
  --header "Authorization: Bearer pnx_YOUR_KEY"

Claude Desktop, Cursor and Windsurf

Add one entry under mcpServers in the client's config file (Claude Desktop also accepts it as a custom connector):

{
  "mcpServers": {
    "polynyx": {
      "url": "https://polynyx.com/mcp",
      "headers": { "Authorization": "Bearer pnx_YOUR_KEY" }
    }
  }
}

ChatGPT and stdio-only clients

In ChatGPT (developer mode), add a custom connector with the URL and the bearer header. Clients that only speak stdio bridge with npx mcp-remote https://polynyx.com/mcp --header "Authorization: Bearer pnx_YOUR_KEY".

What to ask it

• “Who are the smartest wallets holding Yes on the Fed rate-cut market, and what was their entry?”
• “List the live League of Legends markets with the most 24h volume and tell me where the smart money leans.”
• “Pull the track record of 0x… — win rate, best category, open positions.”
• “Show the largest trades in the last hour over $10k by top-100 traders.”

Every tool is read-only. The server never places orders, holds no funds and asks for no wallet.

Keys and limits

One key works for the REST API and the MCP server. Plans start at $49.99/month for 50,000 requests, and each tool call counts as one request. Create keys in the developer dashboard; the tool list, parameters and payloads are in the API reference, and the install page for every client is the Polymarket MCP server page.

No code at all? The same data is on every market page and wallet page, and in the dashboards you can build from them.