Content & Writing

by CharlesWiltgen

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

by CharlesWiltgen

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.

by CharlesWiltgen

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.

by CharlesWiltgen

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

by CharlesWiltgen

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

by CharlesWiltgen

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

by CharlesWiltgen

Use when localizing apps, using String Catalogs, generating type-safe symbols (Xcode 26+), handling plurals, RTL layouts, locale-aware formatting, or migrating from .strings files - comprehensive i18n patterns for Xcode 15-26

by CharlesWiltgen

Use when you see memory warnings, 'retain cycle', app crashes from memory pressure, or when asking 'why is my app using so much memory', 'how do I find memory leaks', 'my deinit is never called', 'Instruments shows memory growth', 'app crashes after 10 minutes' - systematic memory leak detection and fixes for iOS/macOS

by CharlesWiltgen

Use when porting OpenGL/DirectX to Metal - translation layer vs native rewrite decisions, migration planning, anti-patterns

by CharlesWiltgen

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

by CharlesWiltgen

Use when converting shaders or looking up API equivalents - GLSL to MSL, HLSL to MSL, GL/DirectX to Metal mappings, MTKView setup code

by CharlesWiltgen

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

by CharlesWiltgen

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

by CharlesWiltgen

Use when implementing Network.framework connections, debugging connection failures, migrating from sockets/URLSession streams, or adopting structured concurrency networking patterns - prevents deprecated API usage, reachability anti-patterns, and thread-safety violations with iOS 12-26+ APIs

by CharlesWiltgen

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

by CharlesWiltgen

This skill should be used when working with NWConnection patterns for iOS 12-25, supporting apps that can't use async/await yet, or maintaining backward compatibility with completion handler networking.

by CharlesWiltgen

Network framework migration guides. Use when migrating from BSD sockets to NWConnection, NWConnection to NetworkConnection (iOS 26+), or URLSession StreamTask to NetworkConnection.

by CharlesWiltgen

Use when Now Playing metadata doesn't appear on Lock Screen/Control Center, remote commands (play/pause/skip) don't respond, artwork is missing/wrong/flickering, or playback state is out of sync - provides systematic diagnosis, correct patterns, and professional push-back for audio/video apps on iOS 18+

by CharlesWiltgen

MusicKit Now Playing integration patterns. Use when playing Apple Music content with ApplicationMusicPlayer and understanding automatic vs manual Now Playing info updates.

by CharlesWiltgen

Use when debugging memory leaks from blocks, blocks assigned to self or properties, network callbacks, or crashes from deallocated objects - systematic weak-strong pattern diagnosis with mandatory diagnostic rules

by CharlesWiltgen

Use when optimizing large value type performance, working with noncopyable types, reducing ARC traffic, or using InlineArray/Span for zero-copy memory access. Covers borrowing, consuming, inout modifiers, consume operator, ~Copyable types, InlineArray, Span, value generics.

by CharlesWiltgen

Use when app feels slow, memory grows over time, battery drains fast, or you want to profile proactively - decision trees to choose the right Instruments tool, deep workflows for Time Profiler/Allocations/Core Data, and pressure scenarios for misinterpreting results

by CharlesWiltgen

PHPicker, PhotosPicker, photo selection, limited library access, presentLimitedLibraryPicker, save to camera roll, PHPhotoLibrary, PHAssetCreationRequest, Transferable, PhotosPickerItem, photo permissions

by CharlesWiltgen

Reference — PHPickerViewController, PHPickerConfiguration, PhotosPicker, PhotosPickerItem, Transferable, PHPhotoLibrary, PHAsset, PHAssetCreationRequest, PHFetchResult, PHAuthorizationStatus, limited library APIs

by CharlesWiltgen

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

by CharlesWiltgen

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

by CharlesWiltgen

SQLiteData queries, @Table models, Point-Free SQLite, RETURNING clause, FTS5 full-text search, CloudKit sync, CTEs, JSON aggregation, @DatabaseFunction

by CharlesWiltgen

Use when migrating from SwiftData to SQLiteData — decision guide, pattern equivalents, code examples, CloudKit sharing (SwiftData can't), performance benchmarks, gradual migration strategy

by CharlesWiltgen

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

by CharlesWiltgen

Use when asking 'where should I store this data', 'should I use SwiftData or files', 'CloudKit vs iCloud Drive', 'Documents vs Caches', 'local or cloud storage', 'how do I sync data', 'where do app files go' - comprehensive decision framework for all iOS storage options

by CharlesWiltgen

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

by CharlesWiltgen

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

by CharlesWiltgen

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

by CharlesWiltgen

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

by CharlesWiltgen

Use when writing unit tests, adopting Swift Testing framework, making tests run faster without simulator, architecting code for testability, testing async code reliably, or migrating from XCTest - covers @Test/@Suite macros, #expect/#require, parameterized tests, traits, tags, parallel execution, host-less testing

by CharlesWiltgen

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

by CharlesWiltgen

Use when creating SwiftData custom schema migrations with VersionedSchema and SchemaMigrationPlan - property type changes, relationship preservation (one-to-many, many-to-many), the willMigrate/didMigrate limitation, two-stage migration patterns, and testing migrations on real devices

by CharlesWiltgen

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

by CharlesWiltgen

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+

by CharlesWiltgen

Use when implementing SwiftUI animations, understanding VectorArithmetic, using @Animatable macro, zoom transitions, UIKit/AppKit animation bridging, choosing between spring and timing curve animations, or debugging animation behavior - comprehensive animation reference from iOS 13 through iOS 26

by CharlesWiltgen

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+

by CharlesWiltgen

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

by CharlesWiltgen

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

by CharlesWiltgen

Use when SwiftUI view debugging requires systematic investigation - view updates not working after basic troubleshooting, intermittent UI issues, complex state dependencies, or when Self._printChanges() shows unexpected update patterns - systematic diagnostic workflows with Instruments integration

by CharlesWiltgen

Use when implementing SwiftUI gestures (tap, drag, long press, magnification, rotation), composing gestures, managing gesture state, or debugging gesture conflicts - comprehensive patterns for gesture recognition, composition, accessibility, and cross-platform support

by CharlesWiltgen

Use when layouts need to adapt to different screen sizes, iPad multitasking, or iOS 26 free-form windows — decision trees for ViewThatFits vs AnyLayout vs onGeometryChange, size class limitations, and anti-patterns preventing device-based layout mistakes

by CharlesWiltgen

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

by CharlesWiltgen

Use when implementing navigation patterns, choosing between NavigationStack and NavigationSplitView, handling deep links, adopting coordinator patterns, or requesting code review of navigation implementation - prevents navigation state corruption, deep link failures, and state restoration bugs for iOS 18+

by CharlesWiltgen

Use when debugging navigation not responding, unexpected pops, deep links showing wrong screen, state lost on tab switch or background, crashes in navigationDestination, or any SwiftUI navigation failure - systematic diagnostics with production crisis defense

by CharlesWiltgen

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

by CharlesWiltgen

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

by CharlesWiltgen

Use when needing thread-safe primitives for performance-critical code. Covers Mutex (iOS 18+), OSAllocatedUnfairLock (iOS 16+), Atomic types, when to use locks vs actors, deadlock prevention with Swift Concurrency.

by CharlesWiltgen

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

by CharlesWiltgen

Use when testing async code with Swift Testing. Covers confirmation for callbacks, @MainActor tests, async/await patterns, timeout control, XCTest migration, parallel test execution.

by CharlesWiltgen

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

by CharlesWiltgen

Apple platform typography reference (San Francisco fonts, text styles, Dynamic Type, tracking, leading, internationalization) through iOS 26

by CharlesWiltgen

Use when setting up UI test recording in Xcode 26, enhancing recorded tests for stability, or configuring test plans for multi-configuration replay. Based on WWDC 2025-344 "Record, replay, and review".

by CharlesWiltgen

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

by CharlesWiltgen

subject segmentation, VNGenerateForegroundInstanceMaskRequest, isolate object from hand, VisionKit subject lifting, image foreground detection, instance masks, class-agnostic segmentation, VNRecognizeTextRequest, OCR, VNDetectBarcodesRequest, DataScannerViewController, document scanning, RecognizeDocumentsRequest

by CharlesWiltgen

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

by CharlesWiltgen

Use when needing Vision framework API details for hand/body pose, segmentation, text recognition, barcode detection, document scanning, or Visual Intelligence integration. Covers VNRequest types, coordinate conversion, DataScannerViewController, RecognizeDocumentsRequest, SemanticContentDescriptor, IntentValueQuery.

by CharlesWiltgen

Use when encountering BUILD FAILED, test crashes, simulator hangs, stale builds, zombie xcodebuild processes, "Unable to boot simulator", "No such module" after SPM changes, or mysterious test failures despite no code changes - systematic environment-first diagnostics for iOS/macOS projects

by CharlesWiltgen

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

by CharlesWiltgen

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

by CharlesWiltgen

Use when deploying custom ML models on-device, converting PyTorch models, compressing models, implementing LLM inference, or optimizing CoreML performance. Covers model conversion, compression, stateful models, KV-cache, multi-function models, MLTensor.

by CharlesWiltgen

CoreML diagnostics - model load failures, slow inference, memory issues, compression accuracy loss, compute unit problems, conversion errors.

by CharlesWiltgen

CoreML API reference - MLModel lifecycle, MLTensor operations, coremltools conversion, compression APIs, state management, compute device availability, performance profiling.

by CharlesWiltgen

Use when implementing speech-to-text, live transcription, or audio transcription. Covers SpeechAnalyzer (iOS 26+), SpeechTranscriber, volatile/finalized results, AssetInventory model management, audio format handling.

by joelhooks

Multi-agent coordination patterns for OpenCode swarm workflows. Use when working on complex tasks that benefit from parallelization, when coordinating multiple agents, or when managing task decomposition. Do NOT use for simple single-agent tasks.

by bgruening

Maintain and upgrade the bgruening/docker-galaxy project: bump Galaxy/Ubuntu versions, update Ansible roles and scheduler support, adjust startup/CI/tests, and manage CVMFS.

by anshumanbh

Identify agentic AI security threats based on OWASP Top 10 for Agentic Applications 2026. Use when analyzing AI agents, LLM-powered applications, chatbots, auto-reply systems, tool-using AI, browser automation, sandbox execution, or any application that uses AI/LLM APIs (Anthropic, OpenAI, Claude, GPT) to process user input and take actions.

by anshumanbh

Validate authorization failures including IDOR, privilege escalation, and missing access controls. Test by attempting unauthorized access with lower-privileged credentials. Use when testing CWE-639 (IDOR), CWE-269 (Improper Privilege Management), CWE-862 (Missing Authorization), CWE-863 (Incorrect Authorization), CWE-284 (Improper Access Control), CWE-285 (Improper Authorization), or CWE-425 (Direct Request / Forced Browsing) findings.