diff --git a/Memorystore/samples/V1/MemorystoreClient/list_backup_collections.php b/Memorystore/samples/V1/MemorystoreClient/list_backup_collections.php
index 24752316186..69a6f19a988 100644
--- a/Memorystore/samples/V1/MemorystoreClient/list_backup_collections.php
+++ b/Memorystore/samples/V1/MemorystoreClient/list_backup_collections.php
@@ -25,6 +25,7 @@
 // [START memorystore_v1_generated_Memorystore_ListBackupCollections_sync]
 use Google\ApiCore\ApiException;
 use Google\ApiCore\PagedListResponse;
+use Google\Cloud\Memorystore\V1\BackupCollection;
 use Google\Cloud\Memorystore\V1\Client\MemorystoreClient;
 use Google\Cloud\Memorystore\V1\ListBackupCollectionsRequest;
 
@@ -55,6 +56,7 @@ function list_backup_collections_sample(string $formattedParent): void
         /** @var PagedListResponse $response */
         $response = $memorystoreClient->listBackupCollections($request);
 
+        /** @var BackupCollection $element */
         foreach ($response as $element) {
             printf('Element data: %s' . PHP_EOL, $element->serializeToJsonString());
         }
diff --git a/Memorystore/samples/V1/MemorystoreClient/list_backups.php b/Memorystore/samples/V1/MemorystoreClient/list_backups.php
index 3f58de5af3b..b8fecda9600 100644
--- a/Memorystore/samples/V1/MemorystoreClient/list_backups.php
+++ b/Memorystore/samples/V1/MemorystoreClient/list_backups.php
@@ -25,6 +25,7 @@
 // [START memorystore_v1_generated_Memorystore_ListBackups_sync]
 use Google\ApiCore\ApiException;
 use Google\ApiCore\PagedListResponse;
+use Google\Cloud\Memorystore\V1\Backup;
 use Google\Cloud\Memorystore\V1\Client\MemorystoreClient;
 use Google\Cloud\Memorystore\V1\ListBackupsRequest;
 
@@ -49,6 +50,7 @@ function list_backups_sample(string $formattedParent): void
         /** @var PagedListResponse $response */
         $response = $memorystoreClient->listBackups($request);
 
+        /** @var Backup $element */
         foreach ($response as $element) {
             printf('Element data: %s' . PHP_EOL, $element->serializeToJsonString());
         }
diff --git a/Memorystore/samples/V1/MemorystoreClient/list_instances.php b/Memorystore/samples/V1/MemorystoreClient/list_instances.php
index 9b85db8fe6d..addf717a619 100644
--- a/Memorystore/samples/V1/MemorystoreClient/list_instances.php
+++ b/Memorystore/samples/V1/MemorystoreClient/list_instances.php
@@ -26,6 +26,7 @@
 use Google\ApiCore\ApiException;
 use Google\ApiCore\PagedListResponse;
 use Google\Cloud\Memorystore\V1\Client\MemorystoreClient;
+use Google\Cloud\Memorystore\V1\Instance;
 use Google\Cloud\Memorystore\V1\ListInstancesRequest;
 
 /**
@@ -49,6 +50,7 @@ function list_instances_sample(string $formattedParent): void
         /** @var PagedListResponse $response */
         $response = $memorystoreClient->listInstances($request);
 
+        /** @var Instance $element */
         foreach ($response as $element) {
             printf('Element data: %s' . PHP_EOL, $element->serializeToJsonString());
         }
diff --git a/Memorystore/samples/V1/MemorystoreClient/list_locations.php b/Memorystore/samples/V1/MemorystoreClient/list_locations.php
index 6b2a92cce2d..0f96705f49d 100644
--- a/Memorystore/samples/V1/MemorystoreClient/list_locations.php
+++ b/Memorystore/samples/V1/MemorystoreClient/list_locations.php
@@ -26,6 +26,7 @@
 use Google\ApiCore\ApiException;
 use Google\ApiCore\PagedListResponse;
 use Google\Cloud\Location\ListLocationsRequest;
+use Google\Cloud\Location\Location;
 use Google\Cloud\Memorystore\V1\Client\MemorystoreClient;
 
 /**
@@ -50,6 +51,7 @@ function list_locations_sample(): void
         /** @var PagedListResponse $response */
         $response = $memorystoreClient->listLocations($request);
 
+        /** @var Location $element */
         foreach ($response as $element) {
             printf('Element data: %s' . PHP_EOL, $element->serializeToJsonString());
         }
diff --git a/Memorystore/samples/V1beta/MemorystoreClient/list_instances.php b/Memorystore/samples/V1beta/MemorystoreClient/list_instances.php
index df2eb462d0e..782cb8db5e8 100644
--- a/Memorystore/samples/V1beta/MemorystoreClient/list_instances.php
+++ b/Memorystore/samples/V1beta/MemorystoreClient/list_instances.php
@@ -26,6 +26,7 @@
 use Google\ApiCore\ApiException;
 use Google\ApiCore\PagedListResponse;
 use Google\Cloud\Memorystore\V1beta\Client\MemorystoreClient;
+use Google\Cloud\Memorystore\V1beta\Instance;
 use Google\Cloud\Memorystore\V1beta\ListInstancesRequest;
 
 /**
@@ -49,6 +50,7 @@ function list_instances_sample(string $formattedParent): void
         /** @var PagedListResponse $response */
         $response = $memorystoreClient->listInstances($request);
 
+        /** @var Instance $element */
         foreach ($response as $element) {
             printf('Element data: %s' . PHP_EOL, $element->serializeToJsonString());
         }
diff --git a/Memorystore/samples/V1beta/MemorystoreClient/list_locations.php b/Memorystore/samples/V1beta/MemorystoreClient/list_locations.php
index 12993b3a7e9..60fd00ef769 100644
--- a/Memorystore/samples/V1beta/MemorystoreClient/list_locations.php
+++ b/Memorystore/samples/V1beta/MemorystoreClient/list_locations.php
@@ -26,6 +26,7 @@
 use Google\ApiCore\ApiException;
 use Google\ApiCore\PagedListResponse;
 use Google\Cloud\Location\ListLocationsRequest;
+use Google\Cloud\Location\Location;
 use Google\Cloud\Memorystore\V1beta\Client\MemorystoreClient;
 
 /**
@@ -50,6 +51,7 @@ function list_locations_sample(): void
         /** @var PagedListResponse $response */
         $response = $memorystoreClient->listLocations($request);
 
+        /** @var Location $element */
         foreach ($response as $element) {
             printf('Element data: %s' . PHP_EOL, $element->serializeToJsonString());
         }
diff --git a/Memorystore/src/V1/Client/MemorystoreClient.php b/Memorystore/src/V1/Client/MemorystoreClient.php
index 8a4d6226b16..8afbcb926f9 100644
--- a/Memorystore/src/V1/Client/MemorystoreClient.php
+++ b/Memorystore/src/V1/Client/MemorystoreClient.php
@@ -128,9 +128,9 @@ private static function getClientDefaults()
             'apiEndpoint' => self::SERVICE_ADDRESS . ':' . self::DEFAULT_SERVICE_PORT,
             'clientConfig' => __DIR__ . '/../resources/memorystore_client_config.json',
             'descriptorsConfigPath' => __DIR__ . '/../resources/memorystore_descriptor_config.php',
+            'gcpApiConfigPath' => __DIR__ . '/../resources/memorystore_grpc_config.json',
             'credentialsConfig' => [
                 'defaultScopes' => self::$serviceScopes,
-                'useJwtAccessWithScope' => false,
             ],
             'transportConfig' => [
                 'rest' => [
@@ -140,18 +140,6 @@ private static function getClientDefaults()
         ];
     }
 
-    /** Implements GapicClientTrait::defaultTransport. */
-    private static function defaultTransport()
-    {
-        return 'rest';
-    }
-
-    /** Implements ClientOptionsTrait::supportedTransports. */
-    private static function supportedTransports()
-    {
-        return ['rest'];
-    }
-
     /**
      * Return an OperationsClient object with the same endpoint as $this.
      *
@@ -493,8 +481,9 @@ public static function parseName(string $formattedName, ?string $template = null
      *           default this settings points to the default client config file, which is
      *           provided in the resources folder.
      *     @type string|TransportInterface $transport
-     *           The transport used for executing network requests. At the moment, supports only
-     *           `rest`. *Advanced usage*: Additionally, it is possible to pass in an already
+     *           The transport used for executing network requests. May be either the string
+     *           `rest` or `grpc`. Defaults to `grpc` if gRPC support is detected on the system.
+     *           *Advanced usage*: Additionally, it is possible to pass in an already
      *           instantiated {@see \Google\ApiCore\Transport\TransportInterface} object. Note
      *           that when this object is provided, any settings in $transportConfig, and any
      *           $apiEndpoint setting, will be ignored.
@@ -503,9 +492,11 @@ public static function parseName(string $formattedName, ?string $template = null
      *           each supported transport type should be passed in a key for that transport. For
      *           example:
      *           $transportConfig = [
+     *               'grpc' => [...],
      *               'rest' => [...],
      *           ];
-     *           See the {@see \Google\ApiCore\Transport\RestTransport::build()} method for the
+     *           See the {@see \Google\ApiCore\Transport\GrpcTransport::build()} and
+     *           {@see \Google\ApiCore\Transport\RestTransport::build()} methods for the
      *           supported options.
      *     @type callable $clientCertSource
      *           A callable which returns the client cert as a string. This can be used to
diff --git a/Memorystore/src/V1beta/Client/MemorystoreClient.php b/Memorystore/src/V1beta/Client/MemorystoreClient.php
index ddc12e564cc..2aa46757d4a 100644
--- a/Memorystore/src/V1beta/Client/MemorystoreClient.php
+++ b/Memorystore/src/V1beta/Client/MemorystoreClient.php
@@ -114,9 +114,9 @@ private static function getClientDefaults()
             'apiEndpoint' => self::SERVICE_ADDRESS . ':' . self::DEFAULT_SERVICE_PORT,
             'clientConfig' => __DIR__ . '/../resources/memorystore_client_config.json',
             'descriptorsConfigPath' => __DIR__ . '/../resources/memorystore_descriptor_config.php',
+            'gcpApiConfigPath' => __DIR__ . '/../resources/memorystore_grpc_config.json',
             'credentialsConfig' => [
                 'defaultScopes' => self::$serviceScopes,
-                'useJwtAccessWithScope' => false,
             ],
             'transportConfig' => [
                 'rest' => [
@@ -126,18 +126,6 @@ private static function getClientDefaults()
         ];
     }
 
-    /** Implements GapicClientTrait::defaultTransport. */
-    private static function defaultTransport()
-    {
-        return 'rest';
-    }
-
-    /** Implements ClientOptionsTrait::supportedTransports. */
-    private static function supportedTransports()
-    {
-        return ['rest'];
-    }
-
     /**
      * Return an OperationsClient object with the same endpoint as $this.
      *
@@ -402,8 +390,9 @@ public static function parseName(string $formattedName, ?string $template = null
      *           default this settings points to the default client config file, which is
      *           provided in the resources folder.
      *     @type string|TransportInterface $transport
-     *           The transport used for executing network requests. At the moment, supports only
-     *           `rest`. *Advanced usage*: Additionally, it is possible to pass in an already
+     *           The transport used for executing network requests. May be either the string
+     *           `rest` or `grpc`. Defaults to `grpc` if gRPC support is detected on the system.
+     *           *Advanced usage*: Additionally, it is possible to pass in an already
      *           instantiated {@see \Google\ApiCore\Transport\TransportInterface} object. Note
      *           that when this object is provided, any settings in $transportConfig, and any
      *           $apiEndpoint setting, will be ignored.
@@ -412,9 +401,11 @@ public static function parseName(string $formattedName, ?string $template = null
      *           each supported transport type should be passed in a key for that transport. For
      *           example:
      *           $transportConfig = [
+     *               'grpc' => [...],
      *               'rest' => [...],
      *           ];
-     *           See the {@see \Google\ApiCore\Transport\RestTransport::build()} method for the
+     *           See the {@see \Google\ApiCore\Transport\GrpcTransport::build()} and
+     *           {@see \Google\ApiCore\Transport\RestTransport::build()} methods for the
      *           supported options.
      *     @type callable $clientCertSource
      *           A callable which returns the client cert as a string. This can be used to