I built an open-source market maker for prediction markets (Polymarket/CLOB) — here's how it works

Hey everyone, I've been deep in prediction market infrastructure for a while and just open-sourced a market maker bot designed for CLOB-based prediction markets like Polymarket. What it does: * Quotes both sides of a binary market automatically * Adjusts spreads based on order book depth and volatility * Manages inventory risk to avoid getting stuck on the wrong side of a resolved market * Built on top of Polymarket's CLOB API with Gnosis Safe / EOA wallet support on Polygon The core challenge with prediction markets vs. regular markets: Normal market making is about capturing spread. Prediction markets add a brutal edge case — resolution risk. If you're holding YES at 0.6 and the market resolves NO, you're not just down on the spread, you're down the full position. So the bot has to: * Track time-to-resolution and widen spreads as resolution approaches * Reduce inventory exposure on markets with high directional momentum * Use FAK orders to avoid resting limit orders too long near resolution Stack: * Rust * Polymarket CLOB API * Polygon (USDC settlement) * SQLite for order state tracking What's next: * Dynamic spread model based on implied volatility * Multi-market portfolio rebalancing * Better signal integration (news feeds, oracle data) GitHub: https://github.com/HarrierOnChain/Prediction-Markets-Trading-Bot-Toolkits Happy to answer questions on the architecture, risk model, or anything CLOB-related. Always looking for feedback from others building in this space.