# Skills

Axiom provides 13 production-ready skills for xOS (iOS, iPadOS, watchOS, tvOS) development.

**Version**: 0.1.6
**Status**: Preview Release - Examples Added

## Skill Categories

### UI & Design

Build beautiful, performant interfaces with expert guidance on the latest Apple design systems and testing practices.

- [Liquid Glass](/skills/ui-design/liquid-glass) – Apple's new material design system (iOS 26+)
- [SwiftUI Performance](/skills/ui-design/swiftui-performance) – Master the new SwiftUI Instrument in Instruments 26
- [SwiftUI Debugging](/skills/ui-design/swiftui-debugging) – View updates, preview crashes, and layout issues with decision trees
- [UI Testing](/skills/ui-design/ui-testing) – Recording UI Automation (Xcode 26) and condition-based waiting

### Debugging & Troubleshooting

Systematic debugging strategies to solve issues faster and prevent common problems before they happen.

- [Xcode Debugging](/skills/debugging/xcode-debugging) – Environment-first diagnostics for mysterious issues
- [Memory Debugging](/skills/debugging/memory-debugging) – Systematic leak diagnosis with proven patterns
- [Build Troubleshooting](/skills/debugging/build-troubleshooting) – Dependency resolution for CocoaPods and SPM
- [Performance Profiling](/skills/debugging/performance-profiling) – Instruments decision trees and profiling workflows for CPU, memory, battery

### Concurrency & Async

Master Swift's concurrency model and catch data races at compile time with strict concurrency patterns.

- [Swift Concurrency](/skills/concurrency/swift-concurrency) – Swift 6 strict concurrency, async/await, MainActor, Sendable

### Persistence

Comprehensive database patterns for safe schema evolution and choosing the right persistence framework.

- [Database Migration](/skills/persistence/database-migration) – Safe schema evolution for SQLite/GRDB/SwiftData
- [SQLiteData](/skills/persistence/sqlitedata) – Point-Free's SQLiteData patterns and CloudKit sync
- [GRDB](/skills/persistence/grdb) – Raw SQL queries and ValueObservation patterns
- [SwiftData](/skills/persistence/swiftdata) – iOS 26+ features, @Model definitions, and @Query patterns

## Skill Development Methodology

Skills in Axiom are developed using rigorous quality standards:

### TDD-Tested Skills

- **xcode-debugging** – 6 refinements from pressure testing
- **swift-concurrency** – Critical checklist contradiction found and fixed
- **database-migration** – Already bulletproof, validated under pressure
- **swiftdata** – Many-to-many relationships, unfollow patterns, CloudKit corruption recovery added during testing
- **memory-debugging** – PhotoKit leak patterns and non-reproducible issue debugging added during testing
- **ui-testing** – Network conditioning, multi-factor device testing, crash debugging patterns added from App Store review blocker scenario
- **build-troubleshooting** – Authority bias resistance, 4-step push-back framework, and pressure scenario guidance added from production crisis testing
- **liquid-glass** – Design review pressure handling, professional push-back framework, Regular vs Clear variant decision defense patterns added from client-watching design review scenario
- **swiftui-performance** – Production crisis decision-making, 30-minute diagnostic protocol with time-cost analysis, deployment deadline pressure guidance, and 5-question verification framework added from App Store performance blocker scenario
- **swiftui-debugging** – Intermittent update diagnosis (60-minute protocol), App Store Review deadline pressure handling, co-lead authority pressure resistance, professional push-back scripts from maximum pressure testing, plus 3 real-world examples (list updates, preview crashes, binding issues)
- **performance-profiling** – Self Time vs Total Time distinction under 4-hour App Store deadline, manager authority pressure resistance, misinterpretation prevention from maximum pressure testing, plus 3 real-world examples (N+1 queries, UI lag diagnosis, memory vs leak)
- **sqlitedata** – StructuredQueries migration crash decision framework, data-loss prevention patterns, emergency mitigation guidance, and honest pressure points analysis added from iOS 26 App Store update failure scenario
- **grdb** – Query profiling guidance (database.trace + EXPLAIN QUERY PLAN), ValueObservation optimization patterns with size-based decisions, and migration versioning guarantees added from complex join query performance testing

### Reference Skills

All reference skills are reviewed against 4 quality criteria:

1. **Accuracy** – Every claim cited to official sources, code tested
2. **Completeness** – 80%+ coverage, edge cases documented, troubleshooting sections
3. **Clarity** – Examples first, scannable structure, jargon defined
4. **Practical Value** – Copy-paste ready, expert checklists, real-world impact

## Related Resources

- [WWDC 2025 Sessions](https://developer.apple.com/videos/wwdc2025)
- Claude Code Documentation
- Superpowers TDD Framework

## Contributing

This is a preview release. Feedback welcome!

- **Issues**: Report bugs or request features
- **Discussions**: Share usage patterns and ask questions
