Subarray Key Promotion to Category Column with Sorted Reverse Index

How it works

1. 1.Run Manual Trigger; a Code node emits a fictional payload with two subarrays and one single object
2. 2.A Code node normalizes the single object to an array, then flattens every subarray promoting its key to category, _parent_ref and row_id
3. 3.A Set node locks the row structure while keeping all original fields
4. 4.A Code node builds and descending-sorts the reverse index
5. 5.An IF node checks totals and emits success or failure reports
6. 6.Merge collects branches and a final Code node returns one combined report

Use cases

• Locally flattening nested CRM/API payloads without credentials
• Aggregated reports sorted by category size
• Auditing that no rows are lost during JSON flattening

Requirements

• No credentials needed; fully local with supported nodes
• To use real data: wire a Webhook or HTTP Request node with the same schema in place of the sample node

Setup and testing in n8n

1. Import the JSON, run Manual Trigger, expect one report: 3 categories, 6 rows, matchPassed=true
2. Edit the sample: remove an array or add another single object and rerun to confirm normalization
3. Test edge cases: empty values or non-object rows get wrapped as value without loss

Service Value

Ready-made workflow template for automation delivery and service execution.