n8n Node Guide: Code

Description

Data Transformation node in n8n.

What It Does

Run custom JavaScript for transformations too complex for visual nodes.

When To Use It

Any custom logic: math, string manipulation, API response reshaping, multi-step transforms.

Key Parameters

Mode (Run Once for All Items vs Run Once for Each Item), language (JS/Python)

Common Mistakes

Must return an array of objects like [{json:{…}}]. Returning a bare object breaks downstream nodes.

Example

return items.map(i => ({ json: { …i.json, total: i.json.price * i.json.qty } }));

FAQ

Is this node included in n8n Community Edition?

Yes – Code ships with the free Community Edition. No paid license needed.

Use pairedItem to keep error messages pointing at the right input item.?

Where does it fit in a workflow?

Code works with any other node – connect it after a trigger or data node, and feed its output into the next step. Standard n8n data flow: trigger -> transform -> act.

Is support included?

Yes – message the seller through the store and I will help you wire this node.