wowplus2 / jchessify

Java chess engine framework.

Java chess engine framework

jChessify makes writing chess engines in Java fun.
It lets you focus on the high-level functionality whilst giving you unparalleled flexibility.

• minimax
• alpha-beta pruning
• opening book support

Basic Chess Engine

Board chessBoard = new Board();
chessBoard.loadFromFen("f/e/n");

Engine engine = new Engine(new PieceValueEvaluator());
engine.maxDepth = 2;
Move bestMove = engine.getBestMove(chessBoard);

Note: chess logic (Board, Move) is powered by bhlangonijr/chesslib

This example uses PieceValueEvaluator, an evaluator which evaluates player advantage through piece values.

Custom Evaluation

class CustomEvaluator implements Evaluator {
    // positive if advantage, negative if disadvantage
    public int evaluate(Board board){
        // random value between -100 and 100
        return new Random().nextInt(201) - 100;
    }
}

Engine engine = new Engine(new CustomEvaluator());

Opening Book

OpeningBook openingBook = new OpeningBook("path/to/book.txt");
String bestMoveSAN = openingBook.findNextMove("e4 e5"); //Nf3
chessBoard.doMove(bestMoveSAN);

Note: jChessify's OpeningBook uses a specific format. The default opening book provided should be enough.

Installation

You can install jChessify through Apache Maven. Add the following to your pom.xml:

<dependency>
  <groupId>io.github.colonelparrot</groupId>
  <artifactId>jchessify</artifactId>
  <version>1.0.2</version>
</dependency>

Installation instructions for Gradle and others can be found here.