Security audits for v0 apps.
A v0 app is a Next.js codebase, and its riskiest parts are the ones the preview never shows: server actions with no auth check, keys inlined into the bundle, database rules that were never written. We test all three and hand you the fixes.
Why it matters
v0 is very good at the visible layer, and increasingly it generates the invisible one too: server actions, API routes, a Supabase or Postgres backend. A server action is a public endpoint. If it does not verify who is calling before it reads or writes, anyone can invoke it directly with crafted requests, whatever the interface shows. Add the Next.js habit of inlining any environment variable prefixed NEXT_PUBLIC_ into the client bundle, and one mis-prefixed secret ships to every visitor. Neither problem produces an error, and neither is visible in the preview. Both are exactly what an audit exists to find.
What you get.
Server action and route review
Every server action and API route checked for authorisation before it reads or writes, then tested live by calling it the way an attacker would, outside the interface.
Bundle and environment check
We search the deployed JavaScript, not just the source, for secrets that were inlined at build time, including keys that gained a NEXT_PUBLIC_ prefix so an integration would work.
Database rules review
If your v0 app talks to Supabase, we check row level security table by table, including policies that exist but restrict nothing. On other backends, we verify the equivalent rules.
Two-account access test
Signed in as one user, we try to reach another user's data through pages, actions and the API. The flaw that exposes customers to each other is only visible from two accounts.
Headers, CORS and configuration
Security headers, origin policy, rate limiting on auth endpoints and source maps in production. Small individually, and together a reliable signal of whether any security work was done.
Prioritised report and free re-review
Every finding rated by severity with a concrete fix, and a free re-test once you have applied them.
How it works.
- 01
Access
You share the deployed URL and, ideally, read access to the repository. The bundle tells us a lot; the code lets us confirm the fix.
- 02
Test
We test the live app from outside, call the actions and routes directly, and read the generated code by hand.
- 03
Report
You get a clear, prioritised write-up within days, plus a call to walk through it and the fix for each finding.
- 04
Re-review
After you apply the fixes, we verify the exposed actions and tables are actually closed.
Common questions.
- The app is mostly frontend. What is there to audit?
- Almost every v0 app that does something real has a backend: server actions, API routes, a database. Those are public surfaces reachable without the interface, and they are precisely the parts the preview never exercises. That is where the audit spends its time.
- What is wrong with NEXT_PUBLIC_ variables?
- Nothing, when the value is meant to be public. The problem is that adding the prefix is the quickest way to make a broken integration work, and it inlines the value into JavaScript every visitor downloads. We check what actually shipped in the bundle, because that is the version that counts.
- What do you check?
- Authorisation on every server action and route, secrets in the deployed bundle, database rules behind the app, cross-account access with two real accounts, and the configuration layer: headers, CORS, rate limiting. Every finding comes with a severity and a fix.
- Can you fix the issues, not just find them?
- Yes. We can apply the fixes in the codebase directly or hand you a prioritised list, and we re-test either way at no extra cost.
- How much does a v0 security audit cost?
- It is scoped to a fixed quote up front, with no hourly meter, and typically starts around $750 depending on the size of the app. You will know the price before we begin.
Related services.
Let's build something real.
Tell us about your app or idea. You'll get a clear plan and a fixed quote back within 24 hours.