Axiom Payments

Real-World Payments (Apple Pay / Wallet / Tap to Pay)

You MUST use this skill when accepting ANY real-world payment — physical goods, services, donations, ticketing, loyalty cards, contactless card-present, or post-purchase order tracking. NOT for in-app purchase or digital content.

When to Use

Use this skill when you encounter:

• Adding Apple Pay to an iOS / iPadOS / macOS / Catalyst / visionOS / watchOS app
• Adding Apple Pay to a website (Apple Pay JS or W3C Payment Request API)
• Building Wallet passes (boarding passes, event tickets, coupons, loyalty cards, store cards)
• Accepting contactless card payments on iPhone (Tap to Pay on iPhone / ProximityReader)
• Surfacing post-purchase order tracking in Wallet (Orders in Wallet, FinanceKitUI add-order helpers)
• Issuer or bank card provisioning into Wallet (issuer extensions)
• Apple Pay merchant ID, processing certificate, or merchant identity certificate setup
• Pass Type ID or Order Type ID certificates and PKCS #7 signing chains
• Tap to Pay managed entitlement (com.apple.developer.proximity-reader.payment.acceptance)
• App Review rejections that mention payments, IAP, Apple Pay, Wallet, or Acceptable Use Guidelines
• Domain verification for Apple Pay on the web (.well-known/apple-developer-merchantid-domain-association.txt)
• Sandbox testing with Apple Pay sandbox cards or sandbox tester accounts

When NOT to Use

Quick Reference

Decision Tree

digraph payments {    "Payments question?" [shape=diamond];    "Apple Pay or IAP?" [shape=diamond];    "Where is the surface?" [shape=diamond];    "What kind of pass?" [shape=diamond];    "Something not working?" [shape=diamond];
    "skills/apple-pay-vs-iap.md" [shape=box];    "skills/apple-pay.md" [shape=box];    "skills/apple-pay-web.md" [shape=box];    "skills/tap-to-pay.md" [shape=box];    "skills/wallet-passes.md" [shape=box];    "skills/wallet-orders.md" [shape=box];    "skills/wallet-extensions-ref.md" [shape=box];    "skills/payments-diag.md" [shape=box];    "axiom-integration\n/in-app-purchases.md" [shape=box];
    "Payments question?" -> "Apple Pay or IAP?";    "Apple Pay or IAP?" -> "skills/apple-pay-vs-iap.md" [label="boundary unclear"];    "Apple Pay or IAP?" -> "axiom-integration\n/in-app-purchases.md" [label="digital content /\nsubscription for digital"];    "Apple Pay or IAP?" -> "Where is the surface?" [label="real-world payment"];
    "Where is the surface?" -> "skills/apple-pay.md" [label="native app"];    "Where is the surface?" -> "skills/apple-pay-web.md" [label="website"];    "Where is the surface?" -> "skills/tap-to-pay.md" [label="contactless on iPhone"];    "Where is the surface?" -> "What kind of pass?" [label="pass / order"];    "Where is the surface?" -> "skills/wallet-extensions-ref.md" [label="card provisioning\n(issuer / bank)"];
    "What kind of pass?" -> "skills/wallet-passes.md" [label="boarding / ticket /\ncoupon / loyalty"];    "What kind of pass?" -> "skills/wallet-orders.md" [label="post-purchase\norder tracking"];
    "Payments question?" -> "Something not working?";    "Something not working?" -> "skills/payments-diag.md" [label="yes"];}

Simplified routing:

1. Is this a digital good or subscription for digital content? → Use axiom-integration/skills/in-app-purchases.md instead.
2. Selling physical goods / services / donations, or unsure? → skills/apple-pay-vs-iap.md
3. Native Apple Pay (iOS / iPadOS / macOS / Catalyst / visionOS / watchOS)? → skills/apple-pay.md + skills/apple-pay-ref.md
4. Apple Pay on the web? → skills/apple-pay-web.md + skills/apple-pay-web-ref.md
5. Tap to Pay on iPhone (ProximityReader)? → skills/tap-to-pay.md + skills/tap-to-pay-ref.md
6. Wallet passes (ticket / coupon / loyalty / store card)? → skills/wallet-passes.md + skills/wallet-passes-ref.md
7. Orders in Wallet (post-purchase tracking)? → skills/wallet-orders.md
8. Issuer / bank card provisioning? → skills/wallet-extensions-ref.md
9. Something not working (no sheet / merchant validation fails / pass won't import / Tap to Pay never enables)? → skills/payments-diag.md

Cross-Suite Routing

Apple Pay vs IAP boundary (the most common cross-suite question):

• Selling physical goods, services, or donations → stay here (skills/apple-pay-vs-iap.md)
• Selling digital content, premium app features, subscriptions for digital content → use axiom-integration (skills/in-app-purchases.md)
• App was rejected for using the wrong one → skills/apple-pay-vs-iap.md then skills/payments-diag.md

Payments + App Review rejection:

• Rejection cites Section 3.1 / 3.2 / Apple Pay AUG → stay here (skills/payments-diag.md) for the root cause; also invoke axiom-shipping (skills/app-store-diag.md) for appeal workflow

Payments + cert management:

• Merchant Identity Certificate, Pass Type ID Certificate, Order Type ID Certificate, Payment Processing Certificate — operational discipline → stay here
• Generic Keychain export / .p12 mechanics → also invoke axiom-security (skills/keychain-ref.md)
• Tap to Pay managed entitlement → stay here (skills/tap-to-pay.md); generic managed-capability mental model → axiom-security (skills/code-signing.md)

Payments + Xcode capability / provisioning:

• Apple Pay capability checkbox in Xcode, merchant ID selection, Tap to Pay entitlement plumbing in the provisioning profile → also invoke axiom-build for capability/profile mechanics; payment-specific guidance stays here

Payments + HIG:

• Apple Pay button vs Apple Pay Mark, Wallet pass design specs, Tap to Pay button label → stay here
• Cross-cutting design context → also invoke axiom-design (skills/hig.md)

Payments + Catalyst / macOS:

• Apple Pay on Mac and Catalyst (window requirement, web security model, static merchant validation URL) → stay here (skills/apple-pay.md Catalyst section)
• Generic Catalyst patterns → axiom-macos

Payments + Apple Watch:

• WKInterfacePaymentButton, watchOS payment delegate flow → stay here (skills/apple-pay-ref.md watchOS section)
• Generic watchOS patterns → axiom-watchos

Anti-Rationalization

Out of Scope

This suite intentionally does not cover:

• In-App Purchase (StoreKit 2) — Use axiom-integration/skills/in-app-purchases.md and axiom-integration/skills/storekit-ref.md. The boundary rule lives in skills/apple-pay-vs-iap.md.
• FinanceKit consumer banking (account aggregation, transaction queries) — not covered. We only use FinanceKitUI for order-add buttons.
• PKSecureElementPass, transit cards, car keys — issuer-controlled Wallet surfaces, not merchant-developer territory.
• Tap to Present ID (MobileDocumentReader) — uses ProximityReader but for identity verification, not payment. Brief cross-ref appears in skills/tap-to-pay-ref.md; identity-verification UX as a whole is axiom-integration territory if it lands anywhere.
• Generic NFC reads (Core NFC) — different framework. PassKit NFC is Wallet-specific (loyalty / contactless ticket / boarding).

Example Invocations

User: "Should I use Apple Pay or IAP for my hotel-booking app?" → See skills/apple-pay-vs-iap.md

User: "How do I set up Apple Pay in my iOS app?" → See skills/apple-pay.md

User: "What's the structure of PKPaymentRequest?" → See skills/apple-pay-ref.md

User: "Apple Pay on my website doesn't show the button in Chrome" → See skills/apple-pay-web.md

User: "Domain verification keeps failing" → See skills/payments-diag.md

User: "I want to add Tap to Pay on iPhone to my point-of-sale app" → See skills/tap-to-pay.md

User: "My Tap to Pay entitlement has been Submitted for two weeks" → See skills/tap-to-pay.md and skills/payments-diag.md

User: "How do I build a Wallet pass for my event tickets?" → See skills/wallet-passes.md

User: "My .pkpass file won't import — Wallet says invalid" → See skills/payments-diag.md

User: "I want order tracking to appear in Wallet after Apple Pay checkout" → See skills/wallet-orders.md

User: "App Review rejected my app for using IAP for restaurant delivery" → See skills/apple-pay-vs-iap.md then skills/payments-diag.md

User: "How does Apple Pay differ from In-App Purchase?" → See skills/apple-pay-vs-iap.md

User: "Implementing card provisioning for our bank's iOS app" → See skills/wallet-extensions-ref.md

Resources

WWDC: 2020-10662, 2021-10092, 2022-10041, 2023-10114, 2024-10108

Tech Talks: 111381 (Apple Pay on the Web), 110336 (Implementing Apple Pay Orders)

MIG: Apple Pay Merchant Integration Guide (2026 edition) — operational spine, cited throughout this suite

Docs: /passkit, /applepayontheweb, /proximityreader, /walletpasses, /design/human-interface-guidelines/apple-pay, /design/human-interface-guidelines/wallet, /apple-pay/acceptable-use-guidelines-for-websites

App Review: Section 3.1 (In-App Purchase), Section 3.1.3(e) (Goods and Services Outside of the App), Section 3.2 (Other Business Model Issues), Section 4.9 (Apple Pay)

Skills: axiom-integration (in-app-purchases, storekit-ref), axiom-shipping (app-store-diag, app-review-guidelines), axiom-security (keychain-ref, code-signing), axiom-design (hig, hig-ref), axiom-macos