diff --git a/AddOn/Fehlzeitenimport/TimeTrackingAPI.php b/AddOn/Fehlzeitenimport/TimeTrackingAPI.php
new file mode 100644
index 00000000..c405bfd0
--- /dev/null
+++ b/AddOn/Fehlzeitenimport/TimeTrackingAPI.php
@@ -0,0 +1,78 @@
+<?php
+
+class TimeTrackingAPI
+{
+    private string $baseUrl;
+    private string $token;
+    private string $apiSite;
+
+    public function __construct(string $baseUrl, string $token, string $apiSite = '')
+    {
+        $this->baseUrl = rtrim($baseUrl, '/');
+        $this->token = $token;
+        $this->apiSite = trim($apiSite, '/');
+    }
+
+    private function request(string $method, string $endpoint, array $headers = [], ?array $body = null): array
+    {
+        $url = "{$this->baseUrl}/{$this->apiSite}/{$endpoint}";
+        $ch = curl_init($url);
+
+        $defaultHeaders = [
+            "Authorization: {$this->token}",
+        ];
+        if ($body !== null) {
+            $defaultHeaders[] = 'Content-Type: application/json';
+            $body = json_encode($body);
+        }
+
+        curl_setopt_array($ch, [
+            CURLOPT_RETURNTRANSFER => true,
+            CURLOPT_CUSTOMREQUEST => strtoupper($method),
+            CURLOPT_HTTPHEADER => array_merge($defaultHeaders, $headers),
+            CURLOPT_POSTFIELDS => $body,
+        ]);
+
+        $response = curl_exec($ch);
+        if (curl_errno($ch)) {
+            throw new RuntimeException('cURL Error: ' . curl_error($ch));
+        }
+
+        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+        curl_close($ch);
+
+        $data = json_decode($response, true);
+        if ($httpCode >= 400) {
+            throw new RuntimeException("API request failed with status $httpCode: " . ($data['Message'] ?? $response));
+        }
+
+        return $data;
+    }
+
+    public function getExportDefinitions(): array
+    {
+        return $this->request('GET', 'api/export/');
+    }
+
+    public function getOrganizationUnits(): array
+    {
+        return $this->request('GET', 'api/organization/');
+    }
+
+    public function requestExport(string $exportDefinitionId, string $organizationUnitId, string $dateFrom, string $dateUntil): string
+    {
+        $body = [
+            'ExportDefinition' => $exportDefinitionId,
+            'organizationUnit' => $organizationUnitId,
+            'DateFrom' => $dateFrom,
+            'DateUntil' => $dateUntil,
+        ];
+        $response = $this->request('POST', 'api/export', [], $body);
+        return $response['Result'] ?? throw new RuntimeException('Unexpected response: ' . json_encode($response));
+    }
+
+    public function getExportData(string $guid): array
+    {
+        return $this->request('GET', "api/export/{$guid}");
+    }
+}