Build an Exchange, as working pages.
Every episode of Build an Exchange is driven through the order book terminal on screen. These are those terminals — one per episode, each frozen at the build it was recorded with, so what you can do here matches what you saw in the video.
Episodes
Ep
Episode
Published
State
01
How every market price is made
The order book, live — bids, asks, the spread, and where a price actually comes from.
12 Jul 2026
Live
02
Market vs limit orders, decided live
What a market order walks through the book, what a limit order waits for, and what each one costs you.
17 Jul 2026
Live
03
Why you're 0% filled
Price-time priority — your place in the queue, partial fills, and why an order at the best price can still sit untouched.
29 Jul 2026
Live
The engine is open source. The matching engine behind these pages lives at
github.com/MoneyInternals/mini-exchange.
Each page here matches a tagged release —
ep01-order-book,
ep02-market-vs-limit,
ep03-price-time-priority —
so you can read the exact code each episode ran on.