LumiKit

A UIKit design system and component kit for iOS 18+, iPadOS, and Mac Catalyst, written in Swift 6.2: a value-type theme that re-renders live, a Style struct on every component, 60+ components and controls, a photo module, debug tooling, and Foundation utilities. Strings ship in English, Spanish, Simplified Chinese, and Traditional Chinese.

Products

Product	Depends on	What it holds
LumiKitCore	Foundation	LMKLogger, LMKDate and LMKDateFormat, LMKFormat, LMKFile, LMKConcurrency, LMKURLValidator, Gregorian calendar day and selection types, string and collection extensions
LumiKitUI	Core, SnapKit	Tokens and the theme, styles, components, controls, lists, navigation, calendar, detail cards, alerts, toasts, share sheet, haptics, animation, utilities, UIKit extensions
LumiKitPhoto	Core, UI	Photo browser, photo grid, crop editor, pick-and-crop coordinator, share preview, LMKPhotoMetadata
LumiKitDebug	Core, UI	LMKNetworkLogger (URLProtocol capture with redaction) and the request inspector; DEBUG builds only
LumiKitLottie	UI, Lottie	LMKLottieRefreshControl with its bundled ring animation

Link LumiKitPhoto only where you show photos, and LumiKitDebug only in debug builds. LumiKitUI links LumiKitCore but does not re-export it: import LumiKitCore in files that name its types.

Screenshots

Catalog	Buttons	Chips	Text fields

List rows	Detail cards	Month calendar	Photo grid

Navigation bar	Tab bar	Action sheet	Banners

Requirements

Swift 6.2 or later (Xcode 26 or Xcode 27), iOS 18 / Mac Catalyst 18 as the floor (LumiKitCore and LumiKitDebug also build for macOS 15). iOS 26 features (Liquid Glass, concentric corners, scroll-edge effects, tab bar minimize, and more) are adopted behind #available with same-API fallbacks, so callers never gate. Details in docs/PLATFORM.md.

Installation

dependencies: [
    .package(url: "https://github.com/Luminoid/LumiKit.git", from: "1.0.0"),
],
targets: [
    .target(name: "MyApp", dependencies: [
        .product(name: "LumiKitUI", package: "LumiKit"),
        .product(name: "LumiKitPhoto", package: "LumiKit"),   // optional
        .product(name: "LumiKitLottie", package: "LumiKit"),  // optional
    ]),
]

Upgrading from 0.x: read docs/MIGRATION-1.0.md and run Scripts/migrate-1.0.sh <your-app> --dry-run.

Quick start

import LumiKitUI

// 1. A theme is a value. Override only what differs; apply it at launch or any time later.
extension LMKTheme {
    static let myApp = LMKTheme(colors: LMKColorTheme(primary: .systemIndigo, secondary: .systemTeal))
}
LMKTheme.apply(.myApp)

// 2. Tokens are dynamic: every LMKColor re-resolves on theme, dark mode, and contrast changes.
view.backgroundColor = LMKColor.backgroundPrimary
let title = UILabel.lmk_make(.h2, text: "Hello")

// 3. Components take a Style; nil fields fall back to the theme.
let save = LMKButton(title: "Save", style: .filled(.primary)) { print("saved") }
let chip = LMKChipView(text: "Outdoor", style: .outlined.tint(.systemGreen))
chip.onTap = { chip.isSelected.toggle() }

// 4. Presenters end in `present(from:)`; installed views end in `show(in:)`.
LMKToast.show(.success, "Saved", in: self)
LMKAlert.presentDeleteConfirmation(from: self, itemName: "Photo", onConfirm: { delete() })

App-wide defaults for any component live on the theme (theme.button.variant = .tinted), per-instance tweaks on style, and anything the Style does not cover in a didApplyStyle hook that re-runs on every theme change.

Logging

LMKLogger (in LumiKitCore) writes through os.Logger under your app's subsystem.

import LumiKitCore

LMKLogger.configure(subsystem: Bundle.main.bundleIdentifier ?? "com.example.app")
LMKLogger.enableLogStore()                          // optional: an in-memory ring buffer for a debug screen
LMKLogger.entryHandler = { entry in breadcrumbs.add(entry) } // optional: forward every written entry

LMKLogger.notice("Sync finished: \(count) records", category: .data)
LMKLogger.error("Upload failed", private: fileURL.path, error: error, category: .network)

• Six levels, debug < info < notice < warning < error < fault, written at the unified-logging types os.Logger's own methods use: .debug, .info, .default, .error, .error, .fault. Only notice and above are saved on the device, so a line you will need from a user's sysdiagnose is a notice or higher.
• Runtime threshold. LMKLogger.minimumLevel defaults to .debug in DEBUG builds and .info otherwise, and can change at any time. Nothing is compiled out. The threshold clamps at .error, so errors and faults are always written.
• Public message, private detail. The message is public: keep it to static text, codes, ids, counts, dimensions, and type names. Pass user data (URLs, file paths, user content, text shown to the user) as private:; it is written as private and redacted in field logs. messagePrivacy = .private additionally redacts the message text; the [File.swift:12] function prefix is always public.
• Errors. Attach them with error: instead of interpolating a description. LMKLogger.describe(_:) puts the type and case of a Swift enum error, or the NSError domain and code plus the underlying error's, in the public message as [NSURLErrorDomain -1001 <- NSPOSIXErrorDomain 60], and the full description in the private detail.
• Floods. LMKLogger.once(key, level, message) writes a line once per key until resetOnce(key), for failures on per-frame or polling paths.
• Other packages' logs. A package with its own logger can forward its entries into the app's store and handler with LMKLogger.record(_:), which writes nothing to the unified log again and applies no threshold.
• LumiKit's own lines use the LumiKit category (LMKLogger.LogCategory.lumiKit): filter on it in Console or log stream --predicate 'category == "LumiKit"'. They reach the log store and the handler with no extra setup, and alerts, LMKErrorHandler, and LMKConcurrency.executeTask name your call site.

Example app

Example/ is a catalog of 69 pages in 12 sections (Foundations, Buttons & Controls, Text Input & Forms, Labels & Indicators, Cards & Lists, Dates, Navigation, Feedback & Status, Sheets & Panels, Photos & Media, Utilities, Debug), with search and a live theme switcher. Generate it with XcodeGen:

cd Example && xcodegen generate && open LumiKitExample.xcodeproj

It doubles as the accessibility test bed: -lmk-audit-all -lmk-config <name> -lmk-screenshots <dir> walks every page, audits truncation, clipping, overlap, 44pt targets, labels, WCAG contrast, and fixed fonts, and writes a screenshot per page; -lmk-rtl and -lmk-theme <name> cover right-to-left and a second theme.

Documentation

API reference on the Swift Package Index: LumiKitCore, LumiKitUI, LumiKitPhoto, LumiKitDebug, LumiKitLottie. make docs builds the same archives locally. The LumiKitUI catalog carries the guides: Getting Started, Theming, Styling, Components, Controls, Extensions, Localization, Platform Support, and Migrating to 1.0.

Build and test

brew bundle            # swiftlint, swiftformat, xcodegen
make setup-hooks       # pre-commit lint + format
make check             # SwiftLint --strict, SwiftFormat --lint
make build             # iOS Simulator          make build-catalyst   # Mac Catalyst
make test              # iOS Simulator          make test-filter FILTER=LumiKitUITests/LMKButtonTests
make example           # regenerate + build     make example-catalyst # the Example for the Mac idiom
make docs              # DocC archives
make migrate CONSUMER=../MyApp ARGS=--dry-run

UIKit targets need the simulator; make build-host builds LumiKitCore and LumiKitDebug natively on macOS. CI runs the same steps with warnings as errors, testing under Xcode 26 and Xcode 27.

Naming

Public types carry the LMK prefix; extension members on UIKit and Foundation types carry lmk_. Namespaces are subject nouns (LMKAnimation, LMKImage, LMKAlert), view controllers end in ViewController, callbacks are present-tense on<Event> closures (onValueChange for a value), presenters use present(from:) and show(in:), every component has a nested Style and Strings. The full rule set is in CONTRIBUTING.md.

Built with LumiKit

App	Description
Plantfolio Plus	Plant care, watering schedules, collections, and photos for iOS, iPadOS, and Mac
Petfolio	Pet care, health tracking, vet visits, food inventory for iOS, iPadOS, and Mac
TripDays	Collaborative travel planner: day-by-day itineraries, maps, shared trips over iCloud, and expense splitting for iOS, iPadOS, and Mac
Metamer	Color-vision camera for iOS: CVD simulation, daltonize filters, true-color naming, and an Ishihara plate generator

Related projects

• Monolith: CLI that scaffolds iOS apps, Swift Packages, and Swift CLIs, with LumiKit wiring built in
• Everything else at luminoid.dev

License and changelog

MIT, see LICENSE. Release history in CHANGELOG.md; security policy in SECURITY.md.