WWDC26 - Apple OS 27 releases
OS 27 Field Notes
Short developer notes for Apple's OS 27 releases announced at WWDC26, focused on changes that affect app code.
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What's New in UIKit
Scene lifecycle, resizable iPhone apps, effective geometry, traits, tab sidebars, prominent tabs, navigation bars, menus, Siri context, and testing.
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What's New in SwiftData
Sectioned fetches, codable attributes, and model-store observers for app code that lives outside SwiftUI views.
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What's New in Swift
Swift 6.4 availability syntax, async cleanup, Testing migration, Foundation speedups, and measured performance tools.
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What's New in MetricKit
MetricManager, typed reports, StateReporting context, launch attribution, diagnostics, signpost summaries, and real app-health workflows.
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What's New in Foundation Models
Image prompts, Private Cloud Compute, LanguageModel packages, Dynamic Profiles, Evaluations, and Mac-first tooling.
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Local RAG with Core Spotlight
SpotlightSearchTool, Core Spotlight indexing, delegate hydration, source cards, privacy boundaries, and local retrieval architecture.
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Core AI for App Developers
PyTorch conversion, .aimodel integration, Swift inference,
specialization, caching, AOT compilation, and debugging tools.
Covered scope
Apple OS 27 and WWDC26 developer notes.
The index is for practical notes across iOS 27, iPadOS 27, macOS 27, watchOS 27, tvOS 27, visionOS 27, SwiftUI, UIKit, SwiftData, Swift 6.4, MetricKit, and shared Apple SDK changes.