⚙️ Monitor workflow liveness with the n8n API and SMTP email alerts
⚡ 0 views · ⚙️ DevOps & CI/CD
Description
Quick overview
Daily watchdog for self-hosted or cloud n8n: checks whether your scheduled workflows actually ran and emails you only when something is overdue, failing or unusually slow. No catalog to maintain – the expected rhythm is read from each Schedule Trigger.
How it works
- Runs once a day (or manually) and loads all active workflows via the n8n API.
- Reads the rhythm from every enabled Schedule Trigger (interval, weekdays or cron). The largest gap between two planned runs becomes the threshold, so Mon–Fri schedules don’t alarm on weekends.
- Loads the last 50 executions of each watched workflow. Manual test runs never count.
- Reports four findings: OVERDUE (no successful run within the expected gap plus tolerance), NO_SUCCESS (no successful run in the stored executions), ERROR_RATE (more than 20% failed runs in the last 7 days, at least one in the last 24 hours) and SLOW (latest run more than 3x the median).
- Sends one HTML email with all findings – only when there is something to report. Workflows that can’t be assessed are listed separately.
Setup
- Add an n8n API credential to both n8n nodes.
- Add an SMTP credential to the email node.
- Open the Config node and set notifyTo and notifyFrom.
- Set executionRetentionDays to the execution retention of your instance (default 14).
- Set your own error workflow in the workflow settings.
- Run the workflow once manually, check the result, then activate it.
Requirements
- n8n API key (self-hosted or n8n Cloud)
- SMTP account for sending the report
Customization
- overrides (JSON in Config): also watch webhook or sub-workflows, or tune a single workflow, e.g. {“Order webhook”: {“maxGapHours”: 48}}. Use {“ignore”: true} to skip one.
- ignoreNamePattern: skip workflows by name (regular expression).
- defaultToleranceHours, errorRateThreshold and minSlowSeconds: adjust how strict the checks are.
- Replace the email node with Slack, Teams or any other notification node.
Additional info
Limits: workflows that don’t save successful executions can’t be assessed, and rhythms longer than your execution retention are listed as “not assessed”. The watchdog can’t report its own absence – run it from a second instance or add it to an external uptime check if that matters to you.
🔗 Nodes Used
Send Email, n8n, Schedule Trigger
📥 Import
Download workflow.json and import into n8n:
Workflow menu → Import from File