a2ui-core/dev.ynagai.a2ui.core.validation/CatalogValidator/resolve

resolve

fun resolve(explicit: String?, surfaceDefault: String?): CatalogResolution

The catalog a component or call belongs to.

The order is the one the specification fixes: the element's own catalogId wins, the surface's default applies when the element omits it, and naming neither is an error rather than a silent choice among the catalogs the renderer happens to hold. Guessing when only one catalog is loaded would make a payload's meaning depend on the renderer's configuration.