n8n Workflow Health Monitoring: Google Sheets Baselines + Slack Alerts

Keep every n8n workflow healthy—log baselines in Google Sheets and alert in Slack

This n8n workflow monitors other n8n workflows by recording run health to a Google Sheets RunLog, comparing each new run to historical baselines, and sending Slack alerts when volume or required data looks abnormal—or when workflows go silent.

What this workflow does

• Receives a health-check call from another workflow with its name, item count, required fields, a sample item, and a run ID.
• Validates required fields in the sample item, ensuring declared fields exist and are not null or empty.
• Builds a rolling baseline from the Google Sheets RunLog history, preferring same-weekday medians to detect volume drops and slow decay patterns.
• Appends results (verdict + metrics) back into the RunLog.
• Alerts in Slack: posts a detailed alert when the verdict is WARN or BREACH (optionally including WARN alerts).
• Supports failure escalation: can optionally fail the calling execution on BREACH, so your existing error handling and retries can trigger.
• Sends a daily digest every morning at 08:00, scanning the full RunLog to detect workflows that stopped reporting based on learned cadence, and then notifying Slack if issues are found (or if configured to post even when all are healthy).

Use cases

• Catch pipelines that quietly lose throughput (e.g., item counts decaying over time).
• Detect schema/data regressions when required fields go missing or become empty.
• Ensure critical automations resume reporting by flagging workflows that go silent.
• Give SaaS operations teams a daily Slack health digest for monitoring at a glance.

Technical details

• Integrations: Google Sheets (requires a tab named RunLog) and Slack.
• Workflow logic / nodes: if, set, code, no op, slack, and sticky note.

Setup

• Create your Google Sheet with a RunLog tab and the required header columns, then paste the sheet ID into the workflow’s monitor and digest settings.
• Add Google Sheets credentials for the target spreadsheet.
• Add Slack credentials to enable alerts and the daily digest.