ios-persistence
Implement local persistence with SwiftData, Core Data, and Keychain. Use when setting up SwiftData models, Core Data stacks, or local persistence in iOS. (triggers: **/*.xcdatamodeld, **/*Model.swift, PersistentContainer, FetchRequest, ManagedObject, Query, ModelContainer, Repository)
Best use case
ios-persistence is best used when you need a repeatable AI agent workflow instead of a one-off prompt.
Implement local persistence with SwiftData, Core Data, and Keychain. Use when setting up SwiftData models, Core Data stacks, or local persistence in iOS. (triggers: **/*.xcdatamodeld, **/*Model.swift, PersistentContainer, FetchRequest, ManagedObject, Query, ModelContainer, Repository)
Teams using ios-persistence should expect a more consistent output, faster repeated execution, less prompt rewriting.
When to use this skill
- You want a reusable workflow that can be run more than once with consistent structure.
When not to use this skill
- You only need a quick one-off answer and do not need a reusable workflow.
- You cannot install or maintain the underlying files, dependencies, or repository context.
Installation
Claude Code / Cursor / Codex
Manual Installation
- Download SKILL.md from GitHub
- Place it in
.claude/skills/ios-persistence/SKILL.mdinside your project - Restart your AI agent — it will auto-discover the skill
How ios-persistence Compares
| Feature / Agent | ios-persistence | Standard Approach |
|---|---|---|
| Platform Support | Not specified | Limited / Varies |
| Context Awareness | High | Baseline |
| Installation Complexity | Unknown | N/A |
Frequently Asked Questions
What does this skill do?
Implement local persistence with SwiftData, Core Data, and Keychain. Use when setting up SwiftData models, Core Data stacks, or local persistence in iOS. (triggers: **/*.xcdatamodeld, **/*Model.swift, PersistentContainer, FetchRequest, ManagedObject, Query, ModelContainer, Repository)
Where can I find the source code?
You can find the source code on GitHub using the link provided at the top of the page.
SKILL.md Source
# iOS Persistence ## **Priority: P0** ## Implementation Workflow 1. **Choose storage tier** — SwiftData for iOS 17+, Core Data for legacy, Keychain for secrets, UserDefaults for flags only. 2. **Define models** — Use `@Model` macro (SwiftData) or `.xcdatamodeld` (Core Data). 3. **Configure container** — Use `@MainActor` for `ModelContainer` (SwiftData) or `NSPersistentContainer` (Core Data). 4. **Perform background writes** — Use `newBackgroundContext()` (Core Data) to avoid UI lag; never do heavy I/O on `viewContext`. 5. **Secure sensitive data** — Use Keychain for tokens and PII; never store in `UserDefaults`. See [SwiftData and Core Data implementation examples](references/implementation.md) ## Anti-Patterns - ❌ Heavy I/O on `viewContext` — use private background contexts - ❌ String-based predicates — use KeyPaths or generated helpers - ❌ Missing merge strategy — set `mergePolicy` explicitly (e.g., `mergeByPropertyObjectTrump`) ## References - [SwiftData & Core Data Implementation](references/implementation.md)
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