diff --git a/src/Bundle/ChillMainBundle/CRUD/Controller/ApiController.php b/src/Bundle/ChillMainBundle/CRUD/Controller/ApiController.php
index 1d00a2a1a..1c1341aa9 100644
--- a/src/Bundle/ChillMainBundle/CRUD/Controller/ApiController.php
+++ b/src/Bundle/ChillMainBundle/CRUD/Controller/ApiController.php
@@ -138,7 +138,12 @@ class ApiController extends AbstractCRUDController
             return $response;
         }
 
-        return $this->json($entity);
+        return $this->json(
+            $entity,
+            Response::HTTP_OK,
+            [], 
+            $this->getContextForSerializationPostAlter($action, $request, $_format, $entity)
+        );
     }
 
     protected function onAfterValidation(string $action, Request $request, string $_format, $entity, ConstraintViolationListInterface $errors): ?Response
@@ -276,7 +281,26 @@ class ApiController extends AbstractCRUDController
 
     protected function getContextForSerialization(string $action, Request $request, string $_format, $entity): array
     {
-        return [];
+        switch ($request->getMethod()) {
+            case Request::METHOD_GET:
+                return [ 'groups' => [ 'read' ]];
+            case Request::METHOD_PUT:
+            case Request::METHOD_PATCH:
+                return [ 'groups' => [ 'write' ]];
+            default:
+                throw new \LogicException("get context for serialization is not implemented for this method");
+        }
+    }
+
+    /**
+     * Get the context for serialization post alter query (in case of 
+     * PATCH, PUT, or POST method)
+     *
+     * This is called **after** the entity was altered.
+     */
+    protected function getContextForSerializationPostAlter(string $action, Request $request, string $_format, $entity): array
+    {
+        return [ 'groups' => [ 'read' ]];
     }
 
     /**
diff --git a/src/Bundle/ChillPersonBundle/Entity/AccompanyingPeriod.php b/src/Bundle/ChillPersonBundle/Entity/AccompanyingPeriod.php
index 1a6a3faae..2ff24cfb7 100644
--- a/src/Bundle/ChillPersonBundle/Entity/AccompanyingPeriod.php
+++ b/src/Bundle/ChillPersonBundle/Entity/AccompanyingPeriod.php
@@ -33,6 +33,7 @@ use Doctrine\Common\Collections\Collection;
 use Doctrine\ORM\Mapping as ORM;
 use Symfony\Component\Validator\Context\ExecutionContextInterface;
 use Chill\MainBundle\Entity\User;
+use Symfony\Component\Serializer\Annotation\Groups;
 
 /**
  * AccompanyingPeriod Class
@@ -80,6 +81,7 @@ class AccompanyingPeriod
      * @ORM\Id
      * @ORM\Column(name="id", type="integer")
      * @ORM\GeneratedValue(strategy="AUTO")
+     * @Groups({"read"})
      */
     private $id;
 
@@ -87,6 +89,7 @@ class AccompanyingPeriod
      * @var \DateTime
      *
      * @ORM\Column(type="date")
+     * @Groups({"read", "write"})
      */
     private $openingDate;
 
@@ -94,6 +97,7 @@ class AccompanyingPeriod
      * @var \DateTime
      *
      * @ORM\Column(type="date", nullable=true)
+     * @Groups({"read", "write"})
      */
     private $closingDate = null;
 
@@ -101,6 +105,7 @@ class AccompanyingPeriod
      * @var string
      *
      * @ORM\Column(type="text")
+     * @Groups({"read", "write"})
      */
     private $remark = '';
 
@@ -110,6 +115,7 @@ class AccompanyingPeriod
      * @ORM\OneToMany(targetEntity="Chill\PersonBundle\Entity\AccompanyingPeriod\Comment",
      *       mappedBy="accompanyingPeriod"
      *     )
+     * @Groups({"read"})
      */
     private $comments;
 
@@ -119,6 +125,7 @@ class AccompanyingPeriod
      * @ORM\OneToMany(targetEntity=AccompanyingPeriodParticipation::class,
      *     mappedBy="accompanyingPeriod",
      *     cascade={"persist", "refresh", "remove", "merge", "detach"})
+     * @Groups({"read"})
      */
     private $participations;
 
@@ -128,18 +135,21 @@ class AccompanyingPeriod
      * @ORM\ManyToOne(
      *     targetEntity="Chill\PersonBundle\Entity\AccompanyingPeriod\ClosingMotive")
      * @ORM\JoinColumn(nullable=true)
+     * @Groups({"read", "write"})
      */
     private $closingMotive = null;
 
     /**
      * @ORM\ManyToOne(targetEntity=User::class)
      * @ORM\JoinColumn(nullable=true)
+     * @Groups({"read", "write"})
      */
     private $user;
 
     /**
      * @ORM\ManyToOne(targetEntity=User::class)
      * @ORM\JoinColumn(nullable=true)
+     * @Groups({"read"})
      */
     private $createdBy;
 
@@ -152,12 +162,14 @@ class AccompanyingPeriod
     /**
      * @ORM\ManyToOne(targetEntity=Origin::class)
      * @ORM\JoinColumn(nullable=true)
+     * @Groups({"read", "write"})
      */
     private $origin;
 
     /**
      * @var string
      * @ORM\Column(type="string", nullable=true)
+     * @Groups({"read", "write"})
      */
     private $intensity;
 
@@ -172,6 +184,7 @@ class AccompanyingPeriod
      *     joinColumns={@ORM\JoinColumn(name="accompanying_period_id", referencedColumnName="id")},
      *     inverseJoinColumns={@ORM\JoinColumn(name="scope_id", referencedColumnName="id")}
      * )
+     * @Groups({"read"})
      */
     private $scopes;
 
@@ -190,18 +203,21 @@ class AccompanyingPeriod
     /**
      * @var bool
      * @ORM\Column(type="boolean")
+     * @Groups({"read", "write"})
      */
     private $requestorAnonymous = false;
 
     /**
      * @var bool
      * @ORM\Column(type="boolean")
+     * @Groups({"read", "write"})
      */
     private $emergency = false;
 
     /**
      * @var bool
      * @ORM\Column(type="boolean")
+     * @Groups({"read", "write"})
      */
     private $confidential = false;
 
@@ -212,6 +228,7 @@ class AccompanyingPeriod
      *     targetEntity="Chill\PersonBundle\Entity\AccompanyingPeriod\Resource",
      *     mappedBy="accompanyingPeriod"
      * )
+     * @Groups({"read"})
      */
     private $resources;
 
@@ -536,6 +553,7 @@ class AccompanyingPeriod
 
     /**
      * @return Person|ThirdParty
+     * @Groups({"read"})
      */
     public function getRequestor()
     {
diff --git a/src/Bundle/ChillPersonBundle/Entity/AccompanyingPeriod/Origin.php b/src/Bundle/ChillPersonBundle/Entity/AccompanyingPeriod/Origin.php
index 55857de4c..442c129eb 100644
--- a/src/Bundle/ChillPersonBundle/Entity/AccompanyingPeriod/Origin.php
+++ b/src/Bundle/ChillPersonBundle/Entity/AccompanyingPeriod/Origin.php
@@ -24,6 +24,7 @@ namespace Chill\PersonBundle\Entity\AccompanyingPeriod;
 
 use Chill\PersonBundle\Repository\AccompanyingPeriod\OriginRepository;
 use Doctrine\ORM\Mapping as ORM;
+use Symfony\Component\Serializer\Annotation\Groups;
 
 /**
  * @ORM\Entity(repositoryClass=OriginRepository::class)
@@ -35,16 +36,19 @@ class Origin
      * @ORM\Id
      * @ORM\GeneratedValue
      * @ORM\Column(type="integer")
+     * @Groups({"read"})
      */
     private $id;
 
     /**
      * @ORM\Column(type="json")
+     * @Groups({"read"})
      */
     private $label;
 
     /**
      * @ORM\Column(type="date_immutable", nullable=true)
+     * @Groups({"read"})
      */
     private $noActiveAfter;
 
diff --git a/src/Bundle/ChillPersonBundle/Serializer/Normalizer/AccompanyingPeriodNormalizer.php b/src/Bundle/ChillPersonBundle/Serializer/Normalizer/AccompanyingPeriodNormalizer.php
deleted file mode 100644
index b76cd1b4e..000000000
--- a/src/Bundle/ChillPersonBundle/Serializer/Normalizer/AccompanyingPeriodNormalizer.php
+++ /dev/null
@@ -1,61 +0,0 @@
-<?php
-/*
- *
- * Copyright (C) 2014-2021, Champs Libres Cooperative SCRLFS, <http://www.champs-libres.coop>
- *
- * This program is free software: you can redistribute it and/or modify
- *  it under the terms of the GNU Affero General Public License as
- * published by the Free Software Foundation, either version 3 of the
- *  License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-namespace Chill\PersonBundle\Serializer\Normalizer;
-
-use Chill\PersonBundle\Entity\AccompanyingPeriod;
-use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
-use Symfony\Component\Serializer\Normalizer\NormalizerAwareInterface;
-use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
-
-
-class AccompanyingPeriodNormalizer implements NormalizerInterface, NormalizerAwareInterface {
-
-    protected ?NormalizerInterface $normalizer = null;
-
-    public function normalize($period, string $format = null, array $context = array())
-    {
-        /** @var AccompanyingPeriod $period */
-        return [
-            'id' => $period->getId(),
-            'openingDate' => $this->normalizer->normalize($period->getOpeningDate(), $format),
-            'closingDate' => $this->normalizer->normalize($period->getClosingDate(), $format),
-            'remark' => $period->getRemark(),
-            'participations' => $this->normalizer->normalize($period->getParticipations(), $format),
-            'closingMotive' => $this->normalizer->normalize($period->getClosingMotive(), $format),
-            'requestor' => $this->normalizer->normalize($period->getRequestor(), $format),
-            'requestorAnonymous' => $this->normalizer->normalize($period->isRequestorAnonymous(), $format),
-            'user' => $this->normalizer->normalize($period->getUser(), $format),
-            'step' => $period->getStep(),
-            'origin' => $this->normalizer->normalize($period->getOrigin(), $format),
-            'intensity' => $period->getIntensity(),
-            'emergency' => $period->isEmergency(),
-            'confidential' => $period->isConfidential()
-        ];
-    }
-
-    public function supportsNormalization($data, string $format = null): bool
-    {
-        return $data instanceof AccompanyingPeriod;
-    }
-
-    public function setNormalizer(NormalizerInterface $normalizer)
-    {
-        $this->normalizer = $normalizer;
-    }
-}
diff --git a/src/Bundle/ChillPersonBundle/config/services/serializer.yaml b/src/Bundle/ChillPersonBundle/config/services/serializer.yaml
index 843c984f8..0925cc2ed 100644
--- a/src/Bundle/ChillPersonBundle/config/services/serializer.yaml
+++ b/src/Bundle/ChillPersonBundle/config/services/serializer.yaml
@@ -7,10 +7,6 @@ services:
         tags:
             - { name: 'serializer.normalizer', priority: 64 }
 
-    Chill\PersonBundle\Serializer\Normalizer\AccompanyingPeriodNormalizer:
-        tags:
-            - { name: 'serializer.normalizer', priority: 64 }
-
     Chill\PersonBundle\Serializer\Normalizer\AccompanyingPeriodParticipationNormalizer:
         tags:
             - { name: 'serializer.normalizer', priority: 64 }