Mastering Data Transformation in n8n: Your Guide to the Function Node
When building n8n workflows, you’ll inevitably need to reshape, clean, or manipulate data moving between nodes. While n8n offers fantastic nodes like ‘Set’, ‘Rename Keys’, and ‘Merge’ for common transformations, sometimes you hit a wall. For those moments requiring intricate logic, custom calculations, or specific restructuring not covered by standard nodes, the Function Node becomes your superpower.
Why Reach for the Function Node?
You’ll typically turn to it when standard nodes fall short, you need to use built-in JavaScript methods for sophisticated operations, you need to iterate with complex logic, or you’re preparing data for specific API formats.
Before You Code: Understanding n8n’s Data Flow
Data in n8n flows between nodes as an array of items. Inside each item, there’s usually a json property. This json property holds the actual data. When your Function Node runs, it receives this entire array of items, typically accessible via a variable named items. Your job within the node is to process this items array and return a new array of items in the same format.
