diff --git a/demos/_includes/Session.php b/demos/_includes/Session.php
index 8fa9ad2605..09fcb06049 100644
--- a/demos/_includes/Session.php
+++ b/demos/_includes/Session.php
@@ -4,11 +4,19 @@
 
 namespace Atk4\Ui\Demos;
 
+use Atk4\Core\AppScopeTrait;
 use Atk4\Core\NameTrait;
-use Atk4\Core\SessionTrait;
+use Atk4\Ui\App;
+use Atk4\Ui\SessionTrait;
 
 class Session
 {
+    use AppScopeTrait;
     use NameTrait;
     use SessionTrait;
+
+    public function __construct(App $app)
+    {
+        $this->setApp($app);
+    }
 }
diff --git a/demos/interactive/modal.php b/demos/interactive/modal.php
index 586072356f..5bcff81a8d 100644
--- a/demos/interactive/modal.php
+++ b/demos/interactive/modal.php
@@ -11,7 +11,7 @@
 
 \Atk4\Ui\Header::addTo($app, ['Modal View']);
 
-$session = new Session();
+$session = new Session($app);
 // Re-usable component implementing counter
 
 \Atk4\Ui\Header::addTo($app, ['Static Modal Dialog']);
diff --git a/demos/interactive/popup.php b/demos/interactive/popup.php
index e17f94e48e..5036e50082 100644
--- a/demos/interactive/popup.php
+++ b/demos/interactive/popup.php
@@ -20,7 +20,8 @@
 
 /** @var \Atk4\Ui\Lister $cartClass */
 $cartClass = AnonymousClassNameCache::get_class(fn () => new class() extends \Atk4\Ui\Lister {
-    use \Atk4\Core\SessionTrait;
+    use \Atk4\Ui\SessionTrait;
+
     public $items = [];
 
     public $defaultTemplate = 'lister.html';
diff --git a/docs/session.rst b/docs/session.rst
new file mode 100644
index 0000000000..de5dde6ad7
--- /dev/null
+++ b/docs/session.rst
@@ -0,0 +1,62 @@
+=============
+Session Trait
+=============
+
+.. php:trait:: SessionTrait
+
+
+Introduction
+============
+
+SessionTrait is a simple way to let object store relevant data in the session. Specifically used in ATK UI
+some objects want to memorize data.  (see https://github.com/atk4/ui/blob/develop/src/Wizard.php#L12)
+
+You would need 3 things. First make use of session trait::
+
+    use \Atk4\Ui\SessionTrait;
+
+next you may memorize any value, which will be stored independently from any other object (even of a same class)::
+
+    $this->memorize('dsn', $dsn);
+
+Later when you need the value, you can simply recall it::
+
+    $dsn = $this->recall('dsn');
+
+
+Properties
+==========
+
+.. php:attr:: session_key
+
+    Internal property to make sure that all session data will be stored in one
+    "container" (array key).
+
+Methods
+=======
+
+.. php:method:: startSession($options = [])
+
+    Create new session.
+
+.. php:method:: destroySession()
+
+    Destroy existing session.
+
+.. php:method:: memorize($key, $value)
+
+    Remember data in object-relevant session data.
+
+.. php:method:: learn($key, $default = null)
+
+    Similar to memorize, but if value for key exist, will return it.
+
+.. php:method:: recall($key, $default = null)
+
+    Returns session data for this object. If not previously set, then $default
+    is returned.
+
+.. php:method:: forget($key = null)
+
+    Forget session data for arg $key. If $key is omitted will forget all
+    associated session data.
diff --git a/phpstan.neon.dist b/phpstan.neon.dist
index 8aada406cd..a3f9f2158d 100644
--- a/phpstan.neon.dist
+++ b/phpstan.neon.dist
@@ -211,6 +211,10 @@ parameters:
         -
             path: 'src/Panel/Right.php'
             message: '~^Call to an undefined method Atk4\\Ui\\JsExpression::addPanel\(\)\.$~'
+        -
+            path: 'src/SessionTrait.php'
+            count: 4
+            message: '~^Access to an undefined property Atk4\\Ui\\Tests\\SessionAbstractMock::\$name\.$~'
         -
             path: 'src/Table/Column.php'
             message: '~^Call to an undefined method Atk4\\Ui\\AbstractView::setHoverable\(\)\.$~'
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index d59efca385..60055a9dde 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -13,6 +13,7 @@
     <groups>
         <exclude>
             <group>demos_http</group>
+            <group>require_session</group>
         </exclude>
     </groups>
     <listeners>
diff --git a/src/App.php b/src/App.php
index 6665f425d0..dc045afe8a 100644
--- a/src/App.php
+++ b/src/App.php
@@ -105,6 +105,9 @@ class App
     /** @var Persistence|Persistence\Sql */
     public $db;
 
+    /** @var App\Session */
+    public $session;
+
     /** @var string[] Extra HTTP headers to send on exit. */
     protected $response_headers = [
         self::HEADER_STATUS_CODE => '200',
@@ -136,39 +139,11 @@ class App
 
     public $templateClass = HtmlTemplate::class;
 
-    /**
-     * @param array $defaults
-     */
-    public function __construct($defaults = [])
+    public function __construct(array $defaults = [])
     {
         $this->setApp($this);
 
-        // Process defaults
-        if (is_string($defaults)) {
-            $defaults = ['title' => $defaults];
-        }
-
-        if (isset($defaults[0])) {
-            $defaults['title'] = $defaults[0];
-            unset($defaults[0]);
-        }
-
-        /*
-        if (is_array($defaults)) {
-            throw (new Exception('Constructor requires array argument'))
-                ->addMoreInfo('arg', $defaults);
-        }*/
         $this->setDefaults($defaults);
-        /*
-
-        foreach ($defaults as $key => $val) {
-            if (is_array($val)) {
-                $this->{$key} = array_merge(is_array($this->{$key} ?? null) ? $this->{$key} : [], $val);
-            } elseif ($val !== null) {
-                $this->{$key} = $val;
-            }
-        }
-         */
 
         $this->setupTemplateDirs();
 
@@ -208,11 +183,14 @@ static function (int $severity, string $msg, string $file, int $line): bool {
             $this->setupAlwaysRun();
         }
 
-        // Set up UI persistence
         if ($this->ui_persistence === null) {
             $this->ui_persistence = new UiPersistence();
         }
 
+        if ($this->session === null) {
+            $this->session = new App\Session();
+        }
+
         // setting up default executor factory.
         $this->executorFactory = Factory::factory([ExecutorFactory::class]);
     }
diff --git a/src/App/Session.php b/src/App/Session.php
new file mode 100644
index 0000000000..45f680b606
--- /dev/null
+++ b/src/App/Session.php
@@ -0,0 +1,121 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atk4\Ui\App;
+
+use Atk4\Ui\Exception;
+
+class Session
+{
+    /** @var string Session container key. */
+    protected $session_key = '__atk_session';
+
+    /**
+     * Create new session.
+     *
+     * @param array $options Options for session_start()
+     */
+    public function startSession(array $options = []): void
+    {
+        switch (session_status()) {
+            case \PHP_SESSION_DISABLED:
+                // @codeCoverageIgnoreStart - impossible to test
+                throw new Exception('Sessions are disabled on server');
+                // @codeCoverageIgnoreEnd
+            case \PHP_SESSION_NONE:
+                session_start($options);
+
+                break;
+        }
+    }
+
+    /**
+     * Destroy existing session.
+     */
+    public function destroySession(): void
+    {
+        if (session_status() === \PHP_SESSION_ACTIVE) {
+            session_destroy();
+            unset($_SESSION);
+        }
+    }
+
+    /**
+     * Remember data in object-relevant session data.
+     *
+     * @param mixed $value
+     *
+     * @return mixed $value
+     */
+    public function memorize(string $namespace, string $key, $value)
+    {
+        $this->startSession();
+
+        $_SESSION[$this->session_key][$namespace][$key] = $value;
+
+        return $value;
+    }
+
+    /**
+     * Similar to memorize, but if value for key exist, will return it.
+     *
+     * @param mixed $default
+     *
+     * @return mixed Previously memorized data or $default
+     */
+    public function learn(string $namespace, string $key, $default = null)
+    {
+        $this->startSession();
+
+        if (!isset($_SESSION[$this->session_key][$namespace][$key])) {
+            if ($default instanceof \Closure) {
+                $default = $default($key);
+            }
+
+            return $this->memorize($namespace, $key, $default);
+        }
+
+        return $this->recall($namespace, $key);
+    }
+
+    /**
+     * Returns session data for this object. If not previously set, then
+     * $default is returned.
+     *
+     * @param mixed $default
+     *
+     * @return mixed Previously memorized data or $default
+     */
+    public function recall(string $namespace, string $key, $default = null)
+    {
+        $this->startSession();
+
+        if (!isset($_SESSION[$this->session_key][$namespace][$key])) {
+            if ($default instanceof \Closure) {
+                $default = $default($key);
+            }
+
+            return $default;
+        }
+
+        return $_SESSION[$this->session_key][$namespace][$key];
+    }
+
+    /**
+     * Forget session data for $key. If $key is omitted will forget all
+     * associated session data.
+     *
+     * @param string $key Optional key of data to forget
+     */
+    public function forget(string $namespace, string $key = null): void
+    {
+        $this->startSession();
+
+        if ($key === null) {
+            unset($_SESSION[$this->session_key][$namespace]);
+        } else {
+            unset($_SESSION[$this->session_key][$namespace][$key]);
+        }
+    }
+}
diff --git a/src/SessionTrait.php b/src/SessionTrait.php
new file mode 100644
index 0000000000..557d18204a
--- /dev/null
+++ b/src/SessionTrait.php
@@ -0,0 +1,72 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atk4\Ui;
+
+use Atk4\Core\TraitUtil;
+
+trait SessionTrait
+{
+    private function getSession(): App\Session
+    {
+        // all methods use this method, so we better check NameTrait existence here in one place
+        if (!TraitUtil::hasNameTrait($this)) {
+            throw new Exception('Object should have NameTrait applied to use session');
+        }
+
+        return $this->getApp()->session;
+    }
+
+    /**
+     * Remember data in object-relevant session data.
+     *
+     * @param mixed $value
+     *
+     * @return mixed $value
+     */
+    public function memorize(string $key, $value)
+    {
+        return $this->getSession()->memorize($this->name, $key, $value);
+    }
+
+    /**
+     * Similar to memorize, but if value for key exist, will return it.
+     *
+     * @param mixed $default
+     *
+     * @return mixed Previously memorized data or $default
+     */
+    public function learn(string $key, $default = null)
+    {
+        return $this->getSession()->learn($this->name, $key, $default);
+    }
+
+    /**
+     * Returns session data for this object. If not previously set, then
+     * $default is returned.
+     *
+     * @param mixed $default
+     *
+     * @return mixed Previously memorized data or $default
+     */
+    public function recall(string $key, $default = null)
+    {
+        return $this->getSession()->recall($this->name, $key, $default);
+    }
+
+    /**
+     * Forget session data for $key. If $key is omitted will forget all
+     * associated session data.
+     *
+     * @param string $key Optional key of data to forget
+     *
+     * @return $this
+     */
+    public function forget(string $key = null)
+    {
+        $this->getSession()->forget($this->name, $key);
+
+        return $this;
+    }
+}
diff --git a/src/Table/Column/FilterModel.php b/src/Table/Column/FilterModel.php
index d19256a675..e14749a70d 100644
--- a/src/Table/Column/FilterModel.php
+++ b/src/Table/Column/FilterModel.php
@@ -4,19 +4,22 @@
 
 namespace Atk4\Ui\Table\Column;
 
+use Atk4\Core\AppScopeTrait;
 use Atk4\Core\NameTrait;
-use Atk4\Core\SessionTrait;
 use Atk4\Data\Field;
 use Atk4\Data\Model;
 use Atk4\Data\Persistence;
 use Atk4\Data\Types\Types as CustomTypes;
+use Atk4\Ui\App;
+use Atk4\Ui\SessionTrait;
 use Doctrine\DBAL\Types\Types;
 
 /**
  * Implement a generic filter model for filtering column data.
  */
-class FilterModel extends Model
+abstract class FilterModel extends Model
 {
+    use AppScopeTrait; // needed for SessionTrait
     use NameTrait; // needed for SessionTrait
     use SessionTrait;
 
@@ -32,13 +35,20 @@ class FilterModel extends Model
     /** @var Field The field where this filter need to query data. */
     public $lookupField;
 
+    public function __construct(App $app, array $defaults = [])
+    {
+        $this->setApp($app);
+
+        $persistence = new Persistence\Array_();
+
+        parent::__construct($persistence, $defaults);
+    }
+
     /**
      * Factory method that will return a FilterModel Type class.
      */
-    public static function factoryType(Field $field): self
+    public static function factoryType(App $app, Field $field): self
     {
-        $persistence = new Persistence\Array_();
-
         $class = [
             Types::STRING => FilterModel\TypeString::class,
             Types::TEXT => FilterModel\TypeString::class,
@@ -69,7 +79,9 @@ public static function factoryType(Field $field): self
             $class = $field->filterModel;
         }
 
-        return new $class($persistence, ['lookupField' => $field]);
+        $filterModel = new $class($app, ['lookupField' => $field]);
+
+        return $filterModel;
     }
 
     protected function init(): void
@@ -118,10 +130,7 @@ public function recallData(): array
      *
      * @return Model
      */
-    public function setConditionForModel(Model $model)
-    {
-        return $model;
-    }
+    abstract public function setConditionForModel(Model $model);
 
     /**
      * Method that will set Field display condition in a form.
diff --git a/src/Table/Column/FilterPopup.php b/src/Table/Column/FilterPopup.php
index 4229089c36..d58655ceb9 100644
--- a/src/Table/Column/FilterPopup.php
+++ b/src/Table/Column/FilterPopup.php
@@ -38,10 +38,11 @@ class FilterPopup extends Popup
     protected function init(): void
     {
         parent::init();
+
         $this->setOption('delay', ['hide' => 1500]);
         $this->setHoverable();
 
-        $model = FilterModel::factoryType($this->field);
+        $model = FilterModel::factoryType($this->getApp(), $this->field);
         $model = $model->createEntity();
 
         $this->form = Form::addTo($this)->addClass('');
diff --git a/src/Wizard.php b/src/Wizard.php
index f881436b0f..6bab78d541 100644
--- a/src/Wizard.php
+++ b/src/Wizard.php
@@ -11,7 +11,7 @@
  */
 class Wizard extends View
 {
-    use \Atk4\Core\SessionTrait;
+    use SessionTrait;
 
     public $defaultTemplate = 'wizard.html';
     public $ui = 'steps';
diff --git a/tests/SessionTraitTest.php b/tests/SessionTraitTest.php
new file mode 100644
index 0000000000..d3605d3b8c
--- /dev/null
+++ b/tests/SessionTraitTest.php
@@ -0,0 +1,156 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atk4\Ui\Tests;
+
+use Atk4\Core\AppScopeTrait;
+use Atk4\Core\NameTrait;
+use Atk4\Core\Phpunit\TestCase;
+use Atk4\Ui\App;
+use Atk4\Ui\Exception;
+use Atk4\Ui\SessionTrait;
+
+/**
+ * @group require_session
+ * @runTestsInSeparateProcesses
+ */
+class SessionTraitTest extends TestCase
+{
+    /** @var App */
+    protected $app;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->app = new App([
+            'catch_exceptions' => false,
+            'always_run' => false,
+        ]);
+
+        session_abort();
+        $sessionDir = sys_get_temp_dir() . '/atk4_test__ui__session';
+        if (!file_exists($sessionDir)) {
+            mkdir($sessionDir);
+        }
+        ini_set('session.save_path', $sessionDir);
+    }
+
+    protected function tearDown(): void
+    {
+        session_abort();
+        $sessionDir = ini_get('session.save_path');
+        foreach (scandir($sessionDir) as $f) {
+            if (!in_array($f, ['.', '..'], true)) {
+                unlink($sessionDir . '/' . $f);
+            }
+        }
+
+        rmdir($sessionDir);
+
+        parent::tearDown();
+    }
+
+    public function testException1(): void
+    {
+        // when try to start session without NameTrait
+        $this->expectException(Exception::class);
+        $m = new SessionWithoutNameMock($this->app);
+        $m->memorize('test', 'foo');
+    }
+
+    public function testConstructor(): void
+    {
+        $m = new SessionMock($this->app);
+
+        $this->assertFalse(isset($_SESSION));
+        $m->getApp()->session->startSession();
+        $this->assertTrue(isset($_SESSION));
+        $m->getApp()->session->destroySession();
+        $this->assertFalse(isset($_SESSION));
+    }
+
+    /**
+     * Test memorize().
+     */
+    public function testMemorize(): void
+    {
+        $m = new SessionMock($this->app);
+        $m->name = 'test';
+
+        // value as string
+        $m->memorize('foo', 'bar');
+        $this->assertSame('bar', $_SESSION['__atk_session'][$m->name]['foo']);
+
+        // value as null
+        $m->memorize('foo', null);
+        $this->assertNull($_SESSION['__atk_session'][$m->name]['foo']);
+
+        // value as object
+        $o = new \stdClass();
+        $m->memorize('foo', $o);
+        $this->assertSame($o, $_SESSION['__atk_session'][$m->name]['foo']);
+
+        $m->getApp()->session->destroySession();
+    }
+
+    /**
+     * Test learn(), recall(), forget().
+     */
+    public function testLearnRecallForget(): void
+    {
+        $m = new SessionMock($this->app);
+        $m->name = 'test';
+
+        // value as string
+        $m->learn('foo', 'bar');
+        $this->assertSame('bar', $m->recall('foo'));
+
+        $m->learn('foo', 'qwerty');
+        $this->assertSame('bar', $m->recall('foo'));
+
+        $m->forget('foo');
+        $this->assertSame('undefined', $m->recall('foo', 'undefined'));
+
+        // value as callback
+        $m->learn('foo', function ($key) {
+            return $key . '_bar';
+        });
+        $this->assertSame('foo_bar', $m->recall('foo'));
+
+        $m->learn('foo_2', 'another');
+        $this->assertSame('another', $m->recall('foo_2'));
+
+        $v = $m->recall('foo_3', function ($key) {
+            return $key . '_bar';
+        });
+        $this->assertSame('foo_3_bar', $v);
+        $this->assertSame('undefined', $m->recall('foo_3', 'undefined'));
+
+        $m->forget();
+        $this->assertSame('undefined', $m->recall('foo', 'undefined'));
+        $this->assertSame('undefined', $m->recall('foo_2', 'undefined'));
+        $this->assertSame('undefined', $m->recall('foo_3', 'undefined'));
+    }
+}
+
+abstract class SessionAbstractMock
+{
+    use AppScopeTrait;
+    use SessionTrait;
+
+    public function __construct(App $app)
+    {
+        $this->setApp($app);
+    }
+}
+
+class SessionMock extends SessionAbstractMock
+{
+    use NameTrait;
+}
+
+class SessionWithoutNameMock extends SessionAbstractMock
+{
+}