swift-macos

Comprehensive macOS app development with Swift 6.2, SwiftUI, SwiftData, Swift Concurrency, Foundation Models, Swift Testing, ScreenCaptureKit, and app distri...

Security Scan

An instruction-only macOS/Swift development guide that asks for no credentials or installs and is internally consistent with its stated purpose.

Purpose & Capability

Name/description (macOS Swift development) match the skill contents: SKILL.md and many reference docs all target Swift, SwiftUI, SwiftData, ScreenCaptureKit, testing, and distribution. No unrelated credentials, binaries, or distribution mechanisms are requested.

Instruction Scope

The runtime instructions are purely developer guidance and code examples. They do not instruct the agent to read arbitrary host files, access environment variables, or send data to external endpoints. The guidance describes APIs (e.g., screen capture) whose use may require runtime user permissions — which is expected for that functionality.

Install Mechanism

No install spec and no code files to execute — instruction-only skill (lowest-risk install profile).

Credentials

No required environment variables, credentials, or config paths are declared. The content references macOS APIs (e.g., NSPasteboard, NSWorkspace) but does not request secrets or unrelated credentials.

Persistence & Privilege

always is false and the skill is user-invocable. It does not request elevated persistence or modification of other skills or system-wide agent settings.

Scan Findings in Context

[system-prompt-override] unexpected: The static scanner flagged a 'system-prompt-override' pattern in SKILL.md. I reviewed the provided SKILL.md content and supporting reference files: they contain developer-facing guidance and metadata but do not appear to contain explicit instructions to change the agent/system prompt or to exfiltrate data. This is likely a false positive from pattern-matching on natural-language headings or metadata, but you should still glance through the top of SKILL.md for any 'You are' or 'ignore system instructions' lines before use.

Assessment

This skill is an instruction-only Swift/macOS development guide and appears coherent with its stated purpose: it requests no credentials and performs no installs. Because the skill source and homepage are unknown, skim the SKILL.md yourself before enabling — look for any lines that try to override system prompts, ask for secrets, or instruct the agent to run terminal commands on your machine. Be aware that many examples cover screen and audio capture; code that implements those features will require macOS runtime permissions (Screen Recording, Microphone) if you build/run it. If you plan to copy-and-paste code into a project or terminal, review it for dangerous operations (executing shell commands, network calls, or file-system writes) and avoid granting permissions unless you trust the code and its origin.

macOS App Development - Swift 6.2

Build native macOS apps with Swift 6.2 (latest: 6.2.4, Feb 2026), SwiftUI, SwiftData, and macOS 26 Tahoe. Target macOS 14+ for SwiftData/@Observable, macOS 15+ for latest SwiftUI, macOS 26 for Liquid Glass and Foundation Models.

Quick Start

import SwiftUI
import SwiftData

@Model
final class Project {
    var name: String
    var createdAt: Date
    @Relationship(deleteRule: .cascade) var tasks: [Task] = []

    init(name: String) {
        self.name = name
        self.createdAt = .now
    }
}

@Model
final class Task {
    var title: String
    var isComplete: Bool
    var project: Project?

    init(title: String) {
        self.title = title
        self.isComplete = false
    }
}

@main
struct MyApp: App {
    var body: some Scene {
        WindowGroup("Projects") {
            ContentView()
        }
        .modelContainer(for: [Project.self, Task.self])
        .defaultSize(width: 900, height: 600)

        #if os(macOS)
        Settings { SettingsView() }

        MenuBarExtra("Status", systemImage: "circle.fill") {
            MenuBarView()
        }
        .menuBarExtraStyle(.window)
        #endif
    }
}

struct ContentView: View {
    @Query(sort: \Project.createdAt, order: .reverse)
    private var projects: [Project]

    @Environment(\.modelContext) private var context
    @State private var selected: Project?

    var body: some View {
        NavigationSplitView {
            List(projects, selection: $selected) { project in
                NavigationLink(value: project) {
                    Text(project.name)
                }
            }
            .navigationSplitViewColumnWidth(min: 200, ideal: 250)
        } detail: {
            if let selected {
                DetailView(project: selected)
            } else {
                ContentUnavailableView("Select a Project",
                    systemImage: "sidebar.left")
            }
        }
    }
}

Scenes & Windows

Scene	Purpose
WindowGroup	Resizable windows (multiple instances)
Window	Single-instance utility window
Settings	Preferences (Cmd+,)
MenuBarExtra	Menu bar with .menu or .window style
DocumentGroup	Document-based apps

Open windows: @Environment(\.openWindow) var openWindow; openWindow(id: "about")

For complete scene lifecycle, see references/app-lifecycle.md.

Menus & Commands

.commands {
    CommandGroup(replacing: .newItem) {
        Button("New Project") { /* ... */ }
            .keyboardShortcut("n", modifiers: .command)
    }
    CommandMenu("Tools") {
        Button("Run Analysis") { /* ... */ }
            .keyboardShortcut("r", modifiers: [.command, .shift])
    }
}

Table (macOS-native)

Table(items, selection: $selectedIDs, sortOrder: $sortOrder) {
    TableColumn("Name", value: \.name)
    TableColumn("Date") { Text($0.date, format: .dateTime) }
        .width(min: 100, ideal: 150)
}
.contextMenu(forSelectionType: Item.ID.self) { ids in
    Button("Delete", role: .destructive) { delete(ids) }
}

For forms, popovers, sheets, inspector, and macOS modifiers, see references/swiftui-macos.md.

@Observable

@Observable
final class AppState {
    var projects: [Project] = []
    var isLoading = false

    func load() async throws {
        isLoading = true
        defer { isLoading = false }
        projects = try await ProjectService.fetchAll()
    }
}

// Use: @State var state = AppState()          (owner)
// Pass: .environment(state)                    (inject)
// Read: @Environment(AppState.self) var state  (child)

SwiftData

@Query & #Predicate

@Query(filter: #Predicate<Project> { !$0.isArchived }, sort: \Project.name)
private var active: [Project]

// Dynamic predicate
func search(_ term: String) -> Predicate<Project> {
    #Predicate { $0.name.localizedStandardContains(term) }
}

// FetchDescriptor (outside views)
var desc = FetchDescriptor<Project>(predicate: #Predicate { $0.isArchived })
desc.fetchLimit = 50
let results = try context.fetch(desc)
let count = try context.fetchCount(desc)

Relationships

@Model final class Author {
    var name: String
    @Relationship(deleteRule: .cascade, inverse: \Book.author)
    var books: [Book] = []
}

@Model final class Book {
    var title: String
    var author: Author?
    @Relationship var tags: [Tag] = []  // many-to-many
}

Delete rules: .cascade, .nullify (default), .deny, .noAction.

Schema Migration

enum SchemaV1: VersionedSchema { /* ... */ }
enum SchemaV2: VersionedSchema { /* ... */ }

enum MigrationPlan: SchemaMigrationPlan {
    static var schemas: [any VersionedSchema.Type] { [SchemaV1.self, SchemaV2.self] }
    static var stages: [MigrationStage] {
        [.lightweight(fromVersion: SchemaV1.self, toVersion: SchemaV2.self)]
    }
}

// Apply: .modelContainer(for: Model.self, migrationPlan: MigrationPlan.self)

CloudKit Sync

Enable iCloud capability, then .modelContainer(for: Model.self) auto-syncs. Constraints: all properties need defaults/optional, no unique constraints, optional relationships.

For model attributes, background contexts, batch ops, undo/redo, and testing, see SwiftData references below.

Concurrency (Swift 6.2)

Default MainActor Isolation

Opt entire module into main actor - all code runs on main actor by default:

// Package.swift
.executableTarget(name: "MyApp", swiftSettings: [
    .defaultIsolation(MainActor.self),
])

Or Xcode: Build Settings > Swift Compiler > Default Isolation > MainActor.

@concurrent

Mark functions for background execution:

@concurrent
func processFile(_ url: URL) async throws -> Data {
    let data = try Data(contentsOf: url)
    return try compress(data) // runs off main actor
}
// After await, automatically back on main actor
let result = try await processFile(fileURL)

Use for CPU-intensive work, I/O, anything not touching UI.

Actors

actor DocumentStore {
    private var docs: [UUID: Document] = [:]
    func add(_ doc: Document) { docs[doc.id] = doc }
    func get(_ id: UUID) -> Document? { docs[id] }
    nonisolated let name: String
}
// Requires await: let doc = await store.get(id)

Structured Concurrency

// Parallel with async let
func loadDashboard() async throws -> Dashboard {
    async let profile = fetchProfile()
    async let stats = fetchStats()
    return try await Dashboard(profile: profile, stats: stats)
}

// Dynamic with TaskGroup
func processImages(_ urls: [URL]) async throws -> [NSImage] {
    try await withThrowingTaskGroup(of: (Int, NSImage).self) { group in
        for (i, url) in urls.enumerated() {
            group.addTask { (i, try await loadImage(url)) }
        }
        var results = [(Int, NSImage)]()
        for try await r in group { results.append(r) }
        return results.sorted { $0.0 < $1.0 }.map(\.1)
    }
}

Sendable

struct Point: Sendable { var x, y: Double }              // value types: implicit
final class Config: Sendable { let apiURL: URL }          // final + immutable
actor SharedState { var count = 0 }                       // mutable: use actors
// Enable strict mode: .swiftLanguageMode(.v6) in Package.swift

AsyncSequence & Observations

// Stream @Observable changes (Swift 6.2)
for await state in Observations(of: manager) {
    print(state.progress)
}

// Typed NotificationCenter (Swift 6.2)
struct DocSaved: MainActorMessage { let id: UUID }
NotificationCenter.default.post(DocSaved(id: doc.id))
for await n in NotificationCenter.default.notifications(of: DocSaved.self) {
    refresh(n.id)
}

For concurrency deep dives, see concurrency references below.

Foundation Models (macOS 26+)

On-device ~3B LLM. Free, offline, private:

import FoundationModels

let session = LanguageModelSession()
let response = try await session.respond(to: "Summarize: \(text)")

// Structured output
@Generable struct Summary { var title: String; var points: [String] }
let result: Summary = try await session.respond(to: prompt, generating: Summary.self)

For tool calling, streaming, and sessions, see references/foundation-models.md.

Testing

import Testing

@Suite("Project Tests")
struct ProjectTests {
    @Test("creates with defaults")
    func create() {
        let p = Project(name: "Test")
        #expect(p.name == "Test")
    }

    @Test("formats sizes", arguments: [(1024, "1 KB"), (0, "0 KB")])
    func format(bytes: Int, expected: String) {
        #expect(formatSize(bytes) == expected)
    }
}

// SwiftData testing
let container = try ModelContainer(
    for: Project.self,
    configurations: ModelConfiguration(isStoredInMemoryOnly: true)
)
let ctx = ModelContext(container)
ctx.insert(Project(name: "Test"))
try ctx.save()

For exit tests, attachments, UI testing, see references/testing.md.

Distribution

Method	Sandbox	Notarization	Review
App Store	Required	Automatic	Yes
Developer ID	Recommended	Required	No
Ad-Hoc	No	No	Local only

xcodebuild archive -scheme MyApp -archivePath MyApp.xcarchive
xcodebuild -exportArchive -archivePath MyApp.xcarchive \
  -exportPath ./export -exportOptionsPlist ExportOptions.plist
xcrun notarytool submit ./export/MyApp.dmg \
  --apple-id [e-mail] --team-id TEAM_ID \
  --password @keychain:AC_PASSWORD --wait
xcrun stapler staple ./export/MyApp.dmg

For complete distribution guide, see references/distribution.md.

SPM

// swift-tools-version: 6.2
let package = Package(
    name: "MyApp",
    platforms: [.macOS(.v14)],
    targets: [
        .executableTarget(name: "MyApp", swiftSettings: [
            .swiftLanguageMode(.v6),
            .defaultIsolation(MainActor.self),
        ]),
        .testTarget(name: "MyAppTests", dependencies: ["MyApp"]),
    ]
)

For build plugins, macros, and Swift Build, see references/spm-build.md.

Liquid Glass (macOS 26)

Apps rebuilt with Xcode 26 SDK get automatic Liquid Glass styling. Use .glassEffect() for custom glass surfaces, GlassEffectContainer for custom hierarchies. Opt out: UIDesignRequiresLiquidGlass = NO in Info.plist.

ScreenCaptureKit

Capture screen content, app audio, and microphone (macOS 12.3+):

import ScreenCaptureKit

let content = try await SCShareableContent.excludingDesktopWindows(false, onScreenWindowsOnly: true)
guard let display = content.displays.first else { return }

// Filter: specific apps only
let filter = SCContentFilter(display: display, including: [targetApp], exceptingWindows: [])

// Configure
let config = SCStreamConfiguration()
config.capturesAudio = true
config.sampleRate = 48000
config.channelCount = 2
config.excludesCurrentProcessAudio = true

// Audio-only: minimize video overhead
config.width = 2; config.height = 2
config.minimumFrameInterval = CMTime(value: 1, timescale: CMTimeScale.max)

let stream = SCStream(filter: filter, configuration: config, delegate: self)
try stream.addStreamOutput(self, type: .screen, sampleHandlerQueue: nil)
try stream.addStreamOutput(self, type: .audio, sampleHandlerQueue: audioQueue)
try await stream.startCapture()

macOS 15+: SCRecordingOutput for simplified file recording, config.captureMicrophone for mic capture. macOS 14+: SCContentSharingPicker for system picker UI, SCScreenshotManager for single-frame capture.

For complete API reference, audio writing (AVAssetWriter/AVAudioFile), permissions, and examples, see references/screen-capture-audio.md.

AppKit Interop

struct WebViewWrapper: NSViewRepresentable {
    let url: URL
    func makeNSView(context: Context) -> WKWebView { WKWebView() }
    func updateNSView(_ v: WKWebView, context: Context) {
        v.load(URLRequest(url: url))
    }
}

For hosting SwiftUI in AppKit and advanced bridging, see references/appkit-interop.md.

Architecture

Pattern	Best For	Complexity
SwiftUI + @Observable	Small-medium, solo	Low
MVVM + @Observable	Medium, teams	Medium
TCA	Large, strict testing	High

See references/architecture.md for all patterns with examples.

References

File	When to read
SwiftUI & macOS
references/app-lifecycle.md	Window management, scenes, DocumentGroup, MenuBarExtra gotchas, async termination, LSUIElement issues
references/swiftui-macos.md	Sidebar, Inspector, Table, forms, popovers, sheets, search
references/appkit-interop.md	NSViewRepresentable, hosting controllers, AppKit bridging, NSPanel/floating HUD
references/screen-capture-audio.md	ScreenCaptureKit, SCStream gotchas, AVAudioEngine dual pipeline, AVAssetWriter crash safety, TCC gotchas
references/system-integration.md	Keyboard shortcuts, drag & drop, file access, App Intents, process monitoring, CoreAudio per-process APIs, login items, LSUIElement, idle sleep prevention
references/foundation-models.md	On-device AI: guided generation, tool calling, streaming
references/architecture.md	MVVM, TCA, dependency injection, project structure
references/testing.md	Swift Testing, exit tests, attachments, UI testing, XCTest migration
references/distribution.md	App Store, Developer ID, notarization gotchas, nested bundle signing, sandboxing, universal binaries
references/spm-build.md	Package.swift, Swift Build, plugins, macros, manual .app bundle assembly, mixed ObjC targets, CLT testing
Concurrency
references/approachable-concurrency.md	Default MainActor isolation, @concurrent, nonisolated async, runtime pitfalls
references/actors-isolation.md	Actor model, global actors, custom executors, reentrancy
references/structured-concurrency.md	Task, TaskGroup, async let, cancellation, priority, named tasks
references/sendable-safety.md	Sendable protocol, data race safety, @unchecked Sendable + serial queue, @preconcurrency import
references/async-patterns.md	AsyncSequence, AsyncStream, Observations, continuations, Clock
references/migration-guide.md	GCD to async/await, Combine to AsyncSequence, Swift 6 migration
SwiftData
references/models-schema.md	@Model, @Attribute options, Codable, transformable, external storage
references/relationships-predicates.md	Advanced relationships, inverse rules, compound predicates
references/container-context.md	ModelContainer, ModelContext, background contexts, undo/redo, batch ops
references/cloudkit-sync.md	CloudKit setup, conflict resolution, sharing, debugging sync
references/migrations.md	VersionedSchema, lightweight/custom migration, Core Data migration