Pink KOS-MOS isn't Real, Pink KOS-MOS can't hurt you. (Xenosaga I Depack/Repack Kit)

jessiray · July 11, 2026, 5:20pm

Pink KOS-MOS:

Hi Friends!

I have been pretty busy the past few months learning a lot about agentic LLM coding environments and Python at my job. While I understand this is controversial (for good reasons and I have places were I use AI and others were I’d never use AI that I might talk about in another thread but not here) I am trying to at least apply what I am learning to good use while these tools are available to the general public (which I don’t feel will be forever). I feel like preservation is a valid use case and I am hoping to help set up pipelines for myself and others to begin doing that for Xenosaga and potentially other PS2 games.

With that air cleared out of the way, I present to y’all the beta of the Xenosaga I Python Depack/Repack kit!

This kit includes tools for unpacking content from the XSI disc, converting the file formats, and making very minor texture and text edits such as below:

The documentation is unfortunately pretty verbose because I did have claude code document itself as I went along not to miss anything. But it will be a lot of manual testing and revision from this point.

I hope that this pack enables the community to do cool translations and mods. Please let me know if you have any questions or trouble. I am sure there will be bugs. I’ll try and fix em as they come up.

Thanks everyone!

Edit: because it’s super wordy on the GitHub page tl;dr if you want to use the GUI you can click either the app (MacOS) or .exe file (Windows) that are hosted in the “dist” folder to open the compiled version of the application in your browser. That should make it easy if you are not super technically inclined to get up and running with the files.

I will manually clean up the guide over the next week or so. Thanks

Luxqaer · July 11, 2026, 5:24pm

It will be really cool if you can make KOS-MOS’s outfit pink too and make a pink KOS-MOS mod for Episode 2 & 3.

jessiray · September 25, 2026, 3:24am

Decided to finish the update I’ve been working on tonight. Several fixes to textures, though they’re still WIP.

But most importantly - We got audio! Music, SFX and dialog lines are now decoded.

Here’s a document that goes over how the music and audio was compiled for Episode I. I had no idea it was a streamed MIDI before going into this project.

github.com/LinuxJessi/Xenosaga1PythonExtractor

docs/MUSIC.md

main

# The music of Xenosaga Episode I — how it works, and what the disc told us

Xenosaga Episode I does not stream its music. The orchestral score by
Yasunori Mitsuda is *sequenced*: the disc carries note data (`.SMD`) and
instrument banks of sampled orchestra (`.SWD`), and a driver on the PS2's
sound processor plays them live, the way a MIDI file plays against a
SoundFont. This kit turns those files back into MIDI, SoundFont 2 and
rendered WAV/FLAC — and because Monolith shipped the driver with its
debug symbols intact, everything below is read from the game's own code,
not guessed.

```sh
python cli.py extract --iso GAME.iso --out OUTDIR         # once
python cli.py music-export --dump OUTDIR/dump --out OUTDIR/browse/music
python cli.py browse --out OUTDIR --kinds banks,battle_audio,audio
```

| Output | What it is |
|---|---|
| `browse/music/*.mid` | each sequence as a standard MIDI file (96 PPQN, tempo map, loop markers) |

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jessiray · October 14, 2026, 11:02pm

I released a rather large update today that should allow folks to extract the models:

The eyelashes and anime features on their faces are a seperate texture layer than everything else so it took a bit longer than it should have.

I am working on forking some of the work in this project: GitHub - poketony/XS1KOR: 제노사가 에피소드 I 한글패치 작업 공간입니다(Xenosaga Episode I Korean Translation) · GitHub to help expand the language/translation tools in this pack kit to be more flexible for unsupported character sets and for variable text size support. My hope is to help translation teams the world over get the game out there.