Reads everything Explains it simply Stops what would break

We untangle your vibe-coded app.

Like a senior engineer on your team — reads everything, explains it simply, and stops the changes that would break things.

checkout.js
// somewhere in a 4,000-line file you've never opened
function applyShipping(order) {
  const bulky = order.items.some(i => i.bulky)
  if (order.total > 500 && !bulky) {
    order.shipping = 0            // free
  }
  if (order.code === 'WELCOME10')
    order.discount = order.discount * 2  // ← applied twice
}
Untangly reads itfinds this
1 × A user can empty someone else’s walletCritical
A logged-in user could empty another’s wallet.

Wallet balance updates never check who owns the wallet.

Fix this for me✧ Explain this
3 × Admin checks that only run in the browser3 Critical
1 × A multi-step checkout can half-finishMinor
Grounded in your app — new feature or old

Featurecraft

A generic prompt sent straight to Lovable or Cursor doesn’t know what your app already does — that’s how a broken prompt quietly tangles a feature you already shipped. Featurecraft engineers the prompt against your verified app: it works out the blast radius, designs the feature so it can’t break what you’ve got, and checks the plan fits your real code — then writes one self-contained prompt you paste into any builder.

You asked
“Let customers save several addresses and pick one at checkout”
Your prompt — paste into any builderCopy
Feature — let a signed-in customer save several shipping addresses and pick one at checkout.

Add
• A saved-addresses table tied to the signed-in customer: label, name, street, city, postcode, country, and a “default” flag.
• On the checkout page, an address picker that starts on their default address.

Who can see what (row-level security)
• A customer can view and edit ONLY their own saved addresses — never anyone else’s.
• Only one address per customer can be the default; choosing a new one clears the old.
• The address is read at checkout, but the order’s shipping details are still written server-side, not trusted from the browser.

Must NOT change these existing rules
• Free shipping still applies only when the order is over 500 SEK.
• WELCOME10 still applies once, to a first order only.
• Refunds still close 30 days after the order date.

Leave completely untouched
• Login, sessions, and how customers authenticate.
• Payment capture and the Stripe integration.
• The existing orders and products tables.
Every table it touches, every rule it must not break, every fence — spelled out from your real app. The prompt is so precise that a cheaper, faster model builds the feature right the first time. You don’t need the smartest model — you need the clearest instructions.
Change, without the fear

Know what your app does. Change it without fear.

Every rule in your app reads as one plain sentence — “orders over 500 kr ship free,” “refunds close after 30 days.” Change one in plain language and see the full consequence before anything changes: what it becomes, and what else it touches. If a change would break a neighbouring rule, it's blocked and rolled back. Nothing ships unverified.

You asked
“Make shipping free over 400 kr”
You see this consequence, and confirm it, before any code is written.
The whole problem, in one line

You shipped an app you can't read.

Untangly can.

It opens every route, service and handler, finds the ~40 business rules buried across them, and hands you plain sentences you can judge true or false — no code, no jargon, no "ask your developer."

For Lovable, Bolt, Cursor & v0 builders

Your Lovable app is running rules you've never seen.

AI built it fast — and smeared your pricing, discounts, refunds, stock and access logic across thousands of lines, some of it wrong. So when the app breaks, double-charges a customer, or lets someone refund what they shouldn't, you're stuck reading code you didn't write. Untangly reads your broken Lovable app for you and tells you, in plain English, exactly what it does — and what's quietly wrong.

Every prompt burns credits whether it works or not — and a vague one often takes three tries, or fixes one thing while quietly breaking another you now have to pay to fix too. Untangly scopes each change to exactly what it touches, so a small update stays a small, isolated prompt — not a guess at rewriting the whole app.

LovableBolt.newCursorv0Replithand-written
Also shipped

A couple more things, while we're here.

Not roadmap — already live.

01

I don’t actually know what my app does.

The verified map

Every business rule extracted into plain language — “users can only edit their own bookings,” “orders over 500 SEK ship free” — grouped by area. No code, no jargon.

Coverage: 31 of 34 entry points analyzed — and here’s exactly what we couldn’t see.
02

Just fix it for me.

One-click fixes that check themselves

Applied, re-verified against your rules, and rolled back automatically if anything else moved.

The fix: add the missing owner check before the wallet update.
  1. Confirming the change
  2. Writing the fix
  3. Re-running your rules — 6/6 green
⇧ Ship (merge PR)PR #128 open — review
Why you can trust the output

The honesty is the product.

We tell you what we couldn’t analyze.Coverage is on the page. The parts we couldn’t see are named — not quietly left out.
Every finding is verified before it’s shown.No finding without the code to prove it — you can open the exact lines it’s based on.
Our false-positive rate is measured.And published, not hidden. Most tools can’t say any of this — so we lead with it.
AI gets you most of the way. We can finish it.

We get you from vibe-coded to production — faster.

The self-serve loop above — read, edit, fix, verify — handles the vast majority of it yourself, starting at $29/mo. When you want it fully done, not just understood, a staff engineer picks up where the AI leaves off and takes it the rest of the way live.

Questions founders actually search

Broken Lovable app? Start here.

Why is my Lovable app broken or buggy?

AI builders like Lovable, Bolt and Cursor generate a lot of code fast, and business logic ends up copied across handlers and routes — so a discount applies twice, an order has no duplicate-charge guard, a price is trusted from the browser. Nothing warns you. Untangly reads the whole app and shows every rule in plain language, so the broken ones are the ones you'll read and say “that's wrong.”

I asked AI to fix one thing and it broke another — how do I stop that?

That's the core risk of editing a vibe-coded app: every AI change can quietly break a rule that used to work. Untangly derives tests from your app's rules independently of the code, so a change ships only if the neighbouring rules still pass. If a fix would break something else, it's blocked and rolled back — and you see exactly what an edit touches before any code is written.

How do I get out of the AI loop — fix one bug, break two more?

That loop happens because the AI has no independent way to check its own work — it just trusts its own fix. Untangly breaks the loop by deriving tests from your rules separately from the code, so every change is checked against something the AI didn't write. A fix that would break another rule is caught and rolled back before it ships — not after your customers find it.

My vibe-coded app has a bug I can't find — how do I fix it without a developer?

Untangly turns your app's rules into plain sentences you can judge true or false. The bug is usually a rule that reads false. You fix it by editing the sentence — Untangly writes the code, tests it against your rule, and only ships if it passes.

Why did my AI prompt break something that already worked?

A prompt sent straight to Lovable, Bolt or Cursor with no context of your app doesn't know what it might tangle — it'll happily rewrite logic another feature depends on. Untangly's Featurecraft grounds every prompt in your verified app first — which tables it touches, which rules it must not break — so a broken prompt never reaches your builder in the first place.

Is my Lovable / AI-generated app secure?

AI-generated apps often leak on the money path: prices trusted from the browser, missing duplicate-order guards, weak row-level security, secret keys shipped to the client. Untangly flags these money-path and security risks in plain language, with what to do about each.

How do I understand what my vibe-coded app actually does?

You read it — in English. Untangly maps every route, service and handler to one plain-language rule per behaviour, grouped by area (orders, payments, shipping, refunds). No code, no jargon, no “ask your developer.”

Can I safely change a no-code / AI-built app without breaking it?

Yes. You describe the change in plain language; Untangly shows the exact effect before writing any code, derives tests from your rule independently, and rolls back anything that would break a neighbouring rule.

Which app builders does Untangly work with?

Any React + Node or Next.js app — Lovable, Bolt.new, Cursor, v0, Replit, or hand-written. If it runs, Untangly can read it.

How do I stop wasting Lovable credits on trial-and-error fixes?

Every prompt burns credits whether it works or not — and a vague one often takes several tries, or fixes one thing while breaking another you now have to spend more credits fixing. Untangly scopes each change to exactly what it touches, so a small update stays a small, isolated prompt instead of a guess at rewriting the whole app. Featurecraft hands your builder a prompt grounded in your real, verified app — fewer retries, fewer credits burned in the loop.

Scan your app free — your map and first findings in minutes.

Untangly — your app's rules, in plain language. Verified.

UntanglyYou shipped an app you can't read. Untangly can.© 2026 Nayeri Consulting AB