diff --git a/lib/internal/Magento/Framework/Api/CriteriaInterface.php b/lib/internal/Magento/Framework/Api/CriteriaInterface.php
index ead0d31a5fbe0..2ab20482ca1bc 100644
--- a/lib/internal/Magento/Framework/Api/CriteriaInterface.php
+++ b/lib/internal/Magento/Framework/Api/CriteriaInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Api;
 
 /**
  * Interface CriteriaInterface
+ *
+ * @api
  */
 interface CriteriaInterface
 {
diff --git a/lib/internal/Magento/Framework/Async/CancelableDeferredInterface.php b/lib/internal/Magento/Framework/Async/CancelableDeferredInterface.php
index 9b328273595e8..6163ec127b9bd 100644
--- a/lib/internal/Magento/Framework/Async/CancelableDeferredInterface.php
+++ b/lib/internal/Magento/Framework/Async/CancelableDeferredInterface.php
@@ -3,13 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
-
 declare(strict_types=1);
 
 namespace Magento\Framework\Async;
 
 /**
  * Described deferred operation that can be canceled.
+ *
+ * @api
  */
 interface CancelableDeferredInterface extends DeferredInterface
 {
diff --git a/lib/internal/Magento/Framework/Async/DeferredInterface.php b/lib/internal/Magento/Framework/Async/DeferredInterface.php
index 8c925fd95a3ab..41fa9ef4511f5 100644
--- a/lib/internal/Magento/Framework/Async/DeferredInterface.php
+++ b/lib/internal/Magento/Framework/Async/DeferredInterface.php
@@ -3,13 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
-
 declare(strict_types=1);
 
 namespace Magento\Framework\Async;
 
 /**
  * Describes a value that will be available at later time.
+ *
+ * @api
  */
 interface DeferredInterface
 {
diff --git a/lib/internal/Magento/Framework/Autoload/AutoloaderInterface.php b/lib/internal/Magento/Framework/Autoload/AutoloaderInterface.php
index 24301063c8929..72753a4a0d98f 100644
--- a/lib/internal/Magento/Framework/Autoload/AutoloaderInterface.php
+++ b/lib/internal/Magento/Framework/Autoload/AutoloaderInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Autoload;
 
 /**
  * Interface for an autoloader class that allows the dynamic modification of PSR-0 and PSR-4 mappings
+ *
+ * @api
  */
 interface AutoloaderInterface
 {
diff --git a/lib/internal/Magento/Framework/Backup/SourceFileInterface.php b/lib/internal/Magento/Framework/Backup/SourceFileInterface.php
index bcc1d18686741..a36f9179688b4 100644
--- a/lib/internal/Magento/Framework/Backup/SourceFileInterface.php
+++ b/lib/internal/Magento/Framework/Backup/SourceFileInterface.php
@@ -3,15 +3,15 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
+namespace Magento\Framework\Backup;
 
 /**
  * Interface for work with archives
  *
- * @author      Magento Core Team <core@magentocommerce.com>
+ * @api
  */
-
-namespace Magento\Framework\Backup;
-
 interface SourceFileInterface
 {
 
diff --git a/lib/internal/Magento/Framework/Cache/ConfigInterface.php b/lib/internal/Magento/Framework/Cache/ConfigInterface.php
index 4f35ab3bf4298..8e9d7fc41d237 100644
--- a/lib/internal/Magento/Framework/Cache/ConfigInterface.php
+++ b/lib/internal/Magento/Framework/Cache/ConfigInterface.php
@@ -1,15 +1,16 @@
 <?php
 /**
- * Cache configuration model. Provides cache configuration data to the application
- *
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Cache;
 
 /**
  * Interface \Magento\Framework\Cache\ConfigInterface
  *
+ * @api
  */
 interface ConfigInterface
 {
diff --git a/lib/internal/Magento/Framework/Cache/StaleCacheNotifierInterface.php b/lib/internal/Magento/Framework/Cache/StaleCacheNotifierInterface.php
index 135777d9d8d2a..95dbd3e67aadc 100644
--- a/lib/internal/Magento/Framework/Cache/StaleCacheNotifierInterface.php
+++ b/lib/internal/Magento/Framework/Cache/StaleCacheNotifierInterface.php
@@ -3,11 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\Cache;
 
 /**
  * Notifier for stale cache retrieval detection
+ *
+ * @api
  */
 interface StaleCacheNotifierInterface
 {
diff --git a/lib/internal/Magento/Framework/Code/Generator/CodeGeneratorInterface.php b/lib/internal/Magento/Framework/Code/Generator/CodeGeneratorInterface.php
index 59fc5522a12e2..cc08dabb4e1ef 100644
--- a/lib/internal/Magento/Framework/Code/Generator/CodeGeneratorInterface.php
+++ b/lib/internal/Magento/Framework/Code/Generator/CodeGeneratorInterface.php
@@ -3,11 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Code\Generator;
 
 /**
  * Interface \Magento\Framework\Code\Generator\CodeGeneratorInterface
  *
+ * @api
  */
 interface CodeGeneratorInterface extends \Laminas\Code\Generator\GeneratorInterface
 {
diff --git a/lib/internal/Magento/Framework/Code/Minifier/AdapterInterface.php b/lib/internal/Magento/Framework/Code/Minifier/AdapterInterface.php
index a9ad4a95a9d72..a787b26c40868 100644
--- a/lib/internal/Magento/Framework/Code/Minifier/AdapterInterface.php
+++ b/lib/internal/Magento/Framework/Code/Minifier/AdapterInterface.php
@@ -3,15 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
-/**
- * Interface for minification adapters
- */
 namespace Magento\Framework\Code\Minifier;
 
 /**
  * Interface \Magento\Framework\Code\Minifier\AdapterInterface
  *
+ * @api
  */
 interface AdapterInterface
 {
diff --git a/lib/internal/Magento/Framework/Code/Reader/ClassReaderInterface.php b/lib/internal/Magento/Framework/Code/Reader/ClassReaderInterface.php
index b7a26ba114fe4..41ddbdf3499d7 100644
--- a/lib/internal/Magento/Framework/Code/Reader/ClassReaderInterface.php
+++ b/lib/internal/Magento/Framework/Code/Reader/ClassReaderInterface.php
@@ -1,15 +1,16 @@
 <?php
 /**
- *
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\Code\Reader;
 
 /**
  * Interface \Magento\Framework\Code\Reader\ClassReaderInterface
  *
+ * @api
  */
 interface ClassReaderInterface
 {
diff --git a/lib/internal/Magento/Framework/Code/ValidatorInterface.php b/lib/internal/Magento/Framework/Code/ValidatorInterface.php
index cb8a625decbf3..a47b4a1ec11f6 100644
--- a/lib/internal/Magento/Framework/Code/ValidatorInterface.php
+++ b/lib/internal/Magento/Framework/Code/ValidatorInterface.php
@@ -3,11 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Code;
 
 /**
  * Interface \Magento\Framework\Code\ValidatorInterface
  *
+ * @api
  */
 interface ValidatorInterface
 {
diff --git a/lib/internal/Magento/Framework/Component/ComponentRegistrarInterface.php b/lib/internal/Magento/Framework/Component/ComponentRegistrarInterface.php
index eb7144306b593..ba1bc919f56c9 100644
--- a/lib/internal/Magento/Framework/Component/ComponentRegistrarInterface.php
+++ b/lib/internal/Magento/Framework/Component/ComponentRegistrarInterface.php
@@ -3,8 +3,15 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Component;
 
+/**
+ * Component Registrar Interface
+ *
+ * @api
+ */
 interface ComponentRegistrarInterface
 {
     /**
diff --git a/lib/internal/Magento/Framework/Crontab/CrontabManagerInterface.php b/lib/internal/Magento/Framework/Crontab/CrontabManagerInterface.php
index 0760f30e71a00..1fcf65a8ff8c4 100644
--- a/lib/internal/Magento/Framework/Crontab/CrontabManagerInterface.php
+++ b/lib/internal/Magento/Framework/Crontab/CrontabManagerInterface.php
@@ -3,6 +3,8 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Crontab;
 
 use Magento\Framework\Exception\LocalizedException;
@@ -10,6 +12,7 @@
 /**
  * Interface \Magento\Framework\Crontab\CrontabManagerInterface
  *
+ * @api
  */
 interface CrontabManagerInterface
 {
diff --git a/lib/internal/Magento/Framework/Crontab/TasksProviderInterface.php b/lib/internal/Magento/Framework/Crontab/TasksProviderInterface.php
index 404485df8c6e5..5e013d505df45 100644
--- a/lib/internal/Magento/Framework/Crontab/TasksProviderInterface.php
+++ b/lib/internal/Magento/Framework/Crontab/TasksProviderInterface.php
@@ -3,11 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Crontab;
 
 /**
  * Interface \Magento\Framework\Crontab\TasksProviderInterface
  *
+ * @api
  */
 interface TasksProviderInterface
 {
diff --git a/lib/internal/Magento/Framework/Css/PreProcessor/ErrorHandlerInterface.php b/lib/internal/Magento/Framework/Css/PreProcessor/ErrorHandlerInterface.php
index 282e8d6c80f89..44f485ada9f88 100644
--- a/lib/internal/Magento/Framework/Css/PreProcessor/ErrorHandlerInterface.php
+++ b/lib/internal/Magento/Framework/Css/PreProcessor/ErrorHandlerInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Css\PreProcessor;
 
 /**
  * Error handler interface
+ *
+ * @api
  */
 interface ErrorHandlerInterface
 {
diff --git a/lib/internal/Magento/Framework/DB/DataConverter/DataConverterInterface.php b/lib/internal/Magento/Framework/DB/DataConverter/DataConverterInterface.php
index b5cc23b7263b6..fc029555e4381 100644
--- a/lib/internal/Magento/Framework/DB/DataConverter/DataConverterInterface.php
+++ b/lib/internal/Magento/Framework/DB/DataConverter/DataConverterInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\DB\DataConverter;
 
 /**
  * Convert from one format to another
+ *
+ * @api
  */
 interface DataConverterInterface
 {
diff --git a/lib/internal/Magento/Framework/DB/LoggerInterface.php b/lib/internal/Magento/Framework/DB/LoggerInterface.php
index f072254c0f76e..494b7f0678d45 100644
--- a/lib/internal/Magento/Framework/DB/LoggerInterface.php
+++ b/lib/internal/Magento/Framework/DB/LoggerInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\DB;
 
 /**
  * DB logger interface
+ *
+ * @api
  */
 interface LoggerInterface
 {
diff --git a/lib/internal/Magento/Framework/DB/MapperInterface.php b/lib/internal/Magento/Framework/DB/MapperInterface.php
index cfe2c53a155fd..38f4d50a7f194 100644
--- a/lib/internal/Magento/Framework/DB/MapperInterface.php
+++ b/lib/internal/Magento/Framework/DB/MapperInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\DB;
 
 /**
  * Interface MapperInterface
+ *
+ * @api
  */
 interface MapperInterface
 {
diff --git a/lib/internal/Magento/Framework/DB/Query/BatchIteratorInterface.php b/lib/internal/Magento/Framework/DB/Query/BatchIteratorInterface.php
index b1ce64e610fb5..d7f4bda763e7d 100644
--- a/lib/internal/Magento/Framework/DB/Query/BatchIteratorInterface.php
+++ b/lib/internal/Magento/Framework/DB/Query/BatchIteratorInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\DB\Query;
 
 /**
  * Batch Iterator interface
+ *
+ * @api
  */
 interface BatchIteratorInterface extends \Iterator
 {
diff --git a/lib/internal/Magento/Framework/DB/QueryInterface.php b/lib/internal/Magento/Framework/DB/QueryInterface.php
index 2afd21c0f5c26..36587347574ca 100644
--- a/lib/internal/Magento/Framework/DB/QueryInterface.php
+++ b/lib/internal/Magento/Framework/DB/QueryInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\DB;
 
 /**
- * Class QueryInterface
+ * Interface QueryInterface
+ *
+ * @api
  */
 interface QueryInterface
 {
diff --git a/lib/internal/Magento/Framework/DB/Select/QueryModifierInterface.php b/lib/internal/Magento/Framework/DB/Select/QueryModifierInterface.php
index 110e4148410a9..8450f19c2e980 100644
--- a/lib/internal/Magento/Framework/DB/Select/QueryModifierInterface.php
+++ b/lib/internal/Magento/Framework/DB/Select/QueryModifierInterface.php
@@ -3,12 +3,16 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\DB\Select;
 
 use Magento\Framework\DB\Select;
 
 /**
  * Modify query, add custom conditions
+ *
+ * @api
  */
 interface QueryModifierInterface
 {
diff --git a/lib/internal/Magento/Framework/DB/Select/RendererInterface.php b/lib/internal/Magento/Framework/DB/Select/RendererInterface.php
index 34be306a3d16d..ab8da6898b70e 100644
--- a/lib/internal/Magento/Framework/DB/Select/RendererInterface.php
+++ b/lib/internal/Magento/Framework/DB/Select/RendererInterface.php
@@ -3,6 +3,7 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\DB\Select;
 
@@ -10,6 +11,8 @@
 
 /**
  * Interface RendererInterface
+ *
+ * @api
  */
 interface RendererInterface
 {
diff --git a/lib/internal/Magento/Framework/DB/Sequence/SequenceInterface.php b/lib/internal/Magento/Framework/DB/Sequence/SequenceInterface.php
index 58d83c9524a74..a3a8687891ee8 100644
--- a/lib/internal/Magento/Framework/DB/Sequence/SequenceInterface.php
+++ b/lib/internal/Magento/Framework/DB/Sequence/SequenceInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\DB\Sequence;
 
 /**
  * Interface represents sequence
+ *
+ * @api
  */
 interface SequenceInterface
 {
diff --git a/lib/internal/Magento/Framework/DB/Sql/ExpressionInterface.php b/lib/internal/Magento/Framework/DB/Sql/ExpressionInterface.php
index 80ab6537de311..04e0f6e964f59 100644
--- a/lib/internal/Magento/Framework/DB/Sql/ExpressionInterface.php
+++ b/lib/internal/Magento/Framework/DB/Sql/ExpressionInterface.php
@@ -3,6 +3,8 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\DB\Sql;
 
 /**
@@ -11,11 +13,15 @@
  * Defines interface was implemented in Zend_Db_Expr.
  * Interface for SQL Expressions for DB Adapter/Select.
  * By using this interface a developer can strictly control type for code that manages an Expression directly.
+ *
+ * @api
  */
 interface ExpressionInterface
 {
     /**
-     * @return string The string of the SQL expression stored in this object.
+     * The string of the SQL expression stored in this object.
+     *
+     * @return string
      */
     public function __toString();
 }
diff --git a/lib/internal/Magento/Framework/Data/Collection/Db/FetchStrategyInterface.php b/lib/internal/Magento/Framework/Data/Collection/Db/FetchStrategyInterface.php
index d4ddf8b530be9..38371839a6687 100644
--- a/lib/internal/Magento/Framework/Data/Collection/Db/FetchStrategyInterface.php
+++ b/lib/internal/Magento/Framework/Data/Collection/Db/FetchStrategyInterface.php
@@ -3,10 +3,8 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
-/**
- * Interface of collection data retrieval
- */
 namespace Magento\Framework\Data\Collection\Db;
 
 use Magento\Framework\DB\Select;
@@ -14,6 +12,7 @@
 /**
  * Interface \Magento\Framework\Data\Collection\Db\FetchStrategyInterface
  *
+ * @api
  */
 interface FetchStrategyInterface
 {
diff --git a/lib/internal/Magento/Framework/Data/Collection/EntityFactoryInterface.php b/lib/internal/Magento/Framework/Data/Collection/EntityFactoryInterface.php
index 7f8bbeafc9f12..670edae5dc365 100644
--- a/lib/internal/Magento/Framework/Data/Collection/EntityFactoryInterface.php
+++ b/lib/internal/Magento/Framework/Data/Collection/EntityFactoryInterface.php
@@ -3,11 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Data\Collection;
 
 /**
  * Interface \Magento\Framework\Data\Collection\EntityFactoryInterface
  *
+ * @api
  */
 interface EntityFactoryInterface
 {
diff --git a/lib/internal/Magento/Framework/Data/CollectionDataSourceInterface.php b/lib/internal/Magento/Framework/Data/CollectionDataSourceInterface.php
index 41c044db400fe..1d2d7f97f2ce5 100644
--- a/lib/internal/Magento/Framework/Data/CollectionDataSourceInterface.php
+++ b/lib/internal/Magento/Framework/Data/CollectionDataSourceInterface.php
@@ -3,12 +3,16 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Data;
 
 use Magento\Framework\View\Element\Block\ArgumentInterface;
 
 /**
  * Interface CollectionDataSourceInterface
+ *
+ * @api
  */
 interface CollectionDataSourceInterface extends ArgumentInterface
 {
diff --git a/lib/internal/Magento/Framework/Data/CollectionModifierInterface.php b/lib/internal/Magento/Framework/Data/CollectionModifierInterface.php
index 92242824cb4e1..15967dc21f0ba 100644
--- a/lib/internal/Magento/Framework/Data/CollectionModifierInterface.php
+++ b/lib/internal/Magento/Framework/Data/CollectionModifierInterface.php
@@ -3,6 +3,8 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Data;
 
 use Magento\Framework\Data\Collection\AbstractDb;
@@ -10,6 +12,8 @@
 /**
  * Represents specific condition, that can be applied on product collection.
  * This condition can be some join statement, some filter, some derived query, etc...
+ *
+ * @api
  */
 interface CollectionModifierInterface
 {
diff --git a/lib/internal/Magento/Framework/Data/SearchResultInterface.php b/lib/internal/Magento/Framework/Data/SearchResultInterface.php
index 736fa209970f5..0b548d699e017 100644
--- a/lib/internal/Magento/Framework/Data/SearchResultInterface.php
+++ b/lib/internal/Magento/Framework/Data/SearchResultInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Data;
 
 /**
- * Class SearchResultInterface
+ * Interface SearchResultInterface
+ *
+ * @api
  */
 interface SearchResultInterface
 {
diff --git a/lib/internal/Magento/Framework/Data/SearchResultProcessorInterface.php b/lib/internal/Magento/Framework/Data/SearchResultProcessorInterface.php
index ed5fc060799fc..43b906e9fa44e 100644
--- a/lib/internal/Magento/Framework/Data/SearchResultProcessorInterface.php
+++ b/lib/internal/Magento/Framework/Data/SearchResultProcessorInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Data;
 
 /**
  * Interface SearchResultProcessorInterface
+ *
+ * @api
  */
 interface SearchResultProcessorInterface
 {
diff --git a/lib/internal/Magento/Framework/Data/ValueSourceInterface.php b/lib/internal/Magento/Framework/Data/ValueSourceInterface.php
index 12618fa94376e..790a72b3684d1 100644
--- a/lib/internal/Magento/Framework/Data/ValueSourceInterface.php
+++ b/lib/internal/Magento/Framework/Data/ValueSourceInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Data;
 
 /**
  * Interface ValueSourceInterface
+ *
+ * @api
  */
 interface ValueSourceInterface
 {
diff --git a/lib/internal/Magento/Framework/DataObject/IdentityGeneratorInterface.php b/lib/internal/Magento/Framework/DataObject/IdentityGeneratorInterface.php
index 6cfab9b8d4683..752e774a52ed0 100644
--- a/lib/internal/Magento/Framework/DataObject/IdentityGeneratorInterface.php
+++ b/lib/internal/Magento/Framework/DataObject/IdentityGeneratorInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\DataObject;
 
 /**
- * Interface UuidInterface
+ * Interface Identity Generator
+ *
+ * @api
  */
 interface IdentityGeneratorInterface
 {
@@ -16,7 +20,7 @@ interface IdentityGeneratorInterface
      * @return string
      **/
     public function generateId();
-    
+
     /**
      * Generate id for data
      *
diff --git a/lib/internal/Magento/Framework/DataObject/IdentityInterface.php b/lib/internal/Magento/Framework/DataObject/IdentityInterface.php
index 42bc9c570b128..51f378ea1a3c2 100644
--- a/lib/internal/Magento/Framework/DataObject/IdentityInterface.php
+++ b/lib/internal/Magento/Framework/DataObject/IdentityInterface.php
@@ -3,12 +3,16 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\DataObject;
 
 /**
  * Interface for
  * 1. models which require cache refresh when it is created/updated/deleted
  * 2. blocks which render this information to front-end
+ *
+ * @api
  */
 interface IdentityInterface
 {
diff --git a/lib/internal/Magento/Framework/DataObject/IdentityValidatorInterface.php b/lib/internal/Magento/Framework/DataObject/IdentityValidatorInterface.php
index a1979721f0cc9..ff8fc11e1d424 100644
--- a/lib/internal/Magento/Framework/DataObject/IdentityValidatorInterface.php
+++ b/lib/internal/Magento/Framework/DataObject/IdentityValidatorInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\DataObject;
 
 /**
  * Interface IdentityValidatorInterface
+ *
+ * @api
  */
 interface IdentityValidatorInterface
 {
diff --git a/lib/internal/Magento/Framework/DataObject/KeyValueObjectInterface.php b/lib/internal/Magento/Framework/DataObject/KeyValueObjectInterface.php
index 52e012c639a47..c81609d8969c6 100644
--- a/lib/internal/Magento/Framework/DataObject/KeyValueObjectInterface.php
+++ b/lib/internal/Magento/Framework/DataObject/KeyValueObjectInterface.php
@@ -3,12 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\DataObject;
 
 /**
  * Interface \Magento\Framework\DataObject\KeyValueObjectInterface
  *
+ * @api
  */
 interface KeyValueObjectInterface
 {