Catch what your users hit.

Shipped an app from Cursor, Lovable, or Bolt? One script tag captures production errors — stack trace, browser, frequency — ready to paste into your agent.

8 min read

Export onRequestError from instrumentation.ts to capture every uncaught Next.js server error — components, actions, route handlers — in one function.

9 min read

This Vite error means an open tab requested a lazy chunk your deploy deleted. Fix it with a vite:preloadError reload handler, router fixes, and cache headers.

7 min read

Error boundaries only catch render errors. Three fixes for async and event-handler errors: showBoundary, React 19's onUncaughtError, and global window handlers.

8 min read

Map app.js:1:45 back to a real file, line, and function. How to generate source maps in Vite, webpack, and esbuild — and unminify stack traces safely.

9 min read

window.onerror misses resource failures and promise rejections. What addEventListener('error') and unhandledrejection catch, with one complete runnable handler.

10 min read