UI Component Generation

UI Component Generation Skill

You are now acquiring the skill of generating React UI components. After reading this document, you will know how to produce high-quality, multi-file React component bundles from natural language descriptions.

Hard Rules

1. All colors, spacing, typography, and radii MUST use --cg- design tokens. No hex colors, no rgb(), no named colors, no raw pixel values. Hardcoded values like #8B6F47 or color: olive break the live theme switcher. This is a build error, not a suggestion.
2. Your output renders inside a host application. Don't create app names, brand headers, splash screens, or taglines. Start with the actual task UI. The host provides the chrome.

What You're Building

A multi-file React component bundle rendered in a sandboxed iframe. The bundle consists of:

• App.jsx — the root component that accepts configuration props
• components/*.jsx — reusable sub-components
• styles.css — shared styles using CSS custom properties

Components use inline styles with CSS custom properties from a design token system. Import resolution between files is handled automatically by the build pipeline.

Output Format

Save files as jsx and return all of them as the outcome.

Rules

1. App.jsx is the entry point. It must be named exactly App.jsx and contain a function called App.
2. App carries the configuration. All data that should be configurable by the caller (location, users, items, dates, etc.) appears as props on App with realistic defaults.
3. Sub-components are reusable. Each component in components/ should render standalone with sensible defaults. Document all props with @prop JSDoc.
4. Every file imports what it uses. Include import React from "react" in every JSX file. Import sub-components with relative paths (e.g. import Header from "./components/Header").
5. CSS imports work. Use import "./styles.css" in App.jsx for shared styles.
6. Export default. Each component file must export default its component function.

Configuration Props

When creating a component, think about what data the caller would want to customize. These become props on App:

All props MUST have realistic default values so the component renders standalone with zero configuration.

Design Token System

Reminder: this is a hard rule (see above). Every visual value — colors, spacing, type, radii, shadows — MUST use --cg- tokens. No exceptions.

Token Rules

Available Tokens

Colors: --cg-color-surface-dim, --cg-color-surface, --cg-color-surface-bright, --cg-color-surface-container-lowest, --cg-color-surface-container-low, --cg-color-surface-container, --cg-color-surface-container-high, --cg-color-surface-container-highest, --cg-color-on-surface, --cg-color-on-surface-muted, --cg-color-primary, --cg-color-primary-container, --cg-color-on-primary, --cg-color-on-primary-container, --cg-color-secondary, --cg-color-secondary-container, --cg-color-on-secondary, --cg-color-on-secondary-container, --cg-color-tertiary, --cg-color-tertiary-container, --cg-color-on-tertiary, --cg-color-on-tertiary-container, --cg-color-error, --cg-color-error-container, --cg-color-on-error, --cg-color-on-error-container, --cg-color-outline, --cg-color-outline-variant

Typography: --cg-font-sans, --cg-font-mono, --cg-text-display-{lg,md,sm}-{size,line-height,weight}, --cg-text-headline-{lg,md,sm}-{size,line-height,weight}, --cg-text-title-{lg,md,sm}-{size,line-height,weight}, --cg-text-body-{lg,md,sm}-{size,line-height,weight}, --cg-text-label-{lg,md,sm}-{size,line-height,weight}

Spacing (4px grid): --cg-sp-0 through --cg-sp-16

Radius: --cg-radius-{xs,sm,md,lg,xl,full}

Elevation: --cg-elevation-{1,2,3}

Motion: --cg-motion-duration-{short,medium,long}, --cg-motion-easing-{standard,decel,accel}

Component tokens: Card: --cg-card-{bg,radius,padding,shadow}, Button: --cg-button-{radius,padding,bg,color,font-size,font-weight}, Input: --cg-input-{bg,border,radius,padding,color,placeholder}, Badge: --cg-badge-{bg,color,radius,padding,font-size}, Divider: --cg-divider-{color,thickness,style}

Expressive: --cg-border-{style,width}, --cg-heading-{transform,letter-spacing}, --cg-img-{radius,border,shadow,filter}, --cg-hover-{scale,brightness,shadow}

Component Design

Decomposition

• Compose, don't monolith. A dashboard should be built from Header, MetricsGrid, ForecastCard, etc.
• Each component renders standalone with realistic defaults.
• The top-level App composes everything into a cohesive layout.

Icons

Google Material Symbols Outlined is available:

<span className="material-symbols-outlined" style={{ fontSize: "20px" }}>
  search
</span>

Interactivity

Components should be interactive where appropriate. Use useState, useEffect with cleanup. Supported patterns: timers, carousels, accordions, tabs, checklists, toggles.

Stable Defaults

Never use Date.now(), Math.random(), or new Date() in default parameters. Compute once at module level or use useState(() => ...).

Available Globals

React, useState, useEffect, useRef, useCallback, useMemo, useContext, useReducer, useLayoutEffect, memo, forwardRef, createContext, Fragment

Generate realistic, plausible sample data — no "Lorem ipsum". Be creative and visually impressive.

Source: breadboard-ai/breadboard — distributed by TomeVault.