A beginner-friendly guide to setting up and running your first automated trading bot on Polymarket.

Repository: https://github.com/Obsidian-Trades/polymarket-copy-trading-bot

This bot places real money trades on the blockchain. Please read this before doing anything:

• You can lose money. This is not guaranteed to be profitable.
• Start with very small amounts (e.g. $5–$10) while you're learning.
• Use a separate, dedicated wallet — never your main crypto wallet.
• This is a tool for experienced users who understand the risks. If you're brand new to crypto trading, take time to learn the basics first.

In plain English: Polymarket runs short-duration prediction markets where you can bet on whether Bitcoin's price will go Up or Down in the next 5 minutes. Every pair of Up + Down tokens always resolves to a combined value of $1.

This bot exploits small pricing gaps in those markets:

1. It watches for a moment when you can buy both Up and Down tokens for a combined price less than $1.
2. It buys both sides simultaneously — no matter which direction Bitcoin moves, the pair is worth $1 at resolution.
3. The difference between what you paid and $1 is your profit.

It also includes a copy-trading mode that mirrors the trades of a target wallet you choose to follow.

Here's what the bot's activity looks like in practice:

This repo has two main modes. Pick the one that fits your goal:

Before installing anything, make sure you have all of the following:

• A computer running Windows, Mac, or Linux
• Node.js version 18 or newer — Download here. To check your version, run node --version in your terminal.
• A Polymarket account — Sign up at polymarket.com
• A Polygon wallet — this is where your funds live (e.g. MetaMask set to Polygon network)
• Your wallet's private key — the secret key for your trading wallet (⚠️ never share this with anyone)
• Your Polymarket proxy wallet address — found in your Polymarket account settings
• USDC on Polygon — the stablecoin used for trading (not Ethereum USDC, it must be on Polygon)
• A small amount of MATIC — Polygon's native token, used to pay for gas fees (a few dollars' worth is enough)

• A private Polygon RPC endpoint from a service like Alchemy or Infura. The free public RPC can be unreliable. Both services have free tiers.

If you have Git installed:

git clone https://github.com/Obsidian-Trades/polymarket-copy-trading-bot.git
cd polymarket-copy-trading-bot

Or click the green Code button on GitHub and choose Download ZIP, then unzip it.

Open a terminal inside the project folder and run:

npm install

This downloads all the libraries the bot needs. It may take a minute.

On Mac/Linux:

cp .env.example .env

On Windows (PowerShell):

Copy-Item .env.example .env

This creates a file called .env where you'll put all your private settings. This file stays on your computer only — it is never uploaded anywhere.

Open .env in any text editor (Notepad, VS Code, etc.) and fill in your details. See the configuration section below for a full explanation of every setting.

npm start

That's it! The bot will start logging activity to your terminal and to a file called bot.log.

Your .env file controls everything. Here's what each setting means, explained in plain English.

These must be filled in or the bot won't start:

These control how aggressively the bot trades. Start with conservative (smaller) values.

POLY_API_KEY=
POLY_API_SECRET=
POLY_API_PASSPHRASE=

Leave these blank on your first run. The bot will automatically generate them from your wallet. Only fill these in if you've been given credentials directly from Polymarket.

If you want to follow another trader instead of running the arb bot, use these settings.

npm start

Or alternatively:

npm run arb

Set TARGET_WALLET in your .env, then run the same command:

npm start

The bot will mirror future buys from that wallet while also running its own arb logic.

node src/copy/index.js

💡 Always test copy trading with COPY_DRY_RUN=true first until you're confident it's working the way you expect.

npm run dev

.
├── .env.example          ← Template for your settings — copy this to .env
├── package.json          ← Project metadata and scripts
├── img/                  ← Screenshots used in this README
└── src/
    ├── index.js          ← Main entry point — starts everything up
    ├── trader.js         ← Core arb logic (ladder posting, order management)
    ├── market.js         ← Finds and tracks Polymarket markets
    ├── clob.js           ← Handles communication with Polymarket's order book
    ├── onchain.js        ← Blockchain interactions (approvals, merges, redeems)
    ├── copy-trader.js    ← Integrated wallet-mirroring module
    ├── pnl.js            ← Profit/loss tracking
    ├── logger.js         ← Logging setup
    └── copy/
        ├── index.js          ← Entry point for standalone copy trader
        ├── activityFeed.js   ← Watches target wallet for new trades
        ├── copyTrader.js     ← Copy trade execution and risk checks
        └── config.js         ← Copy trader configuration loader

The bot outputs two streams of logs:

• Terminal (console): Color-coded logs so you can watch activity live
• bot.log file: Full JSON logs saved to disk for review later

Use bot.log to investigate any issues after a session — it contains full error details, order IDs, and timing info.

Your .env file is missing required fields. Open it and double-check that these are filled in (not blank):

• PRIVATE_KEY
• PROXY_WALLET
• COPY_TARGETS (if using copy trading)

• Make sure PRIVATE_KEY matches the wallet connected to your Polymarket account
• Make sure PROXY_WALLET is the correct proxy address for that account (not your main wallet address)
• Try using a private RPC endpoint (Alchemy/Infura) instead of the default public one
• Leave POLY_API_* fields blank — the bot will auto-generate them

• Check that target wallet addresses are all lowercase in your settings
• The target wallet must be placing new buy orders — the bot ignores sells and old fills
• Check that your spend caps (COPY_MAX_USDC_PER_TRADE, etc.) aren't set to zero or too low
• Make sure COPY_DRY_RUN is set to false if you want real orders

• Make sure you have enough MATIC for gas fees
• The market must be fully resolved before you can redeem winnings
• Check bot.log for the full error message — it will tell you what went wrong specifically

Follow these steps your very first time:

• Created a separate, dedicated wallet for the bot
• Added a small amount of USDC on Polygon (start with $10–$20)
• Added a small amount of MATIC for gas (a few dollars is enough)
• Filled in .env with real wallet details
• Set a private RPC endpoint (Alchemy or Infura free tier)
• Set MAX_SPEND_PER_MARKET to a small value (e.g. 5)
• Set MAX_LOSS_PER_HOUR_USDC to a number you're comfortable losing
• If testing copy trading: set COPY_DRY_RUN=true first
• Ran the bot and reviewed bot.log after a session
• Only scaled up after confirming everything works as expected

This software is provided for research and use by experienced traders. It is not financial advice and does not guarantee profit. Real-money trading involves market risk, execution risk, smart contract risk, and operational risk. You are fully responsible for how you configure and use this software.

Built for Polymarket on Polygon. Not affiliated with Polymarket.