External Purchases Skill for Claude

External Purchases (US Web Checkout)

On the US storefront, apps may link out to a web checkout for digital goods using the

StoreKit External Purchase Link entitlement — and as of mid-2026, court orders have Apple's

commission on those purchases at 0%, with the fee case still moving through district court.

This is the largest indie revenue unlock of the era, and it is *reversible by a ruling* — so the

engineering rule is: ship it now, architect it so a commission can be flipped on later.

> Verify current state before relying on this: the entitlement terms, the commission rate, and

> the litigation status have each changed more than once. Treat every number here as

> "true as of 2026-07, re-check."

When This Skill Activates

• "Add a web checkout / Stripe / external purchase link" for digital goods
• Deciding IAP vs web checkout for a US-heavy revenue base
• The store-growth audit flags P8.4
• Reviewing an app whose external links might be non-compliant (wrong storefront, no entitlement)

The rules of the road

• US storefront only — elsewhere Guideline 3.1.1 still applies (EU/JP/KR have separate

entitlements/terms; don't extrapolate from the US).

• Entitlement required: com.apple.developer.storekit.external-purchase-link + matching

Info.plist declaration — a bare Link("Buy", …) without it is still a rejection (see

app-store/rejection-handler §3.1.1).

• Present the link per the entitlement's UI terms (StoreKit's ExternalPurchaseLink /

disclosure sheet where required). Don't dark-pattern the IAP option away if you keep both.

• Purchases made on the web are your customer relationship — payment processor, refunds,

taxes; Apple's merchant-of-record role no longer applies.

Architecture: the commission flip

Design so that a future "Apple takes N% of external purchases initiated in-app" ruling changes a

config value, not your codebase:

• ✅ Route every in-app-initiated web checkout through one link-out service that stamps the

session (source=app, timestamp, storefront) — web-organic checkouts stay unstamped. If a

commission returns, it applies to a knowable, logged subset.

• ✅ Keep a single CommissionPolicy (remote-configurable): rate, applies_to,

effective_date. Report/accrue against it from day one — at 0% it's just a counter.

• ✅ Log day-one analytics: link taps → checkout starts → completions, vs the IAP funnel. The

conversion drop through a web checkout (Apple's sheet, Safari hop, payment form) is real;

whether 0% beats IAP's frictionless 85–70% is an *empirical* per-app question.

• ❌ Scattering openURL("https://…/buy") calls through features — un-auditable, un-flippable.
• ❌ Ripping out StoreKit. Keep IAP as a fallback path (non-US storefronts still need it, and

some US users convert better in-sheet).

Decision sketch

| Situation | Lean |

|---|---|

| Subscriptions, US-heavy, ARPU high enough to absorb processor fees + your own support | Web checkout for new subs; keep IAP for the rest of world |

| Impulse-priced consumables/unlocks | IAP — checkout friction eats more than 15–30% commission |

| Existing subscriber base on IAP | Don't force-migrate; offer web at renewal decision points |

| B2B/prosumer, invoicing needs | Web checkout regardless of commission math |

Output Format

Status: entitlement present? · storefront scope correct (US-only gating)? ·
link-out service centralized? · CommissionPolicy flippable? · funnel analytics live?
Verdict + the one next step.

References

• https://developer.apple.com/documentation/storekit/externalpurchaselink
• https://developer.apple.com/support/storekit-external-entitlement-us/
• https://developer.apple.com/app-store/review/guidelines/#in-app-purchase
• Related skills: app-store/rejection-handler (the non-entitled rejection pattern), generators/subscription-lifecycle, monetization (pricing), growth/store-growth-audit