Polymarket Copy Trading Bot

A TypeScript bot that watches a target Polymarket wallet, detects trades in real time, and mirrors buy orders to your own account. Supports EOA and proxy/safe auth (signature types 0, 1, 2).

Inspired by Building a Polymarket Copy Trading Bot | QuickNode Guides.

Overview

Polymarket CLOB: Your bot signs orders; the API handles order flow; settlement stays non-custodial on-chain (Polygon).
Data API (discovery): Finds new trades from the wallet you want to copy via REST polling.
WebSocket (optional): Faster market/user updates once subscribed.
Executor: Sizes the copied order, runs checks, and submits it.
Risk & positions: Tracks exposure and can block trades above your limits.
Demo guardrail: By default the flow is BUY-only (SELL trades from the target are skipped).

Prerequisites

Node.js (v18+) and npm
A funded wallet on Polygon mainnet with USDC.e and POL (for gas)
Polygon RPC URL (e.g. QuickNode Polygon endpoint)
The Polymarket CLOB SDK expects ethers v5 (included in this project)

Quick Start

1. Install dependencies

npm install

2. Configure environment

cp .env.example .env

Edit .env and set at least:

TARGET_WALLET — Polymarket wallet address to copy (0x...)
PRIVATE_KEY — Your wallet private key (0x...)
RPC_URL — Polygon RPC URL (e.g. QuickNode)

For a small demo, use modest sizing (e.g. MAX_TRADE_SIZE=5, POSITION_MULTIPLIER=0.1).

3. Run the bot

npm start

On first run in EOA mode, the bot may trigger approval transactions for USDC.e/CTF spenders. Ensure the wallet has enough POL for gas.

Architecture

Component	Role
TradeMonitor	REST polling of Polymarket Data API to discover new trades from the target wallet.
WebSocketMonitor	Optional real-time updates via Polymarket `market` or `user` WebSocket channels.
TradeExecutor	Sizes copy trades, checks balance/allowance, places orders via CLOB client (FOK/FAK/LIMIT).
PositionTracker	Tracks positions from fills (in-memory; loaded/updated from successful copies).
RiskManager	Enforces session notional cap and per-market notional cap before execution.

The main loop: detect trade → (if BUY) subscribe WS if needed → compute copy size → risk check → execute → record fill and stats.

Environment variables

Variable	Required	Description
`TARGET_WALLET`	Yes	Polymarket wallet address to copy (e.g. `0x...`).
`PRIVATE_KEY`	Yes	Your wallet private key (0x-prefixed).
`RPC_URL`	Yes	Polygon RPC URL (e.g. QuickNode).
`SIG_TYPE`	No	Polymarket signature type. `0` = EOA (default), `1` = Poly Proxy, `2` = Poly Polymorphic.
`PROXY_WALLET_ADDRESS`	For 1/2	Funder/proxy/safe address when using `SIG_TYPE=1` or `2`. Leave empty for EOA.
`POLYMARKET_GEO_TOKEN`	No	Geo token if provided by Polymarket for your region.
`POSITION_MULTIPLIER`	No	Copy size multiplier (default `0.1` = 10%).
`MAX_TRADE_SIZE`	No	Max copy trade size in USDC (default `100`).
`MIN_TRADE_SIZE`	No	Min copy trade size in USDC (default `1`).
`SLIPPAGE_TOLERANCE`	No	Slippage (default `0.02` = 2%).
`ORDER_TYPE`	No	`FOK`, `FAK`, or `LIMIT` (default `FOK`).
`USE_WEBSOCKET`	No	`true` / `false` (default `true`).
`USE_USER_CHANNEL`	No	Use user channel for WebSocket (default `false`).
`POLL_INTERVAL`	No	REST poll interval in ms (default `2000`).
`WS_ASSET_IDS`	No	Comma-separated asset IDs for market WebSocket.
`WS_MARKET_IDS`	No	Comma-separated market/condition IDs for user channel.
`MAX_SESSION_NOTIONAL`	No	Session notional cap in USDC; `0` = no cap.
`MAX_PER_MARKET_NOTIONAL`	No	Per-market notional cap; `0` = no cap.
`MIN_PRIORITY_FEE_GWEI`	No	Min priority fee for Polygon txs (default `30`).
`MIN_MAX_FEE_GWEI`	No	Min max fee for Polygon txs (default `60`).

Auth (SIG_TYPE and PROXY_WALLET_ADDRESS)

SIG_TYPE=0 (EOA)
Default. Your signer is an EOA. Do not set PROXY_WALLET_ADDRESS. API credentials are derived or created from PRIVATE_KEY at startup.
SIG_TYPE=1 (Poly Proxy)
Set PROXY_WALLET_ADDRESS to your Polymarket proxy/safe address (funder).
SIG_TYPE=2 (Poly Polymorphic)
Set PROXY_WALLET_ADDRESS to your polymorphic safe address (funder).

All CLOB usage (trader, generate-api-creds, test-api-creds) uses auth from config, driven by SIG_TYPE and PROXY_WALLET_ADDRESS in .env.

Commands

Command	Description
`npm start`	Run the bot.
`npm run generate-api-creds`	Generate and write API credentials to `.polymarket-api-creds` (uses `SIG_TYPE` and `PROXY_WALLET_ADDRESS` from `.env`).
`npm run test-api-creds`	Validate static API credentials (same auth env vars).
`npm run build`	Compile TypeScript to `dist/`.
`npm run start:prod`	Run compiled `dist/index.js`.

Example output

Startup:

🤖 Polymarket Copy Trading Bot
================================
Target wallet: 0x...
Position multiplier: 10%
Max trade size: 100 USDC
Order type: FOK
WebSocket: Enabled
Auth: EOA (signature type 0)
================================

✅ Configuration validated
✅ Trader initialized
✅ WebSocket monitor initialized (market channel)
🚀 Bot started! Monitoring via: WebSocket + REST API

When a BUY is detected and copied:

🎯 NEW TRADE DETECTED
   Side: BUY YES
   Size: 12.5 USDC @ 0.620
   ...
📈 Executing copy trade (FOK): Copy notional: 1.25 USDC
✅ Successfully copied trade!
📊 Session Stats: 1/1 copied, 0 failed

When a SELL is detected (skipped):

⚠️  Skipping SELL trade (BUY-only safeguard enabled)

Disclaimer

This code has not been audited. Use at your own risk. Audit any code before using real funds or deploying to production. Start with small sizes (e.g. MAX_TRADE_SIZE=5 or lower) for testing.

References

Building a Polymarket Copy Trading Bot | QuickNode
Polymarket — prediction markets on Polygon
Polymarket CLOB — order book client

sssorryMaker/polymarket-trading-bot

README