Chess Opening Info

General chess opening dataset, made to be easily used with JavaScript applications.

Also presents an SQLite3 API to interact with the dataset.

The original dataset is due to https://github.com/niklasf/chess-openings. (TSV Format)

codes.json contains FEN : {...otherInfo} and can be used like so:

const getInfo = (FEN) => require("codes.json")[FEN];

For Typescript, set "resolveJsonModule": true in your tsconfig.json, and you can simply import the JSON file

Note: Object[key] lookup (even from JSON) in extremely fast in JavaScript, so if your only requirement is getting ECO Code and Name from an FEN, you should probably just use this, and not bother with the SQLite API.

openings.sqlite contains an SQLite3 table

CREATE TABLE openings (FEN PRIMARY KEY TEXT, ECO TEXT, NAME TEXT, MOVES TEXT);

and openings.js exposes a better-sqlite3 API to access this database.

openings.js depends on the popular chess.js, which you probably already use if you need this repo.

Usage

For npm:

npm i chess-opening-info

For yarn:

yarn add chess-opening-info

Then in your project,

const { Openings } = require("chess-opening-info");

or with import,

import { Openings } from "chess-opening-info";

API

const op = new Openings("./data/openings.sqlite");
/*
    Note that all FENs are stored without the last two fields (the ply information),
    but the query looks for an instring, so both FENs with and without the ply information
    will work.
*/

console.log(
    op.findEcoAndNameOfFen(
        "rn1qkbnr/ppp2ppp/8/3p4/8/6PB/PPPPP3/RNBQ1RK1 b kq - 0 6"
    )
);
// Will give { eco: 'A00', name: 'Amar Opening: Gent Gambit' }

console.log(
    op.findEcoAndNameOfFen(
        "rn1qkbnr/ppp2ppp/8/3p4/8/6PB/PPPPP3/RNBQ1RK1 b kq -"
    )
);
// Will give { eco: 'A00', name: 'Amar Opening: Gent Gambit' }

/*
    returns FEN and Moves in Smith Notation (often used in chess programming)
    Smith notation is as follows: startSquareEndSquare. e.g 1.e4 is e2e4 and 5. O-O is e1g1 
    Note that there is no space after the last field in FENs.
*/
console.log(op.findFenAndMovesOfName("Nimzowitsch Defense: Wheeler Gambit"));

/* output
    {
        fen: 'r1bqkbnr/pppppppp/2n5/8/1P2P3/8/P1PP1PPP/RNBQKBNR b KQkq -',
        moves: 'e2e4 b8c6 b2b4'
    }
*/

// option `algebraic` is false by default, setting it to
// true converts the movelist to Standard Algebraic Notation
console.log(op.findFenAndMovesOfName("London System", { algebraic: true }));
/* output
    {
        fen: 'rnbqkb1r/pppppp1p/5np1/8/3P1B2/5N2/PPP1PPPP/RN1QKB1R b KQkq -',
        moves: '1. d4 Nf6 2. Nf3 g6 3. Bf4'
    }
*/

// you can also use the standalone conversion function if you wish
console.log(op.convertToAlgebraic("e2e4 e7e5"));
// gives 1. e4 e5
// It can convert any other format to SAN too, so if you are using ICCF notation
// you can just as well pass it to this function, to get back the SAN.

sample.js contains the JSDoc comments.

openings.json is simply the SQLite3 table exported to JSON format.