Claude Skills

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

Use when debugging Foundation Models issues — context exceeded, guardrail violations, slow generation, availability problems, unsupported language, or unexpected output. Systematic diagnostics with production crisis defense.

Use when debugging 'file not syncing', 'CloudKit error', 'sync conflict', 'iCloud upload failed', 'ubiquitous item error', 'data not appearing on other devices', 'CKError', 'quota exceeded' - systematic iCloud sync diagnostics for both CloudKit and iCloud Drive

Complete energy optimization API reference - Power Profiler workflows, timer/network/location/background APIs, iOS 26 BGContinuedProcessingTask, MetricKit monitoring, with all WWDC code examples

Use when implementing haptic feedback, Core Haptics patterns, audio-haptic synchronization, or debugging haptic issues - covers UIFeedbackGenerator, CHHapticEngine, AHAP patterns, and Apple's Causality-Harmony-Utility design principles from WWDC 2021

Use when automating Instruments profiling, running headless performance analysis, or integrating profiling into CI/CD - comprehensive xctrace CLI reference with record/export patterns

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

Use when structuring app entry points, managing authentication flows, switching root views, handling scene lifecycle, or asking 'how do I structure my @main', 'where does auth state live', 'how do I prevent screen flicker on launch', 'when should I modularize' - app-level composition patterns for iOS 26+

Use when making app surface in Spotlight search, Siri suggestions, or system experiences - covers the 6-step strategy combining App Intents, App Shortcuts, Core Spotlight, and NSUserActivity to feed the system metadata for iOS 16+

Use when integrating App Intents for Siri, Apple Intelligence, Shortcuts, Spotlight, or system experiences - covers AppIntent, AppEntity, parameter handling, entity queries, background execution, authentication, and debugging common integration issues for iOS 16+

Use when implementing App Shortcuts for instant Siri/Spotlight availability, configuring AppShortcutsProvider, adding suggested phrases, or debugging shortcuts not appearing - covers complete App Shortcuts API for iOS 16+

Use when implementing 'CloudKit sync', 'CKSyncEngine', 'CKRecord', 'CKDatabase', 'SwiftData CloudKit', 'shared database', 'public database', 'CloudKit zones', 'conflict resolution' - comprehensive CloudKit database APIs and modern sync patterns reference

Use when working with Codable protocol, JSON encoding/decoding, CodingKeys customization, enum serialization, date strategies, custom containers, or encountering "Type does not conform to Decodable/Encodable" errors - comprehensive Codable patterns and anti-patterns for Swift 6.x

Use when profiling async/await performance, diagnosing actor contention, or investigating thread pool exhaustion. Covers Swift Concurrency Instruments template, task visualization, actor contention analysis, thread pool debugging.

Use when debugging schema migration crashes, concurrency thread-confinement errors, N+1 query performance, SwiftData to Core Data bridging, or testing migrations without data loss - systematic Core Data diagnostics with safety-first migration patterns

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