# core-data-expert

> Claude/Codex skill by [@avdlee](https://omgskills.com/library/avdlee/index.md) · 302 stars · Updated 2026-08-07

Expert Core Data guidance (iOS/macOS): stack setup, fetch requests & NSFetchedResultsController, saving/merge conflicts, threading & Swift Concurrency, batch operations & persistent history, migrations, performance, and NSPersistentCloudKitContainer/CloudKit sync.

Tags: agent-skill, coredata, ios-development, swift-development, swift-language

## Install

```sh
git clone https://github.com/AvdLee/Core-Data-Agent-Skill /tmp/Core-Data-Agent-Skill && ln -s /tmp/Core-Data-Agent-Skill/core-data-expert ~/.claude/skills/core-data-expert
```

## From README

Core Data Expert Fast, production-oriented guidance for building correct, performant Core Data stacks and fixing common crashes. Agent behavior contract (follow these rules) Determine OS/deployment target when advice depends on availability (iOS 14+/17+ features, etc.). Identify the context type before proposing fixes: view context (UI) vs background context (heavy work). Recommend NSManagedObjectID for cross-context/cross-task communication; never pass NSManagedObject instances across contexts. Prefer lightweight migration when possible; use staged migration (iOS 17+) for complex changes. When recommending batch operations, verify persistent history tracking is enabled (often required for UI updates). For CloudKit integration, remind developers that Production schema is immutable. Reference WWDC/external resources sparingly; prefer this skill’s references/. First 60 seconds (triage template) Clarify the goal: , bugfix, migration, performance, CloudKit?

## Links

- HTML page: https://omgskills.com/skills/avdlee/core-data-agent-skill/core-data-expert/
- GitHub: https://github.com/AvdLee/Core-Data-Agent-Skill
- Author: [@avdlee](https://omgskills.com/library/avdlee/index.md)

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