Lozza

A Javascript UCI chess engine that can be used in a Web Worker and Node.

Lozza is easy to read and tweak; it's also easy to deploy and is WSAM-free.

Release versions are additionally available as assets for Windows and Linux; ping me if you would like one for a different platform.

Web hello world

All you need is lozza11.0.js from the latest release.

const dump = document.getElementById('dump');
const lozza = new Worker('lozza11.0.js');

lozza.onmessage = function (e) {
  dump.textContent += e.data + '\n';
};

lozza.postMessage('uci');
lozza.postMessage('ucinewgame');
lozza.postMessage('position startpos');
lozza.postMessage('go depth 10');

Try it here: https://op12no2.github.io/lozza/examples/hello_world.html

Node

node lozza.js                     # interactive
node lozza.js uci "go depth 10" q # exec commands and exit

Notes

• Don't use the repo lozza.js because it doesn't have any weights; always use the latest release.
• The code is best read with a folding editor; I use foldit in a WSL terminal - link below.
• Lozza needs a rewrite. It's pretty ugly with a 12x12 board inherited from my 1980 engine and search is way behind the hobby coalface.

Acknowledgements

• https://chessprogramming.org - Chess programming wiki
• https://backscattering.de/chess/uci - UCI protocol
• https://talkchess.com - Talkchess forums
• https://chessprogramming.org/Fruit - Fruit 2.1
• https://nodejs.org/en - Node
• https://github.com/op12no2/foldit - Folding editor
• https://github.com/jw1912/bullet - bullet trainer
• https://github.com/Disservin/fastchess/releases - fastchess - for SPRTs