diff --git a/migrations/Version20260310211017.php b/migrations/Version20260310211017.php
new file mode 100644
index 0000000..c918883
--- /dev/null
+++ b/migrations/Version20260310211017.php
@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * Auto-generated Migration: Please modify to your needs!
+ */
+final class Version20260310211017 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return '';
+    }
+
+    public function up(Schema $schema): void
+    {
+        // this up() migration is auto-generated, please modify it to your needs
+        $this->addSql('CREATE TABLE time_entry (id INT GENERATED BY DEFAULT AS IDENTITY NOT NULL, title VARCHAR(255) DEFAULT NULL, description TEXT DEFAULT NULL, started_at TIMESTAMP(0) WITH TIME ZONE NOT NULL, stopped_at TIMESTAMP(0) WITH TIME ZONE DEFAULT NULL, user_id INT NOT NULL, project_id INT DEFAULT NULL, task_id INT DEFAULT NULL, PRIMARY KEY (id))');
+        $this->addSql('CREATE INDEX IDX_6E537C0CA76ED395 ON time_entry (user_id)');
+        $this->addSql('CREATE INDEX IDX_6E537C0C166D1F9C ON time_entry (project_id)');
+        $this->addSql('CREATE INDEX IDX_6E537C0C8DB60186 ON time_entry (task_id)');
+        $this->addSql('CREATE UNIQUE INDEX uniq_active_timer ON time_entry (user_id) WHERE (stopped_at IS NULL)');
+        $this->addSql('CREATE TABLE time_entry_task_type (time_entry_id INT NOT NULL, task_type_id INT NOT NULL, PRIMARY KEY (time_entry_id, task_type_id))');
+        $this->addSql('CREATE INDEX IDX_BE7A719D1EB30A8E ON time_entry_task_type (time_entry_id)');
+        $this->addSql('CREATE INDEX IDX_BE7A719DDAADA679 ON time_entry_task_type (task_type_id)');
+        $this->addSql('ALTER TABLE time_entry ADD CONSTRAINT FK_6E537C0CA76ED395 FOREIGN KEY (user_id) REFERENCES "user" (id) ON DELETE CASCADE NOT DEFERRABLE');
+        $this->addSql('ALTER TABLE time_entry ADD CONSTRAINT FK_6E537C0C166D1F9C FOREIGN KEY (project_id) REFERENCES project (id) ON DELETE SET NULL NOT DEFERRABLE');
+        $this->addSql('ALTER TABLE time_entry ADD CONSTRAINT FK_6E537C0C8DB60186 FOREIGN KEY (task_id) REFERENCES task (id) ON DELETE SET NULL NOT DEFERRABLE');
+        $this->addSql('ALTER TABLE time_entry_task_type ADD CONSTRAINT FK_BE7A719D1EB30A8E FOREIGN KEY (time_entry_id) REFERENCES time_entry (id) ON DELETE CASCADE');
+        $this->addSql('ALTER TABLE time_entry_task_type ADD CONSTRAINT FK_BE7A719DDAADA679 FOREIGN KEY (task_type_id) REFERENCES task_type (id) ON DELETE CASCADE');
+    }
+
+    public function down(Schema $schema): void
+    {
+        // this down() migration is auto-generated, please modify it to your needs
+        $this->addSql('ALTER TABLE time_entry DROP CONSTRAINT FK_6E537C0CA76ED395');
+        $this->addSql('ALTER TABLE time_entry DROP CONSTRAINT FK_6E537C0C166D1F9C');
+        $this->addSql('ALTER TABLE time_entry DROP CONSTRAINT FK_6E537C0C8DB60186');
+        $this->addSql('ALTER TABLE time_entry_task_type DROP CONSTRAINT FK_BE7A719D1EB30A8E');
+        $this->addSql('ALTER TABLE time_entry_task_type DROP CONSTRAINT FK_BE7A719DDAADA679');
+        $this->addSql('DROP TABLE time_entry');
+        $this->addSql('DROP TABLE time_entry_task_type');
+    }
+}
diff --git a/src/Entity/TimeEntry.php b/src/Entity/TimeEntry.php
new file mode 100644
index 0000000..5852b0e
--- /dev/null
+++ b/src/Entity/TimeEntry.php
@@ -0,0 +1,206 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Entity;
+
+use ApiPlatform\Doctrine\Orm\Filter\DateFilter;
+use ApiPlatform\Doctrine\Orm\Filter\SearchFilter;
+use ApiPlatform\Metadata\ApiFilter;
+use ApiPlatform\Metadata\ApiResource;
+use ApiPlatform\Metadata\Delete;
+use ApiPlatform\Metadata\Get;
+use ApiPlatform\Metadata\GetCollection;
+use ApiPlatform\Metadata\Patch;
+use ApiPlatform\Metadata\Post;
+use App\Repository\TimeEntryRepository;
+use App\State\ActiveTimeEntryProvider;
+use DateTimeImmutable;
+use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
+use Doctrine\DBAL\Types\Types;
+use Doctrine\ORM\Mapping as ORM;
+use Symfony\Component\Serializer\Attribute\Groups;
+
+#[ApiResource(
+    operations: [
+        new GetCollection(),
+        new Get(),
+        new Get(
+            uriTemplate: '/time_entries/active',
+            provider: ActiveTimeEntryProvider::class,
+            description: 'Get the active timer for the current user',
+        ),
+        new Post(security: "is_granted('ROLE_USER')"),
+        new Patch(security: "is_granted('ROLE_ADMIN') or object.getUser() == user"),
+        new Delete(security: "is_granted('ROLE_ADMIN') or object.getUser() == user"),
+    ],
+    normalizationContext: ['groups' => ['time_entry:read']],
+    denormalizationContext: ['groups' => ['time_entry:write']],
+    order: ['startedAt' => 'DESC'],
+)]
+#[ApiFilter(SearchFilter::class, properties: ['user' => 'exact', 'project' => 'exact', 'types' => 'exact'])]
+#[ApiFilter(DateFilter::class, properties: ['startedAt'])]
+#[ORM\Entity(repositoryClass: TimeEntryRepository::class)]
+#[ORM\UniqueConstraint(name: 'uniq_active_timer', columns: ['user_id'], options: ['where' => '(stopped_at IS NULL)'])]
+class TimeEntry
+{
+    #[ORM\Id]
+    #[ORM\GeneratedValue]
+    #[ORM\Column]
+    #[Groups(['time_entry:read'])]
+    private ?int $id = null;
+
+    #[ORM\Column(length: 255, nullable: true)]
+    #[Groups(['time_entry:read', 'time_entry:write'])]
+    private ?string $title = null;
+
+    #[ORM\Column(type: Types::TEXT, nullable: true)]
+    #[Groups(['time_entry:read', 'time_entry:write'])]
+    private ?string $description = null;
+
+    #[ORM\Column(type: Types::DATETIMETZ_IMMUTABLE)]
+    #[Groups(['time_entry:read', 'time_entry:write'])]
+    private ?DateTimeImmutable $startedAt = null;
+
+    #[ORM\Column(type: Types::DATETIMETZ_IMMUTABLE, nullable: true)]
+    #[Groups(['time_entry:read', 'time_entry:write'])]
+    private ?DateTimeImmutable $stoppedAt = null;
+
+    #[ORM\ManyToOne(targetEntity: User::class)]
+    #[ORM\JoinColumn(nullable: false, onDelete: 'CASCADE')]
+    #[Groups(['time_entry:read', 'time_entry:write'])]
+    private ?User $user = null;
+
+    #[ORM\ManyToOne(targetEntity: Project::class)]
+    #[ORM\JoinColumn(nullable: true, onDelete: 'SET NULL')]
+    #[Groups(['time_entry:read', 'time_entry:write'])]
+    private ?Project $project = null;
+
+    #[ORM\ManyToOne(targetEntity: Task::class)]
+    #[ORM\JoinColumn(nullable: true, onDelete: 'SET NULL')]
+    #[Groups(['time_entry:read', 'time_entry:write'])]
+    private ?Task $task = null;
+
+    /** @var Collection<int, TaskType> */
+    #[ORM\ManyToMany(targetEntity: TaskType::class)]
+    #[ORM\JoinTable(name: 'time_entry_task_type')]
+    #[Groups(['time_entry:read', 'time_entry:write'])]
+    private Collection $types;
+
+    public function __construct()
+    {
+        $this->types = new ArrayCollection();
+    }
+
+    public function getId(): ?int
+    {
+        return $this->id;
+    }
+
+    public function getTitle(): ?string
+    {
+        return $this->title;
+    }
+
+    public function setTitle(?string $title): static
+    {
+        $this->title = $title;
+
+        return $this;
+    }
+
+    public function getDescription(): ?string
+    {
+        return $this->description;
+    }
+
+    public function setDescription(?string $description): static
+    {
+        $this->description = $description;
+
+        return $this;
+    }
+
+    public function getStartedAt(): ?DateTimeImmutable
+    {
+        return $this->startedAt;
+    }
+
+    public function setStartedAt(DateTimeImmutable $startedAt): static
+    {
+        $this->startedAt = $startedAt;
+
+        return $this;
+    }
+
+    public function getStoppedAt(): ?DateTimeImmutable
+    {
+        return $this->stoppedAt;
+    }
+
+    public function setStoppedAt(?DateTimeImmutable $stoppedAt): static
+    {
+        $this->stoppedAt = $stoppedAt;
+
+        return $this;
+    }
+
+    public function getUser(): ?User
+    {
+        return $this->user;
+    }
+
+    public function setUser(?User $user): static
+    {
+        $this->user = $user;
+
+        return $this;
+    }
+
+    public function getProject(): ?Project
+    {
+        return $this->project;
+    }
+
+    public function setProject(?Project $project): static
+    {
+        $this->project = $project;
+
+        return $this;
+    }
+
+    public function getTask(): ?Task
+    {
+        return $this->task;
+    }
+
+    public function setTask(?Task $task): static
+    {
+        $this->task = $task;
+
+        return $this;
+    }
+
+    /** @return Collection<int, TaskType> */
+    public function getTypes(): Collection
+    {
+        return $this->types;
+    }
+
+    public function addType(TaskType $type): static
+    {
+        if (!$this->types->contains($type)) {
+            $this->types->add($type);
+        }
+
+        return $this;
+    }
+
+    public function removeType(TaskType $type): static
+    {
+        $this->types->removeElement($type);
+
+        return $this;
+    }
+}
diff --git a/src/Repository/TimeEntryRepository.php b/src/Repository/TimeEntryRepository.php
new file mode 100644
index 0000000..5e7bcf9
--- /dev/null
+++ b/src/Repository/TimeEntryRepository.php
@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Repository;
+
+use App\Entity\TimeEntry;
+use App\Entity\User;
+use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepository;
+use Doctrine\Persistence\ManagerRegistry;
+
+/**
+ * @extends ServiceEntityRepository<TimeEntry>
+ */
+class TimeEntryRepository extends ServiceEntityRepository
+{
+    public function __construct(ManagerRegistry $registry)
+    {
+        parent::__construct($registry, TimeEntry::class);
+    }
+
+    public function findActiveByUser(User $user): ?TimeEntry
+    {
+        return $this->findOneBy([
+            'user'      => $user,
+            'stoppedAt' => null,
+        ]);
+    }
+}