Framework cheatsheet

Next.js 16 Cheatsheet

Create, run and build Next.js apps, and the App Router patterns you reach for most.

Command line

Create an app — Create a new Next.js project with an interactive setup.
Start the development server — Run the app at http://localhost:3000 with hot reload.
Use another port — Start the dev server on port 4000.
Build for production — Create an optimized production build and print the route table.
Run the production build — Start the server after a build.
Print environment info — Show Node, npm and Next.js versions. Handy for bug reports.
Turn off telemetry — Opt out of anonymous usage data collection.

Create a page — A page.tsx file inside app/ is a route. This one serves /about from app/about/page.tsx.
Create a layout — A layout wraps its pages and persists across navigation.
Read a dynamic route parameter — In app/blog/[slug]/page.tsx, params is a promise, so await it.
Link between pages — Navigate on the client without a full page reload.
Create an API route — A route.ts file exports a function per HTTP method.
Show a loading state — A loading.tsx next to a page is shown while the page streams in.
Return a 404 — Call notFound() in a server component to render the closest not-found page.

Fetch data in a server component — Server components can be async, so fetch data directly.
Make a client component — Add this directive at the top of a file to use state, effects and browser APIs.
Create a server action — A function marked "use server" runs on the server and can be called from forms.
Redirect — Send the user to another route from server code.
Refresh cached data — Invalidate cached data for a route after a change.
Read a cookie — cookies() is async in current versions, so await it.

Set page metadata — Export metadata from a page or layout for the title and description.
Optimize an image — Use next/image for resizing, lazy loading and modern formats.
Expose an environment variable to the browser — Only variables prefixed with NEXT_PUBLIC_ are included in the browser bundle.
Write next.config.ts — Configure Next.js in a typed config file.

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