> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getavenir.co/llms.txt
> Use this file to discover all available pages before exploring further.

# Tutorial

> Guided walkthrough of the trading interface

Tutorial is a step-by-step path through the trading UI. Finish it before the other simulators so the ladder, order entry, and position readout feel familiar.

## Objective

Complete the walkthrough and be comfortable with:

* Reading the order book (price ladder)
* Placing and canceling orders
* Tracking position and P\&L

Open Tutorial from the Simulator hub (or go to `/tutorial`).

## Price ladder basics

The ladder is a live view of supply and demand for one instrument. Prices sit in a center column spaced by the tick size.

* **Bids** (buy side) — pending buy orders and sizes at each price
* **Asks** (sell side) — pending sell orders and sizes at each price
* **Spread** — gap between the best bid and the best ask

When you place a limit order, size at that price increases. When you cancel, it decreases. Crossing the book (for example buying at the best ask) produces a trade: last price updates and resting size falls by the filled quantity.

## Related

* Next simulator: [Mirage](/mirage)
* Multi-ladder arb: [Artefact](/artefact)
* Headline trading: [Atlas](/atlas)
* API missions: [Opera](/opera)
* WebSocket API: [Tutorial](/api-reference/tutorial)