n8n-code-javascript

To write JavaScript in n8n Code nodes, use data access patterns like `$input.all()` and `$input.first()` to retrieve items, apply your transformation logic, and return the results in the required n8n array format to pass data downstream.

n8n Code node errors typically occur when JavaScript returns an invalid format or skips null checks. Ensure your JavaScript outputs an array of objects and includes null validation to prevent processing failures when handling incoming webhook data.

n8n expressions use a specific inline syntax for simple data mapping within node fields, whereas the Code node executes standard JavaScript for complex data transformation, allowing full control over variables, loops, and custom return structures.

Yes, you can implement standard JavaScript patterns in n8n Code nodes for data aggregation, filtering, and reporting, using production-ready code structures to transform items before sending them to downstream services.

The best way to access item data in an n8n Code node is using built-in methods like `$input.all()` to fetch every item, `$input.first()` for the initial entry, or `$input.item` for the current iteration.

Yes, implementing null checks is essential in n8n Code nodes to prevent common automation errors, ensuring your JavaScript logic safely handles missing or undefined webhook data before transforming and sending it downstream.