Building from source

You need your own copy of Yo-kai Watch 4++ with the 2.2.0 update, the last one. The build checks it and stops on any other version.

Nothing from the game is in the project. The build reads your files and makes the PC version on your own computer; none of it is ever shared.

1. Get the code.

   git clone https://github.com/ILFforever/YW4Recomp
   cd YW4Recomp

2. Make your config. Copy config.example.toml to config.local.toml and fill in your folders: exefs_dir and romfs_dir for extracted files, or base_nsp, update_nsp, hactool_exe and keys_dir for NSP or XCI files (then run python -m tools.yw4.extract once). dlc_dir is your DLC folder, if you have it.
3. Check it. python tools/yw4/config.py prints your folders, or says what is missing.

Keep work_dir out of OneDrive, Dropbox and other synced folders: the build writes thousands of files there.

Easiest: the launcher takes your files and does every step below for you. To build it yourself:

1. Install the tools. Python 3.11+, Git, llvm-mingw (Clang 19 or newer) and the Vulkan SDK (for glslangValidator). In your config, set [tools] cc to llvm-mingw's clang.exe.
2. Build. In PowerShell, from the project folder:

   python -m tools.yw4.ingest
   python -m recomp.translate
   python -m tools.yw4.shaders
   python -m recomp.shader --check
   python -m recomp.build --run

SDL3 comes with the build. AMD FSR, NVIDIA DLSS and Streamline are downloaded once (about 550 MB); --no-fsr and --no-dlss leave them out.

1. Install the tools from your distribution: Clang 19 or newer (or GCC 15 or newer), Python 3.11+, Git, pkg-config, glslang and SDL3 with its headers. For example:

   # Arch
   sudo pacman -S clang python git pkgconf glslang sdl3
   # Fedora
   sudo dnf install clang python3 git pkgconf glslang SDL3-devel
   # Debian 13, Ubuntu 25.04 or newer
   sudo apt install clang python3 git pkg-config glslang-tools libsdl3-dev

   Set [tools] cc = "clang" in your config (the default is gcc).
2. Build, from the project folder:

   python3 -m tools.yw4.ingest
   python3 -m recomp.translate
   python3 -m tools.yw4.shaders
   python3 -m recomp.shader --check
   python3 -m recomp.build --run

Ubuntu 24.04 has no SDL3 package and an older Clang: install clang-19, build SDL3 with CMake into a folder of your own, and build and run with PKG_CONFIG_PATH=<folder>/lib/pkgconfig and LD_LIBRARY_PATH=<folder>/lib.

After the first build, start the game on its own, with no Python and nothing else to type:

./work/build/yw4          # Linux
.\work\build\yw4.exe      # Windows

• The build wrote your game and DLC folders into work/build/game.ini, which the game reads when it starts with no arguments. Rebuilding updates it.
• Saves go to your user folder: ~/.local/share/YW4Recomp/save on Linux, %APPDATA%\YW4 Recomp\save on Windows.
• After pulling new code, run python -m recomp.translate and python -m recomp.build again.