swift▌

Use this skill to pick the best Swift architecture playbook for SwiftUI/UIKit codebases and apply it to the user’s task.

Native iOS app development with Swift, SwiftUI, and modern async patterns. \n \n Covers MVVM architecture, SwiftUI declarative UI, URLSession networking, and Combine reactive programming \n Includes async/await patterns, Core Data persistence, and Keychain for secure storage \n Best practices emphasize dependency injection, proper error handling, @StateObject for ViewModels, and testing across iOS versions \n Reference guides provided for network services, MVVM setup, and SwiftUI view implementa

Use this skill to design and review Swift APIs that are clear at the point of use, fluent in call sites, and aligned with established Swift naming and labeling conventions. Prioritize readability, explicit intent, and consistency across declarations, call sites, and documentation comments.

Complete iOS/macOS/watchOS/tvOS development with SwiftUI, async/await, protocol-oriented design, and actor-based concurrency. \n \n Covers SwiftUI state management with @Observable, async/await patterns, protocol-oriented architecture with associated types, and actor isolation for thread safety \n Includes validation checkpoints at each workflow stage: compilation verification, strict warning checks for actor isolation, and async test confirmation \n Provides reference guides for SwiftUI pattern

Philosophy: Non-opinionated, correctness-focused. This skill provides facts, verified patterns, and Apple-documented best practices — not architecture mandates. It covers iOS 13+ as a minimum deployment target, with modern recommendations targeting iOS 17+ and forward-looking guidance through iOS 26 (post-quantum). Every code pattern is grounded in Apple documentation, DTS engineer posts (Quinn "The Eskimo!"), WWDC sessions, and OWASP MASTG — never from memory alone.

Encode and decode Swift types using Codable (Encodable & Decodable) with JSONEncoder, JSONDecoder, and related APIs. Targets Swift 6.3 / iOS 26+.

Swift Concurrency review and remediation for Swift 6.2+ codebases. \n \n Diagnoses and fixes actor isolation, Sendable safety, and data-race warnings through targeted edits that preserve existing behavior \n Applies minimal, concrete fixes: @MainActor annotations, actor isolation, Sendable conformance, and completion-handler-to-async/await migrations \n Triages compiler diagnostics by checking project concurrency settings, actor context, and whether code is UI-bound or background work \n Verifie

Write, review, and improve Swift Testing code with modern APIs and best practices. \n \n Validates test structure, assertions, dependency injection, async patterns, and actor isolation against Swift Testing conventions \n Guides migration from XCTest to Swift Testing, including assertion mappings and modern concurrency patterns \n Covers new features like raw identifiers, test scopes, exit tests, attachments, and range-based confirmations \n Targets Swift 6.2+ with emphasis on modern Swift concu

Write, review, and migrate Swift tests using modern Swift Testing APIs with parallel execution and clear diagnostics. \n \n Covers test structure, #expect / #require macros, traits, tags, parameterized tests, and async waiting patterns for readable, maintainable tests \n Guides incremental XCTest migration while preserving UI automation and performance-metric tests that require XCTest \n Prioritizes parallel-safe test design; recommends fixing shared state before applying .serialized isolation \

Core Principle: Optimize Swift code by understanding language-level performance characteristics—value semantics, ARC behavior, generic specialization, and memory layout—to write fast, efficient code without premature micro-optimization.