Axiom

RealityKit 27 represents a major release cycle with advanced rendering and simulation capabilities. Key features include:

• Navigation: NavigationMeshResource → NavigationComponent → NavigationController for pathfinding.
• LOD: LevelOfDetailComponent for automatic mesh detail management.
• Lighting: Soft shadows via SpotLightComponent.Shadow, lightmaps via LightmapComponent, and runtime skybox/IBL generation via SkyboxGenerator and ImageBasedLightTextureGenerator.
• Advanced Rendering: Gaussian splats (visionOS), custom reverb meshes for acoustics, and low-level renderer access via LowLevelRenderer (using your own MTLCommandBuffer).
• Shaders & Deformation: ShaderGraph for code-based shader authoring and LowLevelDeformation for custom GPU mesh deformation.

Most advanced authoring (light baking, navmesh, character graphs) is handled in Reality Composer Pro 3.

Axiom provides a suite of specialized skills, references, diagnostics, and agents designed for building 2D and 3D interactive experiences on Apple platforms. The ecosystem is organized into several key domains:

Skills (Disciplines)

• SpriteKit: 2D game development, including scene graphs, physics, and action systems.
• Game Input: Handling touch controls (via TouchController) and game controllers (via GCController).
• SceneKit: 3D scene graph rendering, animations, and physics.
• RealityKit: Entity-Component-System (ECS) architecture for AR and 3D content.
• Metal Migration: Patterns and APIs for porting OpenGL/DirectX rendering to Metal.
• USDKit: Working with USD/USDZ files, including stage traversal and compressed exports.

References & Diagnostics

• References: Detailed API documentation for spritekit-ref, scenekit-ref, and realitykit-ref.
• Diagnostics: Troubleshooting tools for spritekit-diag, realitykit-diag, and metal-migration-diag to resolve issues like physics failures, entity loading errors, or shader compilation problems.

Agents

• spritekit-auditor: An automated agent that scans SpriteKit code for physics bitmask issues, draw call waste, node accumulation, and action memory leaks.

The camera-capture skill provides patterns for advanced AVFoundation implementations, categorized into several functional areas:

Session Architecture

• AVCaptureSession setup using a dedicated serial queue.
• Atomic configuration using beginConfiguration and commitConfiguration.
• Session presets optimized for photo vs. video.

Capture Patterns

• Photo capture via AVCapturePhotoOutput.
• Video recording via AVCaptureMovieFileOutput with audio support.
• Front/back camera switching with fallback logic.

Responsive Capture Pipeline (iOS 17+)

• Zero-shutter-lag using a ring buffer.
• Responsive capture for overlapping shots and burst-like shooting.
• Readiness coordinator for managing shutter button states.
• Deferred processing using proxy images and background tasks.

Performance and Pro Features

• Deferred Start (iOS 26+): Speeds up camera launch by showing the preview in roughly half the time.
• Pro Video Storage (iOS 27): Provides deterministic ProRes file writes.

Rotation and Lifecycle

• RotationCoordinator: Automatic rotation tracking (replaces deprecated videoOrientation).
• Session Lifecycle: Handling interruptions (phone calls, multitasking, thermal pressure) and managing start/stop operations on background queues.

Axiom provides four native command-line tools designed to give AI coding assistants and developers direct access to system-level data that is typically opaque to LLMs. These tools are auto-resolved on your PATH once the plugin is installed.

Available Tools

• xclog: Captures simulator and device console output (print, os_log, Logger) as structured JSON/JSONL.
• xcprof: Records and analyzes Instruments traces, focusing on CPU bottlenecks and user-code attribution.
• xcsym: Symbolicates and triages crash reports (supporting .ips, MetricKit, legacy .crash, and .xccrashpoint) with automatic dSYM discovery.
• xcui: Drives and asserts on the simulator UI and accessibility tree (handling waits, assertions, a11y settings, system dialogs, and VoiceOver).

Output Formats

By default, all tools emit compact JSON to minimize token usage for LLM consumers.

• To view output in a human-readable prose format, use the --human flag.
• To view indented JSON, pipe the output to jq ..

The swiftdata skill is designed for developers working with Apple's native persistence framework. Use this skill when you need assistance with:

• Defining @Model classes and managing @Relationship macros.
• Writing @Query in SwiftUI views for declarative data fetching.
• Configuring ModelContainer and managing ModelContext operations (insert, fetch, update, delete, batch).
• Integrating CloudKit synchronization.
• Implementing Swift 6 concurrency patterns using @MainActor and background actors.
• Migrating from Realm or Core Data to SwiftData.
• Utilizing iOS 27 features like sectioned queries and ResultsObserver.

Decision Guide:

• Choose SwiftData for native Apple integration and automatic SwiftUI updates.
• Choose SQLiteData if you prefer working with value types (structs) or need CloudKit record sharing.
• Choose GRDB if you require complex, fine-grained raw SQL control.

The xcui CLI is an Axiom-bundled tool designed for scriptable iOS-simulator UI and accessibility testing. It provides high-level test-harness semantics that simctl and AXe lack, such as waiting for conditions, asserting on the accessibility tree, and handling system dialogs.

Key Capabilities:

• Waiting: Poll the accessibility tree for elements to appear or disappear.
• Assertion: Validate element IDs, labels, values, and traits.
• Accessibility: Toggle simulator settings like Dynamic Type or Reduce Motion.
• Dialog Handling: Manage system permission alerts (e.g., Camera, Location).
• VoiceOver: Validate focus order and announcement sequences without audio capture.

Important Note on Input: xcui does not handle direct input. For tap, type, swipe, or touch operations, you must call the axe CLI directly. xcui is used to observe and control the environment, while axe provides the HID touch injection.