Compose UI Builder

The UI builder is an authoring surface served by compose-preview serve: a design is a document of catalog components, edited by an operation log, and exported as Compose Kotlin (or PNG/SVG). A person edits it in the browser at /ui-builder/<catalog>/<designId>; you edit the same live document over the server's MCP endpoint. Both land in one revision log, so you and a designer can work on the same design at the same time.

A design can also live in a checked-in .uid file. For a repository design, inspect its schema and follow the local design-to-code workflow: edit the canonical file, compare real design renders with references, adapt exported Kotlin into the application, then render the affected @Previews. Use compose-preview alongside this skill when a composable already exists.