diff --git a/application/Espo/Classes/Acl/Attachment/AccessChecker.php b/application/Espo/Classes/Acl/Attachment/AccessChecker.php
index c74cad6ff3..3e485d4b09 100644
--- a/application/Espo/Classes/Acl/Attachment/AccessChecker.php
+++ b/application/Espo/Classes/Acl/Attachment/AccessChecker.php
@@ -93,6 +93,7 @@ class AccessChecker implements AccessEntityCREDChecker
         }
 
         if ($parent->getEntityType() === 'Note') {
+            /** @var Note $parent */
             $result = $this->checkEntityReadNoteParent($user, $parent);
 
             if ($result !== null) {
diff --git a/application/Espo/Classes/Acl/User/AccessChecker.php b/application/Espo/Classes/Acl/User/AccessChecker.php
index e56338b37a..bc5f21a1ce 100644
--- a/application/Espo/Classes/Acl/User/AccessChecker.php
+++ b/application/Espo/Classes/Acl/User/AccessChecker.php
@@ -42,6 +42,9 @@ use Espo\Core\{
     AclManager,
 };
 
+/**
+ * @implements AccessEntityCREDSChecker<User>
+ */
 class AccessChecker implements AccessEntityCREDSChecker
 {
     use DefaultAccessCheckerDependency;
@@ -132,6 +135,8 @@ class AccessChecker implements AccessEntityCREDSChecker
 
     public function checkEntityStream(User $user, Entity $entity, ScopeData $data): bool
     {
+        /** @var User $entity */
+
         return $this->aclManager->checkUserPermission($user, $entity, 'user');
     }
 }
diff --git a/application/Espo/Classes/AclPortal/Attachment/AccessChecker.php b/application/Espo/Classes/AclPortal/Attachment/AccessChecker.php
index 416903c7fd..ffb5e45446 100644
--- a/application/Espo/Classes/AclPortal/Attachment/AccessChecker.php
+++ b/application/Espo/Classes/AclPortal/Attachment/AccessChecker.php
@@ -45,6 +45,9 @@ use Espo\Core\{
     Portal\Acl\Traits\DefaultAccessCheckerDependency,
 };
 
+/**
+ * @implements AccessEntityCREDChecker<User>
+ */
 class AccessChecker implements AccessEntityCREDChecker
 {
     use DefaultAccessCheckerDependency;
@@ -94,6 +97,7 @@ class AccessChecker implements AccessEntityCREDChecker
         }
 
         if ($parent->getEntityType() === 'Note') {
+            /** @var Note $parent */
             $result = $this->checkEntityReadNoteParent($user, $parent);
 
             if ($result !== null) {
diff --git a/application/Espo/Classes/DuplicateWhereBuilders/Company.php b/application/Espo/Classes/DuplicateWhereBuilders/Company.php
index 65075e7c38..5ef8483bcb 100644
--- a/application/Espo/Classes/DuplicateWhereBuilders/Company.php
+++ b/application/Espo/Classes/DuplicateWhereBuilders/Company.php
@@ -44,6 +44,8 @@ class Company implements WhereBuilder
 {
     public function build(Entity $entity): ?WhereItem
     {
+        assert($entity instanceof CoreEntity);
+
         $orBuilder = OrGroup::createBuilder();
 
         $toCheck = false;
diff --git a/application/Espo/Classes/DuplicateWhereBuilders/Person.php b/application/Espo/Classes/DuplicateWhereBuilders/Person.php
index c2d4818b7e..553281a455 100644
--- a/application/Espo/Classes/DuplicateWhereBuilders/Person.php
+++ b/application/Espo/Classes/DuplicateWhereBuilders/Person.php
@@ -47,6 +47,8 @@ class Person implements WhereBuilder
 {
     public function build(Entity $entity): ?WhereItem
     {
+        assert($entity instanceof CoreEntity);
+
         $orBuilder = OrGroup::createBuilder();
 
         $toCheck = false;
diff --git a/application/Espo/Classes/FieldProcessing/Email/AddressDataLoader.php b/application/Espo/Classes/FieldProcessing/Email/AddressDataLoader.php
index cfaec19838..46ab79e31b 100644
--- a/application/Espo/Classes/FieldProcessing/Email/AddressDataLoader.php
+++ b/application/Espo/Classes/FieldProcessing/Email/AddressDataLoader.php
@@ -39,6 +39,9 @@ use Espo\Core\{
 
 use Espo\Repositories\Email as EmailRepository;
 
+/**
+ * @implements Loader<\Espo\Entities\Email>
+ */
 class AddressDataLoader implements Loader
 {
     private $entityManager;
diff --git a/application/Espo/Classes/FieldProcessing/Import/CountsLoader.php b/application/Espo/Classes/FieldProcessing/Import/CountsLoader.php
index f4084d7baa..8852151839 100644
--- a/application/Espo/Classes/FieldProcessing/Import/CountsLoader.php
+++ b/application/Espo/Classes/FieldProcessing/Import/CountsLoader.php
@@ -39,6 +39,9 @@ use Espo\Core\{
 
 use Espo\Repositories\Import as ImportRepository;
 
+/**
+ * @implements Loader<\Espo\Entities\Import>
+ */
 class CountsLoader implements Loader
 {
     private $entityManager;
diff --git a/application/Espo/Classes/RecordHooks/Team/BeforeLinkUserCheck.php b/application/Espo/Classes/RecordHooks/Team/BeforeLinkUserCheck.php
index eda6109fe5..0c3185fdc4 100644
--- a/application/Espo/Classes/RecordHooks/Team/BeforeLinkUserCheck.php
+++ b/application/Espo/Classes/RecordHooks/Team/BeforeLinkUserCheck.php
@@ -36,6 +36,9 @@ use Espo\ORM\Entity;
 
 use Espo\Entities\User;
 
+/**
+ * @implements LinkHook<\Espo\Entities\Team>
+ */
 class BeforeLinkUserCheck implements LinkHook
 {
     public function process(Entity $entity, string $link, Entity $foreignEntity): void
@@ -44,6 +47,8 @@ class BeforeLinkUserCheck implements LinkHook
             return;
         }
 
+        assert($foreignEntity instanceof User);
+
         $this->processUserCheck($foreignEntity);
     }
 
diff --git a/application/Espo/Core/Acl/AccessEntityCREDChecker.php b/application/Espo/Core/Acl/AccessEntityCREDChecker.php
index b1e71d1f40..c12a307fe3 100644
--- a/application/Espo/Core/Acl/AccessEntityCREDChecker.php
+++ b/application/Espo/Core/Acl/AccessEntityCREDChecker.php
@@ -29,6 +29,11 @@
 
 namespace Espo\Core\Acl;
 
+/**
+ * @template TEntity of \Espo\ORM\Entity
+ * @extends AccessEntityCreateChecker<TEntity>, AccessEntityCreateChecker<TEntity>, AccessEntityReadChecker<TEntity>,
+ * AccessEntityEditChecker<TEntity>, AccessEntityDeleteChecker<TEntity>
+ */
 interface AccessEntityCREDChecker extends
 
     AccessEntityCreateChecker,
diff --git a/application/Espo/Core/Acl/AccessEntityCREDSChecker.php b/application/Espo/Core/Acl/AccessEntityCREDSChecker.php
index 80f64b3efe..7e61b48556 100644
--- a/application/Espo/Core/Acl/AccessEntityCREDSChecker.php
+++ b/application/Espo/Core/Acl/AccessEntityCREDSChecker.php
@@ -29,6 +29,11 @@
 
 namespace Espo\Core\Acl;
 
+/**
+ * @template TEntity of \Espo\ORM\Entity
+ * @extends AccessEntityCreateChecker<TEntity>, AccessEntityCreateChecker<TEntity>, AccessEntityReadChecker<TEntity>,
+ * AccessEntityEditChecker<TEntity>, AccessEntityDeleteChecker<TEntity>, AccessEntityStreamChecker<TEntity>
+ */
 interface AccessEntityCREDSChecker extends
 
     AccessEntityCreateChecker,
diff --git a/application/Espo/Core/Acl/AccessEntityCreateChecker.php b/application/Espo/Core/Acl/AccessEntityCreateChecker.php
index 86c2dc99e8..9dea19114b 100644
--- a/application/Espo/Core/Acl/AccessEntityCreateChecker.php
+++ b/application/Espo/Core/Acl/AccessEntityCreateChecker.php
@@ -30,13 +30,17 @@
 namespace Espo\Core\Acl;
 
 use Espo\ORM\Entity;
-
 use Espo\Entities\User;
 
+/**
+ * @template TEntity of Entity
+ */
 interface AccessEntityCreateChecker extends AccessCreateChecker
 {
     /**
      * Check 'create' access for an entity.
+     *
+     * @phpstan-param TEntity $entity
      */
     public function checkEntityCreate(User $user, Entity $entity, ScopeData $data): bool;
 }
diff --git a/application/Espo/Core/Acl/AccessEntityDeleteChecker.php b/application/Espo/Core/Acl/AccessEntityDeleteChecker.php
index c3fb213e33..6e47b174b7 100644
--- a/application/Espo/Core/Acl/AccessEntityDeleteChecker.php
+++ b/application/Espo/Core/Acl/AccessEntityDeleteChecker.php
@@ -30,13 +30,17 @@
 namespace Espo\Core\Acl;
 
 use Espo\ORM\Entity;
-
 use Espo\Entities\User;
 
+/**
+ * @template TEntity of Entity
+ */
 interface AccessEntityDeleteChecker extends AccessDeleteChecker
 {
     /**
      * Check 'delete' access for an entity.
+     *
+     * @phpstan-param TEntity $entity
      */
     public function checkEntityDelete(User $user, Entity $entity, ScopeData $data): bool;
 }
diff --git a/application/Espo/Core/Acl/AccessEntityEditChecker.php b/application/Espo/Core/Acl/AccessEntityEditChecker.php
index 12d0256d11..d35b90a6a0 100644
--- a/application/Espo/Core/Acl/AccessEntityEditChecker.php
+++ b/application/Espo/Core/Acl/AccessEntityEditChecker.php
@@ -30,13 +30,17 @@
 namespace Espo\Core\Acl;
 
 use Espo\ORM\Entity;
-
 use Espo\Entities\User;
 
+/**
+ * @template TEntity of Entity
+ */
 interface AccessEntityEditChecker extends AccessEditChecker
 {
     /**
      * Check 'edit' access for an entity.
+     *
+     * @phpstan-param TEntity $entity
      */
     public function checkEntityEdit(User $user, Entity $entity, ScopeData $data): bool;
 }
diff --git a/application/Espo/Core/Acl/AccessEntityReadChecker.php b/application/Espo/Core/Acl/AccessEntityReadChecker.php
index d1d408ed4a..c659c01e75 100644
--- a/application/Espo/Core/Acl/AccessEntityReadChecker.php
+++ b/application/Espo/Core/Acl/AccessEntityReadChecker.php
@@ -30,13 +30,17 @@
 namespace Espo\Core\Acl;
 
 use Espo\ORM\Entity;
-
 use Espo\Entities\User;
 
+/**
+ * @template TEntity of Entity
+ */
 interface AccessEntityReadChecker extends AccessReadChecker
 {
     /**
      * Check 'read' access for entity.
+     *
+     * @phpstan-param TEntity $entity
      */
     public function checkEntityRead(User $user, Entity $entity, ScopeData $data): bool;
 }
diff --git a/application/Espo/Core/Acl/AccessEntityStreamChecker.php b/application/Espo/Core/Acl/AccessEntityStreamChecker.php
index d4fa8c252a..de90890079 100644
--- a/application/Espo/Core/Acl/AccessEntityStreamChecker.php
+++ b/application/Espo/Core/Acl/AccessEntityStreamChecker.php
@@ -30,13 +30,17 @@
 namespace Espo\Core\Acl;
 
 use Espo\ORM\Entity;
-
 use Espo\Entities\User;
 
+/**
+ * @template TEntity of Entity
+ */
 interface AccessEntityStreamChecker extends AccessStreamChecker
 {
     /**
      * Check 'stream' access for an entity.
+     *
+     * @phpstan-param TEntity $entity
      */
     public function checkEntityStream(User $user, Entity $entity, ScopeData $data): bool;
 }
diff --git a/application/Espo/Core/Duplicate/WhereBuilder.php b/application/Espo/Core/Duplicate/WhereBuilder.php
index 4ee93ecfbc..8ccff3dcf6 100644
--- a/application/Espo/Core/Duplicate/WhereBuilder.php
+++ b/application/Espo/Core/Duplicate/WhereBuilder.php
@@ -34,7 +34,13 @@ use Espo\ORM\{
     Entity,
 };
 
+/**
+ * @template TEntity of Entity
+ */
 interface WhereBuilder
 {
+    /**
+     * @phpstan-param TEntity $entity
+     */
     public function build(Entity $entity): ?WhereItem;
 }
diff --git a/application/Espo/Core/FieldProcessing/Loader.php b/application/Espo/Core/FieldProcessing/Loader.php
index 6d4a8d36b7..4183be3b04 100644
--- a/application/Espo/Core/FieldProcessing/Loader.php
+++ b/application/Espo/Core/FieldProcessing/Loader.php
@@ -35,8 +35,13 @@ use Espo\Core\FieldProcessing\Loader\Params;
 
 /**
  * Processes loading special fields before output.
+ *
+ * @template TEntity of Entity
  */
 interface Loader
 {
+    /**
+     * @phpstan-param TEntity $entity
+     */
     public function process(Entity $entity, Params $params): void;
 }
diff --git a/application/Espo/Core/Record/Hook/LinkHook.php b/application/Espo/Core/Record/Hook/LinkHook.php
index c0961348cd..6c5a26948c 100644
--- a/application/Espo/Core/Record/Hook/LinkHook.php
+++ b/application/Espo/Core/Record/Hook/LinkHook.php
@@ -31,7 +31,13 @@ namespace Espo\Core\Record\Hook;
 
 use Espo\ORM\Entity;
 
+/**
+ * @template TEntity of Entity
+ */
 interface LinkHook
 {
+    /**
+     * @phpstan-param TEntity $entity
+     */
     public function process(Entity $entity, string $link, Entity $foreignEntity): void;
 }
diff --git a/application/Espo/EntryPoints/Pdf.php b/application/Espo/EntryPoints/Pdf.php
index 24112bf1b1..86b865b2c2 100644
--- a/application/Espo/EntryPoints/Pdf.php
+++ b/application/Espo/EntryPoints/Pdf.php
@@ -87,7 +87,7 @@ class Pdf implements EntryPoint
             ->setHeader('Content-Disposition', 'inline; filename="' . basename($fileName) . '"');
 
         if (!$request->getServerParam('HTTP_ACCEPT_ENCODING')) {
-            $response->setHeader('Content-Length', strlen($contents));
+            $response->setHeader('Content-Length', (string) strlen($contents));
         }
 
         $response->writeBody($contents);
diff --git a/application/Espo/Hooks/Common/FieldProcessing.php b/application/Espo/Hooks/Common/FieldProcessing.php
index 2f078284a5..02a10c4e37 100644
--- a/application/Espo/Hooks/Common/FieldProcessing.php
+++ b/application/Espo/Hooks/Common/FieldProcessing.php
@@ -30,8 +30,8 @@
 namespace Espo\Hooks\Common;
 
 use Espo\ORM\Entity;
-
 use Espo\Core\FieldProcessing\SaveProcessor;
+use Espo\Core\ORM\Entity as CoreEntity;
 
 class FieldProcessing
 {
@@ -50,6 +50,10 @@ class FieldProcessing
             return;
         }
 
+        if (!$entity instanceof CoreEntity) {
+            return;
+        }
+
         $this->saveProcessor->process($entity, $options);
     }
 }
diff --git a/application/Espo/Hooks/Common/Webhook.php b/application/Espo/Hooks/Common/Webhook.php
index b4d941c23f..34ddbe1812 100644
--- a/application/Espo/Hooks/Common/Webhook.php
+++ b/application/Espo/Hooks/Common/Webhook.php
@@ -30,6 +30,7 @@
 namespace Espo\Hooks\Common;
 
 use Espo\ORM\Entity;
+use Espo\Core\ORM\Entity as CoreEntity;
 
 use Espo\Core\{
     Utils\Metadata,
@@ -60,6 +61,10 @@ class Webhook
             return;
         }
 
+        if (!$entity instanceof CoreEntity) {
+            return;
+        }
+
         if ($entity->isNew()) {
             $this->webhookManager->processCreate($entity);
         }
@@ -78,6 +83,10 @@ class Webhook
             return;
         }
 
+        if (!$entity instanceof CoreEntity) {
+            return;
+        }
+
         $this->webhookManager->processDelete($entity);
     }
 }
diff --git a/application/Espo/Hooks/Note/Mentions.php b/application/Espo/Hooks/Note/Mentions.php
index d1c63e70e7..5771a5d31f 100644
--- a/application/Espo/Hooks/Note/Mentions.php
+++ b/application/Espo/Hooks/Note/Mentions.php
@@ -31,6 +31,7 @@ namespace Espo\Hooks\Note;
 
 use Espo\Tools\Notification\NoteMentionHookProcessor;
 use Espo\ORM\Entity;
+use Espo\Entities\Note;
 
 class Mentions
 {
@@ -49,6 +50,8 @@ class Mentions
             return;
         }
 
+        assert($entity instanceof Note);
+
         $this->processor->beforeSave($entity);
     }
 }
diff --git a/application/Espo/Hooks/Note/Notifications.php b/application/Espo/Hooks/Note/Notifications.php
index 39e5acae6b..43d2781048 100644
--- a/application/Espo/Hooks/Note/Notifications.php
+++ b/application/Espo/Hooks/Note/Notifications.php
@@ -31,6 +31,7 @@ namespace Espo\Hooks\Note;
 
 use Espo\ORM\Entity;
 use Espo\Tools\Notification\NoteHookProcessor;
+use Espo\Entities\Note;
 
 class Notifications
 {
@@ -49,6 +50,8 @@ class Notifications
             return;
         }
 
+        assert($entity instanceof Note);
+
         $this->processor->afterSave($entity);
     }
 }
diff --git a/application/Espo/Hooks/Sms/Numbers.php b/application/Espo/Hooks/Sms/Numbers.php
index d77107aba8..4477c85731 100644
--- a/application/Espo/Hooks/Sms/Numbers.php
+++ b/application/Espo/Hooks/Sms/Numbers.php
@@ -47,6 +47,8 @@ class Numbers
 
     public function beforeSave(Entity $entity): void
     {
+        assert($entity instanceof Sms);
+
         $this->processNumbers($entity);
     }
 
diff --git a/application/Espo/Repositories/Attachment.php b/application/Espo/Repositories/Attachment.php
index 07a482732e..afa9e50d63 100644
--- a/application/Espo/Repositories/Attachment.php
+++ b/application/Espo/Repositories/Attachment.php
@@ -76,7 +76,7 @@ class Attachment extends Database implements
         }
     }
 
-    protected function processBeforeSaveNew(Entity $entity): void
+    protected function processBeforeSaveNew(AttachmentEntity $entity): void
     {
         if (!$entity->get('storage')) {
             $defaultStorage = $this->config->get('defaultFileStorage');