axiom▌

Network.framework is Apple's modern networking API that replaces Berkeley sockets, providing smart connection establishment, user-space networking, built-in TLS support, and seamless mobility. Introduced in iOS 12 (2018) with NWConnection and evolved in iOS 26 (2025) with NetworkConnection for structured concurrency.

AXe is a CLI tool for interacting with iOS Simulators using Apple's Accessibility APIs and HID functionality. Single binary, no daemon required.

Use when:

Block retain cycles are the #1 cause of Objective-C memory leaks. When a block captures self and is stored on that same object (directly or indirectly through an operation/request), you create a circular reference: self → block → self. Core principle 90% of block memory leaks stem from missing or incorrectly applied weak-strong patterns, not genuine Apple framework bugs.

Systematic diagnosis and resolution of app hangs. A hang occurs when the main thread is blocked for more than 1 second, making the app unresponsive to user input.

Core Data issues manifest as production crashes from schema mismatches, mysterious concurrency errors, performance degradation under load, and data corruption from unsafe migrations. Core principle 85% of Core Data problems stem from misunderstanding thread-confinement, schema migration requirements, and relationship query patterns—not Core Data defects.

Systematic Xcode build performance analysis and optimization. Core principle: Measure before optimizing, then optimize the critical path first.

Core principle 90% of file storage problems stem from choosing the wrong storage location, misunderstanding file protection levels, or missing backup exclusions—not iOS file system bugs.

Porting OpenGL/OpenGL ES or DirectX code to Metal on Apple platforms.

Apple bundles for-LLM markdown documentation inside Xcode. These are authoritative, up-to-date guides and diagnostics written by Apple engineers. Use them alongside Axiom skills for the most accurate information.