fix: handle object without schemas and additionalProperties

codegen/pkg/generator/collect.go

@@ -133,7 +133,7 @@ func (g *Generator) registerSchemaUsage(schema *base.SchemaProxy, suggestedName
 
 	name := g.classNameForSchema(schema)
 	if name == "" {
-		if suggestedName == "" || !schemaIsObject(schema) || schemaIsAdditionalPropertiesOnly(schema) {
+		if suggestedName == "" || !schemaShouldGenerateClass(schema) {
 			return ""
 		}
 		name = suggestedName
@@ -164,8 +164,8 @@ func (g *Generator) assignSchemasToTags(usage map[string]*schemaUsage) (map[stri
 	for schemaName, info := range usage {
 		targetTag := typesTagKey
 
-		// Skip schemas that are additionalProperties-only (they'll be treated as arrays)
-		if schemaIsAdditionalPropertiesOnly(info.schema) {
+		// Skip schemas that should remain generic maps in PHP.
+		if !schemaShouldGenerateClass(info.schema) {
 			continue
 		}
 
@@ -209,7 +209,7 @@ func (g *Generator) inlinePropertyClassName(parentName string, propertyName stri
 		return ""
 	}
 
-	if !schemaIsObject(schema) || schemaIsAdditionalPropertiesOnly(schema) {
+	if !schemaShouldGenerateClass(schema) {
 		return ""
 	}
 
@@ -225,7 +225,7 @@ func (g *Generator) inlineArrayItemClassName(parentName string, schema *base.Sch
 		return ""
 	}
 
-	if !schemaIsObject(schema) || schemaIsAdditionalPropertiesOnly(schema) {
+	if !schemaShouldGenerateClass(schema) {
 		return ""
 	}
 

codegen/pkg/generator/operations.go

@@ -309,6 +309,10 @@ func (g *Generator) buildResponseType(schema *base.SchemaProxy, currentNamespace
 			return g.buildResponseTypeFromSpec(schema.Schema(), currentNamespace)
 		}
 
+		if !schemaShouldGenerateClass(schema) {
+			return &responseType{Kind: responseTypeObject}
+		}
+
 		name := schemaClassName(schema)
 		namespace := g.schemaNamespaces[name]
 		typeName := name
@@ -342,7 +346,7 @@ func (g *Generator) buildResponseType(schema *base.SchemaProxy, currentNamespace
 		}
 	}
 
-	if hasSchemaType(spec, "object") && inlineBaseName != "" {
+	if hasSchemaType(spec, "object") && inlineBaseName != "" && schemaShouldGenerateClass(schema) {
 		return &responseType{
 			Kind:            responseTypeClass,
 			ClassName:       fmt.Sprintf("\\SumUp\\Services\\%s", inlineBaseName),

codegen/pkg/generator/properties.go

@@ -205,8 +205,7 @@ func (g *Generator) resolvePHPType(schema *base.SchemaProxy, currentNamespace st
 			return g.resolvePHPTypeFromSpec(schema, schema.Schema(), currentNamespace, parentSchemaName, propertyName)
 		}
 
-		// Check if this is an additionalProperties-only schema - treat as array
-		if schemaIsAdditionalPropertiesOnly(schema) {
+		if !schemaShouldGenerateClass(schema) {
 			return "array", "array<string, mixed>"
 		}
 
@@ -267,7 +266,7 @@ func (g *Generator) resolvePHPTypeFromSpec(schema *base.SchemaProxy, spec *base.
 		}
 		return "array", itemDoc + "[]"
 	case hasSchemaType(spec, "object"):
-		if schema != nil && !schemaIsAdditionalPropertiesOnly(schema) {
+		if schema != nil && schemaShouldGenerateClass(schema) {
 			typeName := g.classNameForSchema(schema)
 			if typeName == "" && parentSchemaName != "" && propertyName != "" {
 				typeName = phpInlineObjectName(parentSchemaName, propertyName)

codegen/pkg/generator/schemas.go

@@ -39,6 +39,60 @@ func schemaIsAdditionalPropertiesOnly(schema *base.SchemaProxy) bool {
 	return true
 }
 
+// schemaHasDeclaredProperties reports whether the schema exposes at least one
+// explicit property directly or through allOf/oneOf/anyOf composition.
+func schemaHasDeclaredProperties(schema *base.SchemaProxy) bool {
+	return schemaHasDeclaredPropertiesWithStack(schema, make(map[*base.SchemaProxy]struct{}))
+}
+
+// schemaShouldGenerateClass reports whether the schema should become a DTO
+// class instead of a generic map. Bare object schemas and
+// additionalProperties-only schemas stay as arrays in the PHP SDK.
+func schemaShouldGenerateClass(schema *base.SchemaProxy) bool {
+	return schemaIsObject(schema) && schemaHasDeclaredProperties(schema) && !schemaIsAdditionalPropertiesOnly(schema)
+}
+
+func schemaHasDeclaredPropertiesWithStack(schema *base.SchemaProxy, stack map[*base.SchemaProxy]struct{}) bool {
+	if schema == nil {
+		return false
+	}
+
+	if _, ok := stack[schema]; ok {
+		return false
+	}
+	stack[schema] = struct{}{}
+	defer delete(stack, schema)
+
+	spec := schema.Schema()
+	if spec == nil {
+		return false
+	}
+
+	if spec.Properties != nil && spec.Properties.Len() > 0 {
+		return true
+	}
+
+	for _, composite := range spec.AllOf {
+		if schemaHasDeclaredPropertiesWithStack(composite, stack) {
+			return true
+		}
+	}
+
+	for _, composite := range spec.AnyOf {
+		if schemaHasDeclaredPropertiesWithStack(composite, stack) {
+			return true
+		}
+	}
+
+	for _, composite := range spec.OneOf {
+		if schemaHasDeclaredPropertiesWithStack(composite, stack) {
+			return true
+		}
+	}
+
+	return false
+}
+
 func schemaIsObjectWithStack(schema *base.SchemaProxy, stack map[*base.SchemaProxy]struct{}) bool {
 	if schema == nil {
 		return false

codegen/pkg/generator/services.go

@@ -453,7 +453,7 @@ func shouldGenerateRequestBodyClass(op *operation) bool {
 		return false
 	}
 
-	return !schemaIsAdditionalPropertiesOnly(op.BodySchema)
+	return schemaShouldGenerateClass(op.BodySchema)
 }
 
 func buildEmptyRequestBodyClass(className string) string {

src/Checkouts/Checkouts.php

@@ -42,10 +42,6 @@ public function __construct(array $data = [])
 
 }
 
-class CheckoutsCreateApplePaySessionResponse
-{
-}
-
 class CheckoutsListAvailablePaymentMethodsResponse
 {
     /**
@@ -194,13 +190,13 @@ public function create(\SumUp\Types\CheckoutCreateRequest|array $body, ?RequestO
      * @param CheckoutsCreateApplePaySessionRequest|array<string, mixed>|null $body Optional request payload
      * @param RequestOptions|null $requestOptions Optional typed request options
      *
-     * @return \SumUp\Services\CheckoutsCreateApplePaySessionResponse
+     * @return array<string, mixed>
      * @throws \SumUp\Exception\ApiException
      * @throws \SumUp\Exception\UnexpectedApiException
      * @throws \SumUp\Exception\ConnectionException
      * @throws \SumUp\Exception\SDKException
      */
-    public function createApplePaySession(string $id, CheckoutsCreateApplePaySessionRequest|array|null $body = null, ?RequestOptions $requestOptions = null): \SumUp\Services\CheckoutsCreateApplePaySessionResponse
+    public function createApplePaySession(string $id, CheckoutsCreateApplePaySessionRequest|array|null $body = null, ?RequestOptions $requestOptions = null): array
     {
         $path = sprintf('/v0.2/checkouts/%s/apple-pay-session', rawurlencode((string) $id));
         $payload = [];
@@ -213,7 +209,9 @@ public function createApplePaySession(string $id, CheckoutsCreateApplePaySession
 
         $response = $this->client->send('PUT', $path, $payload, $headers, $requestOptions);
 
-        return ResponseDecoder::decodeOrThrow($response, \SumUp\Services\CheckoutsCreateApplePaySessionResponse::class, [
+        return ResponseDecoder::decodeOrThrow($response, [
+            '200' => ['type' => 'object'],
+        ], [
             '400' => ['type' => 'mixed'],
             '404' => ['type' => 'class', 'class' => \SumUp\Types\Error::class],
         ], 'PUT', $path);

src/ResponseDecoder.php

@@ -135,7 +135,15 @@ private static function castValue($value, array $descriptor)
             case 'scalar':
                 return self::castScalar($value, isset($descriptor['scalar']) ? $descriptor['scalar'] : 'mixed');
             case 'object':
-                return is_array($value) ? $value : [];
+                if (is_array($value)) {
+                    return $value;
+                }
+
+                if (is_object($value)) {
+                    return get_object_vars($value);
+                }
+
+                return [];
             case 'void':
                 return null;
             case 'mixed':

src/Types/ProcessCheckout.php

@@ -40,16 +40,16 @@ class ProcessCheckout
     /**
      * Raw `PaymentData` object received from Google Pay. Send the Google Pay response payload as-is.
      *
-     * @var ProcessCheckoutGooglePay|null
+     * @var array<string, mixed>|null
      */
-    public ?ProcessCheckoutGooglePay $googlePay = null;
+    public ?array $googlePay = null;
 
     /**
      * Raw payment token object received from Apple Pay. Send the Apple Pay response payload as-is.
      *
-     * @var ProcessCheckoutApplePay|null
+     * @var array<string, mixed>|null
      */
-    public ?ProcessCheckoutApplePay $applePay = null;
+    public ?array $applePay = null;
 
     /**
      * Saved-card token to use instead of raw card details when processing with a previously stored payment instrument.

src/Types/Receipt.php

@@ -26,9 +26,9 @@ class Receipt
     /**
      * EMV-specific metadata returned for card-present payments.
      *
-     * @var ReceiptEmvData|null
+     * @var array<string, mixed>|null
      */
-    public ?ReceiptEmvData $emvData = null;
+    public ?array $emvData = null;
 
     /**
      * Acquirer-specific metadata related to the card authorization.

tests/HydratorTest.php

@@ -8,6 +8,7 @@
 use SumUp\Types\CheckoutCurrency;
 use SumUp\Types\MandateResponse;
 use SumUp\Types\MandateResponseStatus;
+use SumUp\Types\ProcessCheckout;
 
 class HydratorTest extends TestCase
 {
@@ -46,6 +47,23 @@ public function testHydrateNestedObjectWithNormalizedPropertyNames()
         $this->assertSame(MandateResponseStatus::ACTIVE, $checkout->mandate->status);
     }
 
+    public function testHydrateOpaqueObjectSchemaAsArray()
+    {
+        $checkout = Hydrator::hydrate([
+            'apple_pay' => [
+                'token' => [
+                    'paymentData' => [
+                        'version' => 'EC_v1',
+                    ],
+                ],
+            ],
+        ], ProcessCheckout::class);
+
+        $this->assertInstanceOf(ProcessCheckout::class, $checkout);
+        $this->assertIsArray($checkout->applePay);
+        $this->assertSame('EC_v1', $checkout->applePay['token']['paymentData']['version']);
+    }
+
     public function testHydrateArrayItemsFromDocblockClassNames()
     {
         $response = Hydrator::hydrate([

tests/ResponseDecoderTest.php

@@ -70,6 +70,28 @@ public function testDecodeOrThrowDecodesSuccessArrayDescriptorWithClassItems()
         $this->assertSame('ONE', $result[0]->errorCode);
     }
 
+    public function testDecodeOrThrowDecodesOpaqueObjectDescriptorFromStdClass()
+    {
+        $response = new Response(200, (object) [
+            'merchantSessionIdentifier' => 'session_123',
+            'nested' => (object) ['value' => 'ok'],
+        ]);
+
+        $result = ResponseDecoder::decodeOrThrow(
+            $response,
+            [
+                '200' => ['type' => 'object'],
+            ],
+            null,
+            'POST',
+            '/v0.1/checkouts/chk_123/create_apple_pay_session'
+        );
+
+        $this->assertIsArray($result);
+        $this->assertSame('session_123', $result['merchantSessionIdentifier']);
+        $this->assertInstanceOf(\stdClass::class, $result['nested']);
+    }
+
     public function testDecodeOrThrowUsesUnexpectedFallbackForUnknownStatusWithNestedPayload()
     {
         $rawBody = [