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:

{
  "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.