ui-imgui — Claude Code skill: Unity editor IMGUI code
Writes and edits legacy IMGUI code in Unity: EditorWindow classes, custom inspectors, PropertyDrawers and OnGUI scripts for the editor.
npx skills add Unity-Technologies/skills --skill ui-imgui -a claude-codeWhat ui-imgui does
The skill kicks in for existing IMGUI editor code or when you ask for immediate mode outright. Ask for a new editor window or inspector without naming OnGUI and it will point you to UI Toolkit with CreateGUI() instead of writing IMGUI. That is by design: IMGUI is treated as the legacy path here.
Once active, it loads two reference files. references/templates.md holds the starting templates for EditorWindow, Inspector and PropertyDrawer; references/gui-elements.md covers GUI elements, layout groups and styling. Expect guidance that follows the usual IMGUI discipline: cache GUIStyle objects rather than build them inside OnGUI, drive inspectors with SerializedProperty plus ApplyModifiedProperties(), keep every BeginHorizontal matched by an EndHorizontal. Any script touching the UnityEditor namespace has to sit in an Editor folder, or the build breaks.
Before writing, the skill searches your project for existing editor scripts and copies their naming and folder layout. Projects with their own conventions get code that fits rather than a generic template.
What it helps with
- extend an existing editor window with
OnGUI() - build a custom inspector that supports undo
- write a PropertyDrawer for a type or attribute
- clean up layout groups in an older tool window
- debug with an OnGUI overlay at runtime
Example prompts for the agent
- Add a settings tab to
LevelEditorWindow.csusingEditorGUILayout - Write an IMGUI inspector for the
Enemycomponent and bind fields throughSerializedProperty - Find where
OnGUI()allocates a newGUIStyleeach frame and remove it
How to install ui-imgui
1Skills CLI (Vercel)
npx skills add Unity-Technologies/skills --skill ui-imgui -a claude-code2Manually: put the files in place
~/.claude/skills/ui-imgui/SKILL.mdCopy the whole skill folder; for one project use .claude/skills/ui-imgui/
1Skills CLI (Vercel)
npx skills add Unity-Technologies/skills --skill ui-imgui -a codex2Manually: put the files in place
.agents/skills/ui-imgui/SKILL.mdFor all projects use ~/.agents/skills/
1Skills CLI (Vercel)
npx skills add Unity-Technologies/skills --skill ui-imgui -a cursor2Manually: put the files in place
.cursor/skills/ui-imgui/SKILL.mdCursor also reads .agents/skills/ and .claude/skills/
1GitHub CLI
gh skill install Unity-Technologies/skills ui-imgui2Manually: put the files in place
.github/skills/ui-imgui/SKILL.md1Skills CLI (Vercel)
npx skills add Unity-Technologies/skills --skill ui-imgui -a gemini-cli2Platform CLI
gemini skills install https://github.com/Unity-Technologies/skills --path skills/ui-imguiManually: put the files in place
.devin/skills/ui-imgui/SKILL.mdThe legacy .windsurf/skills/ path still works
Skills CLI (Vercel)
npx skills add Unity-Technologies/skills --skill ui-imgui -a opencodeClaude.ai
Zip the folder and upload it in Settings → Capabilities → Skills
Step by step, with commands for each platform: How to install skills in Claude Code: five ways
Questions about ui-imgui
How do I install ui-imgui in Claude Code?
Run npx skills add Unity-Technologies/skills --skill ui-imgui -a claude-code. The skill file then lands at ~/.claude/skills/ui-imgui/SKILL.md.
What does ui-imgui do?
It generates and edits Unity editor code in immediate mode: EditorWindow windows, Editor custom inspectors, PropertyDrawer classes and OnGUI() inside a MonoBehaviour. Two reference files supply templates and GUI elements.
Does it cover new editor windows, or should I use UI Toolkit?
For brand-new windows, inspectors and PropertyDrawers the skill itself recommends UI Toolkit with CreateGUI(). It proceeds with IMGUI when you ask for it directly, when you are editing code that already exists, or when the whole toolset is IMGUI.
