BenBot

A UCI chess engine.

This is a command-line chess playing program, designed to be used with a chess GUI.

Strength

We are currently using a handcrafted evaluation, and our search function is still in its early days. The engine's ELO is approximately 1700-1800.

Repository layout

• Board representation and move generation is in libchess/
• Evaluation and search is in libbenbot/
• ben-bot/ is the actual engine executable

See each subdirectory's readme for details.

Links

• Lichess profile
• Documentation
• CDash dashboard
• Latest release

Building

Building or using ben-bot, libbenbot or libchess requires CMake and C++23.

All dependencies are fetched via FetchContent, so everything should "just work" out of the box.

CMake presets are provided for IDE integration, but are not mandatory.

Notes on building:

• If using gcc, at least version 14 is required
• Clang on Linux may need the -stdlib=libc++ flag in order to find std::expected. This flag is added by the clang configure preset.

Our automated CI & releases include the following builds:

OS	Compiler
Ubuntu	Clang
Ubuntu	GCC
Windows	Clang
Windows	MSVC
MacOS	Clang

CMake options

• BENBOT_DOCS: controls whether docs are built (defaults to off unless this is the top-level project)
• BENBOT_TESTS: controls whether tests are built (defaults to off unless this is the top-level project)

Thanks

Special thanks to the following open source chess projects, which have provided guidance and inspiration (in no particular order):

• Stockfish
• Ethereal
• Stormphrax
• Coding Adventure Chess Bot