iOS Data & Persistence Router
You MUST use this skill for ANY data persistence, database, axiom-storage, CloudKit, or serialization work.
When to Use
Use this router when working with:
Databases (SwiftData, Core Data, GRDB, SQLiteData) Schema migrations CloudKit sync File storage (iCloud Drive, local storage) Data serialization (Codable, JSON) Storage strategy decisions Routing Logic SwiftData
Working with SwiftData → /skill axiom-swiftdata Schema migration → /skill axiom-swiftdata-migration Migration issues → /skill axiom-swiftdata-migration-diag Migrating from Realm → /skill axiom-realm-migration-ref SwiftData vs SQLiteData → /skill axiom-sqlitedata-migration
Other Databases
GRDB queries → /skill axiom-grdb SQLiteData → /skill axiom-sqlitedata Advanced SQLiteData → /skill axiom-sqlitedata-ref Core Data patterns → /skill axiom-core-data Core Data issues → /skill axiom-core-data-diag
Migrations
Database migration safety → /skill axiom-database-migration (critical - prevents data loss)
Serialization
Codable issues → /skill axiom-codable
Cloud Storage
Cloud sync patterns → /skill axiom-cloud-sync CloudKit → /skill axiom-cloudkit-ref iCloud Drive → /skill axiom-icloud-drive-ref Cloud sync errors → /skill axiom-cloud-sync-diag
File Storage
Storage strategy → /skill axiom-storage Storage issues → /skill axiom-storage-diag Storage management → /skill axiom-storage-management-ref File protection → /skill axiom-file-protection-ref
Decision Tree User asks about data/storage ├─ Database? │ ├─ SwiftData? → swiftdata, axiom-swiftdata-migration │ ├─ Core Data? → core-data, axiom-core-data-diag │ ├─ GRDB? → grdb │ └─ SQLiteData? → sqlitedata │ ├─ Migration? → database-migration (ALWAYS - prevents data loss) │ ├─ Cloud storage? │ ├─ Sync architecture? → cloud-sync │ ├─ CloudKit? → cloudkit-ref │ ├─ iCloud Drive? → icloud-drive-ref │ └─ Sync errors? → cloud-sync-diag │ ├─ Serialization? → codable │ └─ File storage? → storage, axiom-storage-diag, axiom-storage-management-ref
Critical Pattern: Migrations
ALWAYS invoke /skill axiom-database-migration when adding/modifying database columns.
This prevents:
"FOREIGN KEY constraint failed" errors "no such column" crashes Data loss from unsafe migrations Example Invocations
User: "I need to add a column to my SwiftData model" → Invoke: /skill axiom-database-migration (critical - prevents data loss)
User: "How do I query SwiftData with complex filters?" → Invoke: /skill axiom-swiftdata
User: "CloudKit sync isn't working" → Invoke: /skill axiom-cloud-sync-diag
User: "Should I use SwiftData or SQLiteData?" → Invoke: /skill axiom-sqlitedata-migration