diff --git a/README.md b/README.md
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--- a/README.md
+++ b/README.md
@@ -41,6 +41,7 @@ Team and project-specific instructions to enhance GitHub Copilot's behavior for
| [Performance Optimization Best Practices](instructions/performance-optimization.instructions.md) | The most comprehensive, practical, and engineer-authored performance optimization instructions for all languages, frameworks, and stacks. Covers frontend, backend, and database best practices with actionable guidance, scenario-based checklists, troubleshooting, and pro tips. | [](https://vscode.dev/redirect?url=vscode%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Fperformance-optimization.instructions.md) [](https://insiders.vscode.dev/redirect?url=vscode-insiders%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Fperformance-optimization.instructions.md) |
| [Python Coding Conventions](instructions/python.instructions.md) | Python coding conventions and guidelines | [](https://vscode.dev/redirect?url=vscode%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Fpython.instructions.md) [](https://insiders.vscode.dev/redirect?url=vscode-insiders%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Fpython.instructions.md) |
| [Secure Coding and OWASP Guidelines](instructions/security-and-owasp.instructions.md) | Comprehensive secure coding instructions for all languages and frameworks, based on OWASP Top 10 and industry best practices. | [](https://vscode.dev/redirect?url=vscode%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Fsecurity-and-owasp.instructions.md) [](https://insiders.vscode.dev/redirect?url=vscode-insiders%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Fsecurity-and-owasp.instructions.md) |
+| [TanStack Start with Shadcn/ui Development Guide](instructions/tanstack-start-shadcn-tailwind.md) | Guidelines for building TanStack Start applications | [](https://vscode.dev/redirect?url=vscode%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Ftanstack-start-shadcn-tailwind.md) [](https://insiders.vscode.dev/redirect?url=vscode-insiders%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Ftanstack-start-shadcn-tailwind.md) |
> 💡 **Usage**: Copy these instructions to your `.github/copilot-instructions.md` file or create task-specific `.github/.instructions.md` files in your workspace's `.github/instructions` folder.
diff --git a/instructions/tanstack-start-shadcn-tailwind.md b/instructions/tanstack-start-shadcn-tailwind.md
new file mode 100644
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+---
+description: 'Guidelines for building TanStack Start applications'
+applyTo: '**/*.ts, **/*.tsx, **/*.js, **/*.jsx, **/*.css, **/*.scss, **/*.json'
+---
+
+# TanStack Start with Shadcn/ui Development Guide
+
+You are an expert TypeScript developer specializing in TanStack Start applications with modern React patterns.
+
+## Tech Stack
+- TypeScript (strict mode)
+- TanStack Start (routing & SSR)
+- Shadcn/ui (UI components)
+- Tailwind CSS (styling)
+- Zod (validation)
+- TanStack Query (client state)
+
+## Code Style Rules
+
+- NEVER use `any` type - always use proper TypeScript types
+- Prefer function components over class components
+- Always validate external data with Zod schemas
+- Include error and pending boundaries for all routes
+- Follow accessibility best practices with ARIA attributes
+
+## Component Patterns
+
+Use function components with proper TypeScript interfaces:
+
+```typescript
+interface ButtonProps {
+ children: React.ReactNode;
+ onClick: () => void;
+ variant?: 'primary' | 'secondary';
+}
+
+export default function Button({ children, onClick, variant = 'primary' }: ButtonProps) {
+ return (
+
+ );
+}
+```
+
+## Data Fetching
+
+Use Route Loaders for:
+- Initial page data required for rendering
+- SSR requirements
+- SEO-critical data
+
+Use React Query for:
+- Frequently updating data
+- Optional/secondary data
+- Client mutations with optimistic updates
+
+```typescript
+// Route Loader
+export const Route = createFileRoute('/users')({
+ loader: async () => {
+ const users = await fetchUsers()
+ return { users: userListSchema.parse(users) }
+ },
+ component: UserList,
+})
+
+// React Query
+const { data: stats } = useQuery({
+ queryKey: ['user-stats', userId],
+ queryFn: () => fetchUserStats(userId),
+ refetchInterval: 30000,
+});
+```
+
+## Zod Validation
+
+Always validate external data. Define schemas in `src/lib/schemas.ts`:
+
+```typescript
+export const userSchema = z.object({
+ id: z.string(),
+ name: z.string().min(1).max(100),
+ email: z.string().email().optional(),
+ role: z.enum(['admin', 'user']).default('user'),
+})
+
+export type User = z.infer
+
+// Safe parsing
+const result = userSchema.safeParse(data)
+if (!result.success) {
+ console.error('Validation failed:', result.error.format())
+ return null
+}
+```
+
+## Routes
+
+Structure routes in `src/routes/` with file-based routing. Always include error and pending boundaries:
+
+```typescript
+export const Route = createFileRoute('/users/$id')({
+ loader: async ({ params }) => {
+ const user = await fetchUser(params.id);
+ return { user: userSchema.parse(user) };
+ },
+ component: UserDetail,
+ errorBoundary: ({ error }) => (
+ Error: {error.message}
+ ),
+ pendingBoundary: () => (
+
+ ),
+});
+```
+
+## UI Components
+
+Always prefer Shadcn/ui components over custom ones:
+
+```typescript
+import { Button } from '@/components/ui/button';
+import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
+
+
+
+ User Details
+
+
+
+
+
+```
+
+Use Tailwind for styling with responsive design:
+
+```typescript
+
+
+
+```
+
+## Accessibility
+
+Use semantic HTML first. Only add ARIA when no semantic equivalent exists:
+
+```typescript
+// ✅ Good: Semantic HTML with minimal ARIA
+
+
+// ✅ Good: ARIA only when needed (for dynamic states)
+
+
+// ✅ Good: Semantic form elements
+
+
+{errors.email && (
+ {errors.email}
+)}
+```
+
+## File Organization
+
+```
+src/
+├── components/ui/ # Shadcn/ui components
+├── lib/schemas.ts # Zod schemas
+├── routes/ # File-based routes
+└── routes/api/ # Server routes (.ts)
+```
+
+## Import Standards
+
+Use `@/` alias for all internal imports:
+
+```typescript
+// ✅ Good
+import { Button } from '@/components/ui/button'
+import { userSchema } from '@/lib/schemas'
+
+// ❌ Bad
+import { Button } from '../components/ui/button'
+```
+
+## Adding Components
+
+Install Shadcn components when needed:
+
+```bash
+npx shadcn@latest add button card input dialog
+```
+
+## Common Patterns
+
+- Always validate external data with Zod
+- Use route loaders for initial data, React Query for updates
+- Include error/pending boundaries on all routes
+- Prefer Shadcn components over custom UI
+- Use `@/` imports consistently
+- Follow accessibility best practices