SE Dev Game Code Skill

Allows reading the decompiled C# code of Space Engineers version 1.

⚠️ CRITICAL: Commands run in a UNIX shell (busybox), NOT Windows CMD. Use bash syntax!

Examples:

✅ test -f file.txt && echo exists
✅ ls -la | head -10
❌ if exist file.txt (echo exists) - This will NOT work

Actions:

prepare: Run the one-time preparation (Prepare.bat)
bash: Run UNIX shell commands via busybox
search: Run code searches using search_game_code.py
test: Test this skill by running test_search_game_code.bat

Routing Decision

Check these patterns in order - first match wins:

Priority	Pattern	Example	Route
1	Empty or bare invocation	`se-dev-game-code`	Show this help
2	Prepare keywords	`se-dev-game-code prepare`, `se-dev-game-code setup`, `se-dev-game-code init`	prepare
3	Bash/shell keywords	`se-dev-game-code bash`, `se-dev-game-code grep`, `se-dev-game-code cat`	bash
4	Search keywords	`se-dev-game-code search`, `se-dev-game-code find class`, `se-dev-game-code lookup`	search
5	Test keywords	`se-dev-game-code test`, `se-dev-game-code verify`, `se-dev-game-code check`	test

Requirements

The host system must have the following on PATH:

Python 3.13 or newer
git command line client (used to version each decompiled game build)
dotnet SDK (for installing ilspycmd)

Getting Started

⚠️ CRITICAL: Before running ANY commands, read CommandExecution.md to avoid common mistakes that cause command failures.

If the Prepare.DONE file is missing in this folder, you MUST run the one-time preparation steps first. See the prepare action.

Folder Layout

After preparation the skill folder contains a Data junction. The actual data lives outside the skill folder so that it is preserved across Clean.bat / Prepare.bat cycles.

skills/se-dev-game-code/
├── Data/                 (junction → %USERPROFILE%\.se-dev\game-code)
│   ├── .git/             local Git repository tracking decompiled sources
│   ├── .gitignore        ignores CodeIndex/, Content/, __pycache__, *.py[cod], *.bak, *.log
│   ├── game_version.txt  recorded SE_VERSION / CLIENT_BUILD_NUMBER / SERVER_BUILD_NUMBER
│   ├── Decompiled/       decompiled C# sources, organised per assembly (committed)
│   ├── Content/          textual game content (NOT committed - regenerated)
│   └── CodeIndex/        CSV indexes (NOT committed - regenerated)
├── Bin64/                (junction → game's Bin64, removed after preparation)
└── ...                   skill scripts and documentation

The Data folder is a junction to %USERPROFILE%\.se-dev\game-code\. (%USERPROFILE% is used rather than %LOCALAPPDATA% so the data sits outside any per-app UWP filesystem virtualization.) Treat Data/Decompiled, Data/Content and Data/CodeIndex exactly as before.

Local Versioning of Decompiled Sources

The Data folder is a local Git repository. Every successful preparation creates a commit of the decompiled C# sources whose message is the game's version label, e.g. 1.208.015 b4.

This means:

All previously decompiled game versions are preserved in the local Git history. You can git checkout any past commit inside Data/ to inspect or diff against an older build.
Game updates are detected automatically by comparing the binaries' embedded version constants with Data/game_version.txt. If they differ (or the file is missing), Decompiled/, Content/ and CodeIndex/ are wiped and a fresh decompilation runs.
This makes it easy to update plugins, mods and scripts for compatibility with new game releases: diff the relevant source between two commits inside Data/ to see exactly what changed.

The repository uses an internal author/email (se-dev-skills@localhost) so commits work even on machines without a configured global Git identity.

Essential Documentation

CommandExecution.md - ⚠️ READ THIS FIRST - How to run commands correctly on Windows

Code Search Documentation

QuickStart.md - More examples and quick reference
CodeSearch.md - Complete guide to searching classes, methods, fields, etc.
HierarchySearch.md - Finding class/interface inheritance and implementations
Advanced.md - Power user techniques for complex searches
Troubleshooting.md - What to do when searches return NO-MATCHES or too many results
Implementation.md - Technical details for skill contributors (optional)

Quick Search Examples

# Find class declarations
uv run search_game_code.py class declaration MyCubeBlock

# Find method signatures
uv run search_game_code.py method signature UpdateBeforeSimulation

# Find class hierarchy
uv run search_game_code.py class children MyTerminalBlock

# Count results before viewing (useful for large result sets)
uv run search_game_code.py class usage MyEntity --count

# Limit number of results
uv run search_game_code.py class usage MyEntity --limit 10

# Paginate through results
uv run search_game_code.py class usage MyEntity --limit 10 --offset 0
uv run search_game_code.py class usage MyEntity --limit 10 --offset 20

Always check the game code when:

You're unsure about the game's internal APIs and how to interface with them.
The inner workings of Space Engineers is unclear.

Custom Scripting

For building your own utility scripts to work with the indexes and decompiled code:

ScriptingGuide.md - How to write Python scripts, use BusyBox, handle Windows paths

Game Content Data

The textual part of the game's Content is copied into the Data/Content folder for free text search:

Language translations, including the string IDs
Block and other entity definitions
Default blueprints and scenarios
See ContentTypes.md for the full list of content types

Content Index

Data/CodeIndex/content_index.csv maps every textual content file to the decompiled C# source files that reference it. Columns: rel_path (path relative to Data/Content/) and usage (path of a C# source file in Data/Decompiled/ that references it). Each content file appears once per usage, so you can filter and page by rel_path to see all C# code that loads or references a given content file. Files with no known usages have a single row with an empty usage column.

General Rules

In the Data/Decompiled folder search only inside the C# source files (.cs) in general. If you work on transpiler or preloader patches, then also search in the IL code (.il) files.
In the Data/Content folder search the files appropriate for the task. See ContentTypes.md for the list of types.
Do not search for decompiled game code outside the Data/Decompiled folder. The decompiled game source tree must be there if the preparation succeeded.
Do not search for game content data outside the Data/Content folder. The copied game content must be there if the preparation succeeded.

Action References

Follow the detailed instructions in:

prepare action - One-time preparation
bash action - Running UNIX shell commands via busybox
search action - Running code searches
test action - Testing this skill

Remarks

The original source of this skill: https://github.com/viktor-ferenczi/se-dev-skills