Polymarket & Kalshi Arbitrage MCP Server

Real-time Polymarket, Kalshi & Manifold prediction market odds aggregator and cross-venue arbitrage spread scanner for Claude, Cursor, Codex & AI agents.

Looking for a Polymarket MCP or Kalshi arbitrage MCP server? polymarket-kalshi-arb-mcp gives Claude Desktop, Cursor, OpenAI Codex, and autonomous trading agents live probability spreads, order-book volume, and cross-exchange mispricing alerts across Polymarket, Kalshi, and Manifold Markets — with zero setup and zero npm dependencies.

Why Use polymarket-kalshi-arb-mcp?

• Cross-Venue Arbitrage Detection (kalshi_polymarket_arb) — Scans matching contracts across Kalshi, Polymarket, and Manifold to surface probability spreads and implied arbitrage edges in real time.

• Deep Polymarket Odds & Liquidity (prediction_markets) — Pulls active Polymarket event probabilities, 24h volume, liquidity depth, and resolution rules by topic (bitcoin, fed, elections, ai, tariffs, etc.).

• Zero Dependencies & Dual Transport — Pure Node.js >=18 (readline + fetch) stdio binary OR zero-install Streamable-HTTP remote MCP.

• 2 Free Calls / Day Out of the Box — Works immediately with zero configuration and no API key required.

• Instant Unlimited Upgrade — Need high-volume production calls? Grab an instant API key at https://agent-kiosk.vercel.app/buy ($1 Starter 7-Day Pass or $5 Pro 30-Day Pass) or pay per request natively via x402 (USDC on Base).

Related MCP server: telekash-mcp-server

Option 1: Zero-Install Remote MCP URL (Fastest)

Connect directly via Streamable-HTTP MCP without installing anything locally:

• Free Tier (2 Free Calls/Day, Zero Config):

  https://agent-kiosk.vercel.app/mcp

• Paid Unlimited URL (With Prepaid Pass Key):

  https://agent-kiosk.vercel.app/mcp?api_key=ak_live_YOUR_KEY_HERE

Get an Instant API Key in 10 Seconds: https://agent-kiosk.vercel.app/buy

• $1.00 USDC — 7-Day Starter Pass (Instant ak_live_... key)

• $5.00 USDC — 30-Day Pro Pass (Full unmasked datasets across all endpoints)

Option 2: Local npx / Stdio Setup (Claude Desktop, Cursor, Codex)

This package is pure Node.js >= 18 with zero external npm dependencies, exposing only the 2 focused tools for this workflow so your LLM context window stays lean.

Claude Desktop (claude_desktop_config.json)

{
  "mcpServers": {
    "polymarket-kalshi-arb-mcp": {
      "command": "npx",
      "args": ["-y", "github:ralf9090/polymarket-kalshi-arb-mcp"],
      "env": {
        "AGENT_KIOSK_API_KEY": ""
      }
    }
  }
}

(Leave AGENT_KIOSK_API_KEY empty for 2 free calls/day, or paste your ak_live_... key from agent-kiosk.vercel.app/buy for unlimited access.)

Cursor (.cursor/mcp.json)

{
  "mcpServers": {
    "polymarket-kalshi-arb-mcp": {
      "command": "npx",
      "args": ["-y", "github:ralf9090/polymarket-kalshi-arb-mcp"],
      "env": {
        "AGENT_KIOSK_API_KEY": "ak_live_OPTIONAL_PASS_KEY"
      }
    }
  }
}

OpenAI Codex CLI (~/.codex/config.toml)

[mcp_servers.polymarket_kalshi_arb_mcp]
command = "npx"
args = ["-y", "github:ralf9090/polymarket-kalshi-arb-mcp"]
env = { AGENT_KIOSK_API_KEY = "" }

Run Directly via git clone + node index.js

git clone https://github.com/ralf9090/polymarket-kalshi-arb-mcp.git
cd polymarket-kalshi-arb-mcp
node index.js

Included MCP Tools (2)

kalshi_polymarket_arb

Unified Kalshi, Polymarket & Manifold Prediction Market Aggregator and Cross-Venue Probability Spread / Arbitrage Scanner ($0.015 USDC).

prediction_markets

Query live prediction market odds & real-money implied probabilities (%) from Polymarket and Manifold Markets for any crypto, macro-economic, political, or technology event.

Example Prompts

• "Scan Kalshi and Polymarket for Bitcoin and Fed rate cut arbitrage spreads right now."

• "What are the highest-volume Polymarket prediction markets on AI regulation and US macro?"

• "Compare Kalshi vs Polymarket implied probabilities on recession markets and flag spreads > 3%."

Pricing & Rate Limits

License

MIT © ralf9090 — Powered by Agent Kiosk (Upgrade / Buy API Key).