diff --git a/lib/Service/OpenAiAPIService.php b/lib/Service/OpenAiAPIService.php
index 050d82d6..50e1fd2f 100644
--- a/lib/Service/OpenAiAPIService.php
+++ b/lib/Service/OpenAiAPIService.php
@@ -72,6 +72,26 @@ public function getServiceName(): string {
 		}
 	}
 
+	/**
+	 * @param mixed $models
+	 * @return boolean
+	 */
+	private function isModelListValid($models): bool {
+		if (!is_array($models) || !array_is_list($models)) {
+			return false;
+		}
+		if (count($models) === 0) {
+			return false;
+		}
+		foreach ($models as $model) {
+			if (!isset($model['id'])) {
+				return false;
+			}
+		}
+
+		return true;
+	}
+
 	/**
 	 * @param string $userId
 	 * @return array|string[]
@@ -111,11 +131,22 @@ public function getModels(string $userId): array {
 			$this->areCredsValid = false;
 			throw $e;
 		}
-		if (!isset($modelsResponse['data'])) {
+		if (isset($modelsResponse['error'])) {
 			$this->logger->warning('Error retrieving models: ' . \json_encode($modelsResponse));
 			$this->areCredsValid = false;
-			throw new Exception($this->l10n->t('Unknown models error'), Http::STATUS_INTERNAL_SERVER_ERROR);
+			throw new Exception($modelsResponse['error'], Http::STATUS_INTERNAL_SERVER_ERROR);
+		}
+		if (!isset($modelsResponse['data'])) {
+			// also consider responses without 'data' as valid
+			$modelsResponse = ['data' => $modelsResponse];
 		}
+
+		if (!$this->isModelListValid($modelsResponse['data'])) {
+			$this->logger->warning('Invalid models response: ' . \json_encode($modelsResponse));
+			$this->areCredsValid = false;
+			throw new Exception($this->l10n->t('Invalid models response received'), Http::STATUS_INTERNAL_SERVER_ERROR);
+		}
+
 		$cache->set($cacheKey, $modelsResponse, Application::MODELS_CACHE_TTL);
 		$this->modelsMemoryCache = $modelsResponse;
 		$this->areCredsValid = true;