feat(core): Expose queue metrics for Prometheus (#10559)

packages/@n8n/config/src/configs/endpoints.config.ts

@@ -49,6 +49,14 @@ class PrometheusMetricsConfig {
 	/** Whether to include metrics derived from n8n's internal events */
 	@Env('N8N_METRICS_INCLUDE_MESSAGE_EVENT_BUS_METRICS')
 	includeMessageEventBusMetrics: boolean = false;
+
+	/** Whether to include metrics for jobs in scaling mode. Not supported in multi-main setup. */
+	@Env('N8N_METRICS_INCLUDE_QUEUE_METRICS')
+	includeQueueMetrics: boolean = false;
+
+	/** How often (in seconds) to update queue metrics. */
+	@Env('N8N_METRICS_QUEUE_METRICS_INTERVAL')
+	queueMetricsInterval: number = 20;
 }
 
 @Config

packages/@n8n/config/test/config.test.ts

@@ -165,6 +165,8 @@ describe('GlobalConfig', () => {
 				includeApiMethodLabel: false,
 				includeCredentialTypeLabel: false,
 				includeApiStatusCodeLabel: false,
+				includeQueueMetrics: false,
+				queueMetricsInterval: 20,
 			},
 			additionalNonUIRoutes: '',
 			disableProductionWebhooksOnMainProcess: false,