storekit

storekit is a skill for Claude Code, Codex from TalissonVitorino/kmp-ios-skills. It costs 242 tokens per session (4,270 once invoked), scanned A, original, MIT.

A guide to adding digital purchases and subscriptions to Apple apps with StoreKit 2, Apple's in-app purchasing system. It covers fetching products, buying them, checking transactions, and deciding which paid features a user can access.

In plain words
What is it for?
Use it to sell subscriptions or digital goods in iPhone, iPad, or Mac apps and connect purchase access to a server.
Why use it?
It helps avoid treating unverified purchases as valid and clarifies the difference between digital purchases and real-world payments.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: positional $N argument.

Good fit Use it to sell subscriptions or digital goods in iPhone, iPad, or Mac apps and connect purchase access to a server.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/talissonvitorino/kmp-ios-skills/storekit
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add TalissonVitorino/kmp-ios-skills --skill storekit
Clone the repo
git clone --depth 1 https://github.com/TalissonVitorino/kmp-ios-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for storekit

README.md
[![agentmods](https://agentmods.dev/badge/skills/talissonvitorino/kmp-ios-skills/storekit/github.svg)](https://agentmods.dev/skills/talissonvitorino/kmp-ios-skills/storekit)
Your own site
<a href="https://agentmods.dev/skills/talissonvitorino/kmp-ios-skills/storekit"><img src="https://agentmods.dev/badge/skills/talissonvitorino/kmp-ios-skills/storekit/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for storekit

Your own site · 80×15
<a href="https://agentmods.dev/skills/talissonvitorino/kmp-ios-skills/storekit"><img src="https://agentmods.dev/badge/skills/talissonvitorino/kmp-ios-skills/storekit.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 242 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,270 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00242 $0.04270
Opus 5 $0.00121 $0.02135
Sonnet 5 $0.00048 $0.00854
Haiku 4.5 $0.00024 $0.00427

Measured 7d ago against content hash c84403979f06, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

storekit scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

ios/storekit/SKILL.md · 383 lines

How it starts

The opening of the file, as written. The whole thing — 383 lines — stays where its author put it; the contents beside it link to each section on GitHub.

StoreKit 2 (In-App Purchases & Subscriptions)

Modern async StoreKit for a fintech iOS app: sell products, verify transactions, gate entitlements, and keep the server as the source of truth. Grounded in Apple's StoreKit, StoreKit Views, and StoreKit Test frameworks (iOS 15+ APIs; iOS 26 era).

  • Use StoreKit 2 (import StoreKit, Product/Transaction), not the deprecated SKPaymentQueue/SKProduct StoreKit 1 API, for any new code.
  • Digital goods and subscriptions only. Real-world goods/services and money movement go through Apple Pay / your PSP — see passkit. Mixing them up is an App Store rejection (see app-store-review).
  • KMP boundary: IAP is Apple-native — keep it in iosMain/Swift. Expose a commonMain interface EntitlementStore { fun isSubscribed(): Boolean } and bind an actual that reads the verified StoreKit entitlement; see expect-actual and kmp-ios-integration. Never let shared code decide purchase validity.
  • Trust the server, not the client. The device signal is for UX; grant paid features from a server that validates transactions (App Store Server API) and reacts to App Store Server Notifications V2 — see references/server-and-security.md.

Contents

Setup

  • Add the In-App Purchase capability; configure products in App Store Connect (or a .storekit file for local testing — see below).
  • Product IDs are opaque strings; keep them in one typed source of truth:

Read the full file on GitHub · 383 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 7d ago First seen · 383 lines · 242 tokens per session scan A c84403979f06

Subscribe to this mod's changes

storekit is a skill published in the GitHub repository TalissonVitorino/kmp-ios-skills (12 stars, last pushed 17d ago), licensed MIT. It adds 242 tokens to every session and 4,270 once invoked, about $0.0012 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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