Apple-skills guide-swiftdata

SwiftData patterns — autosave, relationships, dangerous predicates, CloudKit constraints, indexing, class inheritance. Use when writing, reviewing, or debugging SwiftData code.

install

source · Clone the upstream repo

git clone https://github.com/vabole/apple-skills

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/vabole/apple-skills "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/guide-swiftdata" ~/.claude/skills/vabole-apple-skills-guide-swiftdata && rm -rf "$T"

manifest: skills/guide-swiftdata/SKILL.md

source content

Guide Skill — This is an expert workflow/pattern guide, not API reference documentation. Originally from twostraws/SwiftData-Agent-Skill by Paul Hudson. MIT License.

SwiftData Patterns

Write and review SwiftData code for correctness, modern API usage, and adherence to project conventions. Report only genuine problems — do not nitpick or invent issues.

Core Instructions

Target Swift 6.2 or later, using modern Swift concurrency.
Prefer SwiftData across the board. Do not suggest Core Data unless the feature cannot be solved with SwiftData.
Do not introduce third-party frameworks without asking first.

Review Process

Check for core SwiftData issues using
```
references/core-rules.md
```
.
Check that predicates are safe and supported using
```
references/predicates.md
```
.
If the project uses CloudKit, check for CloudKit-specific constraints using
```
references/cloudkit.md
```
.
If the project targets iOS 18+, check for indexing opportunities using
```
references/indexing.md
```
.
If the project targets iOS 26+, check for class inheritance patterns using
```
references/class-inheritance.md
```
.

If doing partial work, load only the relevant reference files.

References

Topic	Reference
Autosave, relationships, delete rules, `@Query` restrictions, `#Unique` , `@Transient`	`references/core-rules.md`
Supported predicates, dangerous patterns that crash at runtime, unsupported methods	`references/predicates.md`
CloudKit constraints: no `#Unique` , optional requirements, eventual consistency	`references/cloudkit.md`
Database indexing (iOS 18+), single and compound property indexes	`references/indexing.md`
Model subclassing (iOS 26+), `@available` requirements, predicate filtering	`references/class-inheritance.md`