n8n workflow automation

Designs and outputs n8n workflow JSON with robust triggers, idempotency, error handling, logging, retries, and human-in-the-loop review queues. Use when you need an auditable automation that won’t silently fail.

n8n workflow automation with retries, logging, and review queues

PURPOSE

Designs and outputs n8n workflow JSON with robust triggers, idempotency, error handling, logging, retries, and human-in-the-loop review queues.

WHEN TO USE

• TRIGGERS:
  • Build an n8n workflow that runs every Monday and emails the compliance summary.
  • Add error handling and retries to this workflow, plus a review queue for failures.
  • Create a webhook workflow that logs every run and writes a status row to a tracker.
  • Make this n8n flow idempotent so it does not duplicate records when it reruns.
  • Instrument this workflow with audit logs and a human approval step.
• DO NOT USE WHEN…
  • You need code-only automation without n8n (use a scripting/CI skill).
  • You need to bypass security controls or hide audit trails.
  • You need to purchase or recommend prohibited items/services.

INPUTS

• REQUIRED:
  • Workflow intent: trigger type + schedule/timezone + success criteria.
  • Targets: where to write results (email/Drive/Sheet/DB) and required fields.
• OPTIONAL:
  • Existing n8n workflow JSON to modify.
  • Sample payloads / example records.
  • Definition of dedup keys (what makes a record unique).
• EXAMPLES:
  • Cron: Monday 08:00 Europe/London; send summary email + Drive upload
  • Webhook: receive JSON; route to folders

OUTPUTS

• Default (read-only): a workflow design spec (nodes, data contracts, failure modes).
• If explicitly requested: workflow.json (n8n importable JSON) + runbook.md (from template). Success = workflow is idempotent, logs every run, retries safely, and routes failures to a review queue.

WORKFLOW

1. Clarify trigger:
   • Cron/webhook/manual; schedule/timezone; concurrency expectations.
2. Define data contract:
   • input schema, required fields, and validation rules.
3. Design idempotency:
   • choose dedup key(s) and storage (DB/Sheet) to prevent duplicates on retries.
4. Add observability:
   • generate run_id, log start/end, store status row and error details.
5. Implement error handling:
   • per-node error branches, retry with backoff, and final failure notification.
6. Add human-in-the-loop (HITL) review queue:
   • write failed items to a queue (Sheet/DB) and require approval to reprocess.
7. “No silent failure” gates:
   • if counts/thresholds fail, stop workflow and alert.
8. Output:
   • If asked for JSON: produce importable n8n workflow JSON + runbook.
9. STOP AND ASK THE USER if:
   • destination systems are unknown,
   • no dedup key exists,
   • credential strategy (env vars) is not specified,
   • the workflow needs privileged access not yet approved.

OUTPUT FORMAT

If outputting n8n workflow JSON, conform to:

json

{
  "name": "<workflow name>",
  "nodes": [ { "name": "Trigger", "type": "n8n-nodes-base.cron", "parameters": {}, "position": [0,0] } ],
  "connections": {},
  "settings": {},
  "active": false
}

Also output runbook.md using assets/runbook-template.md.

SAFETY & EDGE CASES

• Read-only by default; only emit workflow JSON when explicitly requested.
• Do not include secrets in JSON; reference env vars/credential names only.
• Include audit logging + failure notifications; avoid workflows that can silently drop data.
• Prefer least privilege: call only required APIs and minimize scopes.

EXAMPLES

• Input: “Cron every Monday, email compliance summary, retry failures.”
  Output: Node map + workflow.json with Cron → Fetch → Aggregate → Email, plus error branches to review queue.

• Input: “Webhook that logs runs and writes status row.”
  Output: Webhook → Validate → Process → Append status row; on error → log + notify + queue.