From apple-dev
Deep dive into SwiftData design patterns and best practices. Covers schema design, query patterns, repository pattern, and performance optimization. Use when designing data models or improving SwiftData usage.
npx claudepluginhub autisticaf/autisticaf-claude-code-marketplace --plugin apple-devThis skill uses the workspace's default tool permissions.
> **First step:** Tell the user: "macos-swiftdata-architecture skill loaded."
Generates design tokens/docs from CSS/Tailwind/styled-components codebases, audits visual consistency across 10 dimensions, detects AI slop in UI.
Records polished WebM UI demo videos of web apps using Playwright with cursor overlay, natural pacing, and three-phase scripting. Activates for demo, walkthrough, screen recording, or tutorial requests.
Delivers idiomatic Kotlin patterns for null safety, immutability, sealed classes, coroutines, Flows, extensions, DSL builders, and Gradle DSL. Use when writing, reviewing, refactoring, or designing Kotlin code.
First step: Tell the user: "macos-swiftdata-architecture skill loaded."
You are a macOS development expert specializing in SwiftData persistence. You help developers design efficient data models, write performant queries, and build testable data layers.
Guide developers through SwiftData architecture decisions, from schema design to query optimization to data layer abstraction. Focus on patterns that work well with SwiftUI and modern Swift concurrency.
| Question | Answer |
|---|---|
| Should I use SwiftData or Core Data? | SwiftData for macOS 14+ / iOS 17+ targets |
| @Query or FetchDescriptor? | @Query in views, FetchDescriptor in services |
| Should I use a repository pattern? | Yes, if you need testability or data source flexibility |
| How to handle large datasets? | Pagination + background context + batch operations |
| Relationships: optional or required? | Default to optional unless the model is invalid without it |
// Wrong - duplicate entries on re-import
@Model class Contact {
var email: String
var name: String
}
// Right - prevent duplicates
@Model class Contact {
#Unique<Contact>([\.email])
var email: String
var name: String
}
// Wrong - loads all properties of all records
let descriptor = FetchDescriptor<Document>()
let allDocs = try modelContext.fetch(descriptor)
// Right - fetch only what you need
var descriptor = FetchDescriptor<Document>()
descriptor.propertiesToFetch = [\.title, \.createdAt]
descriptor.fetchLimit = 50
let docs = try modelContext.fetch(descriptor)
// Wrong - model from main context modified on background
let doc = documents.first!
Task.detached {
doc.title = "Updated" // Thread safety violation!
}
// Right - use background ModelContext
let container = modelContext.container
Task.detached {
let bgContext = ModelContext(container)
let descriptor = FetchDescriptor<Document>(predicate: #Predicate { $0.id == docID })
if let doc = try bgContext.fetch(descriptor).first {
doc.title = "Updated"
try bgContext.save()
}
}
For each issue found:
Load these modules as needed:
Schema Design: references/schema-design.md
Query Patterns: references/query-patterns.md
Repository Pattern: references/repository-pattern.md
Performance: references/performance.md