diff --git a/config/api_platform/CommandGroup.yaml b/config/api_platform/CommandGroup.yaml
index 6e0cda9..40ede0b 100644
--- a/config/api_platform/CommandGroup.yaml
+++ b/config/api_platform/CommandGroup.yaml
@@ -24,6 +24,13 @@ resources:
             ApiPlatform\Metadata\Post: ~
             ApiPlatform\Metadata\Delete: ~
 
+            add_commands:
+                class: ApiPlatform\Metadata\Post
+                method: POST
+                input: App\Dto\Input\CommandGroupAddCommandsInput
+                uriTemplate: /command-groups/{uuid}/add-commands
+                controller: App\Controller\CommandGroupAddCommandsAction
+
 properties:
     App\Entity\CommandGroup:
         id:
diff --git a/src/Controller/CommandGroupAddCommandsAction.php b/src/Controller/CommandGroupAddCommandsAction.php
new file mode 100644
index 0000000..e779057
--- /dev/null
+++ b/src/Controller/CommandGroupAddCommandsAction.php
@@ -0,0 +1,35 @@
+<?php
+
+namespace App\Controller;
+
+use App\Dto\Input\CommandGroupAddCommandsInput;
+use App\Entity\Command;
+use App\Entity\CommandGroup;
+use Doctrine\ORM\EntityManagerInterface;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\JsonResponse;
+use Symfony\Component\HttpFoundation\Response;
+
+class CommandGroupAddCommandsAction extends AbstractController
+{
+    public function __construct(
+        private readonly EntityManagerInterface $entityManager
+    )
+    {
+    }
+
+    public function __invoke(CommandGroupAddCommandsInput $input, CommandGroup $commandGroup): JsonResponse
+    {
+        $commands = $input->commands;
+
+        /** @var Command $command */
+        foreach ($commands as $command) {
+            $commandGroup->addCommand($command->getEntity());
+        }
+
+        $this->entityManager->persist($commandGroup);
+        $this->entityManager->flush();
+
+        return new JsonResponse(data: 'Commands added to command group successfully', status: Response::HTTP_OK);
+    }
+}
\ No newline at end of file
diff --git a/src/Dto/Input/CommandGroupAddCommandsInput.php b/src/Dto/Input/CommandGroupAddCommandsInput.php
new file mode 100644
index 0000000..2b14a7b
--- /dev/null
+++ b/src/Dto/Input/CommandGroupAddCommandsInput.php
@@ -0,0 +1,17 @@
+<?php
+
+namespace App\Dto\Input;
+
+use App\Dto\Output\CommandOutput;
+use Symfony\Component\Serializer\Annotation\Groups;
+use Symfony\Component\Validator\Constraints as Assert;
+
+final class CommandGroupAddCommandsInput
+{
+    /**
+     * @var CommandOutput[]
+     */
+    #[Assert\NotNull]
+    #[Groups(['command-group:write'])]
+    public array $commands = [];
+}
\ No newline at end of file
diff --git a/src/State/Provider/CommandGroupProvider.php b/src/State/Provider/CommandGroupProvider.php
index c3092db..767d0cc 100644
--- a/src/State/Provider/CommandGroupProvider.php
+++ b/src/State/Provider/CommandGroupProvider.php
@@ -36,7 +36,7 @@ readonly class CommandGroupProvider implements ProviderInterface
         }
     }
 
-    private function provideCollection(Operation $operation, array $uriVariables = [], array $context = []): object
+    private function provideCollection(Operation $operation, array $uriVariables = [], array $context = []): object|array|null
     {
         $paginator = $this->collectionProvider->provide($operation, $uriVariables, $context);