diff --git a/lib/internal/Magento/Framework/Setup/ConfigOptionsListInterface.php b/lib/internal/Magento/Framework/Setup/ConfigOptionsListInterface.php
index 88a389f57af99..2c32771a5c2ab 100644
--- a/lib/internal/Magento/Framework/Setup/ConfigOptionsListInterface.php
+++ b/lib/internal/Magento/Framework/Setup/ConfigOptionsListInterface.php
@@ -3,12 +3,16 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup;
 
 use Magento\Framework\App\DeploymentConfig;
 
 /**
  * Interface for handling options in deployment configuration tool
+ *
+ * @api
  */
 interface ConfigOptionsListInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/DataCacheInterface.php b/lib/internal/Magento/Framework/Setup/DataCacheInterface.php
index f698e1fe73c30..55cb3d81f6d97 100644
--- a/lib/internal/Magento/Framework/Setup/DataCacheInterface.php
+++ b/lib/internal/Magento/Framework/Setup/DataCacheInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup;
 
 /**
  * Data setup cache
+ *
+ * @api
  */
 interface DataCacheInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/DataSavior/DataSaviorInterface.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/DataSavior/DataSaviorInterface.php
index d8453b3a76222..e4835ec524500 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/DataSavior/DataSaviorInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/DataSavior/DataSaviorInterface.php
@@ -3,6 +3,7 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\Setup\Declaration\Schema\DataSavior;
 
@@ -11,6 +12,8 @@
 /**
  * This interface allows to dump data during declarative installation process
  * and revert changes with applying previously saved data, if something goes wrong
+ *
+ * @api
  */
 interface DataSaviorInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/DataSavior/DumpAccessorInterface.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/DataSavior/DumpAccessorInterface.php
index dbfb5eb8512c5..47f81c13bb278 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/DataSavior/DumpAccessorInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/DataSavior/DumpAccessorInterface.php
@@ -3,11 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\Setup\Declaration\Schema\DataSavior;
 
 /**
  * Allows to access dump, that can be persisted in any file format or in database
+ *
+ * @api
  */
 interface DumpAccessorInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/DDLTriggerInterface.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/DDLTriggerInterface.php
index 596e66367c727..1f06005e9d7d1 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/DDLTriggerInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/DDLTriggerInterface.php
@@ -25,6 +25,8 @@
  * This approach is correct from prospective of declaration but is not so fast as ALTER TABLE is.
  * So if you need to perform some renaming operations quickly, please use raw SQL dump instead, that can be taken with
  * help of --dry-run mode
+ *
+ * @api
  */
 interface DDLTriggerInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/DbDefinitionProcessorInterface.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/DbDefinitionProcessorInterface.php
index 1bfae47601568..f08aa2ddb44c5 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/DbDefinitionProcessorInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/DbDefinitionProcessorInterface.php
@@ -3,6 +3,7 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\Setup\Declaration\Schema\Db;
 
@@ -13,6 +14,8 @@
  * For example, from VARCHAR(255) to:
  * 'type' => 'varchar'
  * 'length' => 255
+ *
+ * @api
  */
 interface DbDefinitionProcessorInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/DbSchemaReaderInterface.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/DbSchemaReaderInterface.php
index 9f1391970e975..3feb08c3f3384 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/DbSchemaReaderInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/DbSchemaReaderInterface.php
@@ -3,12 +3,15 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\Setup\Declaration\Schema\Db;
 
 /**
  * This class is responsible for read different schema
  * structural elements: indexes, constraints, table names and columns.
+ *
+ * @api
  */
 interface DbSchemaReaderInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/DbSchemaWriterInterface.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/DbSchemaWriterInterface.php
index 6366843a72bf1..38efcc671f914 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/DbSchemaWriterInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/DbSchemaWriterInterface.php
@@ -3,12 +3,15 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\Setup\Declaration\Schema\Db;
 
 /**
  * This class is responsible for read different schema structural elements: indexes, constraints,
  * table names and columns.
+ *
+ * @api
  */
 interface DbSchemaWriterInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/StatementAggregator.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/StatementAggregator.php
index 6efece3c98fbd..d24c18e7fbf96 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/StatementAggregator.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Db/StatementAggregator.php
@@ -10,6 +10,8 @@
  * Statement aggregator.
  *
  * Statements are concatenated conditionally, decides which statements go separately and which may be concatenated.
+ *
+ * @api
  */
 class StatementAggregator
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Declaration/ValidationInterface.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Declaration/ValidationInterface.php
index 0f90a6bb8b1e5..c606e096505ba 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Declaration/ValidationInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Declaration/ValidationInterface.php
@@ -3,12 +3,16 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup\Declaration\Schema\Declaration;
 
 use Magento\Framework\Setup\Declaration\Schema\Dto\Schema;
 
 /**
  * This class is responsible for basic validation rules.
+ *
+ * @api
  */
 interface ValidationInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Diff/DiffInterface.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Diff/DiffInterface.php
index 139e9b902684a..06d1c4a004647 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Diff/DiffInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Diff/DiffInterface.php
@@ -3,6 +3,7 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\Setup\Declaration\Schema\Diff;
 
@@ -11,6 +12,8 @@
 /**
  * DiffInterface is type of classes, that holds all information
  * that need to be changed from one installation to another.
+ *
+ * @api
  */
 interface DiffInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Columns/ColumnDefaultAwareInterface.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Columns/ColumnDefaultAwareInterface.php
index 6c043cd8ed838..74daefcfcfca1 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Columns/ColumnDefaultAwareInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Columns/ColumnDefaultAwareInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup\Declaration\Schema\Dto\Columns;
 
 /**
  * Provides default value for column.
+ *
+ * @api
  */
 interface ColumnDefaultAwareInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Columns/ColumnIdentityAwareInterface.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Columns/ColumnIdentityAwareInterface.php
index 63c13711404fd..2d957a365c970 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Columns/ColumnIdentityAwareInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Columns/ColumnIdentityAwareInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup\Declaration\Schema\Dto\Columns;
 
 /**
  * Provides auto_increment flag for column.
+ *
+ * @api
  */
 interface ColumnIdentityAwareInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Columns/ColumnNullableAwareInterface.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Columns/ColumnNullableAwareInterface.php
index 086a4466a17b0..98b18c2f93095 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Columns/ColumnNullableAwareInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Columns/ColumnNullableAwareInterface.php
@@ -3,11 +3,15 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup\Declaration\Schema\Dto\Columns;
 
 /**
  * Provides nullable flag for element.
  * If column element implement this interface, then it will have NULL or NOT NULL flag in column definition.
+ *
+ * @api
  */
 interface ColumnNullableAwareInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Columns/ColumnUnsignedAwareInterface.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Columns/ColumnUnsignedAwareInterface.php
index c5fc550cf7886..09bac056d3ce2 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Columns/ColumnUnsignedAwareInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Columns/ColumnUnsignedAwareInterface.php
@@ -3,12 +3,16 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup\Declaration\Schema\Dto\Columns;
 
 /**
  * Unsigned flag provider for element.
  * If column element implement this interface, then it will have UNSIGNED flag in column
  * definition.
+ *
+ * @api
  */
 interface ColumnUnsignedAwareInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/ElementDiffAwareInterface.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/ElementDiffAwareInterface.php
index 54413cc7234f5..fb6c92ac5ebda 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/ElementDiffAwareInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/ElementDiffAwareInterface.php
@@ -3,12 +3,16 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup\Declaration\Schema\Dto;
 
 /**
  * Element diff provider interface.
  *
  * This interface provides all params, that should participate in elements comparison.
+ *
+ * @api
  */
 interface ElementDiffAwareInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Factories/FactoryInterface.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Factories/FactoryInterface.php
index 26ed3e8a4d277..786800eed3c19 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Factories/FactoryInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Factories/FactoryInterface.php
@@ -3,12 +3,16 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup\Declaration\Schema\Dto\Factories;
 
 use Magento\Framework\Setup\Declaration\Schema\Dto\ElementInterface;
 
 /**
  * DTO Element Factory Interface.
+ *
+ * @api
  */
 interface FactoryInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Schema.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Schema.php
index fbbe188d127ae..9a308f537ea76 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Schema.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Schema.php
@@ -11,6 +11,8 @@
  * Schema DTO element.
  *
  * Aggregation root for all structural elements. Provides access to tables by their names.
+ *
+ * @api
  */
 class Schema
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Table.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Table.php
index b864a3d927b0a..dfbb3939b82cd 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Table.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/Table.php
@@ -13,6 +13,8 @@
  * Table structural element
  * Aggregate inside itself: columns, constraints and indexes
  * Resource is also specified on this strucural element
+ *
+ * @api
  */
 class Table extends GenericElement implements
     ElementInterface,
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/TableElementInterface.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/TableElementInterface.php
index 630f09b18aa26..78da4d7a237bf 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/TableElementInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/Dto/TableElementInterface.php
@@ -3,12 +3,16 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup\Declaration\Schema\Dto;
 
 /**
  * Table DTO Element interface.
  *
  * This interface can be used for elements that hold tables, like constraints.
+ *
+ * @api
  */
 interface TableElementInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/ElementHistory.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/ElementHistory.php
index f609d2715d324..755fe8daea6bc 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/ElementHistory.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/ElementHistory.php
@@ -12,6 +12,8 @@
  * Element history container.
  *
  * This class holds history about element modifications.
+ *
+ * @api
  */
 class ElementHistory
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/OperationInterface.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/OperationInterface.php
index 5b7c97a4ef8ce..8268948c849a9 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/OperationInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/OperationInterface.php
@@ -3,6 +3,7 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\Setup\Declaration\Schema;
 
@@ -10,6 +11,8 @@
 
 /**
  * Schema operation interface.
+ *
+ * @api
  */
 interface OperationInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Declaration/Schema/SchemaConfigInterface.php b/lib/internal/Magento/Framework/Setup/Declaration/Schema/SchemaConfigInterface.php
index 1e6c5d63c8b3c..541b3db3ff8cb 100644
--- a/lib/internal/Magento/Framework/Setup/Declaration/Schema/SchemaConfigInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Declaration/Schema/SchemaConfigInterface.php
@@ -3,6 +3,7 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\Setup\Declaration\Schema;
 
@@ -14,6 +15,8 @@
  * Used to fetch schema object with data from either db or XML file.
  *
  * Declaration has 2 schema builders, that build schema from db and from XML.
+ *
+ * @api
  */
 interface SchemaConfigInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Patch/DataPatchInterface.php b/lib/internal/Magento/Framework/Setup/Patch/DataPatchInterface.php
index e768d045e83be..68f1e114ad60f 100644
--- a/lib/internal/Magento/Framework/Setup/Patch/DataPatchInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Patch/DataPatchInterface.php
@@ -3,11 +3,15 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup\Patch;
 
 /**
  * This interface describe script, that atomic operations with data (DML, DQL) in SQL database
  * This is wrapper for @see PatchInterface in order to define what kind of patch we have
+ *
+ * @api
  */
 interface DataPatchInterface extends PatchInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Patch/DependentPatchInterface.php b/lib/internal/Magento/Framework/Setup/Patch/DependentPatchInterface.php
index 7573441fa9466..a96ed260d3456 100644
--- a/lib/internal/Magento/Framework/Setup/Patch/DependentPatchInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Patch/DependentPatchInterface.php
@@ -3,6 +3,8 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup\Patch;
 
 /**
@@ -14,6 +16,8 @@
  * Patch1
  *
  * Here you see dependency of Patch1 to Patch2
+ *
+ * @api
  */
 interface DependentPatchInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Patch/NonTransactionableInterface.php b/lib/internal/Magento/Framework/Setup/Patch/NonTransactionableInterface.php
index 30800b3c89323..3f3f0097ecc97 100644
--- a/lib/internal/Magento/Framework/Setup/Patch/NonTransactionableInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Patch/NonTransactionableInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup\Patch;
 
 /**
  * Means that patch can`t be run in transaction
+ *
+ * @api
  */
 interface NonTransactionableInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Patch/PatchInterface.php b/lib/internal/Magento/Framework/Setup/Patch/PatchInterface.php
index 7063404276cc7..4bbd66be6c4b5 100644
--- a/lib/internal/Magento/Framework/Setup/Patch/PatchInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Patch/PatchInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup\Patch;
 
 /**
  * This interface describe script, that is presented by atomic operations for data and schema
+ *
+ * @api
  */
 interface PatchInterface extends DependentPatchInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Patch/PatchRevertableInterface.php b/lib/internal/Magento/Framework/Setup/Patch/PatchRevertableInterface.php
index a69e0c61ad22f..c4df324c097f3 100644
--- a/lib/internal/Magento/Framework/Setup/Patch/PatchRevertableInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Patch/PatchRevertableInterface.php
@@ -3,6 +3,8 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup\Patch;
 
 /**
@@ -13,6 +15,8 @@
  * - use only some DML operations: INSERT, UPDATE
  * - DELETE DML operation is prohibited, because it can cause triggering foreign keys constraints
  * - all schema patches are not revertable
+ *
+ * @api
  */
 interface PatchRevertableInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/Patch/SchemaPatchInterface.php b/lib/internal/Magento/Framework/Setup/Patch/SchemaPatchInterface.php
index ebc7c6f631c81..a303d4239b69c 100644
--- a/lib/internal/Magento/Framework/Setup/Patch/SchemaPatchInterface.php
+++ b/lib/internal/Magento/Framework/Setup/Patch/SchemaPatchInterface.php
@@ -3,11 +3,15 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup\Patch;
 
 /**
  * This interface describe script, that atomic operations with schema (DDL) in SQL database
  * This is wrapper for @see PatchInterface in order to define what kind of patch we have
+ *
+ * @api
  */
 interface SchemaPatchInterface extends PatchInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/SampleData/InstallerInterface.php b/lib/internal/Magento/Framework/Setup/SampleData/InstallerInterface.php
index 7bad230243c2e..ff69ffa66da80 100644
--- a/lib/internal/Magento/Framework/Setup/SampleData/InstallerInterface.php
+++ b/lib/internal/Magento/Framework/Setup/SampleData/InstallerInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup\SampleData;
 
 /**
  * Interface for SampleData modules installation
+ *
+ * @api
  */
 interface InstallerInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/SampleData/StateInterface.php b/lib/internal/Magento/Framework/Setup/SampleData/StateInterface.php
index 2fe3ead419f6c..26c4690289dc2 100644
--- a/lib/internal/Magento/Framework/Setup/SampleData/StateInterface.php
+++ b/lib/internal/Magento/Framework/Setup/SampleData/StateInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Setup\SampleData;
 
 /**
  * Interface for SampleData modules installation
+ *
+ * @api
  */
 interface StateInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/SchemaListenerDefinition/DefinitionConverterInterface.php b/lib/internal/Magento/Framework/Setup/SchemaListenerDefinition/DefinitionConverterInterface.php
index f273d5d35f012..9a59cb5b04211 100644
--- a/lib/internal/Magento/Framework/Setup/SchemaListenerDefinition/DefinitionConverterInterface.php
+++ b/lib/internal/Magento/Framework/Setup/SchemaListenerDefinition/DefinitionConverterInterface.php
@@ -3,11 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\Setup\SchemaListenerDefinition;
 
 /**
  * Definition formatting interface.
+ *
+ * @api
  */
 interface DefinitionConverterInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/SchemaListenerHandlers/SchemaListenerHandlerInterface.php b/lib/internal/Magento/Framework/Setup/SchemaListenerHandlers/SchemaListenerHandlerInterface.php
index b55127fb7e4d8..bf7304a99dbc2 100644
--- a/lib/internal/Magento/Framework/Setup/SchemaListenerHandlers/SchemaListenerHandlerInterface.php
+++ b/lib/internal/Magento/Framework/Setup/SchemaListenerHandlers/SchemaListenerHandlerInterface.php
@@ -3,11 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
 
 namespace Magento\Framework\Setup\SchemaListenerHandlers;
 
 /**
  * Here we will put schema listener handlers.
+ *
+ * @api
  */
 interface SchemaListenerHandlerInterface
 {
diff --git a/lib/internal/Magento/Framework/Setup/UpToDateValidatorInterface.php b/lib/internal/Magento/Framework/Setup/UpToDateValidatorInterface.php
index 033fdaa3de2e9..f6316ee1ab888 100644
--- a/lib/internal/Magento/Framework/Setup/UpToDateValidatorInterface.php
+++ b/lib/internal/Magento/Framework/Setup/UpToDateValidatorInterface.php
@@ -17,6 +17,8 @@
  *  - In Future (maybe): triggers, stored procedures, etc
  *
  * Old way implies, that each module has 2 components: data and schema
+ *
+ * @api
  */
 interface UpToDateValidatorInterface
 {