Apple Documentation Router

Apple bundles for-LLM markdown documentation inside Xcode. These are authoritative, up-to-date guides and diagnostics written by Apple engineers. Read them directly as files (in Claude Code, with the Read tool) — no MCP server or special tool required.

When to Use

• You need the exact API signature or behavior from Apple
• An Axiom skill references an Apple framework and you want the official source
• A Swift compiler diagnostic needs explanation
• The user asks about a specific Apple framework feature

Priority: Axiom skills provide opinionated guidance (decision trees, anti-patterns, pressure scenarios). Apple docs provide authoritative API details. Use both together.

How to Read These Docs

Axiom's session context names the Xcode the user has switched to. In Claude Code it lists the literal base directories ("Apple for-LLM Documentation: Xcode detected at <path>"); other harnesses name the app ("Installed on this machine: Xcode … (<path>)") — substitute that .app for /Applications/Xcode.app in the table below. Read <base>/<filename> as a file (the Read tool in Claude Code).

Default Xcode location (/Applications/Xcode.app) base directories:

Content	Base directory
AdditionalDocumentation guides	/Applications/Xcode.app/Contents/PlugIns/IDEIntelligenceChat.framework/Versions/A/Resources/AdditionalDocumentation/
Swift compiler diagnostics	/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/share/doc/swift/diagnostics/

Example invocation Claude should produce:

Read /Applications/Xcode.app/Contents/PlugIns/IDEIntelligenceChat.framework/Versions/A/Resources/AdditionalDocumentation/SwiftUI-Implementing-Liquid-Glass-Design.md

These paths assume the default install; use the path from session context instead. Without session context: use AXIOM_XCODE_PATH if it is set; otherwise run xcode-select -p (it honors DEVELOPER_DIR), which prints <Xcode>.app/Contents/Developer — drop /Contents/Developer and put that .app in place of /Applications/Xcode.app above. If it prints /Library/Developer/CommandLineTools, no Xcode is selected; try /Applications/Xcode.app.

Guide Files (AdditionalDocumentation)

20 files. Read with the path pattern {guides base}/{filename}.

UI & Design

Topic	Filename
Liquid Glass in SwiftUI	SwiftUI-Implementing-Liquid-Glass-Design.md
Liquid Glass in UIKit	UIKit-Implementing-Liquid-Glass-Design.md
Liquid Glass in AppKit	AppKit-Implementing-Liquid-Glass-Design.md
Liquid Glass in WidgetKit	WidgetKit-Implementing-Liquid-Glass-Design.md
SwiftUI new toolbar features	SwiftUI-New-Toolbar-Features.md
SwiftUI styled text editing	SwiftUI-Styled-Text-Editing.md
SwiftUI WebKit integration	SwiftUI-WebKit-Integration.md
SwiftUI AlarmKit integration	SwiftUI-AlarmKit-Integration.md
Swift Charts 3D visualization	Swift-Charts-3D-Visualization.md
Foundation AttributedString updates	Foundation-AttributedString-Updates.md

Data & Persistence

Topic	Filename
SwiftData class inheritance	SwiftData-Class-Inheritance.md

Concurrency & Performance

Topic	Filename
Swift concurrency updates	Swift-Concurrency-Updates.md
InlineArray and Span	Swift-InlineArray-Span.md

Apple Intelligence

Topic	Filename
Foundation Models (on-device LLM)	FoundationModels-Using-on-device-LLM-in-your-app.md

System Integration

Topic	Filename
App Intents updates	AppIntents-Updates.md
StoreKit updates	StoreKit-Updates.md
MapKit GeoToolbox PlaceDescriptors	MapKit-GeoToolbox-PlaceDescriptors.md
Widgets for visionOS	Widgets-for-visionOS.md

Accessibility

Topic	Filename
Assistive Access in iOS	Implementing-Assistive-Access-in-iOS.md

Computer Vision

Topic	Filename
Visual Intelligence in iOS	Implementing-Visual-Intelligence-in-iOS.md

Swift Compiler Diagnostics

46 files in the diagnostics directory. Read with the path pattern {diagnostics base}/{filename}.

Concurrency Diagnostics

Diagnostic	Filename
Actor-isolated call from nonisolated context	actor-isolated-call.md
Conformance isolation	conformance-isolation.md
Isolated conformances	isolated-conformances.md
Nonisolated nonsending by default	nonisolated-nonsending-by-default.md
Sendable closure captures	sendable-closure-captures.md
Sendable metatypes	sendable-metatypes.md
Explicit Sendable annotations	explicit-sendable-annotations.md
Sending closure risks data race	sending-closure-risks-data-race.md
Sending risks data race	sending-risks-data-race.md
Mutable global variable	mutable-global-variable.md
Preconcurrency import	preconcurrency-import.md
Dynamic exclusivity	dynamic-exclusivity.md
Exclusivity violation	exclusivity-violation.md

Type System Diagnostics

Diagnostic	Filename
Existential any	existential-any.md
Existential member access limitations	existential-member-access-limitations.md
Nominal types	nominal-types.md
Multiple inheritance	multiple-inheritance.md
Protocol type non-conformance	protocol-type-non-conformance.md
Opaque type inference	opaque-type-inference.md
Foreign reference type	foreign-reference-type.md

Build & Migration Diagnostics

Diagnostic	Filename
Deprecated declaration	deprecated-declaration.md
Error in future Swift version	error-in-future-swift-version.md
Strict language features	strict-language-features.md
Strict memory safety	strict-memory-safety.md
Implementation only deprecated	implementation-only-deprecated.md
Member import visibility	member-import-visibility.md
Missing module on known paths	missing-module-on-known-paths.md
Module not testable	module-not-testable.md
Module version missing	module-version-missing.md
Clang declaration import	clang-declaration-import.md
Availability unrecognized name	availability-unrecognized-name.md
Always-available domain	always-available-domain.md
Upcoming language features	upcoming-language-features.md
Unknown warning group	unknown-warning-group.md
Compilation caching	compilation-caching.md
Embedded restrictions	embedded-restrictions.md

Swift Language Diagnostics

Diagnostic	Filename
Dynamic callable requirements	dynamic-callable-requirements.md
Property wrapper requirements	property-wrapper-requirements.md
Result builder methods	result-builder-methods.md
String interpolation conformance	string-interpolation-conformance.md
Trailing closure matching	trailing-closure-matching.md
Temporary pointers	temporary-pointers.md
Semantic copies	semantic-copies.md
Performance hints	performance-hints.md

Index

Diagnostic	Filename
Diagnostic groups (taxonomy)	diagnostic-groups.md
All diagnostics index	diagnostics.md

If a diagnostic you need isn't listed above, list the diagnostics directory first:

ls "<Xcode>.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/share/doc/swift/diagnostics/"

<Xcode>.app is the app session context names; without session context, derive it as above. Command Line Tools keep the same files at /Library/Developer/CommandLineTools/usr/share/doc/swift/diagnostics/.

Filenames follow the diagnostic's short name (lowercase, hyphenated).

Routing Decision Tree

User question about Apple API/framework?
├── Specific compiler error/warning → Read {diagnostics base}/<diagnostic-name>.md
├── Liquid Glass implementation     → Read {guides base}/<Framework>-Implementing-Liquid-Glass-Design.md
├── Swift concurrency patterns      → Read {guides base}/Swift-Concurrency-Updates.md
├── Foundation Models / on-device AI → Read {guides base}/FoundationModels-Using-on-device-LLM-in-your-app.md
├── SwiftData features              → Read {guides base}/SwiftData-Class-Inheritance.md
├── StoreKit / IAP                  → Read {guides base}/StoreKit-Updates.md
├── App Intents / Siri              → Read {guides base}/AppIntents-Updates.md
├── Charts / visualization          → Read {guides base}/Swift-Charts-3D-Visualization.md
├── Text editing / AttributedString → Read {guides base}/SwiftUI-Styled-Text-Editing.md or Foundation-AttributedString-Updates.md
├── WebKit in SwiftUI               → Read {guides base}/SwiftUI-WebKit-Integration.md
├── Toolbar features                → Read {guides base}/SwiftUI-New-Toolbar-Features.md
└── Other                           → ls the base directory to see what's available

Fallback When Xcode Is Unavailable

If the resolved Xcode has no IDEIntelligenceChat.framework documentation directory (older Xcode, or only Command Line Tools installed), fall back to the list below. For a Swift diagnostic, first try the Command Line Tools copy at /Library/Developer/CommandLineTools/usr/share/doc/swift/diagnostics/.

1. sosumi.ai (markdown mirror of developer.apple.com — see skills/apple-docs-research.md)
2. The SDK's own declarations – its Swift interfaces and Objective-C headers (also in skills/apple-docs-research.md); Command Line Tools includes only the macOS SDK
3. Suggest installing the latest Xcode for full Apple docs coverage

Do not silently fail — tell the user when Xcode docs aren't available locally and which fallback you used.

MCP Convenience Path

Clients using axiom-mcp can also invoke axiom_read_skill with the legacy ID (e.g., apple-guide-swiftui-implementing-liquid-glass-design). The MCP server reads the same Xcode files and returns the same content. Both paths are supported — the file-Read path works everywhere; the MCP path is a convenience for catalog/search workflows.

Research Methodology

When the bundled guides don't cover it — Apple's full API reference, the SDK's own declarations, or a WWDC session's transcript and code — see skills/apple-docs-research.md.

Resources

Skills: axiom-swiftui, axiom-concurrency, axiom-data, axiom-ai, axiom-integration