Swift Development Skill

A Claude Code skill for comprehensive Swift iOS/macOS development. Provides patterns, commands, and tooling for building, testing, and deploying Swift applications.

Installation

Copy the skill to your Claude skills directory:

cp -r swift-development ~/.claude/skills/

Or manually create and copy:

mkdir -p ~/.claude/skills/swift-development
cp -r swift-development/* ~/.claude/skills/swift-development/

Usage

Invoke the skill in Claude Code:

/swift-development

Or reference it naturally - Claude will activate the skill when working on Swift projects.

What's Included

Quick Patterns (SKILL.md)

• SwiftUI with Observable (iOS 17+) and ObservableObject (iOS 13+)
• Navigation patterns: NavigationStack (iOS 16+), NavigationView (iOS 13-15), coordinator pattern
• Swift 6 concurrency: async/await, actors, Sendable
• XCTest and Swift Testing frameworks (with expanded examples)
• Common xcodebuild and simctl commands

Reference Documentation

Topic	File
Swift Package Manager	references/spm.md
xcodebuild commands	references/xcodebuild.md
Simulator control	references/simctl.md
Code signing	references/code-signing.md
Swift 6 concurrency	references/concurrency.md
Architecture patterns	references/architecture.md
CI/CD setup	references/cicd.md
Troubleshooting	references/troubleshooting.md

Helper Scripts

Script	Purpose
scripts/new_package.sh	Create new Swift package with config files, version warnings, and naming guidance
scripts/run_tests.sh	Run tests with parallel execution and coverage (SPM or xcodebuild)
scripts/format_and_lint.sh	Format and lint Swift code (SwiftFormat, SwiftLint, swift-format)
scripts/simulator.sh	Quick simulator management (boot, install, launch, screenshots, etc.)

Features:

• Colored output: All scripts use color-coded messages (green for steps, yellow for warnings, red for errors)
• Smart validation: new_package.sh provides comprehensive warnings for:
  • Swift/Xcode version compatibility (e.g., Swift 6.0 requires Xcode 16+)
  • Package naming conventions (PascalCase guidance)
  • Git repository nesting (suggests using submodules)
  • Missing tools (SwiftFormat/SwiftLint installation checks)
• Robust error handling: Prerequisite checks with helpful installation instructions
• Styled success indicators: Clear visual feedback when operations complete

Asset Templates

• assets/Package.swift.template - Swift package template
• assets/.swiftformat - SwiftFormat configuration
• assets/.swiftlint.yml - SwiftLint configuration
• assets/ExportOptions/ - Archive export plist templates (App Store, Ad Hoc, Development)

Official Documentation

For authoritative reference, this skill points to Apple's official Swift documentation:

• Swift Documentation: https://developer.apple.com/documentation/swift
• SwiftUI: https://developer.apple.com/documentation/swiftui
• Swift Concurrency: https://developer.apple.com/documentation/swift/concurrency
• Swift Testing: https://developer.apple.com/documentation/testing

Live Documentation Fetching: The skill instructs Claude to use WebFetch to retrieve current documentation. Since Apple's documentation sites are JavaScript SPAs that cannot be fetched programmatically, the skill uses raw GitHub markdown URLs instead:

• Swift Testing: https://raw.githubusercontent.com/apple/swift-testing/main/README.md
• Swift Evolution: https://raw.githubusercontent.com/apple/swift-evolution/main/proposals/{NNNN-name}.md
• Swift Async Algorithms: https://raw.githubusercontent.com/apple/swift-async-algorithms/main/README.md
• Swift Collections: https://raw.githubusercontent.com/apple/swift-collections/main/README.md

Regular github.com URLs return garbled HTML/JSON — always use raw.githubusercontent.com for WebFetch. For discovering file names (e.g., proposal numbers), use WebSearch instead.

Requirements

• macOS with Xcode 15+ (Xcode 16+ for Swift 6 features)
• Xcode Command Line Tools: xcode-select --install

Quick Reference

# Build
swift build                    # Debug build
swift build -c release         # Release build

# Test
swift test                     # Run all tests
swift test --filter MyTest     # Run specific test

# Xcode project
xcodebuild -workspace App.xcworkspace -scheme App \
    -destination 'platform=iOS Simulator,name=iPhone 15' build

# Simulators
xcrun simctl list devices      # List devices
xcrun simctl boot "iPhone 15"  # Boot simulator
xcrun simctl install booted ./App.app  # Install app

Acknowledgments

This skill was inspired by and builds upon ios-swift-development by @aj-geddes. The original skill provided a foundation that was expanded with additional reference documentation, helper scripts, and asset templates.