Add Swift and React Native public API baselines

.github/CONTRIBUTING.md

@@ -66,6 +66,18 @@ cd platforms/swift && mint bootstrap
 cd platforms/swift && ./Scripts/lint fix
 ```
 
+### Public API surface
+
+The library's public API is tracked via committed baselines under `platforms/swift/api/`, one JSON file per module (`ShopifyCheckoutProtocol.json`, `ShopifyCheckoutKit.json`, `ShopifyAcceleratedCheckouts.json`). They are produced by `xcrun swift-api-digester -dump-sdk` against the built `.swiftmodule` files. The unified `Breaking Changes` CI workflow runs `dev swift api check` on every PR that touches Swift sources and fails if the digester output for any module diverges from its committed baseline.
+
+If your change intentionally modifies the public API:
+
+1. Run `dev swift api dump` from the repo root to regenerate the baselines.
+2. Review the diff in `platforms/swift/api/*.json` alongside your code changes.
+3. Commit the updated JSON files in the same PR.
+
+When `dev swift api check` fails, it prints both the unified diff and a `swift-api-digester -diagnose-sdk` summary categorizing the changes (removed, renamed, type/protocol/inheritance changes). Use the diagnose summary to decide whether the diff is intentional.
+
 ### Releasing a new Swift version
 
 Open a pull request with the following changes:
@@ -102,7 +114,7 @@ To check for lint issues without auto-correcting:
 
 ### Public API surface
 
-The library's public API is tracked via a committed baseline at `platforms/android/lib/api/lib.api`, managed by the [binary-compatibility-validator](https://github.com/Kotlin/binary-compatibility-validator) Gradle plugin. CI runs `./gradlew :lib:apiCheck` on every PR and fails if the compiled public API diverges from the baseline.
+The library's public API is tracked via a committed baseline at `platforms/android/lib/api/lib.api`, managed by the [binary-compatibility-validator](https://github.com/Kotlin/binary-compatibility-validator) Gradle plugin. The unified `Breaking Changes` CI workflow runs `./gradlew :lib:apiCheck` on every PR that touches Android sources and fails if the compiled public API diverges from the baseline.
 
 If your change intentionally modifies the public API:
 
@@ -126,3 +138,19 @@ Once merged, draft a release on GitHub:
 3. Document the changes since the previous release in the description.
 4. Check "Set as the latest release".
 5. Click "Publish release". This kicks off the [Android publish workflow](../../actions/workflows/android-publish.yml). **A manual approval by a maintainer is required before publication to Maven Central.**
+
+---
+
+## React Native (`platforms/react-native/`)
+
+### Public API surface
+
+The library's public API is tracked via a committed report at `platforms/react-native/modules/@shopify/checkout-kit-react-native/api/checkout-kit-react-native.api.md`, generated by [@microsoft/api-extractor](https://api-extractor.com/) from the bob-produced `.d.ts` files. The unified `Breaking Changes` CI workflow runs `dev rn api check` on every PR that touches React Native sources and fails if the regenerated report diverges from the committed one.
+
+If your change intentionally modifies the public API:
+
+1. Run `dev rn api dump` from the repo root to regenerate the report.
+2. Review the diff in `platforms/react-native/modules/@shopify/checkout-kit-react-native/api/checkout-kit-react-native.api.md` alongside your code changes.
+3. Commit the updated `.api.md` file in the same PR.
+
+If you did *not* intend to change public API and `api:check` is failing, the diff shows what your change inadvertently affected — treat it as a signal that something in your PR has consumer-visible impact.

.github/workflows/android-test.yml

@@ -30,9 +30,6 @@ jobs:
       - name: Run Tests
         run: ./gradlew clean test --console=plain
 
-      - name: Check API Surface
-        run: ./gradlew :lib:apiCheck --console=plain
-
   build:
     runs-on: ubuntu-latest
 

.github/workflows/breaking-changes.yml

@@ -0,0 +1,95 @@
+name: Breaking Changes
+
+on:
+  workflow_call:
+    inputs:
+      swift:
+        type: string
+        required: true
+      android:
+        type: string
+        required: true
+      react-native:
+        type: string
+        required: true
+  workflow_dispatch:
+    inputs:
+      swift:
+        type: string
+        required: false
+        default: 'true'
+      android:
+        type: string
+        required: false
+        default: 'true'
+      react-native:
+        type: string
+        required: false
+        default: 'true'
+
+permissions:
+  contents: read
+
+jobs:
+  swift:
+    name: Swift
+    if: inputs.swift == 'true'
+    runs-on: ${{ vars.MACOS_RUNNER }}
+    defaults:
+      run:
+        working-directory: platforms/swift
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Switch to Xcode 26.2
+        run: sudo xcode-select --switch /Applications/Xcode_26.2.app
+
+      - name: Check public Swift API baseline
+        run: ./Scripts/api check
+
+  android:
+    name: Android
+    if: inputs.android == 'true'
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: platforms/android
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          submodules: true
+
+      - name: Install JDK 1.17
+        uses: actions/setup-java@be666c2fcd27ec809703dec50e508c2fdc7f6654 # v5.2.0
+        with:
+          distribution: zulu
+          java-version: 17
+          cache: 'gradle'
+
+      - name: Check public Android API baseline
+        run: ./gradlew :lib:apiCheck --console=plain
+
+  react-native:
+    name: React Native
+    if: inputs.react-native == 'true'
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    defaults:
+      run:
+        working-directory: platforms/react-native
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Setup Node.js, pnpm, and install dependencies
+        uses: ./.github/actions/setup
+        with:
+          node-version-file: platforms/react-native/package.json
+          cache-dependency-path: platforms/react-native/pnpm-lock.yaml
+          package-json-file: platforms/react-native/package.json
+          working-directory: platforms/react-native
+
+      - name: Check public React Native API baseline
+        run: pnpm module api:check

.github/workflows/ci.yml

@@ -39,6 +39,7 @@ jobs:
               - 'platforms/android/**'
               - '.github/workflows/android-test.yml'
               - '.github/workflows/android-license-headers.yml'
+              - '.github/workflows/breaking-changes.yml'
               - '.github/workflows/ci.yml'
             swift:
               - 'platforms/swift/**'
@@ -48,6 +49,7 @@ jobs:
               - '.github/workflows/swift-build-samples.yml'
               - '.github/workflows/swift-test-workflow.yml'
               - '.github/workflows/swift-lint.yml'
+              - '.github/workflows/breaking-changes.yml'
               - '.github/workflows/ci.yml'
             reactNative:
               - 'platforms/react-native/**'
@@ -57,6 +59,7 @@ jobs:
               - '.github/workflows/rn-license-headers.yml'
               - '.github/workflows/rn-check-packed-files.yml'
               - '.github/workflows/rn-lint.yml'
+              - '.github/workflows/breaking-changes.yml'
               - '.github/workflows/ci.yml'
             web:
               - 'platforms/web/**'
@@ -149,6 +152,19 @@ jobs:
     if: needs.changes.outputs.web == 'true'
     uses: ./.github/workflows/web-license-headers.yml
 
+  breaking-changes:
+    name: Breaking Changes
+    needs: changes
+    if: |
+      needs.changes.outputs.swift == 'true' ||
+      needs.changes.outputs.android == 'true' ||
+      needs.changes.outputs.reactNative == 'true'
+    uses: ./.github/workflows/breaking-changes.yml
+    with:
+      swift: ${{ needs.changes.outputs.swift }}
+      android: ${{ needs.changes.outputs.android }}
+      react-native: ${{ needs.changes.outputs.reactNative }}
+
   # Single required status check for branch protection.
   # Passes when every relevant platform job either succeeded or was skipped
   # because no files in that platform's tree changed.
@@ -170,6 +186,7 @@ jobs:
       - rn-lint
       - web
       - web-license-headers
+      - breaking-changes
     runs-on: ubuntu-latest
     steps:
       - name: Verify all upstream jobs succeeded or were skipped

dev.yml

@@ -210,6 +210,20 @@ commands:
           `dev swift test <test_class_name>` - Run only the specified test class.
         syntax: "[test_class_name]"
         run: cd platforms/swift && ./Scripts/xcode_run test ShopifyCheckoutKit-Package "$1"
+      api:
+        desc: Validate or update the public Swift API baseline (platforms/swift/api/*.json)
+        run: |
+          echo "Usage: dev swift api {check|dump}"
+          echo ""
+          echo "  check  Verify public Swift API matches the committed baselines"
+          echo "  dump   Regenerate the Swift API baselines after intentional public API changes"
+        subcommands:
+          check:
+            desc: Verify public Swift API matches the committed baselines
+            run: cd platforms/swift && ./Scripts/api check
+          dump:
+            desc: Regenerate the Swift API baselines after intentional public API changes
+            run: cd platforms/swift && ./Scripts/api dump
 
   # React Native
   react-native:
@@ -263,3 +277,17 @@ commands:
         desc: Auto-fix Swift lint and format issues
         aliases: [fix]
         run: cd platforms/react-native && ./scripts/lint_swift fix
+      api:
+        desc: Validate or update the public React Native API baseline (api/checkout-kit-react-native.api.md)
+        run: |
+          echo "Usage: dev rn api {check|dump}"
+          echo ""
+          echo "  check  Verify public RN API matches the committed report"
+          echo "  dump   Regenerate the RN API report after intentional public API changes"
+        subcommands:
+          check:
+            desc: Verify public RN API matches the committed report
+            run: cd platforms/react-native && pnpm module api:check
+          dump:
+            desc: Regenerate the RN API report after intentional public API changes
+            run: cd platforms/react-native && pnpm module api:dump

platforms/react-native/modules/@shopify/checkout-kit-react-native/.gitignore

@@ -0,0 +1 @@
+temp/

platforms/react-native/modules/@shopify/checkout-kit-react-native/api-extractor.json

@@ -0,0 +1,45 @@
+{
+  "$schema": "https://developer.microsoft.com/json-schemas/api-extractor/v7/api-extractor.schema.json",
+  "projectFolder": ".",
+  "mainEntryPointFilePath": "<projectFolder>/lib/typescript/src/index.d.ts",
+  "compiler": {
+    "tsconfigFilePath": "<projectFolder>/tsconfig.build.json"
+  },
+  "apiReport": {
+    "enabled": true,
+    "reportFolder": "<projectFolder>/api/",
+    "reportFileName": "checkout-kit-react-native.api.md"
+  },
+  "docModel": {
+    "enabled": false
+  },
+  "dtsRollup": {
+    "enabled": false
+  },
+  "tsdocMetadata": {
+    "enabled": false
+  },
+  "messages": {
+    "compilerMessageReporting": {
+      "default": {
+        "logLevel": "warning"
+      }
+    },
+    "extractorMessageReporting": {
+      "default": {
+        "logLevel": "warning"
+      },
+      "ae-missing-release-tag": {
+        "logLevel": "none"
+      },
+      "ae-forgotten-export": {
+        "logLevel": "none"
+      }
+    },
+    "tsdocMessageReporting": {
+      "default": {
+        "logLevel": "none"
+      }
+    }
+  }
+}