Olivier Vitrac, PhD, HDR - olivier.vitrac@gmail.com MIT License (see LICENSE)

AIchessy — Chess Openings & Endgames Trainer

A fully static web application for learning, replaying, and studying chess openings, endgame techniques, and famous games. No server required, no build step, no external dependencies — works offline on any device.

Live demo: aichessy.pages.dev

Highlights

• Standalone — opens directly from index.html, works offline, no installation
• Responsive — adapts to desktop, tablet, and smartphone screens
• Educational — historical context, per-move comments, and teaching points for every entry
• Interactive — drag-and-drop pieces, legal move validation, smooth animations
• Auto-play — animate through any game at configurable speed (0.5s–3s), Space key shortcut
• Record — record your own games move-by-move, then save, share, or annotate them
• Save & Import — download games as .chessy.json files, import them back anytime
• Shareable URLs — one-click copy of a playable link encoding the full game and your notes
• Personal notes — annotate any move with your own comments, persisted across sessions
• Dark mode — toggle between light and dark themes (persists across sessions)
• 3D perspective — optional CSS 3D board tilt with piece drop-shadows
• Curated library — 23 entries covering openings, endgames, and famous masterpieces

Included Library

Openings (12)

ECO	Opening	Moves
C78	Ruy Lopez — Morphy Defense	16
C54	Italian Game — Giuoco Piano	12
B90	Sicilian Defense — Najdorf Variation	10
B80	Sicilian Defense — Scheveningen Variation	10
C15	French Defense — Winawer Variation	6
B18	Caro-Kann Defense — Classical Variation	8
D37	Queen's Gambit Declined — Orthodox Defense	12
D11	Slav Defense	8
E62	King's Indian Defense	12
E20	Nimzo-Indian Defense	6
A20	English Opening — Reversed Sicilian	10
A09	Reti Opening	9

Endgames (8)

Study	Goal
King & Pawn — Opposition	Win
Lucena Position — Building the Bridge	Win
Philidor Position — Defensive Rook Endgame	Draw
Rook Activity — Cutting Off the King	Win
King + Rook vs King — Basic Checkmate	Checkmate
Drawn Fortress — Rook Pawn + Wrong Bishop	Draw
Key Squares — Pawn Promotion	Win
Rook vs Passed Pawn — King Support	Win

Famous Games (3)

Game	Year	Moves
The Immortal Game — Anderssen vs Kieseritzky	1851	45
The Opera Game — Morphy vs Duke of Brunswick & Count Isouard	1858	33
Kasparov's Immortal — Kasparov vs Topalov	1999	87

Every entry includes historical context (origin, era, significance), per-move comments, teaching points at key positions, and quiz questions.

Quick Start

Open index.html in any modern browser. No build step, no server needed.

1. Browse the Library tab — click any opening, endgame, or game to load it
2. Step through moves using the controls or click individual plies in the move list
3. Press ▶ Play (or Space) to auto-play the game at your chosen speed
4. Read the Notes tab for history, per-move commentary, and teaching points
5. Add your own annotations in the Your Notes textarea (saved automatically)
6. Click ⏺ Record to play a new game from scratch (both sides)
7. Save your game to a .chessy.json file, or Share it as a playable URL
8. Import a previously saved .chessy.json file to reload it
9. Paste your own PGN, SAN, or FEN in the Paste tab

Keyboard shortcuts: Arrow Left/Right (prev/next move), Home/End (first/last move), Space (play/pause).

Responsive Design

The app adapts to any screen size:

• Desktop (> 900px): two-column layout — board left, sidebar right
• Tablet (600–900px): single-column, board scales to viewport width
• Phone (< 600px): compact layout, full-width board, stacked controls
• Small phone (< 380px): ultra-compact, byline hidden, minimal padding

No pinch-to-zoom needed — the board and all UI elements scale automatically.

Stack

Component	Version	Role	License
chess.js	0.10.3	Rules engine, PGN/FEN parsing, move validation	BSD-2-Clause
chessground	9.1.1	Interactive board UI (lichess)	GPL-3.0
cburnett SVGs	—	Piece set from lichess	GPL-3.0

Both libraries are vendored under vendor/ for full offline use.

Repository Structure

/
├── index.html              Main application page
├── css/style.css           Themed styles (light + dark, responsive)
├── js/app.js               Application logic (single IIFE, ~977 lines)
├── data/
│   ├── library.openings.json   12 openings with history & comments
│   └── library.endgames.json   8 endgames + 3 famous games
├── assets/
│   ├── favicon.svg         App icon (chess knight)
│   └── pieces/             12 cburnett SVG pieces
├── vendor/
│   ├── chess.js/            Chess rules engine (UMD)
│   └── chessground/         Board UI + CSS themes
├── CHANGELOG.md            Version history
├── LICENSE                 MIT License
└── README.md               This file

Data Format

Games are stored as JSON arrays. Each entry has:

• type: "opening", "endgame", or "game"
• id, name, tags: identification and search
• moves_san or solution_san: move sequence in Standard Algebraic Notation
• start_fen: starting position (default: "startpos")
• history: { origin, era, significance, famous_games }
• comments: per-move commentary keyed by ply number
• teaching_points: [{ ply, text }] for instructional highlights
• quiz: [{ ply, prompt, answers, explain }] for self-testing

Saved games (.chessy.json)

The Save button exports a JSON file compatible with the library format:

• format: "chessy", version: 1
• moves_san: array of SAN moves
• start_fen: starting position
• comments: personal notes keyed by ply number
• teaching_points, history: preserved from source if loaded from library

Shareable URLs

The Share button encodes the game in the URL hash as #g=<base64url>. The payload uses compact keys: n (name), m (moves), f (FEN, omitted if standard start), c (comments). Opening such a URL loads the game automatically.

License

MIT License — Copyright (c) 2025 Olivier Vitrac