chesstools

If you're looking for a feature-packed and reliable library for your chess application, look no further than chesstools. This powerful tool speaks proper FEN, SAN, and long algebraic notation, and supports both standard chess and chess 960 (Fischer-random) modes for added versatility.

In addition to basic move validation, chesstools also handles checkmate, stalemate, repetition, and 50-move-rule checking to ensure a fair and competitive game. And thanks to its server-side timekeeping, you can benefit from optional latency compensation to keep your game running smoothly.

But where chesstools really shines is in its AI framework. Based on a compact minimax approach, this library utilizes alpha-beta pruning and transposition tables under the hood, giving you the power to easily create a custom bot just by overriding the AI.evaluate feature.

And if that's not enough, chesstools.book provides an intuitive interface for building opening book databases, which can be used in conjunction with an AI to make even more sophisticated moves and strategies. So whether you're a beginner or an experienced developer, chesstools has everything you need to take your chess game to the next level.