This project is pre-1.0 and moves fast. Only main receives fixes.

Please do not open a public issue for security problems.

Report privately via GitHub: Open a security advisory.

Include a description, reproduction steps, and the affected commit or version. You can expect an acknowledgement within a few days. There is no bug-bounty program.

This is a chess engine that reads UCI commands on stdin and an optional Polyglot opening-book file. Relevant concerns include malformed UCI / FEN input, crafted opening-book files, and the multiprocessing shared-memory transposition table. The bundled opening_book/bookfish.bin is third-party data — see opening_book/README.md.