Monitoring for Cursor apps
Monitoring for Cursor apps
Cursor is an IDE, so what comes out depends on your stack. But the pattern is the same: you're editing code through conversation and tab completions, accepting changes across multiple files, and pushing to production faster than you can review everything.
The code compiles. The dev server runs. Production is a different story.
Where things break
Multi-file edits are the big one. A refactor that fixes one module can silently break an import somewhere else. You accept the changes, everything looks right in the editor, but a route is returning 500s or a component stopped rendering.
Merge conflicts are another. You pull from main, Cursor helps resolve the conflicts, and the result looks fine. But a function signature changed in one place and not another, or an edge case got dropped. These bugs pass a quick visual check easily.
The third thing, and this one is harder to catch: you restructure an API layer and something downstream that depends on a specific endpoint path stops working. Payment callbacks, auth redirects, webhook receivers. The app itself runs. You find out later when you check your Stripe dashboard or a user complains about login.
Setup
Two options:
npx upflag init — run it in your project directory. It detects Next.js, Vite, Astro, or plain HTML and adds the error tracking snippet to the right file.
Or add two script tags to your <head> manually:
<script>window.__ufq=[];window.addEventListener("error",function(e){window.__ufq.push(e)});window.addEventListener("unhandledrejection",function(e){window.__ufq.push(e)})</script>
<script src="https://upflag.io/api/v1/snippet?key=uf_YOUR_KEY" defer></script>
Sign up at upflag.io to get your project key. Where to put them depends on your framework: app/layout.tsx for Next.js, index.html for Vite, your layout component for Astro.
Errors start showing up immediately. Set up alerts in the dashboard so you get notified by email, Slack, or SMS when something breaks.
MCP server
You can add Upflag as an MCP server in Cursor so it can see your production errors while you're coding.
Once connected, ask Cursor to check for recent errors and fix them. Instead of copying an error from a dashboard and pasting it into the chat, Cursor already knows what's broken. It sees which page threw, what the error was, and goes straight to the fix.