How to Build a Polymarket Bot

A developer's guide to building automated trading bots for Polymarket prediction markets.

Prerequisites

• Programming experience (Python or TypeScript recommended)
• A funded Polymarket account with API keys
• Basic understanding of REST APIs and WebSockets
• Familiarity with blockchain concepts (transactions, wallets)

Step 1: API Setup

Polymarket provides a CLOB (Central Limit Order Book) API. You'll need to:

• Generate API credentials from your Polymarket account
• Install the Python (py-clob-client) or TypeScript CLOB client
• Test connectivity by fetching market data

The API supports both REST endpoints (for placing/canceling orders, fetching positions) and WebSocket feeds (for real-time price updates and trade notifications).

Step 2: Market Data Ingestion

Your bot needs to consume and process market data efficiently. Key data sources:

• Market list — All available markets with metadata (question, category, resolution date)
• Order book — Current bids and asks for each market outcome
• Trade feed — Real-time stream of executed trades across all markets
• Wallet activity — On-chain transactions for specific wallets you want to track

Step 3: Trading Logic

This is where your strategy lives. For a simple copy trading bot:

1. Maintain a list of target wallets to monitor
2. Subscribe to their on-chain activity via WebSocket or polling
3. When a target wallet buys, determine your position size based on configuration
4. Check price hasn't moved more than your slippage threshold
5. Place a market or limit order via the CLOB API
6. Track the position and handle exits when the target exits

Step 4: Risk Management

This is the most important part. Without risk management, one bug can drain your account:

Step 5: Deployment

Run your bot on a cloud server for 24/7 uptime. Popular choices:

• Railway, Render, Fly.io — Easy deployment, good for Node.js/Python bots
• AWS/GCP — More control, better for high-frequency bots
• VPS (DigitalOcean, Hetzner) — Cheapest for long-running processes

Set up monitoring (error alerts, performance dashboards) and logging (trade history, profit tracking). Health checks ensure the bot restarts if it crashes.

Or Use an Existing Tool

Building from scratch takes weeks or months. If you want to skip the engineering and start copy trading immediately, existing tools handle all of this for you.