The chess engine in Mislisha

Mislisha analyses positions with Stockfish 19, a chess engine written by the Stockfish developers and released under the GNU General Public License, version 3.

Stockfish is a separate program. Mislisha starts it and exchanges positions and moves with it as text, in the UCI protocol that chess programs and engines share. It is not a part of Mislisha, and Mislisha is not built from it. You may use, study, change and share Stockfish under its licence. It comes with no warranty.

Where the engine comes from

Android. The engine is included with the app, as a program of its own. It is built from the unmodified source code of Stockfish 19 with the build file below.
Windows. The app does not include an engine. When you ask for one, it downloads the official Stockfish 19 build from the Stockfish project's own release page, and you can point it at any other engine instead. Without one, evaluations come from online services.

Source code

The source code: Stockfish at the tag sf_19, unmodified. Its authors are listed in AUTHORS.
The build file used for Android: CMakeLists.txt. It is run with the Android NDK's CMake toolchain and -std=c++17, once for each processor type the app is built for.
The neural network the build embeds: nn-1a298aa575a0.nnue, downloaded from Stockfish's own server. Its SHA-256 is 1a298aa575a085434d29027978dc36867fe9c5bcea9376654b7a8eba1e52dfc2.
The official build the Windows app downloads: the Stockfish 19 release.

If any of these addresses stops working, write to us and we will send you the complete source code.

The human-like opponent

The opponent that plays like a person of a chosen rating is played by lc0 (Leela Chess Zero) v0.32.1, a chess engine released under the GNU General Public License, version 3, with the Maia weights of the CSSLab/maia-chess project, also released under the GNU General Public License, version 3. Neither comes with a warranty.

Both are separate from Mislisha, and nothing of either is built into it. Mislisha's own code does not include them. On Windows, when you ask for the opponent, it downloads the program from the lc0 project's own release page and the nine weights files from the Maia repository at the commit named below, checks each file against a checksum it was written with, and starts the program as it starts Stockfish, exchanging positions and moves with it as text in the UCI protocol. It sends the program the moves of the game; the program answers with how likely each legal move is.

On Android the program comes with the app, as a program of its own that the app starts the same way; only the weights are downloaded. We built it ourselves from the unmodified source code of lc0 at the tag below, with the Eigen linear-algebra library instead of a BLAS library, the Android NDK r27 and the build script engine-lc0-build.ps1, once for each processor type the app is built for. No network is built into it.

The source code of the program: lc0 at the tag v0.32.1, unmodified.
The build script used for Android: engine-lc0-build.ps1, which builds the three programs of the app from the tag above.
The official build the Windows app downloads: the lc0 v0.32.1 release, the file lc0-v0.32.1-windows-cpu-dnnl.zip. Its SHA-256 is b9cfcfbd3dabffbfd452f6e8e087c22273721bef48eba19640b6d92006c142f5.
The weights: maia-chess at the commit 749204cf5979ce7f8b0412e804a4ee7c83c49ff8, the files maia-1100.pb.gz to maia-1900.pb.gz, unmodified.
The licences: lc0's COPYING and maia-chess's LICENSE.

If any of these addresses stops working, write to us and we will send you the complete source code.

The licence

The full text of the licence travels with the app: in its settings, under ABOUT, open Open-source licences and choose stockfish, lc0 or maia.