Axiom

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Getting Started ​

Welcome to Axiom, battle-tested Claude Code skills for modern xOS (iOS, iPadOS, watchOS, tvOS) development.

What is Axiom? ​

Axiom provides 17 production-ready TDD-tested skills covering:

🎨 UI & Design Skills ​

  • Liquid Glass – Implement Apple's glass effects correctly and get expert validation
  • SwiftUI Performance – Find what's making your views slow and fix it
  • UI Testing – Record tests that work reliably across devices and languages

🐛 Debugging & Performance ​

  • Xcode Debugging – Fix mysterious build failures and zombie processes fast
  • Memory Debugging – Find memory leaks before users complain about crashes
  • Build Troubleshooting – Resolve dependency conflicts under production pressure

⚡ Concurrency & Async ​

  • Swift Concurrency – Prevent data races and fix actor isolation errors in Swift 6

💾 Data & Persistence ​

  • Database Migration – Add columns without losing user data
  • SQLiteData – Handle batch imports and CloudKit sync without performance issues
  • GRDB – Optimize complex queries and prevent N+1 query problems
  • SwiftData – Prevent CloudKit sync failures and handle concurrent access safely
  • Realm to SwiftData Migration – Migrate before Device Sync sunset (Sept 30, 2025) without breaking threading
  • Core Data Debugging – Fix migration crashes and thread-confinement errors

🔄 UIKit & Legacy ​

  • UIKit Animation Debugging – Fix animations that don't fire or behave differently on device
  • Objective-C Block Retain Cycles – Find and fix memory leaks from blocks

Prerequisites ​

  • macOS 15+ (Sequoia or later)
  • Claude Code (download here)
  • Xcode 26+ (for Liquid Glass, Recording UI Automation, and latest iOS features)
  • iOS 26 SDK (comes with Xcode 26)

Quick Start ​

1. Add the Marketplace ​

In Claude Code, run:

/plugin marketplace add https://charleswiltgen.github.io/Axiom/

2. Install the Plugin ​

Once you've added the marketplace in Claude Code:

  1. Use /plugin to open the plugin menu
  2. Search for "axiom"
  3. Click "Install"

3. Verify Installation ​

Use /plugin and select "Manage and install" to see installed plugins. Axiom should be listed.

4. Use Skills ​

Skills are automatically suggested by Claude Code based on your questions and context. Simply ask questions that match the skill's purpose:

Examples:

  • "I'm getting BUILD FAILED in Xcode with stale builds" → activates xcode-debugging
  • "How do I fix actor isolation errors in Swift 6?" → activates swift-concurrency
  • "I need to add a column to my database safely" → activates database-migration
  • "My app has memory leaks, where should I look?" → activates memory-debugging

Skills available in Axiom:

  • UI & Design: liquid-glass, swiftui-performance, ui-testing, swiftui-debugging
  • Debugging: xcode-debugging, memory-debugging, build-troubleshooting, performance-profiling
  • Concurrency: swift-concurrency
  • Data & Persistence: database-migration, sqlitedata, grdb, swiftdata, realm-to-swiftdata-migration, core-data-debugging
  • Legacy: objc-block-retain-cycles, uikit-animation-debugging

Common Workflows ​

Implementing Liquid Glass ​

When adding Liquid Glass to your app:

  1. Use axiom:liquid-glass skill
  2. Review Regular vs Clear variant decision criteria
  3. Apply .glassEffect() to navigation layer elements
  4. Run the Expert Review Checklist (7 sections) to validate implementation
  5. Test across light/dark modes and accessibility settings

Optimizing SwiftUI Performance ​

When app feels sluggish or animations stutter:

  1. Use axiom:swiftui-performance skill
  2. Profile with Instruments 26 using SwiftUI template
  3. Check Long View Body Updates lane for expensive operations
  4. Use Cause & Effect Graph to identify unnecessary updates
  5. Apply formatter caching or granular dependencies patterns

Recording UI Tests ​

When writing UI tests for new features:

  1. Use axiom:ui-testing skill
  2. Record interactions with Recording UI Automation (Xcode 26)
  3. Replay across devices, languages, and configurations
  4. Review video recordings to debug failures
  5. Apply condition-based waiting for reliable tests

Debugging Xcode Build Failures ​

When you encounter BUILD FAILED or mysterious Xcode issues:

  1. Use axiom:xcode-debugging skill
  2. Run mandatory environment checks (Derived Data, processes, simulators)
  3. Follow the decision tree for your specific error
  4. Apply quick fixes before debugging code

Fixing Swift Concurrency Errors ​

When you see actor isolation or Sendable errors:

  1. Use axiom:swift-concurrency skill
  2. Match your error to the decision tree
  3. Copy the relevant pattern template (delegate capture, weak self, etc.)
  4. Run the code review checklist

Creating Safe Database Migrations ​

When adding database columns or changing schema:

  1. Use axiom:database-migration skill
  2. Follow safe patterns (additive, idempotent, transactional)
  3. Write tests for both fresh install and migration paths
  4. Test manually on device before shipping

What's Next? ​