Single/Array Payload Normalizer with Parent-Derived Semantic Array Names

How it works

1. 1.Run the manual trigger; the Code node emits five test payloads
2. 2.The If node checks whether invoice.lines is an array: true passes through a noOp unchanged, false pre-wraps single objects into arrays and records _originalShape (single/missing/invalid)
3. 3.A Merge node in append mode with two inputs (index 0 and 1) collects items from both branches
4. 4.The naming engine derives semantic names dynamically from parent field keys, keeps scalar fields in scalars, and handles missing/invalid safely (normalized and scalars as empty objects)
5. 5.The engine sorts output by payloadId and a noOp hands off structurally unified output ordered PL-001 through PL-005

Use cases

• Normalizing webhook payloads that alternate between a single object and an array
• Dynamic semantic naming of parallel arrays from the parent field key before splitting
• Explicit type validation with scalar preservation, a safe path for missing or invalid payloads and deterministic output order

Requirements

• No credentials; processing is fully local
• For real input: remove the Emit Sample node and connect a Webhook with the same invoice schema directly to the If node
• The If gate is fixed to the invoice.lines path; adjust the expression if your target array path differs — the naming engine works on any fields inside invoice automatically. Branch collection uses a Merge node in append mode with valid input indexes 0 and 1

Setup and testing in n8n

1. Import the JSON into n8n keeping active = false
2. Execute Manual Trigger and inspect Unified Output Handoff: five items ordered PL-001 through PL-005
3. Verify PL-001 is wrapped into one-element arrays with id kept in scalars, PL-002 keeps count 2 via the pass-through branch, PL-003 has normalized = {} and scalars = {} with missing, PL-004 has normalized = {} with invalid and id retained in scalars, PL-005 passes customer as a two-element array and wraps single lines
4. Add a new field inside invoice in the sample to confirm the semantic name is derived automatically without code changes

Service Value

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