What is the KGL file format?
A .kgl file is a compiled library for the KAGSA programming language, an interpreted language built on Python and released under the MIT license. Developers write Kagsa code in .kg source files and package reusable functions into a .kgl library so other programs can call them.
Under the hood a .kgl file is a .zip archive that has been given a different extension. It always contains at least two Python files: main.py, the compiled entry point, and __memory__.py, which holds the library's stored namespace data. Any extra helper modules are packed in alongside them. Because the container is standard ZIP, the file starts with the familiar PK signature.
Security & safety
RISK: MEDIUMA .kgl is a ZIP archive containing executable Python code that the Kagsa interpreter runs when the library is imported. Extracting the archive is safe, but importing or running a library from an untrusted source executes its code, so only use .kgl files you trust.
Format details
in a nutshellFULL NAMEKagsa Libraryaka Kagsa compiled library, KAGSA library archive
DEVELOPERKagsa (KAGSA project)since 2022
CATEGORYDeveloper Files
MIME TYPEapplication/zip
TYPECompiled library archive (ZIP container)
This extension is also used by…
- kglab / kgl (Python graph library) - The 'kgl' name is also used by DerwenAI's kglab knowledge-graph package, but it does not define a .kgl file type.
- kgl.exe (generic executable) - Various unrelated Windows programs ship an executable named kgl.exe; unrelated to the Kagsa library format.
MAGIC BYTES · FILE SIGNATURE
OFFSET
00010203
HEX
504B0304
ASCII
PK··
A .kgl file is a renamed ZIP archive, so it carries the standard ZIP local-file-header signature PK\x03\x04. Empty or spanned archives use PK\x05\x06 or PK\x07\x08.
Programs that open KGL files
Windows3 apps
WinRAR
Paid Point WinRAR at the file (rename to .zip if needed) to browse and unpack the ZIP contents of the library. 
7-Zip
Open-source Open the .kgl directly or rename a copy to .zip, then extract main.py and __memory__.py to read the packaged Python code. 
Kagsa
Open-source Install Kagsa, then import the library from a .kg program or inspect it with the interpreter; this is the native tool for running .kgl code. 
macOS2 apps
The Unarchiver
Free Rename a copy to .zip and open it to extract the bundled .py files for inspection.
Kagsa
Open-source Install via pip install kagsa and use the interpreter to import and run the library in your Kagsa project. 
Linux2 apps
unzip
Open-source Run unzip lib.kgl (or copy to lib.zip first) to list and extract main.py and __memory__.py.
Kagsa
Open-source Install with pip install kagsa or the official Linux installer, then reference the library from a .kg source file. 
Android1 app
Kagsa on Termux
Open-source Install Kagsa inside Termux and run or import the library from the command line on Android. Technical details
deep spec| Encoding | Binary (ZIP archive) |
| Byte order | Little-endian (ZIP fields) |
| Container | ZIP archive with the .kgl extension instead of .zip |
| Compression | Standard ZIP compression (DEFLATE or stored), inherited from the ZIP container |
| Encryption | None by default; a KGL is a plain archive with no built-in encryption |
| Typical size | A few kilobytes to a few hundred kilobytes, depending on the amount of compiled code |
| Structure | A ZIP archive holding the Python files produced when a Kagsa source library is compiled. It always contains main.py (the compiled library entry point) and __memory__.py (the library's stored state/namespace data), plus any additional helper .py files. |
| Integrity | CRC-32 per entry, provided by the ZIP format |
| Platforms | Windows, Linux, Termux (Android), macOS |
| Notes | Generated by the Kagsa interpreter with the command kagsa -l lib.kg -o lib.kgl. The input must be a .kg source file and the output name must end in .kgl. Because it is just a renamed ZIP, renaming a copy to .zip lets any archiver inspect the contents. |
| Produced By | kagsa command-line interpreter |
| Consumed By | Kagsa runtime when a .kg program imports the library |
| Released | 2022 |
| Latest version | Kagsa 1.2.0 (2023) |
| Specification | www.kagsa.org |
KGL conversions
Not possible
Community Q&A
asked by usersNo questions yet - be the first to ask about KGL files.
Frequently asked questions
What is a .kgl file?
It is a compiled library for the KAGSA programming language. It packages Python files (main.py and __memory__.py) into a ZIP archive so a Kagsa program can call the library's functions.
How do I open a .kgl file?
Install the free Kagsa interpreter to use it in a project, or rename a copy to .zip and open it with 7-Zip, WinRAR or unzip to see the .py files inside.
How do I create a .kgl library?
Compile a Kagsa source file with the command kagsa -l lib.kg -o lib.kgl. The input must end in .kg and the output must end in .kgl.
Is a .kgl file just a ZIP file?
Yes. It uses standard ZIP compression and the PK signature; only the extension differs. That is why archivers can open it after you rename it to .zip.
What is inside a .kgl file?
At minimum main.py, the compiled library entry point, and __memory__.py, which holds the library's stored namespace data, plus any additional helper Python files.
Can I convert a .kgl back to Kagsa source?
No. The archive stores compiled Python, not the original .kg source, so there is no way to recover the readable Kagsa code from it.
References
1KAGSA on GitHubgithub.com
2KAGSA official documentationwww.kagsa.org
