From a sentence to a published app

1. 1Describe the app you want, in a sentence.
2. 2Builddu builds it: server-side code, a database, and pages wired together.
3. 3Look at it running in a live preview.
4. 4Change it — by clicking, by asking, or in the code.
5. 5Publish it to a live URL, and point your own domain at it.
6. 6Keep going: every change is another run, and every build is a version you can return to.

• One sentence is enough to start. There is no form, no stack picker and no diagram.
• You can start from the homepage before you have a project — signing up is what turns the prompt into a build.
• Nothing about your prompt changes what you are charged. The price comes from account and project state only, never from what you asked for.

• A full-stack app: server-side code, not a static front end.
• A managed database, included in every project, with no setup step.
• Pages wired together, and the routes between them.
• Sign-up, login and sessions — the agent is instructed to generate them. Observed in builds, not guaranteed.

What the database actually gives you — your tables, the filters, editing records, file fields and per-environment keys — is in your app’s database.

• The preview is the app really running, not a mock-up or a screenshot.
• Looking at it costs nothing, and it is yours to keep whether or not you ever publish.
• A project that went to sleep wakes when you open it, and waking it is not charged to you.

There are three ways to make one change: click the thing you want different, describe the change and let the agent make it, or open the file and write it yourself. What each one can do and what each one costs is set out in the visual editor.

• One click puts the project on a live URL. Publishing costs 1 credit.
• Publishing needs an active paid plan. Credits alone do not open it — a top-up buys AI runs, not hosting.
• Connect a domain you already own, and the certificate is handled for you.
• Re-publish whenever you change something. The URL stays the same.

Every build is kept as a version you can return to, you can download the whole codebase whenever you want it, and you can sync the project to a GitHub repository you own — what happens to your code is the detail on all three.

• Signing up gives you 50 credits once. No card, and it does not renew.
• Your first AI run is the free build. It is one run per account, enforced in the database rather than by a check in the interface.
• A never-paid account can own 1 project at a time. Deleting it frees the slot, and anyone who has ever paid is permanently outside that limit.
• The free run is bounded upstream as well, so a request too large to finish stops when it stops — with the project and every file it produced intact.

• You keep the project, its preview and its files. None of that is taken away.
• You can keep making visual changes while at least 2 credits remain.
• You can read, edit, save and download your code. None of that is an AI run.
• Another AI run needs 60 credits available, because that is what a run holds before it starts.
• Publishing needs an active plan — Starter is $20 a month and includes 100 credits.

Every one of those figures, where each comes from, and what happens at zero is on the pricing page.