diff --git a/lib/internal/Magento/Framework/Encryption/Adapter/EncryptionAdapterInterface.php b/lib/internal/Magento/Framework/Encryption/Adapter/EncryptionAdapterInterface.php
index b9bbb089ae0cc..b6a91d83ed72b 100644
--- a/lib/internal/Magento/Framework/Encryption/Adapter/EncryptionAdapterInterface.php
+++ b/lib/internal/Magento/Framework/Encryption/Adapter/EncryptionAdapterInterface.php
@@ -8,6 +8,11 @@
 
 namespace Magento\Framework\Encryption\Adapter;
 
+/**
+ * Encryption adapter interface
+ *
+ * @api
+ */
 interface EncryptionAdapterInterface
 {
     /**
diff --git a/lib/internal/Magento/Framework/Event/ConfigInterface.php b/lib/internal/Magento/Framework/Event/ConfigInterface.php
index 40c46c0eea438..0351f15ee714c 100644
--- a/lib/internal/Magento/Framework/Event/ConfigInterface.php
+++ b/lib/internal/Magento/Framework/Event/ConfigInterface.php
@@ -5,11 +5,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Event;
 
 /**
  * Interface \Magento\Framework\Event\ConfigInterface
  *
+ * @api
  */
 interface ConfigInterface
 {
diff --git a/lib/internal/Magento/Framework/Event/InvokerInterface.php b/lib/internal/Magento/Framework/Event/InvokerInterface.php
index d5e8c17ea0870..0daaad516d3a3 100644
--- a/lib/internal/Magento/Framework/Event/InvokerInterface.php
+++ b/lib/internal/Magento/Framework/Event/InvokerInterface.php
@@ -5,11 +5,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Event;
 
 /**
  * Interface \Magento\Framework\Event\InvokerInterface
  *
+ * @api
  */
 interface InvokerInterface
 {
diff --git a/lib/internal/Magento/Framework/Event/ManagerInterface.php b/lib/internal/Magento/Framework/Event/ManagerInterface.php
index 20d01c6a0f099..41b3c70549034 100644
--- a/lib/internal/Magento/Framework/Event/ManagerInterface.php
+++ b/lib/internal/Magento/Framework/Event/ManagerInterface.php
@@ -3,11 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Event;
 
 /**
  * Interface \Magento\Framework\Event\ManagerInterface
  *
+ * @api
  */
 interface ManagerInterface
 {
diff --git a/lib/internal/Magento/Framework/Exception/TemporaryStateExceptionInterface.php b/lib/internal/Magento/Framework/Exception/TemporaryStateExceptionInterface.php
index 048c3684c80e7..9878e6e155aa7 100644
--- a/lib/internal/Magento/Framework/Exception/TemporaryStateExceptionInterface.php
+++ b/lib/internal/Magento/Framework/Exception/TemporaryStateExceptionInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Exception;
 
 /**
  * Temporary state exception that represent recoverable error
+ *
+ * @api
  */
 interface TemporaryStateExceptionInterface
 {
diff --git a/lib/internal/Magento/Framework/Filesystem/Directory/PathValidatorInterface.php b/lib/internal/Magento/Framework/Filesystem/Directory/PathValidatorInterface.php
index ecb7da9aaeab6..3108f062cfc84 100644
--- a/lib/internal/Magento/Framework/Filesystem/Directory/PathValidatorInterface.php
+++ b/lib/internal/Magento/Framework/Filesystem/Directory/PathValidatorInterface.php
@@ -12,6 +12,8 @@
 
 /**
  * Validate paths to be used with directories.
+ *
+ * @api
  */
 interface PathValidatorInterface
 {
diff --git a/lib/internal/Magento/Framework/Filesystem/DriverPoolInterface.php b/lib/internal/Magento/Framework/Filesystem/DriverPoolInterface.php
index d99b285be0f67..c9c6b9397e8ca 100644
--- a/lib/internal/Magento/Framework/Filesystem/DriverPoolInterface.php
+++ b/lib/internal/Magento/Framework/Filesystem/DriverPoolInterface.php
@@ -9,6 +9,8 @@
 
 /**
  * A pool of stream wrappers.
+ *
+ * @api
  */
 interface DriverPoolInterface
 {
diff --git a/lib/internal/Magento/Framework/Filesystem/File/ReadInterface.php b/lib/internal/Magento/Framework/Filesystem/File/ReadInterface.php
index 4277e2b5693e7..4cf37825bdb58 100644
--- a/lib/internal/Magento/Framework/Filesystem/File/ReadInterface.php
+++ b/lib/internal/Magento/Framework/Filesystem/File/ReadInterface.php
@@ -3,11 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Filesystem\File;
 
 /**
  * Interface \Magento\Framework\Filesystem\File\ReadInterface
  *
+ * @api
  */
 interface ReadInterface
 {
diff --git a/lib/internal/Magento/Framework/Filter/DirectiveProcessor/FilterInterface.php b/lib/internal/Magento/Framework/Filter/DirectiveProcessor/FilterInterface.php
index 6512ecfbf6c90..3cf565cef50db 100644
--- a/lib/internal/Magento/Framework/Filter/DirectiveProcessor/FilterInterface.php
+++ b/lib/internal/Magento/Framework/Filter/DirectiveProcessor/FilterInterface.php
@@ -10,6 +10,8 @@
 
 /**
  * Transforms the output of a directive processor
+ *
+ * @api
  */
 interface FilterInterface
 {
diff --git a/lib/internal/Magento/Framework/Filter/DirectiveProcessorInterface.php b/lib/internal/Magento/Framework/Filter/DirectiveProcessorInterface.php
index e8fd00bb3cee1..e1b05f229780d 100644
--- a/lib/internal/Magento/Framework/Filter/DirectiveProcessorInterface.php
+++ b/lib/internal/Magento/Framework/Filter/DirectiveProcessorInterface.php
@@ -10,6 +10,8 @@
 
 /**
  * Responsible for converting a directive data structure to relevant template output
+ *
+ * @api
  */
 interface DirectiveProcessorInterface
 {
diff --git a/lib/internal/Magento/Framework/Filter/FactoryInterface.php b/lib/internal/Magento/Framework/Filter/FactoryInterface.php
index c0d49158b05ee..ff0934a656f16 100644
--- a/lib/internal/Magento/Framework/Filter/FactoryInterface.php
+++ b/lib/internal/Magento/Framework/Filter/FactoryInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Filter;
 
 /**
  * Magento filter factory interface
+ *
+ * @api
  */
 interface FactoryInterface
 {
diff --git a/lib/internal/Magento/Framework/Filter/FilterManager/ConfigInterface.php b/lib/internal/Magento/Framework/Filter/FilterManager/ConfigInterface.php
index 95218bd7b5bc2..8e7117976c19e 100644
--- a/lib/internal/Magento/Framework/Filter/FilterManager/ConfigInterface.php
+++ b/lib/internal/Magento/Framework/Filter/FilterManager/ConfigInterface.php
@@ -3,10 +3,14 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Framework\Filter\FilterManager;
 
 /**
  * Filter manager config interface
+ *
+ * @api
  */
 interface ConfigInterface
 {
diff --git a/lib/internal/Magento/Framework/Filter/SimpleDirective/ProcessorInterface.php b/lib/internal/Magento/Framework/Filter/SimpleDirective/ProcessorInterface.php
index e16991ba50b28..8bc2244c1d21c 100644
--- a/lib/internal/Magento/Framework/Filter/SimpleDirective/ProcessorInterface.php
+++ b/lib/internal/Magento/Framework/Filter/SimpleDirective/ProcessorInterface.php
@@ -12,6 +12,8 @@
 
 /**
  * An easier mechanism to implement custom directives rather than parsing the whole directive manually
+ *
+ * @api
  */
 interface ProcessorInterface
 {
diff --git a/lib/internal/Magento/Framework/Filter/VariableResolverInterface.php b/lib/internal/Magento/Framework/Filter/VariableResolverInterface.php
index 486a66f1ec1b0..b7028c6f4b0a2 100644
--- a/lib/internal/Magento/Framework/Filter/VariableResolverInterface.php
+++ b/lib/internal/Magento/Framework/Filter/VariableResolverInterface.php
@@ -10,6 +10,8 @@
 
 /**
  * Responsible for obtaining the value of variables defined in the template
+ *
+ * @api
  */
 interface VariableResolverInterface
 {