iOS Development Skill

Purpose

Modern iOS development (Swift 6, iOS 18+, SwiftUI, UIKit) with XcodeBuildMCP integration for autonomous Xcode operations.

When Active

User mentions iOS, Swift, SwiftUI, UIKit, iPhone app, iPad app, or iOS-specific commands.

Specialized Sub-Skills

This skill includes 3 specialized sub-skills for different iOS development aspects:

1. Development Patterns

Reference: skills/ios-development/development.md

• •Swift 6 concurrency (async/await, Sendable, Actors)
• •SwiftUI vs UIKit strategy
• •Architecture patterns (MVVM, TCA)
• •State management (@Observable, property wrappers)
• •NavigationStack implementation
• •Networking with URLSession
• •Persistence (SwiftData, Core Data)
• •Common UI components (List, Grid, Sheet, Form)
• •Debugging patterns

2. Build & Simulator Management

Reference: skills/ios-development/build.md

• •Xcode project configuration
• •Build settings and schemes
• •Swift Package Manager
• •Dependency management (SPM, CocoaPods)
• •Asset catalogs and resources
• •Code signing and provisioning
• •Build optimization
• •Simulator management (xcrun simctl + XcodeBuildMCP)
• •Common build errors and fixes
• •MCP tool patterns (discover_projs, list_schemes, build_sim, etc.)

3. Testing Strategies

Reference: skills/ios-development/tester.md

• •XCTest patterns (unit tests)
• •XCUITest patterns (UI tests)
• •Mock dependencies setup
• •Given-When-Then structure
• •Async/await testing
• •Coverage goals and reporting
• •Test organization
• •Accessibility identifiers for UI testing
• •MCP test automation (test_sim, test_device)

XcodeBuildMCP Integration

When XcodeBuildMCP is available, this skill provides autonomous Xcode operations:

MCP Capabilities

• •Project Discovery: Auto-discover projects and schemes
• •Build Automation: Build for simulator, device, or macOS
• •Simulator Management: Boot, install, launch, stop apps
• •Testing: Run XCTest/XCUITest suites
• •UI Automation: Tap, swipe, type, screenshot
• •Log Capture: Stream simulator/device logs
• •Environment Validation: Run diagnostics

Prerequisites

• •macOS 14.5+ with Xcode 16.x+
• •XcodeBuildMCP server: claude mcp add XcodeBuildMCP npx xcodebuildmcp@latest

Expertise

Swift 6 Concurrency

• •async/await patterns
• •Sendable protocol
• •Actors for thread-safety
• •Task cancellation
• •Structured concurrency

SwiftUI vs UIKit

• •SwiftUI for new features
• •UIKit for complex views
• •SwiftUI/UIKit interoperability
• •UIViewRepresentable/UIViewControllerRepresentable

Architecture

• •MVVM pattern
• •The Composable Architecture (TCA)
• •State management with @Observable
• •Dependency injection

Navigation

• •NavigationStack (iOS 16+)
• •NavigationPath
• •Sheet presentations
• •Full-screen covers

Networking

• •async URLSession
• •Codable for JSON
• •Error handling
• •Retry logic

Persistence

• •SwiftData (iOS 17+)
• •Core Data fallback
• •UserDefaults for simple data
• •Keychain for secrets

Testing

• •XCTest for unit tests
• •XCUITest for UI tests
• •Mocking dependencies
• •Test doubles

Performance

• •Instruments profiling
• •Memory management
• •Drawing optimization
• •Lazy loading

Patterns

@Observable (iOS 17+)

@Observable
class ProductsViewModel {
    var products: [Product] = []
    var isLoading = false

    func loadProducts() async {
        isLoading = true
        defer { isLoading = false }
        products = try await productService.fetch()
    }
}

NavigationStack

enum Route: Hashable {
    case product(Product)
    case settings
}

struct AppView: View {
    @State private var path: [Route] = []

    var body: some View {
        NavigationStack(path: $path) {
            HomeView()
                .navigationDestination(for: Route.self) { route in
                    // route handling
                }
        }
    }
}

Actor for Thread-Safety

actor NetworkManager {
    func fetch(_ url: URL) async throws -> Data {
        // Thread-safe networking
    }
}

MCP Workflow Examples

Build for Simulator

// MCP approach:
mcp__xcodebuildmcp__discover_projs({ workspaceRoot: '.' })
mcp__xcodebuildmcp__list_schemes({ workspacePath: 'MyApp.xcworkspace' })
mcp__xcodebuildmcp__build_sim({
  workspacePath: 'MyApp.xcworkspace',
  scheme: 'MyApp',
  simulatorId: 'iPhone-16-Pro-UUID'
})

Run Tests

mcp__xcodebuildmcp__test_sim({
  projectPath: 'MyApp.xcodeproj',
  scheme: 'MyApp',
  simulatorId: 'UUID'
})

UI Automation

// IMPORTANT: Always use describe_ui first
mcp__xcodebuildmcp__describe_ui({ simulatorId: 'UUID' })
// Then parse UI hierarchy and interact
mcp__xcodebuildmcp__tap({ simulatorId: 'UUID', x: 100, y: 200 })

Tech Stack

• •iOS 18+ SDK, Swift 6.0+
• •SwiftUI (primary), UIKit (fallback)
• •SwiftData for persistence
• •XCTest/XCUITest for testing
• •XcodeBuildMCP for automation (optional)