Cloudkit Code Review

Reviews CloudKit code for container setup, record handling, subscriptions, and sharing patterns. Use when reviewing code with import CloudKit, CKContainer, CKRecord, CKShare, or CKSubscription.

Quick Reference

Issue Type	Reference
CKContainer, databases, zones, entitlements	references/container-setup.md
CKRecord, references, assets, batch operations	references/records.md
CKSubscription, push notifications, silent sync	references/subscriptions.md
CKShare, participants, permissions, acceptance	references/sharing.md

Review Checklist

• Account status checked before private/shared database operations
• Custom zones used (not default zone) for production data
• All CloudKit errors handled with retryAfterSeconds respected
• serverRecordChanged conflicts handled with proper merge logic
• CKErrorPartialFailure parsed for individual record errors
• Batch operations used (CKModifyRecordsOperation) not individual saves
• Large binary data stored as CKAsset (records have 1MB limit)
• Record keys type-safe (enums) not string literals
• UI updates dispatched to main thread from callbacks
• CKAccountChangedNotification observed for account switches
• Subscriptions have unique IDs to prevent duplicates
• CKShare uses custom zone (sharing requires custom zones)

When to Load References

• Reviewing container/database setup or zones -> container-setup.md
• Reviewing record CRUD or relationships -> records.md
• Reviewing push notifications or sync triggers -> subscriptions.md
• Reviewing sharing or collaboration features -> sharing.md

Output Format

Report issues using: [FILE:LINE] ISSUE_TITLE

Examples:

• [AppDelegate.swift:24] CKContainer not in custom zone
• [SyncManager.swift:156] Unhandled CKErrorPartialFailure
• [DataStore.swift:89] Missing retryAfterSeconds backoff

Review Questions

1. What happens when the user is signed out of iCloud?
2. Does error handling respect rate limiting (retryAfterSeconds)?
3. Are conflicts resolved or does data get overwritten silently?
4. Is the schema deployed to production before App Store release?
5. Are shared records in custom zones (required for CKShare)?

Hard gates (before reporting)

Complete in order for each finding you intend to report. Do not advance until the pass condition is satisfied.

1. Location artifact — The finding includes [FILE:LINE] (or a line range) copied from the current file contents; the path resolves in this repo.
2. Scope read — You read the full surrounding unit: the type or function that owns the CloudKit work (for example the CKOperation subclass usage, completion handler chain, or CKRecord lifecycle), not only a diff hunk or isolated snippet.
3. CloudKit or deployment claim (only if the finding depends on container identifiers, public vs private database choice, custom zone requirement, iCloud account state, entitlements, or production schema) — You name one concrete artifact you inspected (for example com.apple.developer.icloud-container-environment or container ID in the entitlements file, CKContainer.default() vs custom identifier in source, Info.plist / target capability, or evidence that schema is deployed) or you downgrade the item to an open question in Review Questions.
4. Protocol — Pre-report steps in review-verification-protocol are satisfied for this item (no finding if they are not).

Use the issue format [FILE:LINE] ISSUE_TITLE for each reported finding. Hard gate 4 is the full pre-report checklist for this skill’s review type.