Starter

A desktop and Notification Center widget: a countdown to a date the person picks with Edit Widget, plus the small app that carries it. Made with Summon from its widget template, to the SummonOS surface rules for system extensions (docs/ux-surfaces/07-system-extensions.md in the SummonOS workspace).

Behavior

What	How
Widget	Small and medium; one bold number (days left or since), a live timer on the day itself
Configure	Right-click the widget › Edit Widget: title and date (AppIntentConfiguration); no date shows "Choose a date"
Updates	A timeline entry at each midnight and at the target (at most 8, then .atEnd); no polling, well inside WidgetKit's daily budget
Look	System fonts, semantic colors, .widgetAccentable() on the number, so the desktop's tinted mode reads well
App	One window: previews and how to add the widget, Reload Widgets (⌘R); closing it quits the app
Settings	⌘,; close only, 480 pt, changes apply at once

Layout

This template is the one SummonOS exception to "SwiftPM, no .xcodeproj": a widget is an .appex bundle inside the app, which only Xcode builds. The Xcode project stays small and holds no logic; everything else is a Swift package.

Path	What it is
Sources/StarterCore/	Logic, Foundation only, tested: Countdown (phase, timeline dates), the widget kind
Sources/StarterUI/	CountdownView (the widget's face, also drawn in the app), the app window, Settings, #Previews
Sources/StarterUI/Screenshots.swift	--screenshot <folder>: light and dark PNGs of the window, used by summon project shots
Tests/StarterCoreTests/	swift-testing
Xcode/Starter.xcodeproj	Two targets, app Starter and extension StarterWidget, both linking this package (StarterKit)
Xcode/App/	@main app, AppIcon.icns (a placeholder: replace it with the summon-art skill)
Xcode/Widget/	The WidgetBundle, the Edit Widget intent, the timeline provider, widget previews
Xcode/Config/	Info.plist additions and the extension's sandbox entitlement (widgets must be sandboxed)
scripts/check.sh	The gate: package build and tests, plist lint, the Xcode build, the embedded and signed widget; writes build/check-report.md

Bundle ids: local.summon.widget-starter for the app, local.summon.widget-starter.widget for the widget. Files added to Xcode/App/ or Xcode/Widget/ join their target on their own (synchronized folders): no project edits.

Build and run

scripts/check.sh
scripts/bundle.sh            # build/Starter.app (needs Xcode)
open build/Starter.app       # run it once so the widget appears in the gallery

Then right-click the desktop › Edit Widgets… and search for Starter. Or open Xcode/Starter.xcodeproj and run the Starter scheme; widget previews are in Xcode/Widget/StarterWidget.swift.

Requires macOS 15+, Swift 6 and Xcode. No third-party dependencies.