diff --git a/apps/webhook_listeners/lib/Controller/WebhooksController.php b/apps/webhook_listeners/lib/Controller/WebhooksController.php
index 42870825877b7..e7a05f0983ea7 100644
--- a/apps/webhook_listeners/lib/Controller/WebhooksController.php
+++ b/apps/webhook_listeners/lib/Controller/WebhooksController.php
@@ -10,8 +10,10 @@
 namespace OCA\WebhookListeners\Controller;
 
 use OCA\WebhookListeners\Db\AuthMethod;
+use OCA\WebhookListeners\Db\WebhookListener;
 use OCA\WebhookListeners\Db\WebhookListenerMapper;
 use OCA\WebhookListeners\ResponseDefinitions;
+use OCP\AppFramework\Db\DoesNotExistException;
 use OCP\AppFramework\Http;
 use OCP\AppFramework\Http\Attribute\ApiRoute;
 use OCP\AppFramework\Http\Attribute\AuthorizedAdminSetting;
@@ -20,6 +22,7 @@
 use OCP\AppFramework\OCS\OCSBadRequestException;
 use OCP\AppFramework\OCS\OCSException;
 use OCP\AppFramework\OCS\OCSForbiddenException;
+use OCP\AppFramework\OCS\OCSNotFoundException;
 use OCP\AppFramework\OCSController;
 use OCP\IRequest;
 use OCP\ISession;
@@ -45,15 +48,26 @@ public function __construct(
 	 * List registered webhooks
 	 *
 	 * @return DataResponse<Http::STATUS_OK, WebhookListenersWebhookInfo[], array{}>
+	 * @throws OCSException Other internal error
 	 *
 	 * 200: Webhook registrations returned
 	 */
 	#[ApiRoute(verb: 'GET', url: '/api/v1/webhooks')]
 	#[AuthorizedAdminSetting(settings:'OCA\WebhookListeners\Settings\Admin')]
 	public function index(): DataResponse {
-		$webhookListeners = $this->mapper->getAll();
+		try {
+			$webhookListeners = $this->mapper->getAll();
 
-		return new DataResponse($webhookListeners);
+			return new DataResponse(
+				array_map(
+					fn (WebhookListener $listener): array => $listener->jsonSerialize(),
+					$webhookListeners
+				)
+			);
+		} catch (\Exception $e) {
+			$this->logger->error('Error when listing webhooks', ['exception' => $e]);
+			throw new OCSException('An internal error occurred', Http::STATUS_INTERNAL_SERVER_ERROR, $e);
+		}
 	}
 
 	/**
@@ -62,13 +76,22 @@ public function index(): DataResponse {
 	 * @param int $id id of the webhook
 	 *
 	 * @return DataResponse<Http::STATUS_OK, WebhookListenersWebhookInfo, array{}>
+	 * @throws OCSNotFoundException Webhook not found
+	 * @throws OCSException Other internal error
 	 *
 	 * 200: Webhook registration returned
 	 */
 	#[ApiRoute(verb: 'GET', url: '/api/v1/webhooks/{id}')]
 	#[AuthorizedAdminSetting(settings:'OCA\WebhookListeners\Settings\Admin')]
 	public function show(int $id): DataResponse {
-		return new DataResponse($this->mapper->getById($id));
+		try {
+			return new DataResponse($this->mapper->getById($id)->jsonSerialize());
+		} catch (DoesNotExistException $e) {
+			throw new OCSNotFoundException($e->getMessage(), $e);
+		} catch (\Exception $e) {
+			$this->logger->error('Error when getting webhook', ['exception' => $e]);
+			throw new OCSException('An internal error occurred', Http::STATUS_INTERNAL_SERVER_ERROR, $e);
+		}
 	}
 
 	/**
@@ -106,6 +129,11 @@ public function create(
 		if ($this->session->get('app_api') === true) {
 			$appId = $this->request->getHeader('EX-APP-ID');
 		}
+		try {
+			$authMethod = AuthMethod::from($authMethod ?? AuthMethod::None->value);
+		} catch (\ValueError $e) {
+			throw new OCSBadRequestException('This auth method does not exist');
+		}
 		try {
 			$webhookListener = $this->mapper->addWebhookListener(
 				$appId,
@@ -115,17 +143,17 @@ public function create(
 				$event,
 				$eventFilter,
 				$headers,
-				AuthMethod::from($authMethod ?? AuthMethod::None->value),
+				$authMethod,
 				$authData,
 			);
-			return new DataResponse($webhookListener);
+			return new DataResponse($webhookListener->jsonSerialize());
 		} catch (\UnexpectedValueException $e) {
 			throw new OCSBadRequestException($e->getMessage(), $e);
 		} catch (\DomainException $e) {
 			throw new OCSForbiddenException($e->getMessage(), $e);
 		} catch (\Exception $e) {
 			$this->logger->error('Error when inserting webhook', ['exception' => $e]);
-			throw new OCSException('An internal error occurred', $e->getCode(), $e);
+			throw new OCSException('An internal error occurred', Http::STATUS_INTERNAL_SERVER_ERROR, $e);
 		}
 	}
 
@@ -166,6 +194,11 @@ public function update(
 		if ($this->session->get('app_api') === true) {
 			$appId = $this->request->getHeader('EX-APP-ID');
 		}
+		try {
+			$authMethod = AuthMethod::from($authMethod ?? AuthMethod::None->value);
+		} catch (\ValueError $e) {
+			throw new OCSBadRequestException('This auth method does not exist');
+		}
 		try {
 			$webhookListener = $this->mapper->updateWebhookListener(
 				$id,
@@ -176,17 +209,17 @@ public function update(
 				$event,
 				$eventFilter,
 				$headers,
-				AuthMethod::from($authMethod ?? AuthMethod::None->value),
+				$authMethod,
 				$authData,
 			);
-			return new DataResponse($webhookListener);
+			return new DataResponse($webhookListener->jsonSerialize());
 		} catch (\UnexpectedValueException $e) {
 			throw new OCSBadRequestException($e->getMessage(), $e);
 		} catch (\DomainException $e) {
 			throw new OCSForbiddenException($e->getMessage(), $e);
 		} catch (\Exception $e) {
 			$this->logger->error('Error when updating flow with id ' . $id, ['exception' => $e]);
-			throw new OCSException('An internal error occurred', $e->getCode(), $e);
+			throw new OCSException('An internal error occurred', Http::STATUS_INTERNAL_SERVER_ERROR, $e);
 		}
 	}
 
@@ -215,7 +248,7 @@ public function destroy(int $id): DataResponse {
 			throw new OCSForbiddenException($e->getMessage(), $e);
 		} catch (\Exception $e) {
 			$this->logger->error('Error when deleting flow with id ' . $id, ['exception' => $e]);
-			throw new OCSException('An internal error occurred', $e->getCode(), $e);
+			throw new OCSException('An internal error occurred', Http::STATUS_INTERNAL_SERVER_ERROR, $e);
 		}
 	}
 }
diff --git a/apps/webhook_listeners/lib/Settings/Admin.php b/apps/webhook_listeners/lib/Settings/Admin.php
index e5e0d00221c20..5ef7656ca3e5e 100644
--- a/apps/webhook_listeners/lib/Settings/Admin.php
+++ b/apps/webhook_listeners/lib/Settings/Admin.php
@@ -9,6 +9,7 @@
 
 namespace OCA\WebhookListeners\Settings;
 
+use OCP\AppFramework\Http;
 use OCP\AppFramework\Http\TemplateResponse;
 use OCP\IL10N;
 use OCP\Settings\IDelegatedSettings;
@@ -28,7 +29,8 @@ public function __construct(
 	 * Empty template response
 	 */
 	public function getForm(): TemplateResponse {
-		return new class($this->appName, '') extends TemplateResponse {
+
+		return new /** @template-extends TemplateResponse<Http::STATUS_OK, array{}> */ class($this->appName, '') extends TemplateResponse {
 			public function render(): string {
 				return '';
 			}
diff --git a/apps/webhook_listeners/openapi.json b/apps/webhook_listeners/openapi.json
index 308f0e8b11df4..8488ce8e11758 100644
--- a/apps/webhook_listeners/openapi.json
+++ b/apps/webhook_listeners/openapi.json
@@ -411,6 +411,34 @@
                                 }
                             }
                         }
+                    },
+                    "404": {
+                        "description": "Webhook not found",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object",
+                                    "required": [
+                                        "ocs"
+                                    ],
+                                    "properties": {
+                                        "ocs": {
+                                            "type": "object",
+                                            "required": [
+                                                "meta",
+                                                "data"
+                                            ],
+                                            "properties": {
+                                                "meta": {
+                                                    "$ref": "#/components/schemas/OCSMeta"
+                                                },
+                                                "data": {}
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
                     }
                 }
             },