DenyFirst
// Security for AI-built apps
Get your app secure.
Stress-free.
AI builders ship beautiful apps on backends with no access control. DenyFirst finds the broken rules — the ones that let anyone read or write your users' data — and hands you the exact fix. No noise, no false positives, just what matters.
// runs read-only · only ever on apps you own
// The problem
Your UI is beautiful.
Your backend has no rules.
The AI writes your frontend and wires it straight to Firebase or Supabase. The part it rarely gets right is the access rules — the layer that decides which user is allowed to see which record.
Get that wrong and the app still looks perfect. Every screen works, every test passes. The gap only shows up when someone asks your backend for data that was never theirs — and it answers.
That's the class of issue we check for, and it's the one AI-built apps ship with most often.
// What we check
The six ways AI-built apps leak.
Every scan probes the access-control failure modes these stacks are prone to — not a generic CVE list.
Broken read access (IDOR)
Can user A read user B's documents just by changing an ID? We prove it, safely.
Open writes
Can a stranger create, overwrite or delete records that aren't theirs?
Missing RLS / Firestore rules
Tables and collections with no row-level security or deny-by-default rules at all.
Exposed storage buckets
Avatars, invoices and uploads listed and downloaded by anyone with the URL.
Leaked server keys
Service-role keys and admin secrets shipped inside the public client bundle.
Auth misconfig
Anonymous sign-in left on, and open self-registration that lets anyone mint an account.
// How it works
Three steps. One locked backend.
Prove ownership
OAuth into your Firebase or Supabase project. We never touch apps you don't own — verification comes first, always.
We probe it, safely
A disposable, hardened box reads your client config and checks what an anonymous or signed-in user can actually reach — read-only by default — then cleans up after itself.
Get the exact fix
A report with the precise rule or policy to paste, plus the reproduction — so you can confirm the issue, then re-scan to confirm it's closed.
// Why DenyFirst
Not a noisy scanner. Just the issues that matter — with the fix.
Yours, or we don't touch it
OAuth verification before a single packet. We can only ever scan apps you provably own.
A leak, or public on purpose?
Our test account owns nothing — so if it can read a record, that record is someone else's. That's a leak, stated plainly. A catalogue that's meant to be public gets labelled public, not flagged as a breach.
One line, paste and ship
The precise rule or policy to change, plus the reproduction so you can verify it yourself. Writes are proven without ever persisting data.
// Pricing
Cheaper than one breach.
No free tier — every scan is a real probe in an isolated box, not a static guess.
Pro
$2,388/yr billed annually · or $299/mo month-to-month
- 3 apps, continuous scanning
- Full six-vector probe suite
- Exact one-line fixes + repro
- Re-scan to verify the fix
Agency
$5,988/yr billed annually · or $649/mo month-to-month
- 20 client apps, continuous scanning
Enterprise
For platforms and portfolios
- Unlimited apps
- SSO, audit logs, SLA
- CI/CD & API access
- Dedicated support
Annual billing is the best rate. Month-to-month has no lock-in — cancel anytime. See full pricing →
Ship it locked.
Scan my app// read-only by default · proof before packets · findings only, never your users' data