name: propkit description: Guides creation and refinement of Figma-style property panel patterns ("PropKit") using FigUI3 components. Applies when building or modifying property fields in the playground app (/propkit route), generating consistent field prompts, composing horizontal fig-field rows, or tuning panel UX for controls like image, color, fill, slider, switch, dropdown, segmented control, easing, and angle. user-invocable: false

PropKit

Patterns for composing clean, production-ready Figma property panels with FigUI3.

IMPORTANT: Favor composition and consistency over custom one-off controls. Build panels from existing fig-* elements first.

Current Project Context

!`node -e "const fs=require('fs'); const ok=fs.existsSync('playground/src/main.tsx'); console.log(JSON.stringify({playground:ok, route:'/propkit', example:'horizontal fig-field + label + fig-* control'},null,2))" 2>/dev/null || echo '{"error":"context unavailable"}'`

Principles

1. Use horizontal property rows by default. PropKit fields are primarily fig-field direction="horizontal".
2. One clear label per control. Keep labels concise and aligned with Figma property language.
3. Prefer native FigUI3 controls. Use fig-input-fill, fig-slider, fig-dropdown, fig-switch, etc.
4. Use realistic panel widths and spacing. Match the property panel feel (~240px panel blocks in demos).
5. Keep prompts and examples deterministic. Prompt text should describe exact structure and key attributes.

React + Vite PropKit Usage

Include FigUI3 in React projects

• Import once in app bootstrap:
  • import "@rogieking/figui3/fig.css";
  • await import("@rogieking/figui3/fig.js");
• Register components before first React render to avoid undefined custom elements.
• Keep this setup in entry files (main.tsx / main.jsx), not scattered across feature components.

Vite setup and tree-shaking behavior

• Base Vite React config is sufficient in most cases:

import { defineConfig } from "vite";
import react from "@vitejs/plugin-react";

export default defineConfig({
  plugins: [react()],
});

• In production, FigUI3 side-effect registration can be tree-shaken if only imported for side effects.
• Preferred pattern (from webgpu-effects) is explicit async bootstrap:

import "@rogieking/figui3/fig.css";

const bootstrap = async () => {
  await import("@rogieking/figui3/fig.js");
  createRoot(document.getElementById("app")!).render(<App />);
};

bootstrap();

React composition conventions for PropKit rows

• Continue using canonical row shape in JSX:
  • <fig-field direction="horizontal"> + <label> + one primary fig-* control.
• For customized built-ins in React (<dialog is="fig-popup"> / <dialog is="fig-dialog">), use class, not className.
• Use refs and native event listeners (input, change) for reliable control updates.

Critical Rules

Field Composition

• Default pattern: label + single primary control inside one horizontal fig-field.
• Keep control-specific options on the component itself (not hidden wrapper logic).
• Use full where property controls should stretch within row constraints.
• Avoid mixing unrelated controls in a single field row unless intentionally grouped.

Prompt Generation Style

• Write prompts as imperative build instructions.
• Include field direction, control tag, and meaningful attrs.
• Prefer short explicit phrasing over vague prose.
• Keep wording consistent:
  • Use a horizontal fig-field...
  • With a label of ...
• Include concrete defaults when relevant (value, min/max, step, units, mode, variant) so generated fields are deterministic.
• Avoid placeholder-only prompts for numeric controls; always specify range semantics.

Control Guidance

• Image: prefer fig-image with upload, fit, and aspect-ratio where needed.
• Color: use fig-input-color with text="true" and optional alpha.
• Fill: use fig-input-fill for multi-mode fills; keep value JSON valid.
• Slider: choose proper type (range, opacity, hue, stepper, delta) and include units/transform intentionally.
• Dropdown: use fig-dropdown; include sensible default options.
• Boolean: use fig-switch; avoid using dropdowns for true/false.
• Discrete choices: use fig-segmented-control + fig-segment.
• Motion easing: use fig-easing-curve with/without presets depending on context.
• Angle: use fig-input-angle with text="true" for precision workflows.

Slider Types and Variants

• Default to type="range" for generic numeric properties (opacity %, size, spacing, intensity).
• Use type="opacity" when color context is needed (set color and usually units="%").
• Use type="hue" only for hue selection workflows.
• Use type="stepper" for discrete snap points (include a datalist with valid stops).
• Use type="delta" for offset/relative adjustments around a neutral point (typically include default, and often symmetric min/max).
• Prefer text="true" for precision-critical properties; omit it for compact/simplified rows.
• Use transform when internal value scale differs from UI display (example: internal 0..1, display 0..100%).
• Variants:
  • Default variant for most property panels.
  • variant="neue" for a compact, visually quieter style.
• Always set explicit min, max, and step (and units where applicable) to keep behavior predictable.

Control Selection Heuristics

• Use fig-slider for scrub-friendly continuous values (opacity, intensity, scale, blur amount).
• Use fig-input-number for precise direct entry (sizes, coordinates, exact typed values).
• Use slider + text (text="true") when users need both quick scrubbing and precise adjustment.
• Use fig-segmented-control for small discrete sets (2-5 fixed options).
• Use fig-dropdown for larger or less frequently switched option sets.
• Use fig-switch for binary state, never slider/dropdown for pure on/off.

UX Consistency

• Keep panel patterns visually consistent across sections.
• Preserve theme behavior (light/dark) and avoid non-token color overrides.
• Ensure labels and controls remain keyboard and screen-reader usable.

Key Patterns

<!-- Canonical PropKit row -->
<fig-field direction="horizontal">
  <label>Opacity</label>
  <fig-slider value="75" min="0" max="100" text="true" units="%" full></fig-slider>
</fig-field>

<!-- Non-horizontal (stacked/default column) field -->
<fig-field>
  <label>Opacity</label>
  <fig-slider value="75" min="0" max="100" text="true" units="%"></fig-slider>
</fig-field>

<!-- Fill + blend pair -->
<fig-field direction="horizontal">
  <label>Fill</label>
  <fig-input-fill value='{"type":"solid","color":"#667eea"}' experimental="modern"></fig-input-fill>
</fig-field>
<fig-field direction="horizontal">
  <label>Blend</label>
  <fig-dropdown full experimental="modern">
    <option selected>Normal</option>
    <option>Multiply</option>
  </fig-dropdown>
</fig-field>

Prompt pattern:
Use a horizontal fig-field, with a fig-slider, min=0 max=100 text=true units=%. With a label of Opacity.

<!-- Slider type/variant examples -->
<fig-field direction="horizontal">
  <label>Opacity</label>
  <fig-slider type="opacity" value="0.75" color="#0D99FF" units="%" text="true" full></fig-slider>
</fig-field>
<fig-field direction="horizontal">
  <label>Hue</label>
  <fig-slider type="hue" value="180" text="true" variant="neue" full></fig-slider>
</fig-field>
<fig-field direction="horizontal">
  <label>Offset</label>
  <fig-slider type="delta" value="0" default="0" min="-5" max="5" step="0.25" text="true" full></fig-slider>
</fig-field>

Workflow

1. Identify property intent. Determine if control is boolean, discrete choice, continuous numeric, color/fill, media, or motion.
2. Pick the canonical FigUI3 control. Avoid custom alternatives unless required.
3. Compose row structure. Use horizontal fig-field, then label + control.
4. Set defaults and attrs explicitly. Include values/ranges/units so behavior is deterministic.
5. Verify panel consistency. Check row spacing, width, and theme parity against existing PropKit sections.
6. Validate events and interactions. Ensure controls emit usable input/change and behave well in keyboard workflows.

Delivery Checklist

• Confirm prompts include all behavior-critical attrs (value, min, max, step, units, type, variant as needed).
• Confirm control choice matches intent (continuous vs discrete vs boolean vs exact numeric entry).
• Verify row density and panel width feel consistent with existing PropKit sections.
• Verify keyboard navigation and label association for every field row.
• Verify changes in playground/src/data/sections.ts still mirror recommended patterns in this skill.

Quick Reference

Common PropKit controls:
- fig-image
- fig-input-color
- fig-input-fill
- fig-slider
- fig-switch
- fig-dropdown
- fig-segmented-control
- fig-easing-curve
- fig-input-angle

Primary Files

• playground/src/data/sections.ts - canonical PropKit examples and prompt-copy behavior
• fig.js - control behavior and emitted events
• components.css - visual treatment and layout constraints
• README.md - component API details and usage