Silent failure monitor

Works with: n8n API, Slack, email, Google SheetsSteps: 23 nodesTested on: n8n 2.45 (imports on 1.70 and later)

Some failures never turn a run red: a filter drops every item, an API returns an empty page, a schedule stops firing, someone switches a workflow off. This workflow watches the workflows you list and tells you when they succeeded but did nothing.

What it does

1. Fetch: every 15 minutes, for each workflow in checks_json, it reads the workflow (is it still active?) and its last 50 runs with their data from the n8n API, plus an optional record-check URL.
2. Judge: it flags

• empty runs: fewer items than min_items out of the step you name (or the step never ran),

- missed schedules: no run within max_gap_minutes,

- missing records: your record-check URL returns fewer than record_min rows,

- switched-off workflows,

- failed runs, if you turn on alert_on_errors.

1. Report once: each problem has a key (the run id, the date or the hour), so it is reported a single time.
2. Tell someone: one Slack message and one email per round, with a link to each run, and a row per finding in a Google Sheet.
3. Daily summary: at 8am Slack gets the number of checks and problems in the last 24 hours, which also proves the monitor is running.
4. Retries and alerts: every API, Slack, email and sheet step retries 3 times; anything that still fails posts the step and the reason to Slack.

What you need

• n8n with the public API turned on, and an n8n API key
• A Slack incoming webhook URL
• An SMTP account for the email alerts
• A Google Sheet with a tab named Silent failures

Setup

1. Import workflow.json into n8n.
2. In n8n, open Settings → n8n API and create a key. Add a Header Auth credential with name X-N8N-API-KEY and the key as its value, and select it on Get workflow and Get recent runs.
3. In Config, set n8n_base_url, the Slack URL, the alert email and checks_json.
4. Add your SMTP credential to Alert (email) and Google Sheets to Log to sheet.
5. Click Test workflow to run three sample workflows with problems through the checks.
6. Activate.

checks_json

[{"workflow_id": "12", "name": "Nightly order sync", "max_gap_minutes": 1500, "count_node": "Upsert orders", "min_items": 1,
  "record_check_url": "", "record_min": 1, "alert_on_errors": true}]

• max_gap_minutes: 0 turns the schedule check off. Use 1500 for a nightly job, 90 for an hourly one.
• count_node: blank means the last step that ran.
• record_check_url: any URL that returns today's records as JSON: a list, or an object with count, total, data, results or items.

Notes

• No credentials are included. Every value marked REPLACE_ME or REPLACE_WITH_... must be set before you activate the workflow.
• The watched workflows must save successful runs (workflow settings), or there is no run data to count.
• The list of problems already reported lives in the workflow's static data, which n8n saves on production runs only.
• Tested on n8n 1.110.1 against sample runs and a mocked n8n API.

Importing it

In n8n, open a new workflow, choose the … menu at the top right, then Import from file and pick the downloaded workflow.json. You can also open the file, copy everything and paste it onto an empty canvas. New to n8n? Start with what n8n is and how templates work.

Background reading: n8n silent failures.

Want it set up and running in your own n8n? Send us a short brief.