shadcn

shadcn/ui

A framework for building ui, components and design systems. Components are added as source code to the user's project via the CLI.

IMPORTANT: Run all CLI commands using the project's package runner: npx shadcn@latest, pnpm dlx shadcn@latest, or bunx --bun shadcn@latest — based on the project's packageManager. Examples below use npx shadcn@latest but substitute the correct runner for the project.

When to Use

• Use when adding new components from shadcn/ui or community registries.
• Use when styling, composing, or debugging existing shadcn/ui components.
• Use when initializing a new project or switching design system presets.
• Use to retrieve component documentation, examples, and API references.

Current Project Context

!`npx shadcn@latest info --json 2>/dev/null || echo '{"error": "No shadcn project found. Run shadcn init first."}'`

The JSON above contains the project config and installed components. Use npx shadcn@latest docs <component> to get documentation and example URLs for any component.

Principles

1. Use existing components first. Use npx shadcn@latest search to check registries before writing custom UI. Check community registries too.
2. Compose, don't reinvent. Settings page = Tabs + Card + form controls. Dashboard = Sidebar + Card + Chart + Table.
3. Use built-in variants before custom styles. variant="outline", size="sm", etc.
4. Use semantic colors. bg-primary, text-muted-foreground — never raw values like bg-blue-500.

Critical Rules

These rules are always enforced. Each links to a file with Incorrect/Correct code pairs.

Styling & Tailwind → [styling.md](./rules/styling.md)

• className for layout, not styling. Never override component colors or typography.
• **No space-x- or space-y-.** Use flex with gap-. For vertical stacks, flex flex-col gap-.
• **Use size-* when width and height are equal.** size-10 not w-10 h-10.
• Use truncate shorthand. Not overflow-hidden text-ellipsis whitespace-nowrap.
• No manual dark: color overrides. Use semantic tokens (bg-background, text-muted-foreground).
• Use cn() for conditional classes. Don't write manual template literal ternaries.
• No manual z-index on overlay components. Dialog, Sheet, Popover, etc. handle their own stacking.

Forms & Inputs → [forms.md](./rules/forms.md)

• Forms use FieldGroup + Field. Never use raw div with space-y- or grid gap- for form layout.
• InputGroup uses InputGroupInput/InputGroupTextarea. Never raw Input/Textarea inside InputGroup.
• Buttons inside inputs use InputGroup + InputGroupAddon.
• Option sets (2–7 choices) use ToggleGroup. Don't loop Button with manual active state.
• FieldSet + FieldLegend for grouping related checkboxes/radios. Don't use a div with a heading.
• Field validation uses data-invalid + aria-invalid. data-invalid on Field, aria-invalid on the control. For disabled: data-disabled on Field, disabled on the control.

Component Structure → [composition.md](./rules/composition.md)

• Items always inside their Group. SelectItem → SelectGroup. DropdownMenuItem → DropdownMenuGroup. CommandItem → CommandGroup.
• Use asChild (radix) or render (base) for custom triggers. Check base field from npx shadcn@latest info. → [base-vs-radix.md](./rules/base-vs-radix.md)
• Dialog, Sheet, and Drawer always need a Title. DialogTitle, SheetTitle, DrawerTitle required for accessibility. Use className="sr-only" if visually hidden.
• Use full Card composition. CardHeader/CardTitle/CardDescription/CardContent/CardFooter. Don't dump everything in CardContent.
• Button has no isPending/isLoading. Compose with Spinner + data-icon + disabled.
• TabsTrigger must be inside TabsList. Never render triggers directly in Tabs.
• Avatar always needs AvatarFallback. For when the image fails to load.

Use Components, Not Custom Markup → [composition.md](./rules/composition.md)

• Use existing components before custom markup. Check if a component exists before writing a styled div.
• Callouts use Alert. Don't build custom styled divs.
• Empty states use Empty. Don't build custom empty state markup.
• Toast via sonner. Use toast() from sonner.
• Use Separator instead of <hr> or <div className="border-t">.
• Use Skeleton for loading placeholders. No custom animate-pulse divs.
• Use Badge instead of custom styled spans.

Icons → [icons.md](./rules/icons.md)

• Icons in Button use data-icon. data-icon="inline-start" or data-icon="inline-end" on the icon.
• No sizing classes on icons inside components. Components handle icon sizing via CSS. No size-4 or w-4 h-4.
• Pass icons as objects, not string keys. icon={CheckIcon}, not a string lookup.

CLI

• Never decode or fetch preset codes manually. Pass them directly to npx shadcn@latest init --preset <code>.

Key Patterns

These are the most common patterns that differentiate correct shadcn/ui code. For edge cases, see the linked rule files above.

// Form layout: FieldGroup + Field, not div + Label.
<FieldGroup>
  <Field>
    <FieldLabel htmlFor="email">Email</FieldLabel>
    <Input id="email" />
  </Field>
</FieldGroup>

// Validation: data-invalid on Field, aria-invalid on the control.
<Field data-invalid>
  <FieldLabel>Email</FieldLabel>
  <Input aria-invalid />
  <FieldDescription>Invalid email.</FieldDescription>
</Field>

// Icons in buttons: data-icon, no sizing classes.
<Button>
  <SearchIcon data-icon="inline-start" />
  Search
</Button>

// Spacing: gap-*, not space-y-*.
<div className="flex flex-col gap-4">  // correct
<div className="space-y-4">           // wrong

// Equal dimensions: size-*, not w-* h-*.
<Avatar className="size-10">   // correct
<Avatar className="w-10 h-10"> // wrong

// Status colors: Badge variants or semantic tokens, not raw colors.
<Badge variant="secondary">+20.1%</Badge>    // correct
<span className="text-emerald-600">+20.1%</span> // wrong

Component Selection

| Need | Use | | -------------------------- | --------------------------------------------------------------------------------------------------- | | Button/action | Button with appropriate variant | | Form inputs | Input, Select, Combobox, Switch, Checkbox, RadioGroup, Textarea, InputOTP, Slider | | Toggle between 2–5 options | ToggleGroup + ToggleGroupItem | | Data display | Table, Card, Badge, Avatar | | Navigation | Sidebar, NavigationMenu, Breadcrumb, Tabs, Pagination | | Overlays | Dialog (modal), Sheet (side panel), Drawer (bottom sheet), AlertDialog (confirmation) | | Feedback | sonner (toast), Alert, Progress, Skeleton, Spinner | | Command palette | Command inside Dialog | | Charts | Chart (wraps Recharts) | | Layout | Card, Separator, Resizable, ScrollArea, Accordion, Collapsible | | Empty states | Empty | | Menus