n8n-code-javascript

To return data from an n8n Code node without errors, you must format your output as an array of objects using the exact structure `[{json: {...}}]` to ensure the workflow properly parses the payload.

Run Once for All Items processes the entire input array simultaneously using `$input.all()`, while Run Each Item iterates individually over items using `$input.item` for per-item data transformation.

You can make HTTP requests inside an n8n Code node by utilizing the `$helpers.httpRequest` method, which provides a safe way to integrate external APIs and fetch data during workflow execution.

Yes, n8n JavaScript workflows support Luxon DateTime for date manipulation and `$jmespath` for JSON querying, alongside `$getWorkflowStaticData` for persistent storage across workflow runs.

The best way to handle webhooks safely in n8n Code nodes involves following production-ready patterns for data validation and error prevention to build reliable, secure automated workflows.

An n8n Code node fails when processing multiple items if the return format is incorrect or the wrong execution mode is selected, requiring proper use of `$input.all()` with the `[{json: {...}}]` array.