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

!`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

• Use existing components first. Use npx shadcn@latest search to check registries before writing custom UI. Check community registries too.

• Compose, don't reinvent. Settings page = Tabs + Card + form controls. Dashboard = Sidebar + Card + Chart + Table.

• Use built-in variants before custom styles. variant="outline", size="sm", etc.

• 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

• **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

• **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

• 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

• 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

• 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

• **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.

// 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

Key Fields

The injected project context contains these key fields:

• **aliases** → use the actual alias prefix for imports (e.g. @/, ~/), never hardcode.

• **isRSC** → when true, components using useState, useEffect, event handlers, or browser APIs need "use client" at the top of the file. Always reference this field when advising on the directive.

• **tailwindVersion** → "v4" uses @theme inline blocks; "v3" uses tailwind.config.js.

• **tailwindCssFile** → the global CSS file where custom CSS variables are defined. Always edit this file, never create a new one.

• **style** → component visual treatment (e.g. nova, vega).

• **base** → primitive library (radix or base). Affects component APIs and available props.

• **iconLibrary** → determines icon imports. Use lucide-react for lucide, @tabler/icons-react for tabler, etc. Never assume lucide-react.

• **resolvedPaths** → exact file-system destinations for components, utils, hooks, etc.

• **framework** → routing and file conventions (e.g. Next.js App Router vs Vite SPA).

• **packageManager** → use this for any non-shadcn dependency installs (e.g. pnpm add date-fns vs npm install date-fns).

• **preset** → resolved preset code and values for the current project. Use npx shadcn@latest preset resolve --json when you only need preset information.

See cli.md — info command for the full field reference.

Component Docs, Examples, and Usage

Run npx shadcn@latest docs <component> to get the URLs for a component's documentation, examples, and API reference. Fetch these URLs to get the actual content.

npx shadcn@latest docs button dialog select

**When creating, fixing, debugging, or using a component, always run npx shadcn@latest docs and fetch the URLs first.** This ensures you're working with the correct API and usage patterns rather than guessing.

Workflow

• Get project context — already injected above. Run npx shadcn@latest info again if you need to refresh.

• Check installed components first — before running add, always check the components list from project context or list the resolvedPaths.ui directory. Don't import components that haven't been added, and don't re-add ones already installed.

• Find components — npx shadcn@latest search.

• Get docs and examples — run npx shadcn@latest docs <component> to get URLs, then fetch them. Use npx shadcn@latest view to browse registry items you haven't installed. To preview changes to installed components, use npx shadcn@latest add --diff.

• Install or update — npx shadcn@latest add. When updating existing components, use --dry-run and --diff to preview changes first (see [Updating Components](#updating-components) below).

• Fix imports in third-party components — After adding components from community registries (e.g. @bundui, @magicui), check the added non-UI files for hardcoded import paths like @/components/ui/.... These won't match the project's actual aliases. Use npx shadcn@latest info to get the correct ui alias (e.g. @workspace/ui/components) and rewrite the imports accordingly. The CLI rewrites imports for its own UI files, but third-party registry components may use default paths that don't match the project.

• Review added components — After adding a component or block from any registry, always read the added files and verify they are correct. Check for missing sub-components (e.g. SelectItem without SelectGroup), missing imports, incorrect composition, or violations of the [Critical Rules](#critical-rules). Also replace any icon imports with the project's iconLibrary from the project context (e.g. if the registry item uses lucide-react but the project uses hugeicons, swap the imports and icon names accordingly). Fix all issues before moving on.

• Registry must be explicit — When the user asks to add a block or component, do not guess the registry. If no registry is specified (e.g. user says "add a login block" without specifying @shadcn, @tailark, etc.), ask which registry to use. Never default to a registry on behalf of the user.

• Switching presets — Ask the user first: overwrite, partial, merge, or skip?

• Inspect current preset: npx shadcn@latest preset resolve. Use --json when you need structured values.

• Inspect incoming preset: npx shadcn@latest preset decode <code>. Use preset url <code> or preset open <code> to share or open the preset builder.

• Overwrite: npx shadcn@latest apply <code>. Overwrites detected components, fonts, and CSS variables.

• Partial: npx shadcn@latest apply <code> --only theme,font. Updates only the selected preset parts without reinstalling UI components. Supported values are theme and font; comma-separated combinations are allowed. icon is intentionally not supported, because icon changes may require full component reinstall and transforms.

• Merge: npx shadcn@latest init --preset <code> --force --no-reinstall, then run npx shadcn@latest info to list installed components, then for each installed component use --dry-run and --diff to [smart merge](#updating-components) it individually.

• Skip: npx shadcn@latest init --preset <code> --force --no-reinstall. Only updates config and CSS, leaves components as-is.

• Important: Always run preset commands inside the user's project directory. apply only works in an existing project with a components.json file. The CLI automatically preserves the current base (base vs radix) from components.json. If you must use a scratch/temp directory (e.g. for --dry-run comparisons), pass --base <current-base> explicitly — preset codes do not encode the base.

Updating Components

When the user asks to update a component from upstream while keeping their local changes, use --dry-run and --diff to intelligently merge. NEVER fetch raw files from GitHub manually — always use the CLI.

• Run npx shadcn@latest add <component> --dry-run to see all files that would be affected.

• For each file, run npx shadcn@latest add <component> --diff <file> to see what changed upstream vs local.

• Decide per file based on the diff:

• No local changes → safe to overwrite.

• Has local changes → read the local file, analyze the diff, and apply upstream updates while preserving local modifications.

• User says "just update everything" → use --overwrite, but confirm first.

• **Never use --overwrite without the user's explicit approval.**

Quick Reference

# Create a new project.

npx shadcn@latest init --name my-app --preset base-nova

npx shadcn@latest init --name my-app --preset a2r6bw --template vite

# Create a monorepo project.

npx shadcn@latest init --name my-app --preset base-nova --monorepo

npx shadcn@latest init --name my-app --preset base-nova --template next --monorepo

# Initialize existing project.

npx shadcn@latest init --preset base-nova

npx shadcn@latest init --defaults  # shortcut: --template=next --preset=nova (base style implied)

# Apply a preset to an existing project.

npx shadcn@latest apply a2r6bw

npx shadcn@latest apply a2r6bw --only theme

npx shadcn@latest apply a2r6bw --only font

npx shadcn@latest apply a2r6bw --only theme,font

# Inspect preset codes and project preset state.

npx shadcn@latest preset decode a2r6bw

npx shadcn@latest preset url a2r6bw

npx shadcn@latest preset open a2r6bw

npx shadcn@latest preset resolve

npx shadcn@latest preset resolve --json

# Add components.

npx shadcn@latest add button card dialog

npx shadcn@latest add @magicui/shimmer-button

npx shadcn@latest add --all

# Preview changes before adding/updating.

npx shadcn@latest add button --dry-run

npx shadcn@latest add button --diff button.tsx

npx shadcn@latest add @acme/form --view button.tsx

# Search registries.

npx shadcn@latest search @shadcn -q "sidebar"

npx shadcn@latest search @tailark -q "stats"

# Get component docs and example URLs.

npx shadcn@latest docs button dialog select

# View registry item details (for items not yet installed).

npx shadcn@latest view @shadcn/button

Named presets: nova, vega, maia, lyra, mira, luma

Templates: next, vite, start, react-router, astro (all support --monorepo) and laravel (not supported for monorepo)

Preset codes: Version-prefixed base62 strings (e.g. a2r6bw or b0), from ui.shadcn.com.

Detailed References

• rules/forms.md — FieldGroup, Field, InputGroup, ToggleGroup, FieldSet, validation states

• rules/composition.md — Groups, overlays, Card, Tabs, Avatar, Alert, Empty, Toast, Separator, Skeleton, Badge, Button loading

• rules/icons.md — data-icon, icon sizing, passing icons as objects

• rules/styling.md — Semantic colors, variants, className, spacing, size, truncate, dark mode, cn(), z-index

• rules/base-vs-radix.md — asChild vs render, Select, ToggleGroup, Slider, Accordion

• cli.md — Commands, flags, presets, templates

• customization.md — Theming, CSS variables, extending components