Symptom / Task	Reference
Outdated Swift patterns (Date(), CGFloat, DateFormatter)	See `skills/swift-modern.md`
Foundation modernization (FormatStyle, URL.documentsDirectory)	See `skills/swift-modern.md`
Common Claude hallucinations in Swift code	See `skills/swift-modern.md`
Swift 6.4 idioms — `anyAppleOS`, `weak let`, `~Sendable` (`OS27`)	See `skills/swift-modern.md`
Noncopyable types (~Copyable)	See `skills/ownership-conventions.md`
borrowing/consuming parameter ownership	See `skills/ownership-conventions.md`
InlineArray, Span, value generics; Swift 6.4 `borrow`/`mutate` accessors (`OS27`)	See `skills/ownership-conventions.md`
Reducing ARC overhead	See `skills/ownership-conventions.md`
Drag and drop (.draggable, .dropDestination)	See `skills/transferable-ref.md`
Copy/paste (.copyable, PasteButton)	See `skills/transferable-ref.md`
ShareLink, content sharing	See `skills/transferable-ref.md`
Custom UTType declarations	See `skills/transferable-ref.md`
TransferRepresentation choices	See `skills/transferable-ref.md`
Debug-only deep links for simulator testing	See `skills/deep-link-debugging.md`
Navigate to specific screens for screenshots	See `skills/deep-link-debugging.md`
tvOS Focus Engine, Siri Remote input	See `skills/tvos.md`
tvOS storage constraints (no Documents dir)	See `skills/tvos.md`
tvOS text input, AVPlayer tuning	See `skills/tvos.md`
TVUIKit components	See `skills/tvos.md`
Simplify Swift for clarity (behavior-preserving cleanups)	`swift-simplifier` agent — `/axiom:audit swift-simplify`

Decision Tree

digraph swift {
    start [label="Swift task" shape=ellipse];
    what [label="What do you need?" shape=diamond];

    start -> what;
    what -> "skills/swift-modern.md" [label="modern idioms,\noutdated patterns,\nFoundation APIs"];
    what -> "skills/ownership-conventions.md" [label="~Copyable, borrowing,\nconsuming, InlineArray,\nSpan, ARC reduction"];
    what -> "skills/transferable-ref.md" [label="drag & drop, copy/paste,\nShareLink, UTTypes,\nTransferable conformance"];
    what -> "skills/deep-link-debugging.md" [label="debug deep links,\nsimulator navigation,\nscreenshot automation"];
    what -> "skills/tvos.md" [label="tvOS app,\nFocus Engine,\nSiri Remote, storage"];
}

Outdated Swift patterns / modern API replacements / Claude hallucinations? -> skills/swift-modern.md
~Copyable / borrowing / consuming / InlineArray / Span? -> skills/ownership-conventions.md
Drag and drop / copy/paste / ShareLink / Transferable / UTTypes? -> skills/transferable-ref.md
Debug deep links / simulator navigation / screenshot automation? -> skills/deep-link-debugging.md
tvOS development / Focus Engine / Siri Remote / storage / AVPlayer? -> skills/tvos.md
Swift concurrency (async/await, actors, Sendable) -> /skill axiom-concurrency
Swift performance (COW, ARC, generics optimization) -> See axiom-performance (skills/swift-performance.md)
Codable patterns (JSON, CodingKeys, enum serialization) -> See axiom-data (skills/codable.md)
Simplify Swift for clarity (guard/optional cleanups, if/switch expressions, boilerplate)? -> swift-simplifier agent (/axiom:audit swift-simplify)

Conflict Resolution

swift vs concurrency: When Swift 6 concurrency errors appear:

Use concurrency, NOT swift -- Concurrency errors are actor isolation / Sendable issues. skills/swift-modern.md covers concurrency posture (defaults), but detailed patterns live in axiom-concurrency.

swift vs performance: When optimizing Swift code:

Use swift for ownership if the question is borrowing/consuming/~Copyable/InlineArray/Span -> skills/ownership-conventions.md
Use performance if the question is COW, ARC profiling, generic specialization, or Instruments workflows -> axiom-performance

swift vs swiftui: When implementing drag and drop or copy/paste:

Use swift for Transferable conformance, representation choices, UTType declarations -> skills/transferable-ref.md
Use swiftui for view-level modifiers (.draggable, .dropDestination styling, animations)

swift vs integration: When sharing content:

ShareLink + Transferable -> use swift (skills/transferable-ref.md)
UIActivityViewController customization, share extensions -> use integration

swift vs axiom-build: When tvOS build fails:

Environment/Xcode issues -> use axiom-build first
tvOS platform-specific code issues (Focus Engine, storage, no WebView) -> use swift (skills/tvos.md)

Critical Patterns

Modern Swift Idioms (skills/swift-modern.md):

12+ outdated patterns Claude defaults to (Date(), CGFloat, DateFormatter, DispatchQueue.main.async)
Foundation modernization (FormatStyle, URL.documentsDirectory, .replacing())
SwiftUI convenience APIs Claude misses (ContentUnavailableView.search, LabeledContent)
Swift 6.4 concurrency posture defaults
12 common Claude hallucinations with corrections

Ownership & Noncopyable Types (skills/ownership-conventions.md):

borrowing/consuming parameter modifiers with 7 patterns
~Copyable types: FileHandle pattern, limitations table, common compiler errors
InlineArray: fixed-size stack-allocated arrays with value generics
Span family: safe contiguous memory access replacing UnsafeBufferPointer
Decision tree for when ownership modifiers help vs when to skip

Transferable & Sharing (skills/transferable-ref.md):

Decision tree: CodableRepresentation vs DataRepresentation vs FileRepresentation vs ProxyRepresentation
Drag and drop, copy/paste, ShareLink with complete SwiftUI API
Custom UTType declarations (Swift + Info.plist, both required)
7 common errors with fixes (representation ordering, missing Info.plist, hit testing)
UIKit bridging via NSItemProvider

Debug Deep Links (skills/deep-link-debugging.md):

Debug-only URL scheme for simulator navigation
NavigationPath integration for robust routing
State configuration links (error states, empty states)
Integration with /axiom:screenshot and simulator-tester agent
60-75% faster iteration with visual verification

tvOS Development (skills/tvos.md):

Dual focus system (UIKit Focus Engine + SwiftUI @FocusState)
Siri Remote input (two generations, three input layers)
Storage constraints (no Documents directory, iCloud required)
No WebView (JavaScriptCore only, no DOM)
AVPlayer tuning, Menu button state machine
TVUIKit components

Anti-Rationalization

Thought	Reality
"Date() is fine, everyone uses it"	`Date.now` has been the modern pattern since Swift 5.6. `skills/swift-modern.md` lists 12+ patterns Claude gets wrong.
"I don't need ownership modifiers"	For most code, correct. But ~Copyable types require them, and large value types in hot paths benefit measurably.
"Transferable is just Codable for drag and drop"	Transferable has 4 representation types, ordering rules, and Info.plist requirements. Getting it wrong causes silent cross-app failures.
"I'll just use the same code as iOS for tvOS"	tvOS has no Documents directory, no WebView, a dual focus system, and two generations of remote hardware. It compiles fine and fails at runtime.
"Debug deep links are overkill"	Manual navigation costs 2-3 minutes per iteration. Deep links cut it to 45 seconds. Over a debugging session, that's hours saved.
"CGFloat is what SwiftUI uses"	Swift 5.5+ has implicit Double-CGFloat bridging. Use Double everywhere except optionals, inout, and ObjC-bridged APIs.
"I'll add the Info.plist entry later"	Custom UTTypes work in-app without Info.plist but silently fail cross-app. This is the #1 "works in dev, fails in prod" Transferable issue.
"FormatStyle is too verbose"	`val.formatted(.number.precision(.fractionLength(2)))` is type-safe and localized. `String(format:)` is neither.

Example Invocations

User: "Is this Swift code using modern patterns?" -> Read: skills/swift-modern.md

User: "How do I use borrowing and consuming?" -> Read: skills/ownership-conventions.md

User: "How do I make my model draggable?" -> Read: skills/transferable-ref.md

User: "How do I implement ShareLink with a custom preview?" -> Read: skills/transferable-ref.md

User: "I need debug deep links for simulator testing" -> Read: skills/deep-link-debugging.md

User: "I'm building a tvOS app and focus navigation doesn't work" -> Read: skills/tvos.md

User: "What is InlineArray and when should I use it?" -> Read: skills/ownership-conventions.md

User: "My drag and drop works in-app but not across apps" -> Read: skills/transferable-ref.md

User: "tvOS keeps losing my saved data" -> Read: skills/tvos.md

User: "How do I optimize large struct passing?" -> Read: skills/ownership-conventions.md

User: "I need to fix my async/await code" -> See /skill axiom-concurrency

User: "Check my code for Swift 6 concurrency issues" -> See /skill axiom-concurrency

axiom-swift

Swift Language & Platform

Quick Reference