Open source · SwiftUI design system · 0.2.0
LubaUI is a SwiftUI package for building interfaces across five Apple platforms. Three choices separate it from the usual component library: behaviors are primitives any view can borrow, every value comes from a documented scale, and the system is queryable by a coding agent rather than only readable by a person.
Swift 5.9+ · Swift Package Manager · MIT · five Apple platforms
Most of the work went into the parts nobody demos: contrast ratios, touch targets, what the type scale does when someone enlarges it, and what the animations do when someone switches them off.
What’s different
None of these are exotic on their own. Holding all three at once is what changes how the system is built and how it gets used.
Semantic names, documented rationale, an MCP server, and a single reference file mean a coding agent can ask what a token is instead of inferring it from a hex value. Two tests fail the build if a theme role goes unread, or if a component reaches past the theme for a raw number.
Spacing is a 4pt grid with stated ratios. Press feedback scales inversely with element size. The accent clears 4.5:1 in both modes. Where a number came from is part of its definition, which is also what makes it checkable.
One package covers iOS, macOS, watchOS, tvOS, and visionOS. And because a theme is data rather than a fork, the same components carry a different brand: LubaThemeColors.accented(_:) derives a full palette from a single colour.
Release notes · 0.2.0 · Aug 2026
Earlier versions documented theming, accessibility, and localization more thoroughly than they implemented them. This release closes that gap and adds tests that fail if the wiring comes loose again.
Composability
Press, swipe, long-press, expand, shimmer, and glass attach to any view instead of living inside a button. Below are web approximations of the SwiftUI originals — the interaction is the point, not the pixels.
.lubaPressable().lubaSwipeable().lubaLongPressable().lubaExpandable().lubaShimmerable().lubaGlass().lubaPressable()scale(0.97), spring(0.25s, 0.65 damping)
.lubaExpandable()spring(0.35s, 0.75 damping)
.lubaSwipeable()presets: .delete, .archive, .pin
.lubaShimmerable()1.5s cycle, applied to any view
.lubaLongPressable()progress ring, confirms destructive actions
The numbers
A token is only useful if you can say why it holds that value. These are the arguments behind the scale, the motion, and the defaults.
Three token tiers with strict boundaries: raw values never reach a component, semantic tokens do. Two tests exist purely to guard the rule — they fail if a theme color is declared but never read, or if component code reaches past the theme for a raw dimension.
Smaller elements shrink more on press: compact 0.95, standard 0.97, prominent 0.98. A 44pt icon button needs exaggerated motion to feel responsive; a full-width card needs subtlety or it looks broken.
Sage accent #6B8068 light / #9AB897 dark, both above 4.5:1. Controls grow with the type scale, labels wrap rather than truncate, and small glyphs keep a 44pt target underneath them.
A long-press progress ring keeps its real duration under Reduce Motion, because the fill is the countdown — shortening it would remove information rather than calm it.
On device
Every component, primitive, and pattern in the package, running on a device rather than posed in a mockup.
Tooling
Semantic naming and written rationale help a person and are close to required for an agent. An MCP server answers structured questions; a single reference file covers the rest — either way without reading every source file first.
Ten tools for token and component lookup, spacing and radius validation, colour palettes, token suggestions, and migration planning from an existing system. Works with Claude Code, Cursor, and any MCP-compatible agent.
claude mcp add lubaui -- npx lubaui-mcp
lookup_tokenlookup_tokenslookup_componentlookup_componentslookup_primitivevalidate_spacingvalidate_radiusget_color_palettesuggest_tokensplan_migrationA 651-line agent reference covering the architecture, every token, all component APIs, the primitives, and the usage patterns. One file, kept in step with the package.
shopofluba.de/lubaui/llms.txt
The library
All of them resolve through the theme, and all of them compose with the primitives.
LubaButtonLubaIconButtonLubaTextFieldLubaTextAreaLubaSearchBarLubaCheckboxLubaRadioLubaToggleLubaSliderLubaStepperLubaRatingLubaTabsLubaCardLubaSheetLubaDividerLubaToastLubaAlertLubaProgressBarLubaCircularProgressLubaSpinnerLubaBadgeLubaTooltipLubaAvatarLubaIconLubaCircledIconLubaSkeletonLubaChipLubaLinkLubaMenuLubaBarChartLubaGroupedBarChartLubaLineChartLubaMultiLineChartLubaPieChartLubaSparklineLubaChartSkeletonLubaChartLegendimport LubaUI
struct ContentView: View {
@State private var name = ""
@State private var notify = true
var body: some View {
VStack(spacing: LubaSpacing.lg) {
LubaCard(elevation: .low) {
LubaTextField("Name", text: $name)
LubaToggle(isOn: $notify, label: "Notifications")
}
LubaButton("Save", style: .primary) { save() }
LubaButton("Cancel", style: .ghost) { dismiss() }
}
.lubaPressable { navigate() } // any view, tappable
.lubaTheme(.accented(.indigo)) // and it repaints
}
}Open source, MIT licensed
.package(url: "https://github.com/ermanakar/LubaUI.git", from: "0.2.0")