Next.js App Router Error Handling: Building Resilient Applications

Description

The provided document outlines Next.js App Router's advanced error-handling capabilities, emphasizing a shift to a file-system-based architecture built upon React Error Boundaries. It details how error.tsx handles unexpected errors within specific route segments, providing a fallback UI and a reset function for recovery, while notFound() and not-found.tsx address predictable 404 errors with custom messages. The document further explains the hierarchical error-handling system, including global-error.tsx as a crucial catch-all for root layout failures, and discusses error management in Server Actions and Route Handlers using standard try/catch blocks. Ultimately, it stresses the importance of a comprehensive strategy that balances user experience (UX) through clear error messages and developer experience (DX) via robust logging and observability, utilizing features like error.digest for secure error correlation.