diff --git a/Classes/Controller/GenericModelController.php b/Classes/Controller/GenericModelController.php
index b109fd3..1a453df 100644
--- a/Classes/Controller/GenericModelController.php
+++ b/Classes/Controller/GenericModelController.php
@@ -37,6 +37,7 @@
 use Netlogix\JsonApiOrg\AnnotationGenerics\Domain\Model\GenericModelInterface;
 use Netlogix\JsonApiOrg\AnnotationGenerics\Domain\Model\ReadModelInterface;
 use Netlogix\JsonApiOrg\AnnotationGenerics\Domain\Model\WriteModelInterface;
+use Netlogix\JsonApiOrg\AnnotationGenerics\Domain\Repository\ModelCompanion;
 use Netlogix\JsonApiOrg\AnnotationGenerics\Domain\Repository\GenericModelRepositoryInterface;
 use Netlogix\JsonApiOrg\AnnotationGenerics\Resource\Information\ExposableTypeMap;
 use Netlogix\JsonApiOrg\Controller\ApiController;
@@ -310,18 +311,11 @@ protected function getRepositoryForResourceType(
             ->exposableTypeMap
             ->getExposableTypeByTypeName($resourceType, $apiVersion)
             ->className;
-        $parentClasses = array_merge([$class], class_parents($class));
-        foreach ($parentClasses as $modelCandidate) {
-            $repositoryCandidate = str_replace(
-                    '\\Domain\\Model\\',
-                    '\\Domain\\Repository\\',
-                    $modelCandidate
-                ) . 'Repository';
-            if (class_exists($repositoryCandidate)) {
-                return $this->objectManager->get($repositoryCandidate);
-            }
+        $repositoryClassName = ModelCompanion::forModel($class)->repositoryClassName;
+        if ($repositoryClassName === null) {
+            throw new UnknownObjectException('No Repository found for class "' . $class . '".', 1264589155);
         }
-        throw new UnknownObjectException('No Repository found for class "' . $class . '".', 1264589155);
+        return $this->objectManager->get($repositoryClassName);
     }
 
     /**
@@ -375,6 +369,8 @@ protected function remapActionArguments()
             )
             : null;
 
+        $companion = ModelCompanion::forModel($relationshipClassName ?: $exposableType->className);
+
         $this->remapActionArgument(
             $this->resourceArgumentName,
             $exposableType->className
@@ -382,31 +378,23 @@ protected function remapActionArguments()
 
         $this->remapActionArgument(
             'sort',
-            str_replace(
-                '\\Model\\',
-                '\\Repository\\Sorting\\',
-                $relationshipClassName ?: $exposableType->className
-            ) . 'Sorting'
+            $companion->sortingClassName
         );
 
         $this->remapActionArgument(
             'filter',
-            str_replace(
-                '\\Model\\',
-                '\\Repository\\Filter\\',
-                $relationshipClassName ?: $exposableType->className
-            ) . 'Filter',
+            $companion->filterClassName,
             []
         );
     }
 
-    protected function remapActionArgument(string $argumentName, string $modelClassName, $default = null)
+    protected function remapActionArgument(string $argumentName, ?string $modelClassName, $default = null)
     {
         if (!$this->arguments->hasArgument($argumentName)) {
             return;
         }
 
-        if (false === class_exists($modelClassName)) {
+        if ($modelClassName === null || false === class_exists($modelClassName)) {
             return;
         }
 
diff --git a/Classes/Domain/Repository/ModelCompanion.php b/Classes/Domain/Repository/ModelCompanion.php
new file mode 100644
index 0000000..424a1a3
--- /dev/null
+++ b/Classes/Domain/Repository/ModelCompanion.php
@@ -0,0 +1,86 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Netlogix\JsonApiOrg\AnnotationGenerics\Domain\Repository;
+
+/*
+ * This file is part of the Netlogix.JsonApiOrg.AnnotationGenerics package.
+ *
+ * This package is Open Source Software. For the full copyright and license
+ * information, please view the LICENSE file which was distributed with this
+ * source code.
+ */
+
+use Neos\Flow\Annotations as Flow;
+use function array_values;
+use function class_exists;
+use function class_parents;
+use function str_replace;
+
+/**
+ * Resolves the conventional companion classes of a Domain\Model class:
+ * its Filter, Sorting and Repository. The named constructor checks whether
+ * each companion actually exists; the readonly properties hold the existing
+ * class name or null.
+ *
+ * Usage: ModelCompanion::forModel($modelClassName)->sortingClassName
+ */
+#[Flow\Proxy(false)]
+final class ModelCompanion
+{
+    protected function __construct(
+        /**
+         * @var class-string
+         */
+        public readonly string  $modelClassName,
+        /**
+         * @var class-string
+         */
+        public readonly ?string $filterClassName,
+        /**
+         * @var class-string
+         */
+        public readonly ?string $sortingClassName,
+        /**
+         * @var class-string
+         */
+        public readonly ?string $repositoryClassName,
+    )
+    {
+    }
+
+    /**
+     * @param class-string $modelClassName
+     * @return self
+     */
+    public static function forModel(string $modelClassName): self
+    {
+        $filterClassName = str_replace('\\Model\\', '\\Repository\\Filter\\', $modelClassName) . 'Filter';
+        $sortingClassName = str_replace('\\Model\\', '\\Repository\\Sorting\\', $modelClassName) . 'Sorting';
+
+        return new self(
+            modelClassName: $modelClassName,
+            filterClassName: class_exists($filterClassName) ? $filterClassName : null,
+            sortingClassName: class_exists($sortingClassName) ? $sortingClassName : null,
+            repositoryClassName: self::resolveRepositoryClassName($modelClassName),
+        );
+    }
+
+    /**
+     * The Repository is looked up on the model class and its parent classes,
+     * mirroring GenericModelController::getRepositoryForResourceType().
+     */
+    private static function resolveRepositoryClassName(string $modelClassName): ?string
+    {
+        $modelClassNames = array_values(class_parents($modelClassName) ?: []);
+        foreach ([$modelClassName, ... $modelClassNames] as $candidate) {
+            $repositoryClassName = str_replace('\\Domain\\Model\\', '\\Domain\\Repository\\', $candidate) . 'Repository';
+            if (class_exists($repositoryClassName)) {
+                return $repositoryClassName;
+            }
+        }
+
+        return null;
+    }
+}
diff --git a/Classes/Domain/Resource/GenericModelResourceInformation.php b/Classes/Domain/Resource/GenericModelResourceInformation.php
index f357be5..74e5dad 100644
--- a/Classes/Domain/Resource/GenericModelResourceInformation.php
+++ b/Classes/Domain/Resource/GenericModelResourceInformation.php
@@ -42,7 +42,7 @@ class GenericModelResourceInformation extends ResourceInformation implements Res
                                                                              LinksAwareResourceInformationInterface,
                                                                              MetaAwareResourceInformationInterface
 {
-    private const TYPE_NAME_PATTERN = '%^(?<subPackage>[^/]+)/(?<resourceType>.+)$%';
+    public const TYPE_NAME_PATTERN = '%^(?<subPackage>[^/]+)/(?<resourceType>.+)$%';
 
     /**
      * @var int
diff --git a/Classes/Resource/Information/ExposableTypeMap.php b/Classes/Resource/Information/ExposableTypeMap.php
index d226257..4450c40 100644
--- a/Classes/Resource/Information/ExposableTypeMap.php
+++ b/Classes/Resource/Information/ExposableTypeMap.php
@@ -56,6 +56,14 @@ class ExposableTypeMap extends BaseExposableTypeMap implements ExposableTypeMapI
      */
     protected $exposableTypeMapCache;
 
+    /**
+     * Property names in their original case, mapped to their resolved PHP
+     * type string, e.g. 'string' or 'array<Vendor\Package\Domain\Model\Foo>'.
+     *
+     * @var array<string, array<string, string>>
+     */
+    private array $propertyTypesByClassName = [];
+
     /**
      * All "ExposeType" objects are initialized automatically
      */
@@ -78,7 +86,7 @@ public function initializeObject()
             $exposableType = $this->getExposableTypeByClassIdentifier($className);
             foreach ($properties as $propertyName => $propertyVarType) {
                 try {
-                    $this->registerKnownPropertyType(
+                    $this->propertyTypesByClassName[$className][$propertyName] = $this->registerKnownPropertyType(
                         exposableType: $exposableType,
                         propertyName: $propertyName,
                         varType: $propertyVarType
@@ -97,7 +105,7 @@ public function initializeObject()
             $exposableType = $this->getExposableTypeByClassIdentifier($className);
             foreach ($methods as $methodName => $methodVarType) {
                 try {
-                    $this->registerKnownPropertyType(
+                    $this->propertyTypesByClassName[$className][$methodName] = $this->registerKnownPropertyType(
                         exposableType: $exposableType,
                         propertyName: $methodName,
                         varType: $methodVarType
@@ -113,7 +121,19 @@ public function initializeObject()
         }
     }
 
-    protected function registerKnownPropertyType(ExposableType $exposableType, string $propertyName, string $varType)
+    /**
+     * Public property names (original case) of the given exposed class,
+     * mapped to their resolved PHP type string, e.g. 'string' or
+     * 'array<Vendor\Package\Domain\Model\Foo>'.
+     *
+     * @return array<string, string>
+     */
+    public function getPropertyTypes(string $className): array
+    {
+        return $this->propertyTypesByClassName[$className] ?? [];
+    }
+
+    protected function registerKnownPropertyType(ExposableType $exposableType, string $propertyName, string $varType): string
     {
         $varType = TypeHandling::parseType($varType);
         $isCollection = (bool) $varType['elementType'];
@@ -121,6 +141,7 @@ protected function registerKnownPropertyType(ExposableType $exposableType, strin
 
         $propertyType = $isCollection ? 'array<' . $elementType . '>' : $elementType;
         $this->registerExposableTypeProperty($exposableType, strtolower($propertyName), $propertyType);
+        return $propertyType;
     }
 
     protected static function guessTypeNameFromClassName(PackageManager $packageManager, string $className): string