Spark App Template

Purpose

Spark App Template provides defaults and guidance for building web applications. When a user asks to build a web app, this skill provides the technical foundation and design direction to create functional applications.

When to Use This Skill

Activate Spark App Template when the user:

• Wants to build a new web application from scratch
• Asks "what stack should I use?"
• Needs guidance on design, styling, or tech choices
• Wants to start a dashboard, interactive tool, data app, or content site
• Requests help choosing between frameworks, libraries, or approaches

Quick Start Workflow

CRITICAL: Follow this exact order to avoid configuration errors:

1. Create project: pnpm create vite@latest my-app --template react-ts
2. Install base dependencies: pnpm install
3. Configure TypeScript path aliases (tsconfig.json AND tsconfig.app.json - see Step 1 below)
4. Install Tailwind and tooling: pnpm add -D tailwindcss @tailwindcss/vite @biomejs/biome
5. Configure vite.config.ts: Add Tailwind plugin and path aliases
6. Initialize shadcn: pnpm dlx shadcn@latest init (will now succeed with proper aliases)
7. Install required shadcn components: pnpm dlx shadcn add button card avatar ... (BEFORE writing components)
8. Install additional packages: TanStack Router, Query, Zustand, etc.
9. Write custom components (NOW safe to import from @/components/ui/*)
10. Configure routing and state management
11. Implement features

Steps 3, 6, and 7 must happen in this exact order to avoid TypeScript errors and failed shadcn installations.

Complexity Levels

Understanding complexity helps choose the right stack variation and design approach:

1. Micro Tool (single-purpose)

   • Examples: Calculator, converter, color picker, timer
   • Stack: stacks/default-webapp.md
   • Focus: Simple, focused UI with minimal state

2. Content Showcase (information-focused)

   • Examples: Landing page, portfolio, blog, documentation
   • Stack: stacks/content-showcase.md
   • Focus: Typography, reading experience, visual hierarchy

3. Light Application (multiple features with basic state)

   • Examples: Todo list, meal planner, expense tracker
   • Stack: stacks/default-webapp.md
   • Focus: Feature clarity, data persistence, user flows

4. Complex Application (advanced functionality, multiple views)

   • Examples: CRM, analytics dashboard, project management tool
   • Stack: stacks/complex-application.md or stacks/data-dashboard.md
   • Focus: Navigation, state management, performance optimization

Core Tech Stack (Shared Foundation)

All Spark App Template applications use this foundation:

Build & Development

• Build Tool: Vite (latest stable)
• Framework: React 19+ (leverages new compiler, hooks, and features)
• Language: TypeScript
• Package Manager: pnpm
• Linting: Biome (ESLint fallback for complex plugins)

Routing & Data

• Routing: TanStack Router (file-based, type-safe)
• Data Fetching: TanStack Query
• Forms: react-hook-form + Zod validation

Styling & UI

• Styling: Tailwind CSS v4+ (modern @import syntax)
• Components: shadcn/ui (New York style, 45+ components)
• Icons: Lucide React (1000+ icons)
• Color System: Radix Colors (OKLCH format)
• Theme: next-themes (single theme default, dark mode optional)

Utilities & Enhancement

• Animation: Motion (formerly framer-motion)
• Notifications: Sonner
• Utilities: CVA (or Tailwind Variants) + clsx + tailwind-merge
• Error Handling: react-error-boundary

Stack Variations

All variations share the core foundation above. These templates add specific packages and design guidance:

Default Web App (stacks/default-webapp.md)

• Use for: Most applications, general-purpose tools
• Additive packages: None
• Design focus: Clean, modern, functional

Data Dashboard (stacks/data-dashboard.md)

• Use for: Analytics, admin panels, data visualization
• Additive packages: Recharts (charts), date-fns (date handling)
• Design focus: Data density, hierarchical information, scanning patterns

Content Showcase (stacks/content-showcase.md)

• Use for: Marketing sites, portfolios, blogs, documentation
• Additive packages: marked (markdown parsing)
• Design focus: Typography scale, reading experience, whitespace

Complex Application (stacks/complex-application.md)

• Use for: Multi-view apps, SaaS platforms, enterprise tools
• Additive packages: Zustand (state management), date-fns
• Design focus: Navigation patterns, state architecture, performance

React 19+ Features

Enable these modern React capabilities:

React Compiler

• Status: Available in React 19+
• Benefits: Auto-memoization, significantly faster initial loads and interactions
• Setup: Compatible with React 17+, configure via compiler config

useActionState Hook

• Use for: Form handling, async actions, loading states
• Benefits: Simplified state management, built-in async handling
• Pattern: Consolidates form state, pending state, and error handling

useOptimistic Hook

• Use for: Instant UI updates before server confirmation
• Benefits: Improved perceived performance, better UX
• Pattern: Optimistic updates with automatic rollback on failure

Server Components

• Status: Stable in React 19+ (framework mode only)
• Frameworks: Next.js, TanStack Start
• Note: For Vite + React SPA apps, use client-side rendering

Project Structure Template

my-app/
├── index.html
├── package.json
├── tsconfig.json
├── vite.config.ts
├── tailwind.config.js
├── biome.json
├── src/
│   ├── main.tsx              # App entry point
│   ├── App.tsx               # Root component
│   ├── index.css             # Global styles + theme
│   ├── components/
│   │   ├── ui/               # shadcn components (don't edit)
│   │   └── ...               # Custom components
│   ├── hooks/
│   │   └── use-mobile.tsx
│   ├── lib/
│   │   ├── utils.ts          # cn() utility
│   │   └── data.ts           # Data schemas (if needed)
│   └── routes/               # TanStack Router routes
│       └── __root.tsx
└── public/                   # Static assets

Design Philosophy

Beautiful web applications transcend mere functionality - they evoke emotion and form memorable experiences. Follow these principles:

Core Principles

1. Simplicity Through Reduction: Remove until reaching the simplest effective solution
2. Material Honesty: Digital materials have unique properties; embrace them
3. Obsessive Detail: Excellence emerges from hundreds of thoughtful decisions
4. Coherent Design Language: Every element should feel like part of a unified system
5. Distinctive Visual Identity: Create memorable aesthetics, not generic patterns

Critical Requirements

• Use OKLCH color format (mandatory for 2026)
• Avoid overused fonts: Inter, Roboto, Arial, Space Grotesk
• Choose distinctive typography: See references/typography-pairings.md
• Validate color contrast: WCAG AA (4.5:1 normal, 3:1 large text)
• Single theme by default: No dark mode unless explicitly requested
• Variable fonts: Use single variable font files for performance

See references/design-system.md for comprehensive design guidance.

Performance Targets (Core Web Vitals)

Optimize for these metrics:

• INP (Interaction to Next Paint): < 200ms
• LCP (Largest Contentful Paint): < 2.5s
• CLS (Cumulative Layout Shift): < 0.1

Tools to achieve targets:

• React Compiler for automatic memoization
• Vite code-splitting and lazy loading
• Image optimization (WebP, AVIF, lazy loading)
• Font optimization (variable fonts, font-display: swap)

See references/performance-checklist.md for detailed optimization strategies.

References

Access detailed guidance in the references/ directory:

1. design-system.md - Comprehensive design philosophy, spatial composition, backgrounds, micro-interactions
2. typography-pairings.md - Distinctive font combinations with personality guidance
3. color-palettes.md - Pre-curated OKLCH palettes with WCAG validation
4. component-patterns.md - Common shadcn compositions and usage patterns
5. performance-checklist.md - Web Vitals optimization, React Compiler setup
6. prd-template.md - Simplified planning framework for new apps
7. radix-migration-guide.md - Base UI migration path for Radix concerns

Implementation Workflow

Step 1: Initialize Project

CRITICAL: Configure path aliases BEFORE running shadcn init to avoid validation errors.

# Create Vite project
pnpm create vite@latest my-app --template react-ts
# Note: Working directory is now my-app/ - no need to cd

# Install dependencies
pnpm install

# Add Tailwind CSS and tooling
pnpm add -D tailwindcss@latest @tailwindcss/vite
pnpm add -D @biomejs/biome
pnpm add -D @tanstack/router-plugin

Configure TypeScript Path Aliases (Required for shadcn):

Update tsconfig.json*:

{
  "files": [],
  "references": [
    { "path": "./tsconfig.app.json" },
    { "path": "./tsconfig.node.json" }
  ],
  "compilerOptions": {
    "baseUrl": ".",
    "paths": {
      "@/*": ["./src/*"]
    }
  }
}

Update tsconfig.app.json*:

{
  "compilerOptions": {
    // ... existing options ...
    "baseUrl": ".",
    "paths": {
      "@/*": ["./src/*"]
    }
  }
}

Update vite.config.ts*:

import { defineConfig } from 'vite'
import react from '@vitejs/plugin-react'
import tailwindcss from '@tailwindcss/vite'
import { TanStackRouterVite } from '@tanstack/router-plugin/vite'
import path from 'path'

export default defineConfig({
  plugins: [
    TanStackRouterVite(),
    react(),
    tailwindcss(),
  ],
  resolve: {
    alias: {
      '@': path.resolve(__dirname, './src'),
    },
  },
})

* Configuration samples based on Vite + React + TypeScript template structure

Now shadcn init will succeed:

# Initialize shadcn (path aliases now configured)
pnpm dlx shadcn@latest init

# CRITICAL: Install shadcn components BEFORE writing custom components
# Identify which components you need first
pnpm dlx shadcn@latest add button card input form dialog avatar badge separator

# Add TanStack packages
pnpm add @tanstack/react-router @tanstack/react-query

# Add utilities
pnpm add lucide-react motion sonner react-hook-form zod @hookform/resolvers
pnpm add clsx tailwind-merge class-variance-authority
pnpm add react-error-boundary next-themes

Step 2: Configure Project

See stack templates in stacks/ for specific configuration examples.

Step 3: Create PRD (Optional but Recommended)

Use references/prd-template.md to plan:

• Purpose and mission
• Complexity level
• Essential features
• Design direction
• Color and typography choices

Step 4: Install shadcn Components FIRST

CRITICAL: Component Installation Order

ALWAYS install shadcn components BEFORE writing custom components that import them. This prevents TypeScript errors and failed builds.

❌ WRONG ORDER (causes errors):

# 1. Write PersonDetail.tsx that imports '@/components/ui/card'
# 2. Run pnpm dlx shadcn add card
# 3. Fix TypeScript errors 'Cannot find module @/components/ui/card'

✅ CORRECT ORDER:

# 1. Plan which shadcn components you need
#    Example: Card, Avatar, Badge, Separator, Button

# 2. Install ALL required shadcn components FIRST
pnpm dlx shadcn@latest add card avatar badge separator button

# 3. Verify installation
ls src/components/ui/  # Should show: card.tsx, avatar.tsx, badge.tsx, etc.

# 4. NOW write PersonDetail.tsx that imports from '@/components/ui/*'
#    TypeScript will have proper types and components will exist

Planning Checklist:

1. List all UI components needed for your app
2. Identify which are shadcn components (Card, Button, etc.)
3. Run single shadcn add command with all components
4. Verify they exist in src/components/ui/
5. Write your custom components that import them

Step 5: Implement with Best Practices

• Follow shadcn component patterns
• Use OKLCH colors in :root CSS variables
• Implement responsive design (mobile-first)
• Add error boundaries
• Optimize images and fonts
• Test Core Web Vitals

Common Patterns

Theme Configuration (index.css)

@import 'tailwindcss';

:root {
  /* OKLCH colors - mandatory format */
  --background: oklch(0.97 0.01 75);
  --foreground: oklch(0.25 0.02 55);
  --primary: oklch(0.52 0.14 155);
  --accent: oklch(0.72 0.13 55);

  /* Add more theme variables */
  --radius: 0.75rem;
}

@theme {
  --color-background: var(--background);
  --color-foreground: var(--foreground);
  --color-primary: var(--primary);
  --color-accent: var(--accent);

  /* Radius system */
  --radius-sm: calc(var(--radius) * 0.5);
  --radius-md: var(--radius);
  --radius-lg: calc(var(--radius) * 1.5);
}

Note: Uses Tailwind CSS v4+ @import syntax. For v3, use @tailwind directives instead.

Form Handling

import { useForm } from 'react-hook-form';
import { zodResolver } from '@hookform/resolvers/zod';
import { z } from 'zod';

const schema = z.object({
  email: z.string().email(),
  password: z.string().min(8)
});

function LoginForm() {
  const form = useForm({
    resolver: zodResolver(schema),
    defaultValues: { email: '', password: '' }
  });

  async function onSubmit(data: z.infer<typeof schema>) {
    // Handle form submission
  }

  return <form onSubmit={form.handleSubmit(onSubmit)}>...</form>;
}

Data Fetching

import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';

function UserList() {
  const queryClient = useQueryClient();

  const { data, isLoading } = useQuery({
    queryKey: ['users'],
    queryFn: fetchUsers
  });

  const createUser = useMutation({
    mutationFn: createUserAPI,
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['users'] });
    }
  });

  if (isLoading) return <LoadingSpinner />;
  return <UserGrid users={data} onCreate={createUser.mutate} />;
}

Troubleshooting

Radix UI Maintenance Concerns

Radix UI is receiving fewer updates. For new projects or migration concerns:

• See references/radix-migration-guide.md for Base UI migration path
• shadcn/ui now supports Base UI as an alternative
• React Aria is another excellent option (Adobe-backed, superior accessibility)

Performance Issues

If app feels slow:

1. Enable React Compiler for automatic memoization
2. Check Core Web Vitals in Chrome DevTools
3. Use references/performance-checklist.md
4. Consider code-splitting with TanStack Router's lazy loading

Build Tool Alternatives

Newer Vite versions with Rolldown bundler may offer faster builds when stable. Monitor for stable releases.

System Requirements

• Node.js: 18+ (or current LTS version)
• Package Manager: pnpm recommended for performance
• OS: macOS, Linux, or Windows with WSL2

Next Steps

After scaffolding:

1. Review the stack template for your complexity level
2. Consult design references for styling
3. Create a PRD to plan features and design
4. Implement following best practices
5. Optimize for Core Web Vitals
6. Deploy to production (Vercel, Netlify, etc.)

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Remember: The goal is functional and performant web applications. Start simple, iterate based on user needs, and prioritize user experience over technical complexity.