core-data-expert SKILL.md skillA
core-data-expert from patrickserrano/lacquer is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add patrickserrano/lacquer/core-data-expert@git:20260713.4950395Pins git:20260713.4950395 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- patrickserrano/lacquer
- Path
profiles/ios/skills/core-data-expert/SKILL.md- Versions recorded
- 3
- Latest version
- git:20260713.4950395, committed Jul 13, 2026
- First version recorded
- Jun 17, 2026
- Size
- 5,240 bytes
- Repository stars
- 5
- License
- MIT
Expert Core Data guidance (iOS/macOS) covering stack setup, fetch requests & NSFetchedResultsController, saving/merge conflicts, threading & Swift Concurrency, batch operations & persistent history, migrations, performance, and NSPersistentCloudKitContainer/CloudKit sync. Use when setting up a Core Data stack, debugging threading/concurrency crashes, resolving NSMergeConflict or constraint violations, planning a schema migration, integrating CloudKit sync, or diagnosing Core Data…
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Core Data Expert Fast, production-oriented guidance for building **correct**, **performant** Core Data stacks and fixing common crashes. ## Agent behavior contract (follow these rules) 1. Determine OS/deployment target when advice depends on availability (iOS 14+/17+ features, etc.). 2. Identify the context type before proposing fixes: **view context (UI)** vs **background context (heavy work)**. 3. Recommend `NSManagedObjectID` for cross-context/cross-task communication; **never pass `NSManagedObject` instances** across contexts. 4. Prefer lightweight migration when possible; use staged migration (iOS 17+) for complex changes. 5. When recommending batch operations, verify persistent history tracking is enabled (often required for UI updates). 6. For CloudKit integration, remind developers that **Production schema is immutable**. 7. Reference WWDC/external resources sparingly; prefer this skill’s `references/`. ## First 60 seconds (triage template) - **Clarify the goal**: setup, bugfix, migration, performance, CloudKit? - **Collect minimal facts**: - platform + deployment target - store type (SQLite / in-memory) and whether CloudKit is enabled …
Read the whole file at its exact version.
How to install
mdr add patrickserrano/lacquer/core-data-expert@sha256:a21c5adaa555e544The line at the top of this page pins the label git:20260713.4950395, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_ksmm2llq6jwei4xl)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 3 versions of this file, between Jun 17, 2026 and Jul 13, 2026, about one every 13 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260713.4950395 latest | 2026-07-13 | 4950395 | 5,240 B | A | view · diff |
| git:20260711.abb3d31 | 2026-07-11 | abb3d31 | 5,141 B | A | view · diff |
| git:20260617.2b85357 | 2026-06-17 | 2b85357 | 4,894 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (5240 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
patrickserrano/lacquer · 5 stars · license MIT · pushed 2026-11-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_ksmm2llq6jwei4xl GET https://markdownregistry.com/api/v1/resolve?ref=patrickserrano/lacquer/core-data-expert GET https://markdownregistry.com/api/v1/blob/a21c5adaa555e5445fafd0f16640cb232704741b9eba8aabd43641130999d21b
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.
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