Polymarket MCP Server

A Model Context Protocol (MCP) server that gives Claude — and any MCP client — read-only access to Polymarket, the largest prediction market. Search markets, pull live order books and price history, inspect any wallet's positions, and rank the liquidity-reward markets by where you actually earn the most per dollar quoted.

No API keys. No wallet. No signup. Every tool runs against Polymarket's public APIs, so it works the second you add it to Claude.

"Claude, find me Polymarket markets paying the most liquidity rewards with the least competition."

Why this exists

Most prediction-market tooling stops at "list the markets." This server adds the thing market-makers actually care about: list_reward_markets ranks Polymarket's maker-reward programs by daily reward pool ÷ on-book competition — surfacing where resting liquidity earns the best rate, not just which markets exist.

Built on the official @modelcontextprotocol/sdk, Zod-validated, with graceful error envelopes and a short in-process cache so repeated questions in a single Claude turn stay fast.

60-second quickstart

Claude Code

claude mcp add polymarket -- npx -y polymarket-mcp-server

Claude Desktop

Add this to your claude_desktop_config.json (~/Library/Application Support/Claude/ on macOS, %APPDATA%\Claude\ on Windows):

{
  "mcpServers": {
    "polymarket": {
      "command": "npx",
      "args": ["-y", "polymarket-mcp-server"]
    }
  }
}

Restart Claude Desktop, and the tools appear under the 🔌 menu. That's it — no credentials to configure.

Cursor / other MCP clients

Point any MCP client at the stdio command npx -y polymarket-mcp-server.

Tools

| Tool | What it does | |------|--------------| | search_markets | Full-text search across events & markets → questions, prices, liquidity, volume, and token IDs. | | get_market | Full detail for one market (by ID or slug), enriched with live midpoint & spread per outcome. | | get_orderbook | Live bids/asks for an outcome token, with best bid/ask, midpoint, and spread computed. | | get_price_history | Historical probability time series with summary stats; auto-downsampled for long ranges. | | list_reward_markets | The differentiator. Markets paying maker rewards, ranked by pool ÷ competition. | | get_trader_activity | Any wallet's public positions, recent activity, or total portfolio value (whale-watching). |

Example: ranking reward markets

You:    Which Polymarket reward markets have the best pool-to-competition right now?
Claude: (calls list_reward_markets)
        1. "Will Roberto Sánchez Palomino win the 2026 Peruvian presidential election?"
           daily pool $2,000 · max spread 3.5¢ · min size 20 · competition $40.7k · score 0.049
        ...

score = dailyRewardPool / (competitionNotional + 1), where competitionNotional is the notional liquidity (Σ price·size) already resting within the scoring spread on the order book — a proxy for how crowded the reward is.

How it works

Claude / MCP client  ──stdio──▶  polymarket-mcp-server
                                       │
                 ┌─────────────────────┼─────────────────────┐
                 ▼                     ▼                     ▼
          Gamma API            CLOB API              Data API
   (markets, search)   (books, prices, rewards)  (wallet positions)

• Read-only & credential-free — only public endpoints are called.
• Zod-validated inputs on every tool; malformed input is rejected cleanly.
• Graceful errors — upstream failures come back as readable messages, never raw stack traces.
• Short TTL cache (60s) on hot queries to respect public rate limits.

Local development

git clone https://github.com/Birantx/polymarket-mcp-server.git
cd polymarket-mcp-server
npm install
npm run build
npm test          # end-to-end smoke test against the live public APIs

Run it directly over stdio:

node dist/index.js

Roadmap

• v0.1 (this release): read-only tools, credential-free.
• v0.2 (demand-driven): optional authenticated order placement via the CLOB client, gated behind explicit key configuration.

Disclaimer

This is an unofficial, community-built tool and is not affiliated with Polymarket. It is read-only and for informational use. Nothing here is financial advice. Prediction markets may be restricted in your jurisdiction.

License

MIT © 2026 — see LICENSE.

Keywords: Polymarket MCP server, Model Context Protocol, Claude, Anthropic, prediction markets, market making, liquidity rewards, MCP tools, AI trading research.