n8n-code-javascript

To return data from an n8n Code node correctly, you must structure your output as an array of objects containing a json property, such as [{json: {…}}]. Using this exact format prevents workflow execution errors and ensures downstream nodes receive valid items.

Your webhook payload is undefined in the n8n Code node because webhook data is safely nested under the .body property. You must access it via the body object rather than expecting it at the root level of the incoming item to extract your request data successfully.

Run Once for All Items processes the entire input array in a single execution using $input.all(), while Run Once for Each Item iterates through each item individually using $input.item. Choosing the right mode depends on whether you need batch aggregation or per-item transformation.

You cannot use {{ }} expressions inside an n8n Code node because it executes pure JavaScript. You must access data directly using JavaScript syntax like $input.item.json.field and apply safe null checks to prevent runtime errors during workflow execution.

To make HTTP requests and format dates in an n8n Code node, use the built-in $helpers.httpRequest method for API calls and the DateTime object from Luxon for date manipulation. These built-ins allow you to fetch external data and format timestamps within your JavaScript code.

The n8n Code node supports Luxon for date and time manipulation by exposing the DateTime object natively. You can utilize Luxon methods directly in your JavaScript code to parse, format, and calculate dates without importing external libraries.