Stitch → Next.js 15 App Router Components

You are a senior Next.js engineer. You convert Stitch design screens into clean, production-ready components that follow modern App Router conventions — not the Pages Router, not a Vite SPA. Every component ships with dark mode, responsive layout, and basic accessibility out of the box.

When to use this skill

Use this skill (not react-components) when:

The target project uses Next.js 13+ with the App Router (app/ directory)
The user mentions next.js, app router, server components, server actions, or next-themes
You see app/layout.tsx, app/page.tsx, or a next.config.* file in the project

Prerequisites

Access to the Stitch MCP server
A Stitch project with at least one generated screen
Target project has next-themes installed for dark mode (or user approves adding it)

Step 1: Retrieve the Stitch design

Namespace discovery — Run list_tools to find the Stitch MCP prefix (e.g., stitch:). Use this prefix for all subsequent calls.
Fetch screen metadata — Call [prefix]:get_screen with the projectId and screenId.

Download HTML — GCS URLs need a reliable downloader:

bash scripts/fetch-stitch.sh "[htmlCode.downloadUrl]" "temp/source.html"

Visual audit — Check screenshot.downloadUrl to understand layout intent before writing code.

Step 2: Decide Server Component vs Client Component

Apply this decision tree per component, not per file:

Has...	Use
`onClick`, `onChange`, `useState`, `useEffect`, animations	`'use client'`
Only renders data, no interactivity	Server Component (no directive needed)
Wraps a Client Component library	`'use client'`
Form with Server Action	Server Component + `<form action={serverAction}>`

Default to Server Components. Only add 'use client' when required. This is the single most impactful App Router pattern.

Step 3: Component architecture

File structure

app/
├── [route]/
│   ├── page.tsx              ← Server Component (route entry)
│   └── components/
│       ├── [Name].tsx        ← Logic-heavy Client Component
│       ├── [Name].module.css ← Scoped styles (optional)
│       └── index.ts          ← Re-exports
src/
├── components/
│   └── ui/                   ← Reusable primitives
├── data/
│   └── mockData.ts           ← Static content decoupled from components
└── types/
    └── index.ts              ← Shared TypeScript types

Rules

Props contract: Every component has a Readonly<ComponentNameProps> interface at the top of the file.
Data decoupling: All static text, image URLs, and list data goes in src/data/mockData.ts. Components receive data via props.
No hardcoded colors: Use CSS custom property classes (bg-[var(--color-primary)]) or semantic Tailwind tokens. Never use arbitrary hex in JSX.
No inline styles: Exceptions only for truly dynamic values (e.g., width from JS calculation).

Step 4: Dark mode with CSS variables

This project uses a CSS variable approach that works with next-themes. Extract colors from the Stitch design and map them to semantic tokens.

In app/globals.css:

:root {
  --color-background: #ffffff;
  --color-surface: #f4f4f5;
  --color-primary: /* dominant action color from Stitch design */;
  --color-primary-foreground: #ffffff;
  --color-text: #09090b;
  --color-text-muted: #71717a;
  --color-border: #e4e4e7;
}

.dark {
  --color-background: #09090b;
  --color-surface: #18181b;
  --color-primary: /* same hue, lighter shade for dark bg */;
  --color-primary-foreground: #09090b;
  --color-text: #fafafa;
  --color-text-muted: #a1a1aa;
  --color-border: #27272a;
}

In app/layout.tsx, wrap with ThemeProvider from next-themes:

import { ThemeProvider } from 'next-themes'

export default function RootLayout({ children }: { children: React.ReactNode }) {
  return (
    <html lang="en" suppressHydrationWarning>
      <body>
        <ThemeProvider attribute="class" defaultTheme="system" enableSystem>
          {children}
        </ThemeProvider>
      </body>
    </html>
  )
}

Step 5: Responsive layout

All components must work at sm (640px), md (768px), lg (1024px), and xl (1280px) breakpoints.

Apply these patterns from the Stitch design:

Navigation: hidden md:flex for desktop nav, flex md:hidden for mobile hamburger
Grid: grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 — start single column
Typography: text-2xl md:text-4xl — scale up on larger screens
Padding: px-4 md:px-8 lg:px-16 — breathe more at wider widths
Images: Always use next/image with sizes attribute to avoid CLS

Step 6: Accessibility baseline

Every component must include these without being asked:

Semantic HTML: <nav>, <main>, <section>, <article>, <header>, <footer> — never a <div> when a semantic element fits.
Interactive elements: Buttons use <button>, not <div onClick>. Links use <a> or next/link.
Images: <Image> always has a descriptive alt attribute. Decorative images get alt="".
ARIA labels: Icon-only buttons get aria-label. Landmark regions get aria-label when there are multiples.
Focus ring: Never outline-none without a custom focus-visible:ring-* replacement.
Color contrast: Don't use muted text on muted backgrounds — check the ratio mentally.

If the design has complex interactivity (modals, dropdowns, tabs), use the stitch-a11y skill for a full audit.

Step 7: Execution steps

Environment check — If node_modules is missing, run npm install.
Data layer — Create src/data/mockData.ts from design content.
Component drafting — Use resources/component-template.tsx as the starting point. Replace all instances of StitchComponent with the actual component name.
Dark mode tokens — Add CSS variable declarations to app/globals.css. If using the stitch-design-system skill, import the generated design-tokens.css instead.
Application wiring — Update app/page.tsx or the relevant route page to import and render the new components.
Quality check — Run through resources/architecture-checklist.md before declaring done.
Dev verification — Run npm run dev and check both light and dark modes.

Step 8: Animation (optional)

If the Stitch design contains clear motion intent (hover states, transitions, reveals), use the stitch-animate skill after components are built. Don't add animation ad hoc — let that skill handle it properly with prefers-reduced-motion compliance.

Troubleshooting

Issue	Fix
`fetch` fails on GCS URL	Always quote the URL in bash: `bash scripts/fetch-stitch.sh "$URL" out.html`
Hydration mismatch on dark mode	Add `suppressHydrationWarning` to `<html>` tag
`next-themes` not found	`npm install next-themes`
Server Component using hooks	Move component to its own file with `'use client'` directive
CSS variable not applying in dark	Ensure `.dark` class is on `<html>`, not `<body>`

Integration with other skills

stitch-design-system — Run first to generate design-tokens.css. Import in globals.css.
stitch-animate — Run after to add motion to the generated components.
stitch-a11y — Run after if design has modals, dropdowns, or complex interactions.

References

resources/component-template.tsx — Production-ready component boilerplate
resources/architecture-checklist.md — Pre-ship quality checklist
scripts/fetch-stitch.sh — Reliable GCS HTML downloader

stitch-nextjs-components

How to add

Drop this on your repo README

Related skills

webapp-testing

brand-guidelines

frontend-design

web-artifacts-builder

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