Set Expression Generator from Nested JSON String with Verification

How it works

1. 1.Run manually; sample node emits a valid and a broken JSON text item
2. 2.Code node safely parses and recursively generates rows with internal path verification
3. 3.Set node standardizes fields and retains identifiers via includeOtherFields
4. 4.IF node splits valid path rows from the diagnostic failure row
5. 5.NoOp branches feed a two-input append Merge
6. 6.Final Code node returns one summary report with counters, failure reasons and expressions

Use cases

• Turn nested JSON-in-JSON text into ready n8n expressions
• Generate verified path lists for Set or IF nodes
• Diagnose JSON parse errors (single quotes, trailing comma) without stopping execution
• Document unknown payload structure before building the final workflow

Requirements

• No credentials; no external calls or AI
• For real use: feed any item with a string `payload` field instead of the sample node

Setup and testing in n8n

1. Import the JSON into n8n, open Manual Trigger, click Execute
2. Check Build Summary Report: 13 verified valid rows and 1 failure row (single quotes reason)
3. Edge cases: empty payload, empty array, key with spaces, deeply nested JSON
4. Copy ready_expression values into a Set node and confirm evaluation

Service Value

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