v0 Production Readiness

Auth Check Only in Client Code

The auth gate runs only in a client component (useEffect redirect or conditional render), which an attacker bypasses by disabling JavaScript or hitting the API route directly.

IDOR Vulnerability on REST Endpoint

A REST endpoint returns resources by id without verifying the caller owns that resource. Any authenticated user can access any other user's data by changing the id in the URL.

Missing Row Level Security on Supabase Table

A public Supabase table has RLS disabled or has an overly permissive policy, meaning any authenticated user can read or modify every row regardless of ownership.

Secret API Key Exposed in Client Bundle

A sensitive credential (Stripe secret, OpenAI API key, Supabase service role key) is prefixed with NEXT_PUBLIC_, causing it to be inlined into the browser JavaScript bundle where anyone can read it.

Unverified Stripe Webhook

The Stripe webhook endpoint accepts any POST without verifying the signature header, allowing an attacker to forge subscription events, credit accounts, or cancel subscriptions.

Missing Input Validation on API Route

A POST or PATCH API route spreads the raw request body into a database write without validating that fields exist, match expected types, or lie within expected ranges.

v0 to Production: What Vercel's AI Misses

v0 generates beautiful UI components with Tailwind and shadcn. But UI isn't an app. Here's what v0 gets right, what it misses, and how to take v0 output to production.