n8n Workflow Liveness Monitor with API & SMTP Email Alerts

Never miss a scheduled n8n workflow run—get instant HTML alerts when execution liveness degrades

This n8n Workflow Liveness Monitor with API & SMTP Email Alerts checks active, scheduled workflows via the n8n API and sends an HTML report email over SMTP when it detects missed runs, elevated failure rates, or unusually slow executions.

What this workflow does

• Runs daily (or manually) at 09:30 to start a monitoring cycle (per your configuration).
• Loads monitoring settings such as recipients, tolerances, and thresholds.
• Builds a watch list by fetching active workflows using the n8n API and deriving each workflow’s expected run gap from its enabled Schedule Trigger (or an optional per-workflow override).
• Analyzes recent executions: for each watched workflow, it pulls the last 50 executions and ignores manual executions.
• Flags liveness issues, including:
  • Workflows that are overdue to run
  • Workflows with no recent successful runs
  • Workflows exceeding a 7-day error-rate threshold with a failure in the last 24 hours
  • Workflows running unusually slowly compared to recent execution medians
• Sends an email report only when needed: generates an HTML summary table (including entries skipped due to configuration/retention limits) and sends via SMTP only if at least one finding exists.

Use cases

• Monitor SaaS automation workflows to quickly detect missed scheduled runs
• Catch degrading reliability by alerting on rising failure rates
• Detect performance regressions when jobs slow down versus historical medians
• Ensure critical workflows don’t silently fail when execution retention is insufficient

Technical details

• Integrations / nodes: n8n API, if, set, code, email send, sticky note
• Auth: configure an n8n API key and an n8n API credential for nodes that read workflows/executions
• Delivery: configure SMTP credentials plus sender/recipient addresses
• Data retention requirement: ensure your instance retains successful executions long enough for monitored schedules (and note the workflow’s retention-related skipping behavior)