Use when implementing on-device AI with Apple's Foundation Models framework — prevents context overflow, blocking UI, wrong model use cases, and manual JSON parsing when @Generable should be used. iOS 26+, macOS 26+, iPadOS 26+, axiom-visionOS 26+

Use when first installing Axiom, unsure which skill to use, want an overview of available skills, or need help finding the right skill for your situation — interactive onboarding that recommends skills based on your project and current focus

Use when writing raw SQL queries with GRDB, complex joins, ValueObservation for reactive queries, DatabaseMigrator patterns, query profiling under performance pressure, or dropping down from SQLiteData for performance - direct SQLite access for iOS/macOS

Use when app freezes, UI unresponsive, main thread blocked, watchdog termination, or diagnosing hang reports from Xcode Organizer or MetricKit

Reference — Comprehensive Apple Human Interface Guidelines covering colors (semantic, custom, patterns), backgrounds (material hierarchy, dynamic), typography (built-in styles, custom fonts, Dynamic Type), SF Symbols (rendering modes, color, axiom-localization), Dark Mode, accessibility, and platform-specific considerations

Use when implementing 'iCloud Drive', 'ubiquitous container', 'file sync', 'NSFileCoordinator', 'NSFilePresenter', 'isUbiquitousItem', 'NSUbiquitousKeyValueStore', 'ubiquitous file sync' - comprehensive file-based iCloud sync reference

Use when implementing in-app purchases, StoreKit 2, subscriptions, or transaction handling - testing-first workflow with .storekit configuration, StoreManager architecture, transaction verification, subscription management, and restore purchases for consumables, non-consumables, and auto-renewable subscriptions

Use when fixing or auditing ANY accessibility issue - VoiceOver, Dynamic Type, color contrast, touch targets, WCAG compliance, App Store accessibility review.

Use when implementing ANY Apple Intelligence or on-device AI feature. Covers Foundation Models, @Generable, LanguageModelSession, structured output, Tool protocol, iOS 26 AI integration.

Use when ANY iOS build fails, test crashes, Xcode misbehaves, or environment issue occurs before debugging code. Covers build failures, compilation errors, dependency conflicts, simulator problems, environment-first diagnostics.

Use when writing ANY code with async, actors, threads, or seeing ANY concurrency error. Covers Swift 6 concurrency, @MainActor, Sendable, data races, async/await patterns, performance optimization.

Use when working with ANY GPU rendering, Metal, OpenGL migration, shaders, frame rate, or display performance. Covers Metal migration, shader conversion, variable refresh rate, ProMotion, render loops.

Use when integrating ANY iOS system feature - Siri, Shortcuts, Apple Intelligence, widgets, IAP, camera, photo library, photos picker, audio, axiom-haptics, axiom-localization, privacy. Covers App Intents, WidgetKit, StoreKit, AVFoundation, PHPicker, PhotosPicker, Core Haptics, App Shortcuts, Spotlight.

Use when deploying ANY machine learning model on-device, converting models to CoreML, compressing models, or implementing speech-to-text. Covers CoreML conversion, MLTensor, model compression (quantization/palettization/pruning), stateful models, KV-cache, multi-function models, async prediction, SpeechAnalyzer, SpeechTranscriber.

Use when app feels slow, memory grows, battery drains, or diagnosing ANY performance issue. Covers memory leaks, profiling, Instruments workflows, retain cycles, performance optimization.

Use when writing ANY test, debugging flaky tests, making tests faster, or asking about Swift Testing vs XCTest. Covers unit tests, UI tests, fast tests without simulator, async testing, test architecture.

Use when building, fixing, or improving ANY iOS UI including SwiftUI, UIKit, layout, navigation, animations, design guidelines. Covers view updates, layout bugs, navigation issues, performance, architecture, Apple design compliance.

Use when implementing ANY computer vision feature - image analysis, object detection, pose detection, person segmentation, subject lifting, hand/body pose tracking.

Use when planning comprehensive Liquid Glass adoption across an app, auditing existing interfaces for Liquid Glass compatibility, implementing app icon updates, or understanding platform-specific Liquid Glass behavior - comprehensive reference guide covering all aspects of Liquid Glass adoption from WWDC 2025

Use when implementing Liquid Glass effects, reviewing UI for Liquid Glass adoption, debugging visual artifacts, optimizing performance, or requesting expert review of Liquid Glass implementation - provides comprehensive design principles, API patterns, and troubleshooting guidance from WWDC 2025. Includes design review pressure handling and professional push-back frameworks

Use when ANY Metal porting issue occurs - black screen, rendering artifacts, shader errors, wrong colors, performance regressions, GPU crashes

MetricKit API reference for field diagnostics - MXMetricPayload, MXDiagnosticPayload, MXCallStackTree parsing, crash and hang collection

Reference — Comprehensive Network.framework guide covering NetworkConnection (iOS 26+), NWConnection (iOS 12-25), TLV framing, Coder protocol, NetworkListener, NetworkBrowser, Wi-Fi Aware discovery, and migration strategies

Use when debugging connection timeouts, TLS handshake failures, data not arriving, connection drops, performance issues, or proxy/VPN interference - systematic Network.framework diagnostics with production crisis defense

CarPlay Now Playing integration patterns. Use when implementing CarPlay audio controls, CPNowPlayingTemplate customization, or debugging CarPlay-specific issues.

Use when implementing privacy manifests, requesting permissions, App Tracking Transparency UX, or preparing Privacy Nutrition Labels - covers just-in-time permission requests, tracking domain management, and Required Reason APIs from WWDC 2023

Use when migrating from Realm to SwiftData - comprehensive migration guide covering pattern equivalents, threading model conversion, schema migration strategies, CloudKit sync transition, and real-world scenarios

SQLiteData advanced patterns, @Selection column groups, single-table inheritance, recursive CTEs, database views, custom aggregates, TableAlias self-joins, JSON/string aggregation

Use when debugging 'files disappeared', 'data missing after restart', 'backup too large', 'can't save file', 'file not found', 'storage full error', 'file inaccessible when locked' - systematic local file storage diagnostics

Use when asking about 'purge files', 'storage pressure', 'disk space iOS', 'isExcludedFromBackup', 'URL resource values', 'volumeAvailableCapacity', 'low storage', 'file purging priority', 'cache management' - comprehensive reference for iOS storage management and URL resource value APIs

Reference — Complete StoreKit 2 API guide covering Product, Transaction, AppTransaction, RenewalInfo, SubscriptionStatus, StoreKit Views, purchase options, server APIs, and all iOS 18.4 enhancements with WWDC 2025 code examples

Use when you see 'actor-isolated', 'Sendable', 'data race', '@MainActor' errors, or when asking 'why is this not thread safe', 'how do I use async/await', 'what is @MainActor for', 'my app is crashing with concurrency errors', 'how do I fix data races' - Swift 6 strict concurrency patterns with actor isolation and async/await

Use when optimizing Swift code performance, reducing memory usage, improving runtime efficiency, dealing with COW, ARC overhead, generics specialization, or collection optimization

Use when SwiftData migrations crash, fail to preserve relationships, lose data, or work in simulator but fail on device - systematic diagnostics for schema version mismatches, relationship errors, and migration testing gaps

Use when working with SwiftData - @Model definitions, @Query in SwiftUI, @Relationship macros, ModelContext patterns, CloudKit integration, iOS 26+ features, and Swift 6 concurrency with @MainActor — Apple's native persistence framework

Use when implementing iOS 26 SwiftUI features - covers Liquid Glass design system, performance improvements, @Animatable macro, 3D spatial layout, scene bridging, WebView/WebPage, AttributedString rich text editing, drag and drop enhancements, and visionOS integration for iOS 26+

Use when separating logic from SwiftUI views, choosing architecture patterns, refactoring view files, or asking 'where should this code go', 'how do I organize my SwiftUI app', 'MVVM vs TCA vs vanilla SwiftUI', 'how do I make SwiftUI testable' - comprehensive architecture patterns with refactoring workflows for iOS 26+

Reference — SwiftUI stacks, grids, outlines, and scroll enhancements through iOS 26

Use when debugging SwiftUI view updates, preview crashes, or layout issues - diagnostic decision trees to identify root causes quickly and avoid misdiagnosis under pressure

Reference — Complete SwiftUI adaptive layout API guide covering ViewThatFits, AnyLayout, Layout protocol, onGeometryChange, GeometryReader, size classes, and iOS 26 window APIs

Reference — Comprehensive SwiftUI navigation guide covering NavigationStack (iOS 16+), NavigationSplitView (iOS 16+), NavigationPath, deep linking, state restoration, Tab+Navigation integration (iOS 18+), Liquid Glass navigation (iOS 26+), and coordinator patterns

Use when UI is slow, scrolling lags, animations stutter, or when asking 'why is my SwiftUI view slow', 'how do I optimize List performance', 'my app drops frames', 'view body is called too often', 'List is laggy' - SwiftUI performance optimization with Instruments 26 and WWDC 2025 patterns

Use when ANY beta tester reports a crash, ANY crash appears in Organizer or App Store Connect, crash logs need symbolication, app was killed without crash report, or you need to triage TestFlight feedback

TextKit 2 complete reference (architecture, migration, Writing Tools, SwiftUI TextEditor) through iOS 26

Guide to Xcode 26's Recording UI Automation feature for creating UI tests through user interaction recording.

Use when writing UI tests, recording interactions, tests have race conditions, timing dependencies, inconsistent pass/fail behavior, or XCTest UI tests are flaky - covers Recording UI Automation (WWDC 2025), condition-based waiting, network conditioning, multi-factor testing, crash debugging, and accessibility-first testing patterns

Use when CAAnimation completion handler doesn't fire, spring physics look wrong on device, animation duration mismatches actual time, gesture + animation interaction causes jank, or timing differs between simulator and real hardware - systematic CAAnimation diagnosis with CATransaction patterns, frame rate awareness, and device-specific behavior

Use when starting any iOS/Swift conversation - establishes how to find and use Axiom skills, requiring Skill tool invocation before ANY response including clarifying questions

subject not detected, hand pose missing landmarks, low confidence observations, Vision performance, coordinate conversion, VisionKit errors, observation nil, text not recognized, barcode not detected, DataScannerViewController not working, document scan issues

Use when writing, running, or debugging XCUITests. Covers element queries, waiting strategies, accessibility identifiers, test plans, and CI/CD test execution patterns.