apple-docs-index — Claude Code skill: what it does, how to install

---
name: apple-docs-index
user-invocable: true
description: Index of Apple developer documentation for iOS, macOS, and related frameworks. Use when looking up what APIs exist in a framework, browsing available documentation, or deciding what docs to fetch. Covers SwiftUI, UIKit, Core Animation (QuartzCore), XCTest, HealthKit, Combine, SwiftData, and more.
---

# Apple Documentation Index

This skill provides indexes of Apple framework documentation. Use these to:
- Browse available APIs in a framework
- Find the path to specific documentation
- Decide what detailed docs to download

## Available Indexes

| Framework | File | Size | Topics |
|-----------|------|------|--------|
| SwiftUI | `../swiftui/swiftui-overview.md` | 907KB | Views, modifiers, navigation, state |
| XCTest | `xctest-index.md` | 55KB | Testing, assertions, expectations |
| XCUIAutomation | `xcuiautomation-index.md` | 58KB | UI testing, elements, queries |
| UIKit | `../uikit/uikit-overview.md` | 1.8MB | Views, controllers, controls, scenes |
| Core Animation | `../core-animation/core-animation-index.md` | 80KB | CALayer, CAAnimation, CATransaction, layer subclasses |
| HealthKit | `healthkit-index.md` | 312KB | Health data, workouts, records |
| Combine | `combine-index.md` | 153KB | Publishers, subscribers, operators |
| SwiftData | `swiftdata-index.md` | 86KB | Models, containers, queries |
| Observation | `observation-index.md` | 3KB | @Observable macro |

## How to Use

### 1. Browse an Index

```bash
# See what's in HealthKit
cat healthkit-index.md | head -100

# Search for specific topic
grep -i "workout" healthkit-index.md
grep -i "navigation" ../swiftui/swiftui-overview.md
```

### 2. Find Documentation Paths

Index files list all available documentation pages. Each entry shows the path:

```markdown
- [HKWorkout](/documentation/healthkit/hkworkout)
- [NavigationStack](/documentation/swiftui/navigationstack)
```

### 3. Fetch More Detailed Docs

1. Check whether the detailed page is already available in one of your installed Apple skills.
2. Use skill names, descriptions, or `SKILL.md` frontmatter to find likely skill directories, then grep their local `.md` files before fetching. This is faster and uses less context than fetching new docs from the internet.
3. If no installed skill has the page, use the same path with the `sosumi.ai` Markdown mirror.

For example, `/documentation/healthkit/hkworkout` maps to `https://sosumi.ai/documentation/healthkit/hkworkout`.

### 4. Browse Missing Framework Indexes

If the local indexes don't include the framework you need, use the framework's `sosumi.ai` index:

```text
https://sosumi.ai/documentation/{framework}
```

For example, `https://sosumi.ai/documentation/foundation` provides a Markdown index you can search for Foundation paths.

If the Markdown mirror is unavailable and your environment can parse JSON, Apple's public DocC index endpoint is:

```text
https://developer.apple.com/tutorials/data/index/{framework}
```

The useful path tree is under `interfaceLanguages.swift[0].children`.