next-best-practices

To validate Next.js App Router code, review your project against file conventions for pages, layouts, and route handlers to catch routing conflicts and ensure correct organization. This prevents broken routing and fragile deployments.

Next.js 15 crashes often occur because params, cookies, and headers are now asynchronous. You must await these async request APIs before accessing their values to avoid runtime errors.

The correct server-client boundary requires passing only serializable props to client components, avoiding async client components, and preventing improper use of hooks or server APIs to stop hydration issues.

Fix hydration and server-client boundary issues by validating your React Server Components for non-serializable props, improper hook usage, and async client components. Correcting these prevents runtime mismatches.

This review guidance requires Next.js 15+ because it specifically targets async params promises, async cookies and headers access, and safe React Server Components usage introduced in that version.

The best way to optimize images and generate SEO metadata is by validating your data-fetching patterns and metadata file placement within the App Router to ensure correct runtime selection and performance.