Run

Preview shows what you are designing. Run runs your actual application: the exported Flutter code, compiled for the browser, talking to your project — real sign-in, real records, real functions — inside the phone frame.

What happens when you press it

The Designer exports your document — the same files Export gives you.
Koolbase compiles them to Flutter Web on a build executor. Your project's public key is supplied server-side; it never passes through the Designer.
The result is published and opened in the frame. Usually two to three minutes; the frame shows the stage and a counter.

Run again after a change and only a changed document builds again: identical exports reuse the last build. Exit while a build is in flight and it is cancelled.

What works, what does not

Everything the app does against Koolbase works: authentication, database reads and writes, storage, realtime, functions. Two things are absent because a browser cannot do them — code push (there is no binary to patch) and offline sync (reads are live, writes go straight out). Both work in the app you ship to a phone.

Camera and photo library

Picking an image works in the browser's file chooser. The iOS usage strings the real app needs are listed in the export manifest; Run does not need them.

Limits

Each build spends compute. While the Designer is in beta every project has 20 runs a day, resetting at midnight UTC; the frame tells you when they are used. Every build is recorded — who, when, how long — so the allowance can be set from real numbers rather than guesses.

Run is a project feature

Run needs a project with a live environment key, so it is not available in the no-account demo. Sign up, and it is one button.

When a build fails

The frame shows why and links to the build log. The most common causes are a document the checks would have flagged (fix them and run again) and a document that signs in or out with no sign-in screen, which export refuses for the same reason.