n8n-code-javascript

To write custom JavaScript for data transformation in n8n, you use a Code node to run scripts with direct access to input data via $input.all() and must return an array of { json: ... } objects to produce transformed results.

Run Once for All Items processes the entire batch of input data in a single script execution, while Run Once for Each Item executes the JavaScript logic individually per data item, allowing you to choose between batch processing or per-item logic.

You access input data and node helpers inside an n8n Code node using built-in syntax like $input, $json, $node, and $helpers, enabling you to perform tasks like API calls, date handling, and debugging within a single node.

n8n Code node errors during data transformation often occur because the script environment requires returning an array of objects with json payloads, and failing to format the output correctly will trigger execution errors.

Yes, you can make API calls and handle dates directly within an n8n Code node by writing custom JavaScript logic that leverages node helpers and DateTime functions to manage data without external scripting.

No, you do not need external scripts to extend n8n workflow capabilities for complex data logic because you can write and manage custom JavaScript directly in Code nodes to handle API calls, date handling, and debugging.