MCP Shadcn

shadcn MCP Server

This skill covers using the shadcn MCP server to manage shadcn/ui components in the monorepo, specifically for the lexico-components package.

When to Use

Use shadcn MCP tools when:

• Adding new shadcn/ui components to lexico-components
• Updating existing shadcn components
• Checking available component versions
• Installing component dependencies
• Troubleshooting component integration issues

Available MCP Tools

The shadcn MCP server provides these tools (prefix: mcp_shadcn_):

Component Management

mcp_shadcn_add_component - Add a new shadcn/ui component

Parameters:

• component_name (required): Name of the component to add (e.g., 'button', 'dialog', 'dropdown-menu')
• project_path (optional): Path to project directory (defaults to current directory)
• overwrite (optional): Overwrite existing component files (default: false)

Example usage:

// Add a new button component
mcp_shadcn_add_component({
  component_name: "button",
  project_path: "packages/lexico-components",
});

// Add dialog and overwrite if exists
mcp_shadcn_add_component({
  component_name: "dialog",
  project_path: "packages/lexico-components",
  overwrite: true,
});

mcp_shadcn_list_components - List available shadcn/ui components

Parameters:

• project_path (optional): Path to project directory

Example usage:

// List all available components
mcp_shadcn_list_components({
  project_path: "packages/lexico-components",
});

mcp_shadcn_update_component - Update an existing component

Parameters:

• component_name (required): Name of the component to update
• project_path (optional): Path to project directory

Example usage:

// Update button component to latest version
mcp_shadcn_update_component({
  component_name: "button",
  project_path: "packages/lexico-components",
});

Workflow Patterns

Adding a New Component

1. Check available components:

   mcp_shadcn_list_components({
     project_path: "packages/lexico-components",
   });
   

2. Add the component:

   mcp_shadcn_add_component({
     component_name: "card",
     project_path: "packages/lexico-components",
   });
   

3. Verify installation:

   • Check packages/lexico-components/src/components/ui/card.tsx exists
   • Verify dependencies added to package.json
   • Ensure imports work in your code

4. Export the component: Add to packages/lexico-components/src/index.ts:

   export {
     Card,
     CardHeader,
     CardTitle,
     CardContent,
   } from "./components/ui/card";
   

Updating Existing Components

1. Identify outdated components:

   • Check shadcn changelog for updates
   • Review component issues

2. Update the component:

   mcp_shadcn_update_component({
     component_name: "button",
     project_path: "packages/lexico-components",
   });
   

3. Test changes:

   • Run type checking: nx run lexico-components:typecheck
   • Test in consuming apps: nx run lexico:develop
   • Verify visual changes in Storybook (if available)

Adding Multiple Components

// Add multiple related components
const components = ["dialog", "alert-dialog", "sheet"];

for (const component of components) {
  mcp_shadcn_add_component({
    component_name: component,
    project_path: "packages/lexico-components",
  });
}

Project-Specific Configuration

lexico-components Setup

The lexico-components package is configured for shadcn/ui with:

components.json:

{
  "style": "new-york",
  "tailwind": {
    "config": "tailwind.config.ts",
    "css": "src/styles/globals.css",
    "baseColor": "gray"
  },
  "aliases": {
    "components": "@/components",
    "utils": "@/lib/utils"
  }
}

Key settings:

• Style: New York (modern, minimal design)
• Base color: Gray (neutral palette)
• Path aliases: @/components, @/lib/utils

File Locations

Components are added to:

packages/lexico-components/
  src/
    components/
      ui/                    # shadcn components (DO NOT MANUALLY EDIT)
        button.tsx
        dialog.tsx
        ...
      custom/                # Custom components (safe to edit)
        MyComponent.tsx
    lib/
      utils.ts              # shadcn utilities
    styles/
      globals.css           # Tailwind directives

Important Rules

⚠️ Never Manually Edit UI Components

DO NOT modify files in packages/lexico-components/src/components/ui/

These files are managed by shadcn CLI and will be overwritten on updates.

Instead:

1. Extend components by wrapping them:

   // packages/lexico-components/src/components/custom/MyButton.tsx
   import { Button } from "../ui/button";
   
   export function MyButton(props) {
     return (
       <Button
         className="custom-styles"
         {...props}
       />
     );
   }
   

2. Use composition to create variants:

   // packages/lexico-components/src/components/custom/PrimaryButton.tsx
   import { Button } from "../ui/button";
   import { cn } from "@/lib/utils";
   
   export function PrimaryButton({ className, ...props }) {
     return (
       <Button
         className={cn("bg-primary text-primary-foreground", className)}
         {...props}
       />
     );
   }
   

3. Add to custom directory:

   packages/lexico-components/src/components/custom/
   

Post-Installation Steps

After adding components:

1. Export in index.ts:

   // packages/lexico-components/src/index.ts
   export * from "./components/ui/button";
   export * from "./components/ui/dialog";
   

2. Update package.json if needed: Some components require additional dependencies (e.g., @radix-ui/react-dialog)

3. Run type checking:

   nx run lexico-components:typecheck
   

4. Test in consuming applications:

   nx run lexico:develop
   

Common Components

Form Components

• button - Button element with variants
• input - Text input field
• textarea - Multi-line text input
• select - Dropdown select menu
• checkbox - Checkbox input
• radio-group - Radio button group
• switch - Toggle switch
• slider - Range slider
• label - Form label

Layout Components

• card - Content container with header/footer
• separator - Visual divider
• accordion - Expandable content sections
• tabs - Tabbed interface
• sheet - Slide-out panel
• dialog - Modal dialog
• alert-dialog - Confirmation dialog

Feedback Components

• alert - Alert message
• toast - Notification popup
• badge - Status indicator
• progress - Progress bar
• skeleton - Loading placeholder

Navigation Components

• dropdown-menu - Dropdown menu
• navigation-menu - Navigation bar
• menubar - Menu bar
• breadcrumb - Breadcrumb navigation
• pagination - Page navigation

Data Display

• table - Data table
• avatar - User avatar
• tooltip - Hover tooltip
• popover - Popup content
• calendar - Date picker calendar

Troubleshooting

Component Not Found

Error: Component 'xyz' not found

Solution:

1. List available components:

   mcp_shadcn_list_components({
     project_path: "packages/lexico-components",
   });
   

2. Check component name spelling

3. Verify shadcn/ui version supports the component

Import Errors

Error: Cannot find module '@/components/ui/button'

Solution:

1. Verify component was added successfully

2. Check TypeScript path mappings in tsconfig.json:

   {
     "compilerOptions": {
       "paths": {
         "@/*": ["./src/*"]
       }
     }
   }
   

3. Restart TypeScript server in VS Code

Dependency Conflicts

Error: Conflicting peer dependencies

Solution:

1. Check component dependencies:

   cat packages/lexico-components/package.json
   

2. Update Radix UI packages:

   pnpm update @radix-ui/react-* --filter lexico-components
   

3. Resolve conflicts manually

Style Issues

Problem: Component styles not applying

Solution:

1. Verify Tailwind CSS is configured:

   cat packages/lexico-components/tailwind.config.ts
   

2. Check globals.css imports Tailwind:

   @tailwind base;
   @tailwind components;
   @tailwind utilities;
   

3. Ensure CSS is imported in entry point

Overwrite Existing Components

Problem: Component exists but needs updating

Solution: Use overwrite: true:

mcp_shadcn_add_component({
  component_name: "button",
  project_path: "packages/lexico-components",
  overwrite: true,
});

Best Practices

1. Always use MCP tools instead of manual npx shadcn commands
2. Check available components before adding
3. Never edit UI directory - extend components instead
4. Export new components in index.ts immediately
5. Test after adding components in consuming apps
6. Update regularly to get bug fixes and improvements
7. Use consistent style (New York for this monorepo)
8. Document custom components that wrap shadcn components
9. Follow naming conventions (PascalCase for components)
10. Group related components when adding multiple

Integration with lexico

When adding components used by lexico:

1. Add to lexico-components:

   mcp_shadcn_add_component({
     component_name: "dialog",
     project_path: "packages/lexico-components",
   });
   

2. Export component:

   // packages/lexico-components/src/index.ts
   export * from "./components/ui/dialog";
   

3. Use in lexico:

   // applications/lexico/app/components/MyDialog.tsx
   import {
     Dialog,
     DialogContent,
     DialogHeader,
   } from "@monorepo/lexico-components";
   
   export function MyDialog() {
     return (
       <Dialog>
         <DialogContent>
           <DialogHeader>Title</DialogHeader>
         </DialogContent>
       </Dialog>
     );
   }
   

4. Test integration:

   nx run lexico:develop
   

Related Documentation

• packages/lexico-components/AGENTS.md - Component library architecture
• packages/lexico-components/README.md - Usage guide
• shadcn/ui Documentation - Official shadcn/ui docs
• Radix UI Documentation - Primitive component docs

See Also

• supabase-development skill - For backend integration
• tanstack-start-ssr skill - For SSR patterns with components
• github-actions skill - For CI/CD testing of components

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