gma (Garry's Mod Addon file) explorer
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SharpGMad is a tool used to manipulate Garry's Mod workshop addon packages (.gma files).

The program had been originally created as a straight reimplementation in C# of Garry Newman's GMad, but over time, it was given an extended set of functionality, most notably the graphical interface and realtime access.

(The current version implements and complies with a121a70.)


Realtime mode

This is the main feature and reason for SharpGMad's existence. While gmad can only fully pack a folder into an addon or fully extract an addon to a folder, with SharpGMad, you can effectively browse a file just as how you would be browsing any other archive (for example, ZIP, RAR or TAR files).

The realtime mode supports on-the-fly adding, removing and updating of files. Using the Export feature, a single file can be exported anywhere on your filesystem and edited with any appropriate editor. When you are done with the changes, a single click of a button will pull these changes into the archive.

Both a graphical and a command-line interface is available for realtime mode.


SharpGMad [path]

If the program is started with no command-line arguments (or only one, and that is a file path), a graphical interface will load. (You can also drag & drop a file in your file explorer onto SharpGMad's executable to open it automatically.)

Screenshot of the graphical interface


SharpGMad realtime

Starting SharpGMad with the realtime argument from the terminal loads its shell. If you are more savvy with using the terminal for quick operation, this mode is for you. Every operation possible in the graphical mode has a counterpart in the terminal (and vice-versa).

Type help in the shell to see a list of available commands.

Optionally, you can specifiy a file as an extra argument to have it loaded initally:

SharpGMad realtime -file "C:\steam\etc\garrysmod\addons\my_addon_12345.gma"

gmad mode

SharpGMad provides the legacy interface of gmad just in case a gmad binary is not at hand, so you can execute the "legacy" full-extract and full-create operations the same way you would with gmad. (Just type SharpGMad instead of gmad as the executable's name.)

As per gmad's manual:

Create new GMA file from a folder

SharpGMad create -folder "C:\path\to\addon\folder\" -out "C:\where\to\save\file\out.gma"

Extract an existing file

SharpGMad extract -file "C:\steam\etc\garrysmod\addons\my_addon_12345.gma" -out "C:\this\folder"

Conversion mode

The so-called loose addon structures used in Garry's Mod 12 (subfolders of the addons folder containing each and every file of the addon on the hard disk) are also supported for conversion.

SharpGMad will use an existing info.txt or addon.txtÿfile to load the metadata of the addon. Any missing metadata will be asked from the user.

When converting from a folder, SharpGMad auto-discovers whether it is an old structure or a "new", gmad-compatible structure.

When extracting a gma, you can specify -gmod12 as an extra argument of the extract command if you wish to extract to the old layout.

Corresponding options for back-and-forth conversion are available on the graphical interface, under the option Legacy operations.

Compiling and requirements

SharpGMad is written using the .NET 4.0 framework. This is the only requirement, you can compile the solution with any development environment on any computer compatible with .NET 4.0.

This usually means a computer with at least Windows XP Service Pack 3 installed.

Cross-platform operation with Mono is also supported, though in BETA. Mono has its hiccups (especially with the grahpical interface) here and there, but I try to do my best to test and iron everything out.

CAUTION! Most Linux distributions tend to install an old version of Mono (like 2.10) by default. Such old versions have compatibility issues. Please acquire a newer version, for example 3.2.5, as it and SharpGMad tend to be more compatible.


The program SharpGMad is provided "AS IS" without any expressed or implied warranties.

It is a general rule of thumb that you should NEVER start editing files you hadn't made backup of beforehand. The creators refuse to be held liable for any damange caused by the usage of this piece of software.