Generate UI

Next.js Dashboard UI Stack

Generate a Next.js App Router application using shadcn/ui components, React Server Components by default, and Server Actions for mutations. The runtime is Bun. This is always a dashboard-style interface.

Defaults and Deviations

These are team defaults. Multiple people work on these prototypes. In execution mode, follow these unless the project CLAUDE.md overrides them.

In Plan mode, suggest alternatives using the deviation protocol from the prototyping-skills:team-conventions skill: state the default, name the alternative, explain the trade-off, flag the blast radius, let the human decide.

Workflow

Follow these three interactive checkpoints on every scaffold:

1. Auth gate — Before writing any files, use AskUserQuestion to ask:

   "Do you want Google OAuth authentication on this UI? (Requires GOOGLE_CLIENT_ID, GOOGLE_CLIENT_SECRET, NEXTAUTH_SECRET env vars)" If yes, scaffold the full auth layer (see Authentication section) before pages.

2. UI verification — After scaffolding pages, use TaskCreate to queue a Puppeteer screenshot task so the user can visually confirm the app renders correctly.

See the Verification Checklist section at the end for the exact TaskCreate pattern.

Team Defaults — Follow Unless Explicitly Overridden

1. Component library: shadcn/ui. Not Material UI, Chakra, Ant Design, etc.
2. Icons: Lucide (lucide-react). Not Heroicons, FontAwesome, etc.
3. Data fetching: Server Components with async functions. Not useEffect + fetch, not Tanstack Query, not SWR.
4. Mutations: Server Actions. Not client-side POST calls.
5. State for server data: RSC handles it. No Redux, Zustand, Jotai for data from the API.
6. Router: App Router (app/ directory). Not Pages Router, not getServerSideProps.
7. Client components: Only add "use client" when genuinely needed (event handlers, useState, browser APIs).
8. Types: From @repo/types. Never duplicate.
9. About page: Every app MUST include an /about page (see below).
10. Design tokens: Use CSS custom properties and shadcn theme tokens to separate content from style. Never hard-code colors, spacing, or typography values.

Authentication

Gate this section with AskUserQuestion before scaffolding any files:

"Do you want Google OAuth authentication on this UI? (Requires GOOGLE_CLIENT_ID, GOOGLE_CLIENT_SECRET, NEXTAUTH_SECRET env vars)"

If yes, scaffold the following files using the Auth.js v5 pattern. See references/auth.md for full code.

Files to create:

• packages/ui/auth.ts — NextAuth config with GoogleProvider + domain allowlist callback
• packages/ui/middleware.ts — Route protection with public path exceptions (/login, /api/auth/**)
• packages/ui/providers/auth-provider.tsx — SessionProvider wrapper (Client Component)
• packages/ui/app/(public)/login/page.tsx — Login page with sign-in button
• packages/ui/app/api/auth/[...nextauth]/route.ts — NextAuth API route handler

Required env vars (add to .env.local):

GOOGLE_CLIENT_ID=
GOOGLE_CLIENT_SECRET=
NEXTAUTH_SECRET=
NEXTAUTH_URL=http://localhost:3000

Install dependency:

bun add next-auth

Wrap app/layout.tsx body with <AuthProvider>. Protect all routes except /login and /api/auth/** in middleware.

See references/auth.md for complete file contents including multi-domain allowlist pattern.

Package Setup

packages/ui/
├── src/
│   └── app/
│       ├── layout.tsx         # Root layout with sidebar/nav
│       ├── page.tsx           # Dashboard home
│       ├── [feature]/
│       │   └── page.tsx       # Feature pages
│       ├── actions/           # Server Actions
│       │   └── [resource].ts
│       └── components/        # App-specific components
│           ├── ui/            # shadcn/ui components (managed by CLI)
│           └── [feature]/     # Feature-specific components
├── components.json            # shadcn/ui config
├── postcss.config.mjs         # Tailwind CSS v4 via @tailwindcss/postcss
├── next.config.ts
├── package.json
└── tsconfig.json

package.json must include:

{
  "scripts": {
    "dev": "next dev --port 3000",
    "build": "next build"
  },
  "dependencies": {
    "next": "^16",
    "react": "^19",
    "react-dom": "^19",
    "@repo/types": "workspace:*",
    "tailwindcss": "^4",
    "@tailwindcss/postcss": "^4",
    "class-variance-authority": "latest",
    "clsx": "latest",
    "tailwind-merge": "latest",
    "lucide-react": "latest"
  }
}

Data Fetching Pattern — Server Components

Data loading happens directly in async Server Components. No hooks, no client fetching:

// app/items/page.tsx — Server Component by default, no "use client" needed
import { ItemsTable } from "@/components/items/items-table";

export default async function ItemsPage() {
  const res = await fetch("http://localhost:3001/api/items", {
    cache: "no-store",
  });
  const items = await res.json();

  return (
    <div className="space-y-4">
      <h1 className="text-2xl font-bold">Items</h1>
      <ItemsTable items={items} />
    </div>
  );
}

Mutation Pattern — Server Actions

All mutations use Server Actions defined in app/actions/:

// app/actions/items.ts
"use server";

import { revalidatePath } from "next/cache";

export async function createItem(formData: FormData) {
  const name = formData.get("name") as string;
  await fetch("http://localhost:3001/api/items", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ name }),
  });
  revalidatePath("/items");
}

export async function deleteItem(id: string) {
  await fetch(`http://localhost:3001/api/items/${id}`, { method: "DELETE" });
  revalidatePath("/items");
}

Using Server Actions in components:

// components/items/create-item-form.tsx
"use client";

import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { createItem } from "@/app/actions/items";

export function CreateItemForm() {
  return (
    <form action={createItem} className="flex gap-2">
      <Input name="name" placeholder="Item name" required />
      <Button type="submit">Create</Button>
    </form>
  );
}

Dashboard Layout Pattern

Preferred: Install the full shadcn sidebar block:

npx shadcn@latest add sidebar-01

This installs the complete sidebar-01 block from ui.shadcn.com/blocks/sidebar, including all sub-components, styles, and layout wrapper. Customize the nav items after installation.

Fallback (if block install is not appropriate): Use the manual pattern below.

// app/layout.tsx
import { SidebarProvider, Sidebar, SidebarContent, SidebarMenu,
         SidebarMenuItem, SidebarMenuButton } from "@/components/ui/sidebar";
import { LayoutDashboard, Settings, Info } from "lucide-react";
import Link from "next/link";

export default function RootLayout({ children }: { children: React.ReactNode }) {
  return (
    <html lang="en">
      <body>
        <SidebarProvider>
          <div className="flex min-h-screen">
            <Sidebar>
              <SidebarContent>
                <SidebarMenu>
                  <SidebarMenuItem>
                    <SidebarMenuButton asChild>
                      <Link href="/"><LayoutDashboard className="mr-2 h-4 w-4" />Dashboard</Link>
                    </SidebarMenuButton>
                  </SidebarMenuItem>
                  <SidebarMenuItem>
                    <SidebarMenuButton asChild>
                      <Link href="/settings"><Settings className="mr-2 h-4 w-4" />Settings</Link>
                    </SidebarMenuButton>
                  </SidebarMenuItem>
                  <SidebarMenuItem>
                    <SidebarMenuButton asChild>
                      <Link href="/about"><Info className="mr-2 h-4 w-4" />About</Link>
                    </SidebarMenuButton>
                  </SidebarMenuItem>
                </SidebarMenu>
              </SidebarContent>
            </Sidebar>
            <main className="flex-1 p-6">{children}</main>
          </div>
        </SidebarProvider>
      </body>
    </html>
  );
}

Mandatory About Page

Every app MUST include an /about route. Scaffold it during initial setup:

// app/about/page.tsx — Server Component
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { Info } from "lucide-react";

export default function AboutPage() {
  return (
    <div className="space-y-6">
      <h1 className="text-2xl font-bold flex items-center gap-2">
        <Info className="h-6 w-6" /> About
      </h1>
      <Card>
        <CardHeader>
          <CardTitle>[Project Name]</CardTitle>
        </CardHeader>
        <CardContent className="space-y-2 text-muted-foreground">
          <p>[Brief description of what this prototype does]</p>
          <p className="text-sm">Built with the prototyping-skills stack.</p>
        </CardContent>
      </Card>
    </div>
  );
}

Add the About link to the sidebar layout alongside Dashboard and Settings.

Design Token Conventions

Use shadcn/ui's CSS custom properties (design tokens) to separate content from style. Never hard-code colors, spacing, or font sizes.

Do:

<p className="text-muted-foreground">Subtle text</p>
<div className="bg-card border-border rounded-lg p-4">Card</div>
<span className="text-destructive">Error</span>

Don't:

<p className="text-gray-500">Subtle text</p>
<div className="bg-white border-gray-200 rounded-lg p-4">Card</div>
<span className="text-red-600">Error</span>

Token reference (use these, not raw Tailwind colors):

• Backgrounds: bg-background, bg-card, bg-popover, bg-muted
• Foreground: text-foreground, text-muted-foreground, text-card-foreground
• Borders: border-border, border-input
• Interactive: bg-primary, bg-secondary, bg-accent, bg-destructive
• Spacing: Use Tailwind scale (p-4, gap-6, space-y-4) — don't invent custom spacing

Component Conventions

• shadcn/ui for all standard UI elements. Install via bunx shadcn@latest add [component].
• Dashboard pages: Title + description at top, data table or card grid below.
• Data tables: shadcn/ui <Table> or @tanstack/react-table with shadcn styling when sorting/filtering is needed.
• Charts: recharts with shadcn chart wrapper (ChartContainer, ChartTooltip) when data visualisation is needed. See references/charts.md for BarChart, LineChart, and PieChart patterns.
• Loading states: loading.tsx files (Next.js Suspense boundaries), not spinner state variables.
• Error states: error.tsx files per route segment.

Accessibility (WCAG 2.1 AA)

All scaffolded UIs must meet WCAG 2.1 AA. Apply these rules during generation:

• Color contrast: Minimum 4.5:1 for normal text, 3:1 for large text (≥18pt or ≥14pt bold). Use shadcn tokens — they are pre-tested.
• Keyboard navigation: Every interactive element (buttons, links, inputs, dropdowns) must be reachable via Tab in logical order.
• ARIA labels: Required on icon-only buttons (aria-label="Delete item") and form inputs without visible labels (aria-label or aria-labelledby).
• Semantic HTML: Use <nav>, <main>, <header>, <aside> for structural regions — never <div> for everything.
• Focus visible: Never apply outline: none without replacing it with a custom visible focus indicator. shadcn uses focus-visible:ring — keep it.
• Alt text: All <img> elements need descriptive alt text. Decorative images use alt="".
• shadcn/radix handles primitives: Radix UI manages ARIA roles, aria-expanded, aria-haspopup, keyboard interactions on dropdowns/dialogs. Do not override radix ARIA attributes.

Client vs Server Component Decision

Ask: "Does this component need useState, useEffect, event handlers, or browser APIs?"

• No — Keep as Server Component (default, no directive needed)
• Yes — Add "use client" at the top

Common pattern: Server Component fetches data, passes it to a Client Component for interactivity.

Styling Conventions

• Tailwind CSS v4 only. No CSS modules, no styled-components, no inline style objects.
• No tailwind.config.ts — Tailwind v4 configures everything in CSS via globals.css:
  • @import "tailwindcss" replaces @tailwind base/components/utilities
  • @plugin directives replace the plugins: [] array
  • @theme inline maps CSS custom properties to Tailwind utility classes
• @tailwindcss/postcss is the PostCSS plugin (in postcss.config.mjs). Autoprefixer is included — do not add it separately.
• Use the cn() utility (from lib/utils.ts) for conditional classes.
• Stick to shadcn/ui's design tokens and default theme.
• Dark mode: use class strategy with shadcn's built-in dark mode support.

Verification Checklist

After scaffolding pages, create this task to visually confirm the app renders correctly:

TaskCreate({
  subject: "Verify UI renders with Puppeteer",
  description: "1. Start dev server: bun dev (in packages/ui)\n2. Navigate to http://localhost:3000\n3. Take a screenshot and confirm: sidebar visible, main content area renders, no console errors\n4. If auth is enabled: confirm redirect to /login when unauthenticated\n5. Sign in and confirm protected routes load"
})