axiom-storekit-ref
Reference — Complete StoreKit 2 API guide covering Product, Transaction, AppTransaction, RenewalInfo, SubscriptionStatus, StoreKit Views, purchase options, server APIs, and all iOS 18.4 enhancements with WWDC 2025 code examples
npx skills add majiayu000/claude-skill-registry --skill axiom-storekit-ref-charleswiltgen-axiom-2 --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
What it does
Guides the AI agent to reference StoreKit 2 APIs, covering Product, Transaction, AppTransaction, RenewalInfo, SubscriptionStatus, StoreKit Views, purchase options, server APIs, and iOS 18.4 enhancements with WWDC 2025 code examples. It is a complete API reference intended to assist in implementing in-app purchases and subscription logic using StoreKit 2.
How it works
The skill presents detailed code examples and explanations for:
- Loading and inspecting Product data, including basic properties and subscription specifics.
- Purchase flows with UI contexts and advanced options (e.g., promotional offers, introductory eligibility, SwiftUI purchase usage).
- Handling PurchaseResult, including success verification, user cancellation, and pending states.
- Transaction handling, including new iOS 18.4 fields (appTransactionID, offerPeriod, advancedCommerceInfo), entitlements, and current entitlements queries.
- Transaction history and real-time updates via Transaction.updates, plus verification handling and finishing transactions.
- AppTransaction usage and essential properties, including platform notes and versioning checks.
- RenewalInfo for subscriptions, including appTransactionID and offerPeriod.
The skill instructs the agent to reference specific API signatures, to explain types and properties, and to show concrete Swift code blocks demonstrating typical usage with comments and edge-case handling as described in the reference.
When to use it
Use this reference when:
- Implementing in-app purchases with StoreKit 2
- Understanding new iOS 18.4 fields (appTransactionID, offerPeriod, etc.)
- Looking up specific API signatures and parameters
- Planning subscription architecture
- Debugging transaction issues
- Implementing StoreKit Views
- Integrating with App Store Server APIs
What it can touch
The skill relies on StoreKit 2 APIs and related Swift constructs as shown in the code examples. It references:
- Product, Transaction, AppTransaction, RenewalInfo types
- Purchase APIs (product.purchase, options like .promotionalOffer, .introductoryOfferEligibility, .appAccountToken)
- Transaction.currentEntitlements, Transaction.updates, and verification results
- AppTransaction.shared and RenewalInfo fields
- SwiftUI components (ProductView) and environment purchase key
Caveats
- Compatibility notes specify iOS 15+ baseline with iOS 18.4+ for latest features
- The skill is MIT licensed and uses claude-code as a declared tool
- The material is a reference guide; outcomes depend on implementation and server support as per the API descriptions
# StoreKit 2 — Complete API Reference ## Overview StoreKit 2 is Apple's modern in-app purchase framework with async/await APIs, automatic receipt validation, and SwiftUI integration. This reference covers every API, iOS 18.4 enhancements, and comprehensive WWDC 2025 code examples. ### Product Types Supported **Consumable**: - Products that can be purchased multiple times - Examples: coins, hints, temporary boosts - Do NOT restore on new devices **Non-Consumable**: - Products purchased once, owned forever - Examples: premium features, level packs, remove ads - MUST restore on new devices **Auto-Renewable Subscription**: - Subscriptions that renew automatically - Organized into subscription groups - MUST restore on new devices - Support: free trials, intro offers, promotional offers, win-back offers **Non-Renewing Subscription**: - Fixed duration subscriptions (no auto-renewal) - Examples: seasonal passes - MUST restore on new devices ### Key Improvements Over StoreKit 1 - **Async/Await**: Modern concurrency instead of delegates/closures - **Automatic Verification**: JSON Web Signature (JWS) verification built-in - **Transaction Types**: Strong Swift types instead of SKPaymentTransac
- Overview
- Product Types Supported
- Key Improvements Over StoreKit 1
- When to Use This Reference
- Product
- Loading Products
- Product Properties
- Subscription-Specific Properties
- Purchase Methods
- PurchaseResult
- Transaction
- New Fields (iOS 18.4)
- Essential Properties
- Current Entitlements
What does the axiom-storekit-ref skill do?
Reference — Complete StoreKit 2 API guide covering Product, Transaction, AppTransaction, RenewalInfo, SubscriptionStatus, StoreKit Views, purchase options, server APIs, and all iOS 18.4 enhancements with WWDC 2025 code examples
How do I install it?
Run `npx skills add majiayu000/claude-skill-registry --skill axiom-storekit-ref-charleswiltgen-axiom-2 --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From majiayu000/claude-skill-registry, a repository with 534 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.