Unity UI Toolkit Skills
Use this module for Unity UI Toolkit only: UXML for structure, USS for styling, UIDocument for scene attachment, and PanelSettings for runtime rendering.
Requires Unity 2022.3+. Do not mix this module with ui_* UGUI/Canvas skills. Localization: Match visible UI text to the user's language. Chinese conversation -> Chinese labels/placeholders/button text. USS class names and CSS variables stay English.
Guardrails
Mode: Full-Auto required
DO NOT (common hallucinations):
uitoolkit_create_button / uitoolkit_create_label do not exist -> use uitk_add_elementuitoolkit_set_style does not exist -> use uitk_add_uss_rule, uitk_remove_uss_rule, or uitk_modify_elementuitoolkit_create_canvas does not exist -> UI Toolkit uses UIDocument, not Canvasuitk_* and ui_* are different systems. Do not mix UI Toolkit structure/styling assumptions into UGUI workflows- USS is not full CSS.
display:grid, box-shadow, calc(), @media, ::before, z-index, and gradients are unsupported
Routing:
- For UGUI Canvas/Button/Text/Image -> use the
ui module - For XR world-space Canvas conversion -> use
xr_setup_ui_canvas - For generated starter layouts -> use
uitk_create_from_template - For attaching an existing UXML to a scene object -> use
uitk_create_document or uitk_set_document
Skills
File Skills
| Skill | Use | Key parameters |
|---|
uitk_create_uss | Create USS file | savePath, content? |
uitk_create_uxml | Create UXML file | savePath, content?, ussPath? |
uitk_read_file | Read USS/UXML content | filePath |
uitk_write_file | Overwrite file content | filePath, content |
uitk_delete_file | Delete USS/UXML file | filePath |
uitk_find_files | Search files by name/path | type?, folder?, filter?, limit? |
uitk_create_batch | Create 2+ files in one call | items |
Scene Skills
| Skill | Use | Key parameters |
|---|
uitk_create_document | Create UIDocument GameObject | name, uxmlPath?, panelSettingsPath?, sortOrder?, parentName?/parentInstanceId?/parentPath? |
uitk_set_document | Change UIDocument asset bindings | name/instanceId, uxmlPath?, panelSettingsPath? |
uitk_create_panel_settings | Create PanelSettings asset | savePath, scaleMode, referenceResolutionX/Y, Unity 6 world-space options |
uitk_get_panel_settings | Read PanelSettings values | assetPath |
uitk_set_panel_settings | Update PanelSettings selectively | assetPath, changed fields only |
uitk_list_documents | List scene UIDocuments | none |
uitk_inspect_document | Inspect live VisualElement tree | name/instanceId/path, depth |
UXML Structure Skills
| Skill | Use | Key parameters |
|---|
uitk_add_element | Add a child element | filePath, elementType, parentName?, elementName?, text?, classes? |
uitk_remove_element | Remove by name | filePath, elementName |
uitk_modify_element | Change attributes/classes/text | filePath, elementName, text?, classes?, style?, newName?, bindingPath?, custom attribute fields |
uitk_clone_element | Duplicate an element subtree | filePath, elementName, newName? |
uitk_inspect_uxml | Parse UXML hierarchy | filePath, depth? |
USS Style Skills
| Skill | Use | Key parameters |
|---|
uitk_add_uss_rule | Add or replace selector rule | filePath, selector, properties |
uitk_remove_uss_rule | Remove selector rule | filePath, selector |
uitk_list_uss_variables | Inspect design tokens / var() usage | filePath |
Template and CodeGen Skills
| Skill | Use | Key parameters |
|---|
uitk_create_from_template | Generate paired UXML+USS | template, savePath, name? |
uitk_create_editor_window | Generate EditorWindow script | savePath, className, uxmlPath?, ussPath?, menuPath? |
uitk_create_runtime_ui | Generate runtime MonoBehaviour query scaffold | savePath, className, elementQueries? |
Supported starter templates include menu, hud, dialog, settings, inventory, list, tab-view, toolbar, card, and notification.
Core Domain Knowledge
USS vs CSS
| Pattern | Supported in USS | What to do |
|---|
| Flex layout | Yes | Use flex-direction, flex-wrap, align-items, justify-content |
border-radius, opacity, overflow:hidden | Yes | Safe to use |
| Transforms / transitions | Yes | translate, scale, rotate work |
| CSS variables | Yes | Prefer :root tokens |
display:grid / display:block / display:inline | No | Everything is flex; emulate grids with wrapping rows |
box-shadow | No | Fake with nested background element |
linear-gradient() / radial-gradient() | No | Use image textures |
calc() / @media | No | Use explicit values + PanelSettings.scaleMode |
::before / ::after | No | Add a real child VisualElement |
z-index | No | Later siblings render on top |
Common USS workarounds
| Need | USS-safe workaround |
|---|
| Shadow | Extra child VisualElement behind content |
| Responsive scaling | PanelSettings.scaleMode = ScaleWithScreenSize |
| Grid cards | flex-direction: row + flex-wrap: wrap + child widths |
| Circular avatar | Equal width/height + radius = half size + overflow:hidden |
| Pseudo decoration | Add an extra absolutely positioned child |
High-Frequency Parameters
| Skill | Parameters you usually need first |
|---|
uitk_create_panel_settings | savePath, scaleMode, referenceResolutionX, referenceResolutionY |
uitk_create_document | name, uxmlPath, panelSettingsPath, sortOrder? |
uitk_add_element | filePath, elementType, parentName?, elementName?, text?, classes? |
uitk_modify_element | filePath, elementName, changed attributes only |
uitk_add_uss_rule | filePath, selector, properties |
PanelSettings choices
ScaleWithScreenSize: default for runtime HUD/menu UIConstantPixelSize: use when strict pixel mapping mattersConstantPhysicalSize: rare; only for physically sized UI requirements
Unity 6 world-space flows also need the scene-side document camera setup after configuring PanelSettings.
File and Structure Rules
- Prefer one UXML root that references shared token/style files through
<Style src="..."/>. - Keep USS next to UXML when possible so relative style references stay short.
- Use
uitk_inspect_uxml before complex structural edits if you did not create the file yourself. uitk_create_uxml can auto-reference a stylesheet when ussPath is provided.
Workflow Notes
- Create USS/UXML first, then attach them through
uitk_create_document. - Runtime rendering needs a valid
PanelSettings asset. - When USS and UXML are in the same folder, prefer
<Style src="MyStyle.uss" />; use a full asset path only for cross-folder references. - Start with design tokens, then component rules, then layout containers.
- For incremental edits, prefer
uitk_read_file -> edit -> uitk_write_file. - When creating 2+ files, use
uitk_create_batch. - Unity 6 world-space rendering uses PanelSettings world-space options plus the scene-side
UIDocument camera setup. - Use
uitk_create_from_template when the user needs a starter screen fast; use uitk_add_element / uitk_add_uss_rule for targeted edits on existing files.
Minimal Example
import unity_skills
unity_skills.call_skill("uitk_create_panel_settings",
savePath="Assets/UI/GamePanel.asset",
scaleMode="ScaleWithScreenSize",
referenceResolutionX=1920,
referenceResolutionY=1080
)
unity_skills.call_skill("uitk_create_uss",
savePath="Assets/UI/HUD.uss",
content=":root { --accent: #E8632B; } .title { color: var(--accent); }"
)
unity_skills.call_skill("uitk_create_uxml",
savePath="Assets/UI/HUD.uxml",
content="<?xml version=\"1.0\" encoding=\"utf-8\"?><engine:UXML xmlns:engine=\"UnityEngine.UIElements\"><Style src=\"HUD.uss\" /><engine:Label class=\"title\" text=\"Start\" /></engine:UXML>"
)
unity_skills.call_skill("uitk_create_document",
name="HUD",
uxmlPath="Assets/UI/HUD.uxml",
panelSettingsPath="Assets/UI/GamePanel.asset"
)
Exact Signatures
Exact names, parameters, defaults, and returns are defined by GET /skills/schema or unity_skills.get_skill_schema(), not by this file. Load USS_REFERENCE.md before generating non-trivial USS systems, layout patterns, component styles, or complete examples.
