Polymarket Copy Trading Bot

A Polymarket copy bot for copy trading on Polymarket prediction markets. Watches a target wallet and automatically copies BUY and SELL trades with configurable sizing and risk caps.

Keywords: polymarket trading bot, polymarket copy bot, polymarket copy trading bot, prediction market bot, automated trading

What It Does

• Watches a target wallet via REST polling.
• Uses WebSocket subscriptions for faster market updates when enabled.
• Copies BUY and optionally SELL trades (set COPY_SELLS=true to copy sells; requires holding position from copied BUYs).
• Auto-checks/sets required token approvals in EOA mode.
• Applies position sizing, slippage, and optional notional risk caps.

Prerequisites

• Node.js 18+ and npm
• Polygon EOA funded with USDC.e collateral and POL (MATIC) for gas
• Polymarket account tied to the same EOA/private key
• Polygon RPC URL (QuickNode recommended)

Region Restrictions

Polymarket restricts access in some regions. If you are in a restricted region, the bot will not work — you will see connection or Cloudflare/geo errors. In that case, route traffic through a proxy or VPN (many free proxy services are available). Run the bot from an environment where Polymarket is accessible.

Credentials

• The bot derives/creates User CLOB credentials from PRIVATE_KEY at startup.
• Builder dashboard keys are for attribution and are not valid trading auth credentials for order placement.

Setup

1. Install dependencies:

npm install

2. Create your local env file:

cp .env.example .env

3. Fill required values in .env:

• TARGET_WALLET
• PRIVATE_KEY
• RPC_URL

4. (Optional) Generate and inspect user API credentials:

npm run generate-api-creds

Run

npm start

Dev/watch mode:

npm run dev

Build + run compiled output:

npm run build
npm run start:prod

Key Environment Variables

• TARGET_WALLET: wallet to follow
• PRIVATE_KEY: your EOA private key used for signing/approvals/trades
• RPC_URL: Polygon JSON-RPC endpoint
• USE_WEBSOCKET: true|false
• USE_USER_CHANNEL: true|false (true requires valid API creds for WS auth)
• POSITION_MULTIPLIER: copied size multiplier (e.g. 0.1)
• MAX_TRADE_SIZE, MIN_TRADE_SIZE
• SLIPPAGE_TOLERANCE: e.g. 0.02
• ORDER_TYPE: LIMIT, FOK, or FAK
• COPY_SELLS: true|false — copy SELL trades in addition to BUY (default: true)
• EXIT_AFTER_FIRST_SELL_COPY: true|false — exit successfully after first SELL is copied (default: false)
• MAX_SESSION_NOTIONAL, MAX_PER_MARKET_NOTIONAL: 0 disables caps

See .env.example for the full list.

Notes

• Also known as: polymarket copy bot, polymarket copy trading, polymarket copy trading bot.
• The bot starts copying only trades that happen after startup time.
• User API credentials are derived/generated from PRIVATE_KEY at startup.
• Frequent WebSocket disconnect/reconnect can happen; REST polling remains active as fallback.

Security

• Never commit .env.
• Use a dedicated wallet for bot trading.
• Start with small limits before increasing size.