Polymarket Market Making Bot: A Bot That Will Lose You Money (But That's the Point)

Intro

Prediction markets like Polymarket are fascinating. But running a market making bot on them? That's a different beast. Most devs I know who've tried it ended up with a pile of UNI tokens and a deep understanding of why liquidity provision is hard.

Enter poly-maker – a market making bot for Polymarket that its creator honestly describes as "will lose you money today." That's not a bug. That's a feature. It's a learning tool, a sandbox for devs who want to understand the mechanics of automated market making without risking their life savings. Think of it as the "Hello, World" of prediction market bots.

What It Does

This is a Python bot that places limit orders on Polymarket's CLOB (Central Limit Order Book) for binary outcome markets. It watches the order book for a given market, calculates a fair price (based on a configurable spread), and submits buy/sell orders slightly away from that price. If a trade executes, it updates its position and adjusts orders accordingly.

The bot is not designed to make money. It's designed to make the market. It's a liquidity provider in the truest sense: it provides liquidity, and in return, it gets filled on both sides, often at a loss. But that loss is the cost of learning how the system works.

Why It's Cool

1. Honest documentation – The README literally says "this will lose you money." Refreshing.
2. Simple, understandable code – No complex Rust or Solidity. Pure Python with clear comments.
3. Real Polymarket interaction – It uses the same API as actual traders. You can watch it place real orders on testnet.
4. Configurable parameters – Spread size, order size, market ID, and more.
5. Teachable moment – It shows exactly why market making is hard. The bot gets picked off by informed traders, suffers from adverse selection, and slowly bleeds value.

How to Try It

1. Clone the repo:

   git clone https://github.com/warproxxx/poly-maker.git
   cd poly-maker
   

2. Install dependencies:

   pip install -r requirements.txt
   

3. Set up your environment variables:

   export POLYMARKET_PRIVATE_KEY=your_key_here
   export POLYMARKET_MARKET_ID=your_market_id
   

4. Run it (on testnet first!):

   python main.py --testnet
   

5. Watch the logs. You'll see it place orders, get filled, and slowly realize why professional market makers use fancy models with inventory risk management.

Full instructions are in the repo README.

Final Thoughts

This bot is a perfect weekend project for devs who want to understand prediction market mechanics. Run it on testnet for a few hours. Watch how orders get eaten. Try to tweak the spread size. See if you can make it lose money slower.

It's not a production tool. It's a learning tool. And that's completely fine. The crypto space has too many "make money fast" projects and not enough honest "here's how this actually works" projects. This is the latter.

If you want to understand market making without losing your shirt, this is your starting point. Just remember: it will lose you money today. But tomorrow, you'll know why.

Follow @githubprojects for more developer-focused projects and tools.