Build Mateu UI screens in Java — declarative @UI classes and fluent component trees that render as web UI. Use when creating or editing CRUD screens, forms, wizards, editor/master-detail views, dashboards, application shells, or federated microfrontends with Mateu (io.mateu). Triggers on @UI, AutoCrud, Wizard, ComponentTreeSupplier, CrudStore.
Wire a federated Mateu setup end to end — a shell app that aggregates several @UI modules by Maven (build-time, one deployment) or independent services by RemoteMenu over HTTP (runtime, true microservices). Use when building an app shell, microfrontends, service-owned UI modules, embedding a remote UI in a page, or composing several Mateu backends. Triggers on shell, @Menu, RemoteMenu, MicroFrontend, microfrontend, service-owned UI, compose backends.
Build, run, and screenshot a Mateu screen to see it actually render. Use when asked to run a Mateu app, verify a screen renders in the real UI (not just tests), or capture a PNG of a route (e.g. for docs). Handles the UI-module → app build order and the Playwright screenshot.mjs flow. Triggers on run the app, start the demo, screenshot the screen, verify it renders, spring-boot:run.
Scaffold a new Mateu project or module and wire the Maven build correctly — the two-step annotation processing (indexer + framework AP), the renderer dependency, and the Spring Boot main class. Use when starting a new Mateu app, adding a framework-agnostic @UI module, or fixing "my @UI class compiles but no controller is generated / the route 404s / nothing renders". Triggers on new Mateu project, pom.xml, annotationProcessorPaths, annotation-processor-indexer, annotation-processor-mvc, mvc-core, vaadin-lit.