Part of https://medium.com/@titouanbenoit/internationalization-with-api-platform-the-other-way-5ce9c446737f

Company.php

<?php

namespace App\Entity;

use ApiPlatform\Core\Annotation\ApiResource;
use ApiPlatform\Core\Annotation\ApiSubresource;
use Doctrine\ORM\Mapping as ORM;
use Gedmo\Mapping\Annotation as Gedmo;
use Symfony\Component\Validator\Constraints as Assert;
use Symfony\Component\Serializer\Annotation\MaxDepth;
use Symfony\Component\Serializer\Annotation\Groups;
use Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity;

/**
 * @ApiResource()
 * @ORM\Entity()
 * @ORM\Table(name="company")
 * @Gedmo\TranslationEntity(class="App\Entity\Translation\CompanyTranslation")
 * @UniqueEntity("name")
 */
class Company
{

    /**
     * @var int
     *
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     * @Groups({"out"})
     */
    private $id;

    /**
     * @var string
     *
     * @Assert\NotBlank()
     * @ORM\Column(type="string", unique=true)
     * @Groups({"out", "in", "recruiter_in"})
     */
    private $name;

    /**
     * @var string
     *
     * @Gedmo\Translatable
     * @ORM\Column(type="text", nullable=true)
     * @Groups({"out", "in", "recruiter_in"})
     */
    private $description;

    /**
     * @var string
     *
     * @Gedmo\Translatable
     * @ORM\Column(type="string", nullable=true)
     * @Groups({"out", "in", "recruiter_in"})
     */
    private $catchPhrase;

    /**
     * @var string
     *
     * @ORM\Column(type="string", nullable=false)
     * @Gedmo\Slug(fields={"name"})
     * @Groups({"out"})
     */
    private $slug;

    /**
     * @var Locale
     *
     * @Gedmo\Locale
     */
    private $locale;

    public function __toString()
    {
        return $this->name;
    }

    ............. SETTERS/GETTERS..................
}