Diagnose before fixing (break the AI fix loop)
Forces evidence before edits. Use it the second time the same error shows up.
For people building with Cursor, Claude Code, Codex, Lovable, Bolt, Replit & v0
Your vibe-coded app broke.
Paste the error. Get the fix.
Plain-English explanations for the errors AI-built apps keep hitting, each with a fix prompt you paste straight back into your AI tool. Plus 28 starter prompts for the next build.
Runs in your browser against our fix library. Nothing is uploaded.
Try: · · ·
Most common breakages
All 36 fixes →Works locally, broken after deploy: env var missing in production
.env files stay on your machine. Your host only knows the variables you add in its dashboard.
Supabase: new row violates row-level security policy
Row Level Security is on for that table, but no policy allows this user to insert (or update) this row.
Blocked by CORS policy: No 'Access-Control-Allow-Origin' header
The browser refused to give your page the response because the API didn't say your site is allowed to read it.
Hydration failed: server HTML didn't match the client
The first render on the server and the first render in the browser produced different HTML.
My API secret is in the browser bundle
Anything in client-side code, including NEXT_PUBLIC_ and VITE_ variables, is downloadable by anyone. Treat that key as compromised.
The AI keeps 'fixing' the same bug and making it worse
Each blind retry adds more code and more guesses. Stop patching and get a diagnosis first.
Prompts that save an afternoon
All 28 prompts →Pre-launch security review for a vibe-coded app
A checklist-driven review of the mistakes that most often leak data in AI-built apps.
SaaS starter: auth + database + per-user data (Supabase)
Sign-up, login, and a dashboard where each user only sees their own records, with RLS done right from day one.
MCP server: give your AI tool a custom tool
A minimal Model Context Protocol server that exposes one useful tool to Cursor, Claude, and other MCP clients.
Browser arcade game (HTML canvas)
A complete small game loop: input, movement, collisions, score, and restart. No engine needed.
NASA Astronomy Picture of the Day viewer
Browse NASA's APOD by date, with explanation text, favourites, and a random button.
How it works
- Paste the error. The matcher checks it against our library in your browser.
- Read the cause. One plain-English paragraph, no jargon wall.
- Copy the fix prompt. It tells your AI exactly what to change and what not to break.