Agent skill · data analytics · charleswiltgen
axiom-data
Use when working with ANY data persistence, database, storage, CloudKit, migration, or serialization. Covers SwiftData, Core Data, GRDB, SQLite, Realm, CloudKit sync, file storage, Codable, migrations.
Why this skill is useful
Provides specific domain knowledge on data persistence strategies and migration patterns that the AI wouldn't reliably generate on its own.
What it needs
About 6k tokens when loaded. Last updated 2026-08-06. 1,103 stars on the source repository.
What this skill does
Data & Persistence You MUST use this skill for ANY data persistence, database, storage, CloudKit, or serialization work. <!-- AXIOMAUDITORINLINEBEGIN — rewritten for Codex by scripts/build-codex.ts; do not hand-edit --> Auditors are skills here. Where this router says "Launch some-auditor agent", invoke the matching Codex skill instead — same procedure, no Claude Code agent required. Available: axiom-audit-codable, axiom-audit-core-data, axiom-audit-database-schema, axiom-audit-grdb-performance, axiom-audit-icloud, axiom-audit-storage, axiom-audit-swiftdata. The ones that shell out — builds, tests, simulators, crash symbolication — need shell access to run. <!-- AXIOMAUDITORINLINEEND --> When to Use Use this skill 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 Keychain / secure credential storage Encryption, signing, key management (CryptoKit) Quick Reference Symptom / Task Reference ---------------- ----------- SwiftData @Model, @Query, ModelContext, sectioned queries / ResultsObserver / @Attribute(.codable) / dynamic compound predicates (OS27) See skills/swiftdata.md SwiftData schema migration, VersionedSchema See skills/swiftdata-migration.md SwiftData migration crashes, data loss See skills/swiftdata-migration-diag.md Migrating from Realm to SwiftData See skills/realm-migration-ref.md SwiftData vs SQLiteData decision See skills/sqlitedata-migration.md GRDB queries, upsert, ValueObservation, DatabaseMigrator, encryption See skills/grdb.md GRDB performance, indexes, EXPLAIN QUERY PLAN, cursors, observation not firing See skills/grdb-performance.md Full-text search (FTS5) in GRDB or SQLiteData See skills/sqlite-fts-ref.md Storing or querying JSON inside a SQLite column (JSON1, JSONB) See skills/sql-json-ref.md GRDB shared across app + widget/extension (App Group) See skills/grdb-app-groups.md SQLiteData @Tab …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills charleswiltgen/axiom-data--1becdb