Trade Without
Consequences
A self-contained, Alpaca-compatible stock exchange simulator. Full order book matching, real-time WebSocket streams, and autonomous market participants — all running locally.
The Matching Engine
Buy and sell forces collide — every order finds its match
Price-Time Priority Engine
Full order book with limit, market, stop, trailing stop, and bracket orders. FIFO matching within price levels. Real fills, real positions.
Alpaca API Compatible
Drop-in replacement for Alpaca Paper Trading. REST + WebSocket streams. Just swap your base URL — zero code changes in your trading desk.
Autonomous Market
Noise traders with GBM-perturbed prices and market makers maintaining two-sided quotes. The book has depth from the moment you start.
Architecture
How it works
Infrastructure
OTP supervision trees, ETS storage, PostgreSQL persistence — built to be resilient