axiom-apple-docs
charleswiltgen/axiom
Access Apple's official Xcode documentation and Swift compiler diagnostics directly in Claude Code.
What is axiom-apple-docs?
This skill routes you to Apple's authoritative markdown documentation bundled in Xcode, including 20 framework guides and 46 Swift compiler diagnostic explanations. Use it when you need exact API signatures, official implementation patterns, or explanations of compiler errors—complementing Axiom's opinionated guidance with Apple's source of truth.
- Read Apple's official AdditionalDocumentation guides (SwiftUI, UIKit, AppKit, WidgetKit, Swift Charts, Foundation, SwiftData, StoreKit, App Intents, MapKit, and more)
- Access Swift compiler diagnostic explanations for concurrency, type system, build, and language issues
- Resolve Xcode installation path automatically, including beta versions via AXIOM_XCODE_PATH
- Use Claude Code's native Read tool—no MCP server or special configuration required
How to install axiom-apple-docs
npx skills add https://github.com/charleswiltgen/axiom --skill axiom-apple-docs- Xcode installed (default: /Applications/Xcode.app)
- Claude Code or Cursor with native Read tool support
- Optional: AXIOM_XCODE_PATH environment variable for non-standard Xcode locations
How to use axiom-apple-docs
- 1.After installing, the skill's session-start hook detects your Xcode location and logs the base directories to session context
- 2.When you need Apple docs, identify the topic (e.g., 'Liquid Glass', 'Swift concurrency', 'compiler diagnostic')
- 3.Use the decision tree in the skill to find the correct filename
- 4.Call Read with the full path: {base}/{filename} (e.g., Read /Applications/Xcode.app/Contents/PlugIns/IDEIntelligenceChat.framework/Versions/A/Resources/AdditionalDocumentation/SwiftUI-Implementing-Liquid-Glass-Design.md)
- 5.For unlisted diagnostics, list the diagnostics directory to find the filename
Use cases
- Look up exact API behavior or signature for a framework feature you're implementing
- Understand a Swift compiler warning or error by reading Apple's official diagnostic guide
- Learn implementation patterns for new features like Liquid Glass design or Foundation Models
- Clarify concurrency constraints when a Sendable or actor-isolation error appears
- Reference official SwiftData or StoreKit updates for current best practices
- Swift and iOS/macOS developers using Claude Code or Cursor
- Teams needing authoritative Apple documentation during development
- Developers debugging compiler diagnostics and needing official explanations
axiom-apple-docs FAQ
No. The skill uses Claude Code's native Read tool to access files on your system. Xcode must be installed, and the documentation must exist at the standard paths.
Set the AXIOM_XCODE_PATH environment variable to your beta Xcode location. The skill's hook will detect it and report the resolved path in session context.
This skill reads Apple's official, up-to-date documentation directly from Xcode—exact signatures, current best practices, and compiler diagnostic explanations written by Apple engineers. It's authoritative and current, complementing Axiom's opinionated guidance.
The skill lists 20 guides and 46 diagnostics. For unlisted diagnostics, you can list the diagnostics directory using ls to find the filename, which follows the diagnostic's short name in lowercase with hyphens.
Yes. This skill is independent and works on its own to route you to Apple's documentation. It pairs well with other Axiom skills but doesn't require them.
Full instructions (SKILL.md)
Source of truth, from charleswiltgen/axiom.
name: axiom-apple-docs description: Use when you need Apple's own documentation or a Swift compiler diagnostic explained rather than recalled. license: MIT
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 with Claude Code's native 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
The session-start hook resolves Xcode's location and echoes the literal base directories into session context (look for "Apple for-LLM Documentation: Xcode detected at <path>"). Use the Read tool with <that base>/<filename>.
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
Xcode-beta users: the session-start hook respects AXIOM_XCODE_PATH and reports the resolved path in session context — use that path, not the default above.
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 $AXIOM_XCODE_PATH/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/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 AXIOM_XCODE_PATH is unset, or the path doesn't exist, or the IDEIntelligenceChat.framework directory is missing (older Xcode), fall back to:
- sosumi.ai (markdown mirror of developer.apple.com — see
skills/apple-docs-research.md) - WebFetch of the equivalent developer.apple.com URL
- 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
For WWDC transcript capture (Chrome auto-capture), sosumi.ai documentation access, and multi-session research workflows, see skills/apple-docs-research.md.
Resources
Skills: axiom-swiftui, axiom-concurrency, axiom-data, axiom-ai, axiom-integration
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