Boudica is a UCI chess engine written in C++, vibe-coded almost entirely by Claude Code as an experiment to see how strong an engine could get with minimal human oversight.
~2100-2170 ELO (CCRL-equivalent), estimated via gauntlet tournaments against engines of known strength using ordo and bayeselo.
make
Requires a C++17 compiler. Produces a boudica binary that speaks the UCI protocol.
Boudica can be used with any UCI-compatible chess GUI (Arena, CuteChess, etc.) or from the command line:
./boudica
uci
isready
position startpos
go movetime 5000