Namespace Swift protocol payloads

[markmur]

All Swift event payloads, request results, protocol-only helper models, and checkout/error parameter wrappers now live under EmbeddedCheckoutProtocol. This prevents collisions with Kit’s public Checkout when CocoaPods compiles both source sets into one module. SwiftPM and CocoaPods use the same names, without top-level aliases for protocol payloads.

The generator derives payloads from the event catalog and includes their exclusive dependencies. Shared checkout and order domain types remain top-level, preserving Kit’s direct use of Buyer, LineItem, and CheckoutTotal. Model fields and wire-format strings are unchanged. Generated examples use the same namespace rules as the declarations.

Both API dump and check canonicalize declarations at module and nested-type levels, including members added by extensions. Stored-property and enum-case order, parameter types, and other metadata arrays retain their ordering. Committed baselines use that same representation. Regression tests cover stable dumps and detection of meaningful API changes.

Model round-trip tests use the generated JSON helpers consistently, with fixtures covering absent dates, checkout expiry, and nested delivery dates. The checkout event APIs and production event-decoding fix remain in the Swift PR above this prerequisite.

Stack

Top to bottom:

1. Web: Add protocol-agnostic checkout events for web #766
2. Android: Add protocol-agnostic checkout events for Android #767
3. Swift events: Protocol-agnostic checkout events for Swift #748
4. Swift protocol namespace (this PR): Namespace Swift protocol payloads #777

[github-actions]

React Native — Coverage Report

Lines	Statements	Branches	Functions
	90.97% (363/399)	87.29% (213/244)	100% (92/92)

[github-actions]

Web — Coverage Report

Lines	Statements	Branches	Functions
	94.46% (290/307)	81.11% (146/180)	98.73% (78/79)

[github-actions]

Package Size

Platform	Artifact	Base	Head	Delta
Web	npm tarball	80.1 KiB	80.1 KiB	0 B
React Native	npm tarball	108.6 KiB	108.6 KiB	0 B
Android	release AAR	366.6 KiB	366.6 KiB	0 B

Web file breakdown

File	Base	Head	Delta
dist/index.js.map	217.7 KiB	217.7 KiB	0 B
dist/custom-elements.json	51.4 KiB	51.4 KiB	0 B
dist/index.d.ts	45.9 KiB	45.9 KiB	0 B
dist/index.js	39.5 KiB	39.5 KiB	0 B
README.md	20.0 KiB	20.0 KiB	0 B
package.json	2.9 KiB	2.9 KiB	0 B
LICENSE	1.1 KiB	1.1 KiB	0 B

React Native file breakdown

File	Base	Head	Delta
node_modules/@shopify/checkout-kit-protocol/src/generated/Models.ts	85.4 KiB	85.4 KiB	0 B
node_modules/@shopify/checkout-kit-protocol/src/generated/Models.d.ts	53.0 KiB	53.0 KiB	0 B
android/src/main/java/com/shopify/reactnative/checkoutkit/ShopifyCheckoutKitModule.java	16.2 KiB	16.2 KiB	0 B
ios/ShopifyCheckoutKit.swift	16.1 KiB	16.1 KiB	0 B
ios/AcceleratedCheckoutButtons.swift	14.1 KiB	14.1 KiB	0 B
src/components/AcceleratedCheckoutButtons.tsx	13.0 KiB	13.0 KiB	0 B
src/index.ts	12.7 KiB	12.7 KiB	0 B
lib/commonjs/index.js	12.4 KiB	12.4 KiB	0 B
lib/commonjs/components/AcceleratedCheckoutButtons.js	11.4 KiB	11.4 KiB	0 B
src/index.d.ts	11.3 KiB	11.3 KiB	0 B
lib/commonjs/components/AcceleratedCheckoutButtons.js.map	10.4 KiB	10.4 KiB	0 B
lib/module/index.js	10.4 KiB	10.4 KiB	0 B
lib/module/components/AcceleratedCheckoutButtons.js	10.2 KiB	10.2 KiB	0 B
node_modules/@shopify/checkout-kit-protocol/src/generated/ProtocolNotifications.ts	9.5 KiB	9.5 KiB	0 B
lib/module/components/AcceleratedCheckoutButtons.js.map	9.1 KiB	9.1 KiB	0 B
lib/module/index.js.map	8.1 KiB	8.1 KiB	0 B
src/present-dispatcher.ts	8.0 KiB	8.0 KiB	0 B
lib/commonjs/index.js.map	7.9 KiB	7.9 KiB	0 B
node_modules/@shopify/checkout-kit-protocol/src/generated/ProtocolNotifications.d.ts	7.6 KiB	7.6 KiB	0 B
node_modules/@shopify/checkout-kit-protocol/src/generated/ProtocolRenameMap.ts	7.2 KiB	7.2 KiB	0 B
…and 117 smaller files

Android file breakdown

File	Base	Head	Delta
classes.jar	390.5 KiB	390.5 KiB	0 B
res/layout/checkout_view_content.xml	2.6 KiB	2.6 KiB	0 B
res/layout/checkout_sheet_content.xml	2.0 KiB	2.0 KiB	0 B
res/values/values.xml	1.3 KiB	1.3 KiB	0 B
R.txt	1.2 KiB	1.2 KiB	0 B
AndroidManifest.xml	922 B	922 B	0 B
proguard.txt	798 B	798 B	0 B
res/drawable/close.xml	431 B	431 B	0 B
res/menu/checkout_menu.xml	354 B	354 B	0 B
META-INF/com/android/build/gradle/aar-metadata.properties	157 B	157 B	0 B

Measured from the PR base SHA and PR head SHA. The file breakdown shows uncompressed sizes within each package artifact, so individual files do not sum to the compressed artifact total. This comment reports package artifact sizes only; it is not a final app binary-size report.

[bitrise]

Install this build

Open Tophat, select your target device, then click Install. Links open on the Mac running Tophat.

SDK	Install
React Native	Install with Tophat
Swift	Install with Tophat
Kotlin	Install with Tophat

Checkout Kit E2E results

Status	Tags	Target	Platform	OS version tag	Device
✅	launch, checkout-presentation, checkout-completion, buyer-identity	react-native	ios	latest	iPhone 15 iOS 27 Beta
✅	launch, checkout-presentation, checkout-completion, buyer-identity	react-native	android	latest	Google Pixel 9 Android 17.0
✅	launch, checkout-presentation, checkout-completion, buyer-identity, preload	kotlin	android	latest	Google Pixel 9 Android 17.0
✅	launch, checkout-presentation, checkout-completion, buyer-identity, preload	swift	ios	latest	iPhone 15 iOS 27 Beta

[github-actions]

Protocol — Coverage Report

Lines	Statements	Branches	Functions
	93.58% (146/156)	87.75% (86/98)	90% (27/30)

[github-actions]

React Native — Coverage Report

Lines	Statements	Branches	Functions
	90.97% (363/399)	87.29% (213/244)	100% (92/92)

[github-actions]

Web — Coverage Report

Lines	Statements	Branches	Functions
	94.47% (342/362)	81.77% (166/203)	96.84% (92/95)

[adrian-augustyn]

Nit: This mentions Kit’s public Checkout, but this PR does not add that type. The Swift events PR above this one adds it. Move this sentence there, or rewrite this section to only describe EmbeddedCheckoutProtocol.Checkout.