Game client

The client is a C++ port of the original 0.97k main.exe, rebuilt through reverse engineering. It behaves like the original binary and, on top of that, includes everything the Main.dll injection used to do: windowed mode, resolutions, minimap, options menu, multiple languages and customs.

It runs on Windows and Linux, and the code is at EmanuelCatania/Mu-97k-Client-Source.

The DLL client is deprecated. Main.dll, InfoEncoder and ClientInfo.bmd are no longer used or distributed. If you are coming from that client, see Coming from the DLL client.

Each client version states in its Release which server version it works with. Always use the same version on both sides (for example, client 0.97.30 with server 0.97.30).

How the connection works

The server address and identity are compiled into the client, as in MU 5.2. There is no connection config file to distribute: each server builds its own client.

That is why the client Releases have no executables: a published executable would point to a server that is not yours.

1. Point the client at your server

Clone the repository and edit src/Config/ServerConfig.h:

git clone https://github.com/EmanuelCatania/Mu-97k-Client-Source.git
cd Mu-97k-Client-Source

constexpr char           ConnectServerIP[]   = "mu.your-domain.com";
constexpr unsigned short ConnectServerPort   = 44405;   // 0 = no ConnectServer
constexpr char           GameServerIP[]      = "mu.your-domain.com";
constexpr unsigned short GameServerPort      = 55901;
constexpr char           CustomerName[]      = "MuLinux";
constexpr char           ServerSerial[]      = "TbYehR2hFUPBKgZj";
constexpr char           ClientVersion[]     = "0.97.11";

The address can be an IP or a host name. A name is better: the server can move to a new IP without rebuilding the client. If the domain is on Cloudflare, the record must be unproxied (“DNS only”): the proxy only lets web traffic through and cuts the game connections.

The ports are the server’s: 44405 for the ConnectServer (the server list) and 55901 for the GameServer. With ConnectServerPort = 0 the client connects straight to the GameServer.

The identity must match the server’s MuServer/GameServer/DATA/GameServerInfo - StartUp.dat. If any of these values does not match, the client connects but never gets in, without a useful error:

If you did not change those values on the server, the example values already match the Docker server.

2. Build

The client is always 32-bit (x86), even on 64-bit Windows or Linux: the port reproduces the memory layouts of the original binary.

Windows

Requires Visual Studio 2022 with “Desktop development with C++” (includes CMake). Open mu97k.sln, pick Release and platform Win32, and build. Or from a terminal:

cmake -S . -B build -A Win32 -T v143
cmake --build build --config Release

The executable ends up in bin/Client/main.exe, next to the assets.

Linux

You need CMake 3.25+, Ninja, GCC with -m32 support and the 32-bit development libraries. The package list for Arch, Debian/Ubuntu and Fedora is in the client README.

# Arch. Debian/Ubuntu: /usr/lib/i386-linux-gnu/pkgconfig. Fedora: /usr/lib/pkgconfig
export PKG_CONFIG_LIBDIR=/usr/lib32/pkgconfig:/usr/share/pkgconfig

cmake --preset linux-x86-release
cmake --build --preset linux-x86-release

To build the package you distribute (main, Data, launch.sh and licenses):

python3 .github/scripts/package_linux.py build/linux-x86-release dist

It creates dist/mu97k-0.97.30-linux-x86.tar.gz.

Without installing compilers

If you don’t want to set up a build environment, you can use GitHub Actions: fork the repository, enable Actions on your fork, edit src/Config/ServerConfig.h from the GitHub website and wait for the workflow to finish. In the Actions tab you will find the Windows main.exe and the full Linux package (mu97k-linux-release) as artifacts.

3. Distribute

Windows: zip the bin/Client folder (main.exe, the Data folder and Config.ini). You don’t need to include main.map or debug.log.

Linux: distribute the .tar.gz from the previous step. Players extract it on a Linux partition (NTFS loses the execute permissions) and run ./launch.sh, without sudo. They need the 32-bit system libraries listed in the client README.

If the server address changes, you have to rebuild and redistribute the executable. If you used a host name, pointing the DNS to the new IP is enough.

Player options

Preferences are stored in Config.ini, with the same sections Main.dll used, so an existing Config.ini keeps working. Most of them can be changed from the in-game options menu.

• Windows: Config.ini next to main.exe.
• Linux: ~/.local/share/mu97k/Config.ini. The first start creates it in windowed mode at 1024×768.

Linux with NVIDIA GPUs

With NVIDIA, run the client on X11:

SDL_VIDEODRIVER=x11 ./launch.sh

NVIDIA does not ship the 32-bit Wayland EGL platform: without it Wayland falls back to software rendering (the client detects it and switches to X11 on its own), and with it Wayland works but is much slower than X11. With Intel and AMD, native Wayland works fine.

Coming from the DLL client

The Encoder tables you already had (CustomItem.txt, CustomGlow.txt, etc.) are still used, but they now live on the server.

Troubleshooting

The client connects but never gets in, or stays on “connecting”: check CustomerName, ServerSerial and ClientVersion against the server’s GameServerInfo - StartUp.dat. The client writes a debug.log (on Windows, in the client folder; on Linux, in ~/.local/share/mu97k/) with the address it used and the derived key:

ServerConfig: ConnectServer=mu.your-domain.com:44405 GameServer=mu.your-domain.com:55901 version='09711'
MuEmu: InitKeys CustomerName='MuLinux' Serial='TbYehR2hFUPBKgZj' -> EncDecKey1=0xC2 EncDecKey2=0x01

The server list does not show up: make sure port 44405/tcp is open and that the server’s PUBLIC_IP is the correct public IP. If the domain goes through Cloudflare, it must be “DNS only”.

Custom items look wrong or don’t show: client and server must be the same version, and the item models must be in the client’s Data folder.