n8n workflow automation

# 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.