prediction-market-mcp

A simple MCP server that grabs prediction market data from polymarket, PredictIt, & Kalshi.

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prediction-markets-mcp

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A Model Context Protocol (MCP) server that provides real-time prediction market data from multiple platforms. This server allows you to query prediction markets for current odds, prices, and market information through a unified interface.

Supported Platforms

  • Polymarket - Crypto-based prediction markets with percentage-based odds
  • PredictIt - Traditional prediction markets with dollar-based prices
  • Kalshi - Regulated US prediction markets

Features

  • Multi-platform Support: Query both crypto and traditional prediction markets
  • Real-time Data: Get current odds and prices from live markets
  • Keyword Search: Filter markets by specific keywords or topics
  • Unified Interface: Consistent data format across different platforms
  • Error Handling: Graceful handling of API failures and network issues
  • Type Safety: Full TypeScript support with comprehensive type definitions

Installation

Prerequisites

  • Node.js (v18 or higher)
  • npm or yarn

Setup

  1. Clone the repository:
git clone <repository-url>
cd prediction-markets-mcp
  1. Install dependencies:
npm install
  1. Build the project:
npm run build

Usage

Running the Server

Start the MCP server:

node build/index.js

The server runs on stdio and can be integrated with MCP-compatible clients.

API Endpoints

The server provides a single tool: get-prediction-markets

Parameters

  • keyword (string, required): Search term to filter markets
    • Maximum length: 50 characters
    • Examples: "trump", "election", "supreme court"

Example Queries

// Search for Trump-related markets
{
  "keyword": "trump"
}

// Search for election markets
{
  "keyword": "election"
}

// Search for Supreme Court markets
{
  "keyword": "supreme court"
}

Response Format

The server returns prediction market data in the following format:

Polymarket Markets

**Polymarket: Will Trump win the 2024 election?**
Yes: 45.2% | No: 54.8%

PredictIt Markets

**PredictIt: Which party will win the 2025 gubernatorial election in Virginia?**
Democratic: 89.0% | Republican: 11.0%

Data Sources

Polymarket API

  • Base URL: https://clob.polymarket.com/markets
  • Format: JSON
  • Odds Display: Percentages (e.g., 65.2%)
  • Data: Market questions, active status, token prices

PredictIt API

  • Base URL: https://www.predictit.org/api/marketdata/all/
  • Format: JSON
  • Odds Display: Dollar amounts (e.g., $0.65)
  • Data: Market names, contracts, trade prices, status

Development

Project Structure

prediction-markets-mcp/
├── src/
│   └── index.ts          # Main server implementation
├── build/                # Compiled JavaScript output
├── package.json          # Dependencies and scripts
├── tsconfig.json         # TypeScript configuration
└── README.md            # This file

Key Components

Type Definitions

// Polymarket types
type Market = {
  question: string;
  active: boolean;
  archived: boolean;
  tokens: Token[];
};

// PredictIt types
type PredictItMarket = {
  id: number;
  name: string;
  shortName: string;
  contracts: PredictItContract[];
  status: string;
};

Core Functions

  • getPolymarketPredictionData(): Fetches and processes Polymarket data
  • getPredictItMarkets(): Fetches all PredictIt markets
  • makeApiRequest(): Handles HTTP requests with proper headers

Building

# Development build
npm run build

# Watch mode (if needed)
npm run dev

Testing

To test the server manually:

  1. Start the server:
node build/index.js
  1. Send test requests through an MCP client or test the API endpoints directly.

Troubleshooting

Common Issues

No Markets Found

  • Cause: Keyword too specific or no matching markets
  • Solution: Try broader keywords or check market availability
  • Example: Use "election" instead of "specific candidate name"

Development Setup

  1. Fork the repository
  2. Create a feature branch
  3. Make your changes
  4. Add tests if applicable
  5. Submit a pull request

Code Style

  • Use TypeScript for all new code
  • Follow existing naming conventions
  • Add JSDoc comments for public functions
  • Ensure all builds pass before submitting

License

MIT License - see LICENSE file for details

Support

For issues and questions:

  1. Check the troubleshooting section
  2. Review existing GitHub issues
  3. Create a new issue with detailed information

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