21st.dev Magic + Roo Code: Complete MCP Integration

21st.dev Magic is a MCP server that Create crafted UI components inspired by the best 21st.dev design engineers..

When integrated with Roo Code, you can:

• Generate crafted UI components using AI design patterns
• Live preview of generated components
• Full TypeScript support for generated components

This guide provides step-by-step instructions to set up 21st.dev Magic in Roo Code, including configuration, examples, and troubleshooting.

What You'll Achieve

After completing this setup:

• 21st.dev Magic will be fully integrated and operational
• You can use 21st.dev Magic tools directly in Roo Code
• All 21st.dev Magic capabilities will be available for your workflows
• Access to 4 different tools

Prerequisites

Before starting, ensure you have:

• 21st.dev account
• API key
• 21st.dev Magic API key for authentication
• Roo Code installed and configured
• Compatible operating system (Windows, macOS, Linux)

Installation

Step 1: Install 21st.dev Magic

Manual installation steps:

1. Generate API key from 21st.dev Magic Console
2. Add configuration to IDE-specific JSON config
3. Restart IDE to load MCP server

Configuration

Step 2: Configure Roo Code

1. Locate your configuration file:

   • Windows: %USERPROFILE%\.roo\mcp_settings.json
   • macOS: ~/.roo/mcp_settings.json
   • Linux: ~/.roo/mcp_settings.json

2. Add server configuration:

{
  "mcpServers": {
    "21stdev-magic": {
      "command": "npx",
      "args": ["-y", "21stdev-magic"],
      "env": {
        "API_KEY": "your-21st-dev-api-key"
      }
    }
  }
}

3. Restart Roo Code

Completely quit and restart Roo Code to load the new configuration.

Examples

Once configured, you can use 21st.dev Magic in Roo Code:

Create Navigation Bar

Generate a modern responsive navigation component

Ask Roo Code: "/ui create a modern navigation bar with responsive design"

Expected Result: Responsive navigation component with mobile menu, logo placement, and styling

Generate Dashboard Card

Create a dashboard card with metrics display

Ask Roo Code: "/ui design a dashboard card showing user analytics with charts"

Expected Result: Card component with chart integration, metrics display, and responsive layout

Build Form Component

Create a contact form with validation

Ask Roo Code: "/ui create a contact form with validation and modern styling"

Expected Result: Form component with input validation, error states, and submit handling

Design Landing Hero

Generate a landing page hero section

Ask Roo Code: "/ui build a hero section for a SaaS product with CTA buttons"

Expected Result: Hero component with headline, description, call-to-action buttons, and background

Testing Your Setup

1. Start a new conversation in Roo Code
2. Ask Roo Code to list available tools
3. Try using 21st.dev Magic functionality

Test prompts:

• "Type @ and verify 21st.dev Magic appears in the tools list"
• "Ask: "Use 21st.dev Magic to help with my task""
• "Check Roo Code output panel for server connection status"

Troubleshooting

Common Issues

API Key Invalid

Symptoms: Authentication errors, Access denied messages, Server connection failures

Cause: Invalid or expired API key

Solution:

• Generate new API key from 21st.dev Magic Console
• Update API_KEY in IDE configuration
• Restart IDE to reload configuration

IDE Not Detecting MCP Server

Symptoms: MCP commands not available, Server not listed in IDE

Cause: Incorrect configuration file or location

Solution:

• Verify config file is in correct location for your IDE
• Check JSON syntax in configuration file
• Restart IDE after configuration changes
• Use CLI installation for automatic setup

Component Generation Fails

Symptoms: Empty responses, Error messages during generation

Cause: Network issues or service limitations

Solution:

• Check internet connectivity
• Verify API key has sufficient quota
• Try simpler prompts initially
• Contact support if issues persist

TypeScript Errors in Generated Code

Symptoms: Type errors, Compilation failures

Cause: Missing dependencies or type definitions

Solution:

• Install required TypeScript dependencies
• Update @types packages
• Configure TypeScript strict mode properly
• Import necessary type definitions

MCP Server Not Connecting

Symptoms: Server not appearing in tools list, Connection timeout, MCP tools unavailable

Cause: Incorrect configuration or server not starting

Solution:

• Verify mcp_settings.json syntax is correct
• Check that Node.js and npx are installed and in PATH
• View Roo Code output panel for error messages
• Test server command manually in terminal: npx -y {server_id}
• Ensure environment variables are properly set

Permission Denied Errors

Symptoms: Cannot execute commands, File access denied, Terminal commands blocked

Cause: Roo Code requires explicit permission for file and command operations

Solution:

• Review and approve permission requests when prompted
• Check VS Code workspace trust settings
• Enable necessary permissions in Roo Code settings
• Verify file and folder permissions on your system

API Key or Model Issues

Symptoms: Authentication failed, Model not responding, No AI completions

Cause: AI model API key not configured or invalid

Solution:

• Verify API key is correctly set in Roo Code settings
• Check API key has sufficient credits/quota
• Test with a different AI model provider
• Review Roo Code output panel for API error details

Custom Mode Not Working with MCP

Symptoms: MCP tools not available in custom mode, Mode cannot access server

Cause: Custom mode configuration does not include MCP tool permissions

Solution:

• Edit custom mode configuration to include MCP tools
• Add "Use MCP" to available tools in mode definition
• Ensure mode has appropriate permissions for external tools
• Test with default mode first to verify MCP server works

Extension Conflicts

Symptoms: Roo Code not responding, VS Code performance issues, Unexpected behavior

Cause: Conflicts with other AI coding extensions

Solution:

• Disable other AI coding extensions (Cline, Continue, etc.)
• Restart VS Code after disabling conflicting extensions
• Check VS Code extension logs for conflict errors
• Use only one AI coding assistant extension at a time

21st.dev Magic not appearing in Roo Code

Symptoms: Server not listed, Tools not available

Cause: Configuration or installation issue

Solution:

• Verify configuration syntax
• Check 21st.dev Magic installation
• Restart Roo Code
• Check logs for error messages

Next Steps

Now that 21st.dev Magic is integrated with Roo Code:

• Explore all 21st.dev Magic capabilities through Roo Code
• Check out other MCP servers that work with Roo Code
• Join the MCP community for tips and support
• Consider contributing to 21st.dev Magic development

Need Help?

• Search for 21st.dev Magic documentation
• Check the Roo Code MCP guide
• Join the MCP community discussions