feat(RN): Include remaining public protocol events from native

platforms/react-native/__mocks__/react-native.ts

@@ -56,7 +56,14 @@ const UIManager = {
     if (name === 'RCTAcceleratedCheckoutButtons') {
       return {
         Constants: {
-          checkoutProtocolEventTypes: ['ec.start'],
+          checkoutProtocolEventTypes: [
+            'ec.complete',
+            'ec.error',
+            'ec.line_items.change',
+            'ec.messages.change',
+            'ec.start',
+            'ec.totals.change',
+          ],
         },
       };
     }

platforms/react-native/modules/@shopify/checkout-kit-react-native/android/src/main/java/com/shopify/reactnative/checkoutkit/ProtocolRelay.kt

@@ -35,11 +35,36 @@ object ProtocolRelay {
         var client = CheckoutProtocol.Client()
         for (method in subscribedMethods) {
             when (method) {
+                CheckoutProtocol.complete.method -> {
+                    client = client.on(CheckoutProtocol.complete) { checkout ->
+                        forwardEnvelope(method, checkout, dispatch)
+                    }
+                }
+                CheckoutProtocol.error.method -> {
+                    client = client.on(CheckoutProtocol.error) { error ->
+                        forwardEnvelope(method, error, dispatch)
+                    }
+                }
+                CheckoutProtocol.lineItemsChange.method -> {
+                    client = client.on(CheckoutProtocol.lineItemsChange) { checkout ->
+                        forwardEnvelope(method, checkout, dispatch)
+                    }
+                }
+                CheckoutProtocol.messagesChange.method -> {
+                    client = client.on(CheckoutProtocol.messagesChange) { checkout ->
+                        forwardEnvelope(method, checkout, dispatch)
+                    }
+                }
                 CheckoutProtocol.start.method -> {
                     client = client.on(CheckoutProtocol.start) { checkout ->
                         forwardEnvelope(method, checkout, dispatch)
                     }
                 }
+                CheckoutProtocol.totalsChange.method -> {
+                    client = client.on(CheckoutProtocol.totalsChange) { checkout ->
+                        forwardEnvelope(method, checkout, dispatch)
+                    }
+                }
             }
         }
         return client

platforms/react-native/modules/@shopify/checkout-kit-react-native/android/src/test/java/com/shopify/reactnative/checkoutkit/ProtocolRelayTest.kt

@@ -83,6 +83,56 @@ class ProtocolRelayTest {
         assertThat(logs.single().throwable).isSameAs(failure)
     }
 
+    @Test
+    fun `relay dispatches envelope for every public checkout state event`() {
+        val methods = listOf(
+            "ec.complete",
+            "ec.line_items.change",
+            "ec.messages.change",
+            "ec.start",
+            "ec.totals.change",
+        )
+
+        for (method in methods) {
+            var captured: String? = null
+            val client = ProtocolRelay.makeClient(
+                listOf(method),
+                DispatchCallback { json -> captured = json },
+            )
+
+            client.process(checkoutNotificationFixture(method))
+            shadowOf(Looper.getMainLooper()).runToEndOfTasks()
+
+            val json = captured
+            assertThat(json).isNotNull()
+            val parsed = Json.parseToJsonElement(json!!).jsonObject
+            assertThat(parsed["type"]?.jsonPrimitive?.content).isEqualTo(method)
+            assertThat(parsed["payload"]!!.jsonObject["id"]?.jsonPrimitive?.content).isEqualTo("checkout-123")
+        }
+    }
+
+    @Test
+    fun `relay dispatches envelope on ec error`() {
+        var captured: String? = null
+        val client = ProtocolRelay.makeClient(
+            listOf("ec.error"),
+            DispatchCallback { json -> captured = json },
+        )
+
+        client.process(ecErrorNotificationFixture)
+        shadowOf(Looper.getMainLooper()).runToEndOfTasks()
+
+        val json = captured
+        assertThat(json).isNotNull()
+        val parsed = Json.parseToJsonElement(json!!).jsonObject
+        assertThat(parsed["type"]?.jsonPrimitive?.content).isEqualTo("ec.error")
+
+        val payload = parsed["payload"]!!.jsonObject
+        assertThat(payload["messages"]!!.jsonArray[0].jsonObject["content"]?.jsonPrimitive?.content)
+            .isEqualTo("Something went wrong")
+        assertThat(payload["ucp"]!!.jsonObject["status"]?.jsonPrimitive?.content).isEqualTo("error")
+    }
+
     @Test
     fun `relay ignores methods not in subscribed list`() {
         var captured: String? = null
@@ -120,6 +170,11 @@ private data class SnakePayload(
     @SerialName("line_items") val lineItems: List<String>,
 )
 
+private fun checkoutNotificationFixture(method: String) = ecStartNotificationFixture.replace(
+    "\"method\": \"ec.start\"",
+    "\"method\": \"$method\"",
+)
+
 private val ecStartNotificationFixture = """
 {
   "jsonrpc": "2.0",
@@ -160,3 +215,25 @@ private val ecStartNotificationFixture = """
   }
 }
 """.trimIndent()
+
+private val ecErrorNotificationFixture = """
+{
+  "jsonrpc": "2.0",
+  "method": "ec.error",
+  "params": {
+    "error": {
+      "ucp": {
+        "version": "2026-04-08",
+        "status": "error"
+      },
+      "messages": [
+        {
+          "type": "error",
+          "content": "Something went wrong",
+          "severity": "recoverable"
+        }
+      ]
+    }
+  }
+}
+""".trimIndent()

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

@@ -5,6 +5,9 @@
 ```ts
 
 import { Checkout } from '@shopify/checkout-kit-protocol';
+import { CheckoutProtocol } from '@shopify/checkout-kit-protocol';
+import { CheckoutProtocolPayloads } from '@shopify/checkout-kit-protocol';
+import { ErrorResponse } from '@shopify/checkout-kit-protocol';
 import type { PropsWithChildren } from 'react';
 import { default as React_2 } from 'react';
 
@@ -181,16 +184,9 @@ export enum CheckoutNativeErrorType {
     UnknownError = "UnknownError"
 }
 
-// @public (undocumented)
-export const CheckoutProtocol: {
-    readonly start: "ec.start";
-};
+export { CheckoutProtocol }
 
-// @public (undocumented)
-export interface CheckoutProtocolPayloads {
-    // (undocumented)
-    'ec.start': Checkout;
-}
+export { CheckoutProtocolPayloads }
 
 // @public (undocumented)
 export enum ColorScheme {
@@ -235,6 +231,8 @@ export class DispatchEventParityError extends Error {
     constructor(message: string);
 }
 
+export { ErrorResponse }
+
 // @public
 export interface Features {
     handleGeolocationRequests: boolean;

platforms/react-native/modules/@shopify/checkout-kit-react-native/ios/ProtocolRelay.swift

@@ -16,7 +16,12 @@ struct DispatchEnvelope<Payload: Encodable>: Encodable {
 // event stream. Payloads are emitted in protocol wire casing; JS performs the
 // schema-aware conversion to the public camelCase shape with QuickType.
 let supportedProtocolRelayMethods = [
-    CheckoutProtocol.start.method
+    CheckoutProtocol.complete.method,
+    CheckoutProtocol.error.method,
+    CheckoutProtocol.lineItemsChange.method,
+    CheckoutProtocol.messagesChange.method,
+    CheckoutProtocol.start.method,
+    CheckoutProtocol.totalsChange.method
 ]
 
 func makeRelayClient(
@@ -27,10 +32,30 @@ func makeRelayClient(
 
     for method in subscribedMethods {
         switch method {
+        case CheckoutProtocol.complete.method:
+            client = client.on(CheckoutProtocol.complete) { checkout in
+                forwardEnvelope(type: method, payload: checkout, dispatch: dispatch)
+            }
+        case CheckoutProtocol.error.method:
+            client = client.on(CheckoutProtocol.error) { error in
+                forwardEnvelope(type: method, payload: error, dispatch: dispatch)
+            }
+        case CheckoutProtocol.lineItemsChange.method:
+            client = client.on(CheckoutProtocol.lineItemsChange) { checkout in
+                forwardEnvelope(type: method, payload: checkout, dispatch: dispatch)
+            }
+        case CheckoutProtocol.messagesChange.method:
+            client = client.on(CheckoutProtocol.messagesChange) { checkout in
+                forwardEnvelope(type: method, payload: checkout, dispatch: dispatch)
+            }
         case CheckoutProtocol.start.method:
             client = client.on(CheckoutProtocol.start) { checkout in
                 forwardEnvelope(type: method, payload: checkout, dispatch: dispatch)
             }
+        case CheckoutProtocol.totalsChange.method:
+            client = client.on(CheckoutProtocol.totalsChange) { checkout in
+                forwardEnvelope(type: method, payload: checkout, dispatch: dispatch)
+            }
         default:
             continue
         }

platforms/react-native/modules/@shopify/checkout-kit-react-native/ios/Tests/ProtocolRelayTests.swift

@@ -48,6 +48,53 @@ struct ProtocolRelayTests {
         #expect(paymentHandlers["com.example.loyalty_gold"] != nil)
     }
 
+    @MainActor
+    @Test func relayDispatchesEnvelopeForEveryPublicCheckoutStateEvent() async throws {
+        let methods = [
+            "ec.complete",
+            "ec.line_items.change",
+            "ec.messages.change",
+            "ec.start",
+            "ec.totals.change"
+        ]
+
+        for method in methods {
+            var captured: String?
+            let client = makeRelayClient(
+                subscribedMethods: [method],
+                dispatch: { json in captured = json }
+            )
+
+            _ = await client.process(checkoutNotificationFixture(method: method))
+
+            let json = try #require(captured)
+            let parsed = try #require(JSONSerialization.jsonObject(with: Data(json.utf8)) as? [String: Any])
+            #expect(parsed["type"] as? String == method)
+            let payload = try #require(parsed["payload"] as? [String: Any])
+            #expect(payload["id"] as? String == "checkout-123")
+        }
+    }
+
+    @MainActor
+    @Test func relayDispatchesEnvelopeOnEcError() async throws {
+        var captured: String?
+        let client = makeRelayClient(
+            subscribedMethods: ["ec.error"],
+            dispatch: { json in captured = json }
+        )
+
+        _ = await client.process(ecErrorNotificationFixture)
+
+        let json = try #require(captured)
+        let parsed = try #require(JSONSerialization.jsonObject(with: Data(json.utf8)) as? [String: Any])
+        #expect(parsed["type"] as? String == "ec.error")
+        let payload = try #require(parsed["payload"] as? [String: Any])
+        let messages = try #require(payload["messages"] as? [[String: Any]])
+        #expect(messages.first?["content"] as? String == "Something went wrong")
+        let ucp = try #require(payload["ucp"] as? [String: Any])
+        #expect(ucp["status"] as? String == "error")
+    }
+
     @MainActor
     @Test func relayIgnoresMethodsNotInSubscribedList() async throws {
         var captured: String?
@@ -72,6 +119,13 @@ private struct SnakePayload: Codable {
     }
 }
 
+private func checkoutNotificationFixture(method: String) -> String {
+    ecStartNotificationFixture.replacingOccurrences(
+        of: "\"method\": \"ec.start\"",
+        with: "\"method\": \"\(method)\""
+    )
+}
+
 private let ecStartNotificationFixture = #"""
 {
   "jsonrpc": "2.0",
@@ -112,3 +166,25 @@ private let ecStartNotificationFixture = #"""
   }
 }
 """#
+
+private let ecErrorNotificationFixture = #"""
+{
+  "jsonrpc": "2.0",
+  "method": "ec.error",
+  "params": {
+    "error": {
+      "ucp": {
+        "version": "2026-04-08",
+        "status": "error"
+      },
+      "messages": [
+        {
+          "type": "error",
+          "content": "Something went wrong",
+          "severity": "recoverable"
+        }
+      ]
+    }
+  }
+}
+"""#

platforms/react-native/modules/@shopify/checkout-kit-react-native/src/components/AcceleratedCheckoutButtons.tsx

@@ -92,7 +92,7 @@ interface CommonAcceleratedCheckoutButtonsProps {
   /**
    * Checkout Protocol event handlers scoped to this button instance.
    *
-   * Currently supports CheckoutProtocol.start.
+   * Supports all public Checkout Protocol notification events.
    */
   events?: ProtocolHandlers;
 
@@ -414,10 +414,11 @@ function routeProtocolDispatchEnvelope(
     return;
   }
 
-  const handler = (events as Record<
-    string,
-    ((payload: unknown) => void) | undefined
-  > | undefined)?.[envelope.type];
+  const handler = (
+    events as
+      | Record<string, ((payload: unknown) => void) | undefined>
+      | undefined
+  )?.[envelope.type];
 
   if (handler == null) {
     return;

platforms/react-native/modules/@shopify/checkout-kit-react-native/src/index.d.ts

@@ -14,6 +14,7 @@ export {
 export type {
   Checkout,
   CheckoutProtocolPayloads,
+  ErrorResponse,
   ProtocolHandlers,
 } from './protocol';
 

platforms/react-native/modules/@shopify/checkout-kit-react-native/src/index.ts

@@ -47,6 +47,7 @@ import {CheckoutProtocol} from './protocol';
 import type {
   Checkout,
   CheckoutProtocolPayloads,
+  ErrorResponse,
   ProtocolHandlers,
 } from './protocol';
 
@@ -388,6 +389,7 @@ export type {
   CheckoutException,
   CheckoutProtocolPayloads,
   Configuration,
+  ErrorResponse,
   Features,
   GeolocationRequestEvent,
   IosColors,