n8n Alert: Detect Stalled Scheduled Workflows with Gmail

Stay ahead of silent failures: Gmail alerts for stalled n8n scheduled workflows

This n8n workflow runs hourly to detect schedule-triggered workflows that have gone quiet—then sends a Gmail email alert when a workflow hasn’t completed within your configured timeout window. If a Schedule/Cron/Interval job stops running without errors, you’ll know fast.

What this workflow does

• Runs every hour on a schedule to continuously monitor your n8n instance.
• Fetches active workflows via the n8n REST API (using your API key).
• Fetches recent executions via the n8n REST API and compares them to the active workflows list.
• Filters to schedule-based triggers (Schedule, Cron, or Interval) and keeps only workflows whose last completed run is older than the configured threshold (silentAfterMinutes).
• Sends a Gmail alert for each workflow that appears stalled—one email per affected workflow.

Use cases

• SaaS operations monitoring: Ensure scheduled automations keep running (no silent stoppages in production).
• Automation engineering: Get notified when an interval-based process stops completing for longer than expected.
• Reliable scheduling for critical jobs: Detect issues quickly for workflows triggered by Schedule/Cron/Interval.

Technical details

• Nodes / logic: if, set, code, http request, gmail, and supporting notes.
• Integrations: Uses the n8n REST API with an API key sent as the X-N8N-API-KEY header.
• Alerting: Sends notifications via Gmail (recipient address configured in the Gmail credential). You can swap the Alert node for other channels if needed.

Setup (quick)

• Set your n8n base URL and the timeout window (silentAfterMinutes) in the Settings values.
• Create an n8n API key and configure both HTTP Request nodes to use it via X-N8N-API-KEY.
• Add a Gmail credential, set the recipient, and adjust the alert subject/message to your preferences.