sunfish.js

JavaScript port of Sunfish Python Chess Engine

Example for node:

const sunfish = require('./sunfish.js');

function runCMD(cmd)
{
    sunfish.engine(cmd, (output) => console.log(output));
}

runCMD('uci');
runCMD('isready');
runCMD('position startpos moves e2e4');
runCMD('go depth 4');

Example for browser ran in web worker:

const sunfish = {engine: new Worker('./sunfish.js')};

function runCMD(cmd)
{
    sunfish.engine.postMessage(cmd);
}
sunfish.engine.onmessage = function(evt) {
    console.log(evt && evt.data ? evt.data : evt);
};

runCMD('uci');
runCMD('isready');
runCMD('position startpos moves e2e4');
runCMD('go depth 4');

Output:

id name sunfish 2023
uciok
readyok
bestmove e7e5

NNUE example for node:

• Transform the NNUE model pickle from sunfish repo to JSON using the nnue/nnue-pickle-to-json.py tool (here tanh.pickle NNUE model is used).

const sunfish_nnue = require('./sunfish_nnue.js');

// NNUE json model
sunfish_nnue.nnue(JSON.parse(require('fs').readFileSync(require('path').join(__dirname, './nnue/models/tanh.json'))));

function runCMD(cmd)
{
    sunfish_nnue.engine(cmd, (output) => console.log(output));
}

runCMD('uci');
runCMD('isready');
runCMD('position startpos moves e2e4');
runCMD('go depth 4 wtime 10000 btime 10000');

Output:

id name sunfish nnue
uciok
readyok
bestmove d7d5

NNUE example for browser ran in web worker:

• Transform the NNUE model pickle from sunfish repo to JSON using the nnue/nnue-pickle-to-json.py tool (here tanh.pickle NNUE model is used).

const sunfish_nnue = {engine: new Worker('./sunfish_nnue.js')};
const NNUE_JSON = {/*..*/}; // JSON of NNUE model

function loadNNUE(nnue_json)
{
    // string form of JSON needs to be sent
    sunfish_nnue.engine.postMessage({nnue:"string" === typeof nnue_json ? nnue_json : JSON.stringify(nnue_json)});
}
function runCMD(cmd)
{
    sunfish_nnue.engine.postMessage(cmd);
}
sunfish_nnue.engine.onmessage = function(evt) {
    console.log(evt && evt.data ? evt.data : evt);
};

loadNNUE(NNUE_JSON);
runCMD('uci');
runCMD('isready');
runCMD('position startpos moves e2e4');
runCMD('go depth 4');

Output:

nnueok
id name sunfish nnue
uciok
readyok
bestmove d7d5