{"product_id":"monitor-empty-n8n-workflows-send-slack-alerts-via-api","title":"Monitor Empty n8n Workflows \u0026 Send Slack Alerts via API","description":"\u003ch3\u003eCatch “successful but empty” n8n workflows—and get Slack alerts fast\u003c\/h3\u003e\n\u003cp\u003eThis n8n automation runs hourly to monitor your selected workflows via the \u003cstrong\u003en8n API\u003c\/strong\u003e, records health checks in an \u003cstrong\u003en8n Data Table\u003c\/strong\u003e, and posts \u003cstrong\u003eSlack\u003c\/strong\u003e alerts when a workflow succeeds but produces zero items—or when it becomes stale.\u003c\/p\u003e\n\n\u003ch3\u003eWhat this workflow does\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRuns every hour\u003c\/strong\u003e on a schedule to perform a fresh health sweep.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLoads watchdog thresholds\u003c\/strong\u003e (including grace period, alert cooldown, escalation, and your n8n \u003cem\u003einstance URL\u003c\/em\u003e) and pulls the list of watched workflow IDs from the \u003cstrong\u003eworkflow_output_watchdog\u003c\/strong\u003e Data Table.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChecks each watched workflow\u003c\/strong\u003e by calling the \u003cstrong\u003en8n API\u003c\/strong\u003e to fetch the most recent successful execution and then retrieving the execution’s run data.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDetects “successful but empty” runs\u003c\/strong\u003e by counting how many items the final executed node produced—and also totaling items across the run.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eClassifies health status\u003c\/strong\u003e as \u003cstrong\u003eHEALTHY\u003c\/strong\u003e, \u003cstrong\u003eEMPTY\u003c\/strong\u003e, \u003cstrong\u003eSTALE\u003c\/strong\u003e, \u003cstrong\u003eDARK\u003c\/strong\u003e, or \u003cstrong\u003eUNREADABLE\u003c\/strong\u003e, based on item counts and how long it’s been since the last successful success.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUpserts results back to the Data Table\u003c\/strong\u003e, updating verdicts, counters, timestamps, and the last execution ID.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSends formatted Slack messages\u003c\/strong\u003e only when alert rules are met.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePosts an additional Slack message\u003c\/strong\u003e if any watched workflows were not checked during the sweep.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eUse cases\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eMonitor reporting\/ETL workflows to ensure they don’t “run successfully” but output \u003cstrong\u003ezero items\u003c\/strong\u003e.\u003c\/li\u003e\n  \u003cli\u003eDetect stalled automations by alerting when a workflow becomes \u003cstrong\u003eSTALE\u003c\/strong\u003e (no recent success).\u003c\/li\u003e\n  \u003cli\u003eCatch configuration or API issues when a workflow is \u003cstrong\u003eUNREADABLE\u003c\/strong\u003e or appears \u003cstrong\u003eDARK\u003c\/strong\u003e.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical details\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIntegrations:\u003c\/strong\u003e n8n API (to fetch executions and run data), \u003cstrong\u003eSlack\u003c\/strong\u003e (to send alerts).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNodes\/logic used:\u003c\/strong\u003e \u003ccode\u003eif\u003c\/code\u003e, \u003ccode\u003en8n\u003c\/code\u003e, \u003ccode\u003eset\u003c\/code\u003e, \u003ccode\u003ecode\u003c\/code\u003e, \u003ccode\u003eno op\u003c\/code\u003e, \u003ccode\u003elimit\u003c\/code\u003e.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eData storage:\u003c\/strong\u003e n8n Data Table \u003ccode\u003eworkflow_output_watchdog\u003c\/code\u003e (tracks workflow_id, label, thresholds, verdict state, timestamps, and last_execution_id).\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eResult:\u003c\/strong\u003e you get reliable n8n workflow health monitoring with Slack alerts for empty and stale executions—using only what your workflows already produce.\u003c\/p\u003e","brand":"N8N Commerce","offers":[{"title":"Default Title","offer_id":45962328932531,"sku":"N8N-18914","price":32.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0749\/6279\/6723\/files\/5hrZ2XxDKnbgmbg1UwAmX_fsu4N6Hn.png?v=1788600398","url":"https:\/\/buyflowscripts.com\/products\/monitor-empty-n8n-workflows-send-slack-alerts-via-api","provider":"N8N Commerce","version":"1.0","type":"link"}