shadcn

What this skill does

# 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.

## Current Project Context

```json
!`npx shadcn@latest info --json`
```

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 preset codes or build preset URLs manually.** Use `npx shadcn@latest preset decode <code>`, `preset url <code>`, or `preset open <code>`. For project-aware preset detection, use `npx shadcn@latest preset resolve`.
- **Apply preset codes directly with the CLI.** Use `npx shadcn@latest apply <code>` for existing projects, or `npx shadcn@latest init --preset <code>` when initializing.

## Key Patterns

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

```tsx
// 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                      | `DropdownMenu`, `ContextMenu`, `Menubar`