diff --git a/src/ApiResource/BovineSyncInventoryResult.php b/src/ApiResource/BovineSyncInventoryResult.php
new file mode 100644
index 0000000..adf32ad
--- /dev/null
+++ b/src/ApiResource/BovineSyncInventoryResult.php
@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\ApiResource;
+
+use ApiPlatform\Metadata\ApiProperty;
+use ApiPlatform\Metadata\ApiResource;
+use ApiPlatform\Metadata\Post;
+use ApiPlatform\OpenApi\Model\Operation as OpenApiOperation;
+use App\State\Bovin\BovineSyncInventoryProcessor;
+
+#[ApiResource(
+    operations: [
+        new Post(
+            uriTemplate: '/bovines/sync-inventory',
+            openapi: new OpenApiOperation(
+                summary: "Synchronise l'inventaire bovin local avec EDNOTIF.",
+                description: 'Upsert des bovins par numéro national ; marque comme sortis ceux absents de la réponse EDNOTIF.',
+                tags: ['Bovines'],
+            ),
+            security: "is_granted('ROLE_ADMIN')",
+            input: false,
+            output: self::class,
+            processor: BovineSyncInventoryProcessor::class,
+            read: false,
+        ),
+    ]
+)]
+final class BovineSyncInventoryResult
+{
+    #[ApiProperty(identifier: true)]
+    public string $id = 'current';
+
+    public int $created = 0;
+
+    public int $updated = 0;
+
+    public int $exited = 0;
+
+    public int $total = 0;
+}
diff --git a/src/State/Bovin/BovineSyncInventoryProcessor.php b/src/State/Bovin/BovineSyncInventoryProcessor.php
new file mode 100644
index 0000000..214abc9
--- /dev/null
+++ b/src/State/Bovin/BovineSyncInventoryProcessor.php
@@ -0,0 +1,99 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\State\Bovin;
+
+use ApiPlatform\Metadata\Operation;
+use ApiPlatform\State\ProcessorInterface;
+use App\ApiResource\BovineSyncInventoryResult;
+use App\Entity\Bovine;
+use DateTimeImmutable;
+use Doctrine\ORM\EntityManagerInterface;
+use Malio\EdnotifBundle\Bovin\Api\BovinApiInterface;
+use Malio\EdnotifBundle\Bovin\Dto\AnimalSummaryDto;
+
+/**
+ * @implements ProcessorInterface<mixed, BovineSyncInventoryResult>
+ */
+final class BovineSyncInventoryProcessor implements ProcessorInterface
+{
+    public function __construct(
+        private BovinApiInterface $bovinApi,
+        private EntityManagerInterface $em,
+    ) {}
+
+    public function process(
+        mixed $data,
+        Operation $operation,
+        array $uriVariables = [],
+        array $context = [],
+    ): BovineSyncInventoryResult {
+        $inventory = $this->bovinApi->getInventory(new DateTimeImmutable('2000-01-01'));
+
+        $result        = new BovineSyncInventoryResult();
+        $result->total = count($inventory->animals);
+
+        $existingByNationalNumber = [];
+        foreach ($this->em->getRepository(Bovine::class)->findAll() as $bovine) {
+            $existingByNationalNumber[$bovine->getNationalNumber()] = $bovine;
+        }
+
+        $seen = [];
+        foreach ($inventory->animals as $animal) {
+            $nationalNumber = $animal->identification?->bovin?->nationalNumber;
+            if (null === $nationalNumber || '' === $nationalNumber) {
+                continue;
+            }
+            $seen[$nationalNumber] = true;
+
+            if (isset($existingByNationalNumber[$nationalNumber])) {
+                $bovine = $existingByNationalNumber[$nationalNumber];
+                ++$result->updated;
+            } else {
+                $bovine = new Bovine();
+                $bovine->setNationalNumber($nationalNumber);
+                $this->em->persist($bovine);
+                ++$result->created;
+            }
+
+            $this->applyEdnotifData($bovine, $animal);
+            $bovine->setExitedAt(null);
+        }
+
+        $now = new DateTimeImmutable();
+        foreach ($existingByNationalNumber as $nationalNumber => $bovine) {
+            if (isset($seen[$nationalNumber])) {
+                continue;
+            }
+            if (null !== $bovine->getExitedAt()) {
+                continue;
+            }
+            $bovine->setExitedAt($now);
+            ++$result->exited;
+        }
+
+        $this->em->flush();
+
+        return $result;
+    }
+
+    private function applyEdnotifData(Bovine $bovine, AnimalSummaryDto $animal): void
+    {
+        $identification = $animal->identification;
+        if (null !== $identification) {
+            $bovine->setSex($identification->sex);
+            $bovine->setBreedCode($identification->breedType);
+            $bovine->setWorkNumber($identification->workNumber);
+            $bovine->setBirthDate($identification->birthDate?->date);
+        }
+
+        foreach ($animal->presencePeriods as $period) {
+            if (null === $period->exit && null !== $period->entry?->date) {
+                $bovine->setArrivalDate($period->entry->date);
+
+                break;
+            }
+        }
+    }
+}