Polymarket Paper Trading Bot: Build One in Python

Polymarket Paper Trading Bot: Build One in Python A real-money trading bot is the wrong place to discover that your signal logic, order-book handling, or position accounting is broken. A Polymarket paper trading bot gives you a safer engineering environment: consume real market data, generate real signals, simulate orders and fills, and measure hypothetical performance before connecting execution credentials. The important distinction is that paper trading should simulate the execution layer , not fabricate market data. Polymarket currently exposes public market data without authentication, while its public WebSocket market channel provides real-time order-book and price updates. This article builds that architecture in Python. What You'll Learn How a paper-trading architecture differs from a live bot How to discover markets through the public API How to consume CLOB order-book data How to simulate limit-order fills How to track positions and P&L How to test arbitrage, market-making, and directional strategies How to graduate from paper trading to production safely About the Author Soulcrancerdev Contact: X: @soulcrancerdev Telegram: soulcrancerdev YouTube: YouTube channel The Architecture A useful design separates data, strategy, simulation, and accounting : flowchart LR A[Gamma Market Discovery] --> B[Market Metadata] C[CLOB REST / WebSocket] --> D[Market Data Engine] B --> D D --> E[Strategy Engine] E --> F[Paper Execution Engine] F --> G[Virtual Portfolio] G --> H[P&L / Risk Metrics] D --> I[Logger / Metrics] The key design decision is that PaperExecutionEngine should implement the same interface your live execution engine eventually uses. That means the strategy does not know whether an order is simulated or real. 1. Discover Markets Polymarket's Gamma API provides public market discovery. The current documentation exposes keyset pagination through: https://gamma-api.polymarket.com/markets/keyset Markets include fields such as conditionId , clobTokenIds , outco