# sup3rapp

> The AI app builder that checks the app works before you see it: typecheck, tests, a production build and a smoke test, in a sandbox of your own.

sup3rapp is in private beta. Access is by request; there is no self-serve signup yet. Everything below is stated on https://sup3rapp.com/facts, which is the canonical claim sheet: if any page on this site disagrees with it, that page is wrong.

## What sup3rapp is

sup3rapp is an AI app builder that verifies the application it generates — typecheck, tests, a production build and a smoke test — before the preview reaches you.

Category: AI app builder.

sup3rapp is in private beta. Access is by request; there is no self-serve signup yet.

## The verification chain

Every build runs, in this order: typecheck → tests → production build → smoke test.

- typecheck: 4.2s (measured on the marketing-site scaffold, in a network-less sandbox)
- tests: 4.3s (measured on the marketing-site scaffold, in a network-less sandbox)
- production build: 24.0s (measured on the marketing-site scaffold, in a network-less sandbox)
- smoke test: 3.9s (measured on the marketing-site scaffold, in a network-less sandbox)
- full chain: 37.4s

Wall-clock for one full verification chain, measured on our marketing-site scaffold in a network-less sandbox. The four stages account for 36.4s of it; the remainder is the sandbox handoff between stages.

## Verification claims

- Every build is verified before you see it: typecheck, then tests, then a production build, then a smoke test.
- A verification failure triggers an automatic repair loop rather than an error message. The chain re-runs from the top. Structured diagnostics from the failing stage are fed back for a bounded number of repair attempts before anything surfaces to the user.
- You see a working application or you see honest progress. A failed chain never reaches you as a broken preview.

## Execution and isolation

- Generated code runs in a per-project isolated sandbox. That includes the preview.
- Untrusted generated code never executes on shared infrastructure, and never shares infrastructure with another project.

## Versions and rollback

- Every build produces an immutable, content-hashed version. Iterating creates a new version; nothing is edited in place.
- Rolling back is a pointer change to an earlier version, not a rebuild — so it is instant and cannot fail.

## How the model changes code

- The model proposes structured file-edit operations. A deterministic executor validates them and applies them atomically — all of them or none.
- The model never touches a filesystem or a network directly.
- Generation starts from a pre-built, tested scaffold rather than an empty directory. The model modifies working software; it never invents project structure.

## Scaffolds

- marketing site: A landing page, a lightweight content model, and contact forms. Ships with routing, content model, contact forms, design tokens, a passing test suite.
- SaaS starter: Authentication, a Postgres schema, a dashboard shell, and billing wiring. Ships with auth, Postgres schema, dashboard shell, billing wiring, a passing test suite.
- internal tool: CRUD tables, filtering, and role-based access. Ships with CRUD tables, filtering, role-based access, design tokens, a passing test suite.

## Pricing

Charged per build operation. Prices are not published during the private beta.

## Goals, not shipped metrics

These are engineering targets and are never stated on the site as capability.

- A first build from a cold prompt completing in under 90 seconds.
- The repair loop resolving at least 80% of verification failures without user involvement.

## Not published yet

- The legal name, founding date and the people behind sup3rapp.
- Prices, tiers and limits.
- Code export and ownership terms.

These are omitted rather than approximated. When they are published they appear on /facts first.

# Pages

## Site

- [sup3rapp](https://sup3rapp.com): What sup3rapp is and why verification is the difference.
- [How it works](https://sup3rapp.com/how-it-works): The pipeline in depth: prompt, scaffold, edit operations, verification, repair, preview.
- [Verification](https://sup3rapp.com/verification): The verification chain and the repair loop, stage by stage.
- [Pricing](https://sup3rapp.com/pricing): The per-build credit model and what the private beta includes.
- [Comparisons](https://sup3rapp.com/vs): The AI app builder category and how to choose within it.
- [Answers](https://sup3rapp.com/answers): Question-first answers about AI app builders — what breaks, what is tested, what it costs.
- [Glossary](https://sup3rapp.com/glossary): One-sentence definitions of the terms this category uses loosely.
- [About](https://sup3rapp.com/about): Who is building sup3rapp and why.
- [Request access](https://sup3rapp.com/access): Request private-beta access.
- [Facts](https://sup3rapp.com/facts): The canonical claim sheet: capabilities, measurements, and their scope.

## Comparisons

- [sup3rapp vs Base44](https://sup3rapp.com/vs/base44): Base44 is the most batteries-included tool in the category, and the most restrictive about your code. sup3rapp verifies every build instead.
- [sup3rapp vs Lovable](https://sup3rapp.com/vs/lovable): Both build an app from a prompt. The difference is what happens when the generated code breaks — and who is expected to notice.
- [sup3rapp vs Replit](https://sup3rapp.com/vs/replit): Replit's Agent tests its own work and documents its sandboxing well. The difference is a fixed verification chain that gates the preview.
- [sup3rapp vs v0](https://sup3rapp.com/vs/v0): v0 gives each chat its own virtual machine and previews the full app. What it does not document is anything that has to pass before that preview appears.

## Answers

- [Are Lovable alternatives worth switching to in 2026?](https://sup3rapp.com/answers/are-lovable-alternatives-worth-switching-to): Only for a specific reason, not a general one. Switching costs a working project and everything you have learned about a tool. It is justified if you are repeatedly fixing broken generations yourself, if error fixing is eating your credits, or if you need something Lovable does not do — otherwise it is not.
- [Can an AI-built app handle real users and real data?](https://sup3rapp.com/answers/can-an-ai-built-app-handle-real-users-and-real-data): Often yes for modest traffic, and the deciding factors have little to do with the AI. What matters is whether authentication and permission checks are enforced on the server, whether the database is really yours, whether there are backups, and whether anyone has looked at the parts that handle money and personal data.
- [Can you host and own the code an AI app builder writes?](https://sup3rapp.com/answers/can-you-host-and-own-the-code-an-ai-app-builder-writes): Usually yes, though the exit varies more than the ownership does. Most tools state you own what is generated, and several let you download a zip or sync to GitHub on any plan. At least one puts that behind a paid tier and makes the connection permanent, so read the export terms first.
- [Do AI app builders test the code they generate?](https://sup3rapp.com/answers/do-ai-app-builders-test-the-code-they-generate): Mostly not, and almost never as a condition of showing you the result. Replit documents that its Agent tests its own work as it goes, and Base44 has a testing agent you run on demand. Lovable and v0 do not publicly document any check that must pass before a preview appears.
- [How do AI app builders run generated code safely?](https://sup3rapp.com/answers/how-do-ai-app-builders-run-generated-code-safely): By running it in a sandbox that cannot reach other projects or shared infrastructure. The strength of that sandbox varies: logical separation enforced in software, containers with a shared kernel, or virtual machines with their own. The question worth asking is whether the preview runs inside the same boundary as everything else.
- [How much do AI app builders cost, and why do prices vary so much?](https://sup3rapp.com/answers/how-much-do-ai-app-builders-cost): Published plans run from free tiers to roughly a hundred dollars a month per user, but the headline price is the least useful number. What varies is the unit — credits that scale with task complexity, effort measured in compute time, or per-token rates — so two tools at one price can differ several times over.
- [What is a verification chain in AI code generation?](https://sup3rapp.com/answers/what-is-a-verification-chain-in-ai-code-generation): A verification chain is a fixed sequence of automated checks that generated code must pass before it is shown to anyone. A typical chain runs a typecheck, a test suite, a production build and a smoke test, in that order, and a failure at any stage stops the sequence rather than being noted and ignored.
- [What is the best AI app builder for non-technical founders?](https://sup3rapp.com/answers/what-is-the-best-ai-app-builder-for-non-technical-founders): It depends on one thing more than any other — what the tool does when generation fails. If you cannot read code, a builder that repairs failures before showing you anything is worth more than one with a bigger template gallery, because the failure you cannot diagnose is the failure that ends the project.
- [What is the difference between an AI app builder and an AI coding assistant?](https://sup3rapp.com/answers/what-is-the-difference-between-an-ai-app-builder-and-an-ai-coding-assistant): An AI app builder produces and hosts a running application for someone who does not intend to read the code. An AI coding assistant works inside a codebase an engineer already owns, and assumes that engineer reviews, runs and deploys the result. The difference is who is responsible for noticing that something is broken.
- [What is vibe coding, and where does it break down?](https://sup3rapp.com/answers/what-is-vibe-coding-and-where-does-it-break-down): Vibe coding is building software by describing what you want and accepting the result without reading the code. It works well for small, low-stakes projects and breaks down when unread code accumulates faster than anyone can understand it — usually at the point where a change has to respect a decision nobody remembers making.
- [What should you check before shipping an AI-generated app?](https://sup3rapp.com/answers/what-to-check-before-shipping-an-ai-generated-app): Check the things a build cannot check for you, in order of damage: server-side permission checks, where secrets live, what happens to bad input, whether you can restore a backup, and whether the parts touching money and personal data do what you think. Everything else can be fixed after launch.
- [Why does AI-generated code break after the first few prompts?](https://sup3rapp.com/answers/why-does-ai-generated-code-break-after-the-first-few-prompts): Because the first prompt creates a project structure that was invented rather than designed, and every prompt after it makes changes to that structure without anything checking they hold. The damage is cumulative and invisible until a change has to touch two shaky decisions at once, which is usually somewhere around the third or fourth request.

## Glossary

- [content-hashed build](https://sup3rapp.com/glossary/content-hashed-build): A content-hashed build is an immutable version of an application identified by a hash computed from its own contents.
- [edit operation](https://sup3rapp.com/glossary/edit-operation): An edit operation is a single structured instruction to change one file, which a model proposes and a deterministic executor validates and applies.
- [repair loop](https://sup3rapp.com/glossary/repair-loop): A repair loop is an automated cycle that feeds a failing check's diagnostics back to the model, applies a fix, and runs the checks again.
- [sandbox isolation](https://sup3rapp.com/glossary/sandbox-isolation): Sandbox isolation is the practice of running untrusted code in a confined environment that cannot reach other tenants, projects or shared infrastructure.
- [scaffold](https://sup3rapp.com/glossary/scaffold): A scaffold is a pre-built, tested application that code generation starts from and modifies, rather than inventing a project structure from nothing.
- [smoke test](https://sup3rapp.com/glossary/smoke-test): A smoke test is a minimal check that a built application actually starts and serves a response, rather than merely compiling.
- [spec artifact](https://sup3rapp.com/glossary/spec-artifact): A spec artifact is a structured, versioned document that records what an application should do, in a form a program can read.
- [typecheck](https://sup3rapp.com/glossary/typecheck): A typecheck is a static analysis that verifies every value in a program is used consistently with its declared type, without running the program.
- [verification chain](https://sup3rapp.com/glossary/verification-chain): A verification chain is a fixed sequence of automated checks that a generated build must pass before it is shown to anyone.
- [vibe coding](https://sup3rapp.com/glossary/vibe-coding): Vibe coding is the practice of building software by describing what you want in natural language and accepting the generated result without reviewing the code.

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