Bunnymod XT (BXT for short) is a cross-platform tool that provides speedrunning and TAS-related features for GoldSource games such as Half-Life and its modifications.

Used by hundreds if not thousands of speedrunners worldwide.

Bunnymod XT provides state-of-the-art speedrunning and TASing features and utilities, ranging from detailed HUDs to advanced autostrafing. It is a successor to the obsoleted hlspbunny and Bunnymod Pro.

Despite the "mod" in Bunnymod XT, this is not a mod in the usual sense. Most Half-Life modifications work by modifying the Half-Life SDK and distributing the resulting DLLs. This includes the deprecated Bunnymod Pro. The downside is that while you can "mod" Half-Life itself, you cannot "mod" another Half-Life mod. This is a serious limitation for speedrunners intending to speedrun Half-Life mods and expansions.

To rectify this, Bunnymod XT injects into the Half-Life process while leaving every file on the disk intact. This means all modifications are done on-the-fly in RAM. This also means Bunnymod XT supports a wider range of Half-Life engines, from WON to the latest Steam.

The instructions are described here.

Use the Bunnymod XT Launcher.

On the Wiki pages.

• BXT_SCRIPT - if set to a filename of a hltas script, loads the non-shared RNG from that script on load.
• BXT_LOGFILE - if set, logs all Bunnymod XT messages into a file with that filename.
• SPTLIB_DEBUG - if set to 1, logs all dlopen, dlclose and dlsym calls.

Building on Windows requires

• Visual Studio 2019 or 2022
• Boost
• Rust
  • The i686-pc-windows-msvc target must be installed. You can do that using rustup target add i686-pc-windows-msvc.

Run the following commands, replacing path\to\boost\base\dir with path to the Boost base directory:

git clone https://github.com/YaLTeR/BunnymodXT
cd BunnymodXT
git submodule update --init --recursive
mkdir build
cd build
cmake -A Win32 -DBOOST_ROOT=path\to\boost\base\dir -Wno-dev ..

Then compile the ALL_BUILD project from the generated VS solution.

If you want to make a release build, you need to specify -DCMAKE_BUILD_TYPE=Release in the cmake command line arguments. This is needed because the Rust CMake module uses that variable to determine whether to build the crate in release or debug mode.

1. Set up Flathub by following the guide for your distribution.

2. Install GNOME Builder.

3. Open GNOME Builder.

4. Press the Clone Repository button, enter https://github.com/YaLTeR/BunnymodXT.git and press Clone Project. Wait until it finishes.

   The cloning window should close, and a new window with the BunnymodXT project should open.

5. If Builder prompts you to install missing SDKs, press Install and wait for the process to finish. It will take a while. You can monitor the progress by pressing the circle in the top-right.

6. Click on the bar at the top-center which says BunnymodXT, and click the Build button.

7. Once the build finishes, in the same bar menu click the Export Bundle button. The file manager will open in a path that looks like gnome-builder/projects/BunnymodXT/flatpak/staging/x86_64-master. Navigate up to the BunnymodXT folder, then down to builds/rs.bxt.BunnymodXT.json-... where you will find the built libBunnymodXT.so.

8. Now you can make some changes to the code and press Build, then grab libBunnymodXT.so from the same folder.

Building on Linux requires

• A recent GCC or Clang toolchain
• Boost
• Rust: either from your distribution's packages, or from rustup.
  • The i686-unknown-linux-gnu target must be installed. You can do that using rustup target add i686-unknown-linux-gnu.

Many of these dependencies can be installed from a package manager.

git clone https://github.com/YaLTeR/BunnymodXT
cd BunnymodXT
git submodule update --init --recursive
mkdir build
cd build
cmake -Wno-dev ..
make

Note that -DBOOST_ROOT is not required as CMake should be able to find its location in your system. In case it couldn't, you need to specify it manually like the case on Windows.