nextjs-advanced-routing

Server Actions enable secure server-side mutations directly from forms and client components. Mark functions with 'use server', handle form data server-side, and manage cookies and database operations safely without exposing backend logic to the client.

Parallel Routes and Intercepting Routes let you render overlays without full page navigation. Define separate route segments in brackets, intercept routes to display modals over parent layouts, and use Suspense for streaming content while maintaining back-button behavior.

Route Handlers are server-side functions defined in route.ts files within the app directory. They handle HTTP requests, return responses, and support streaming, making them ideal for building RESTful endpoints and webhooks without a separate API layer.

Yes. Server Actions support secure cookie manipulation through server-only code. Use 'use server' directives, access cookies within action functions, and avoid exposing sensitive data to client-side code, ensuring strict server/client separation.

Parallel Routes render multiple segments simultaneously within the same layout using slot directories. Use them for independent sections like sidebars and feed, conditional content, and modals that coexist without interfering with main route navigation.

Streaming sends content progressively to clients using Suspense boundaries. Wrap async components in Suspense, define fallbacks, and let Next.js stream chunks as they resolve, improving perceived performance on data-heavy pages.