Can I make API calls directly from an n8n Code node?

Yes, you can use the built-in $helpers.httpRequest() function to perform GET, POST, and other HTTP requests directly within your JavaScript code.

When should I use 'Run Once for All Items' mode?

Use this mode for 95% of use cases, particularly when you need to filter, sort, aggregate, or perform operations that compare multiple items in the dataset.

What is the mandatory return format for n8n Code nodes?

All n8n Code nodes must return an array of objects where each object contains a 'json' property, such as: return [{json: { field: value }}].

How do I access data from a Webhook node in n8n?

Webhook data is nested under the body property. Use $json.body.propertyName or $input.first().json.body to access the payload correctly.

How do I handle date manipulation in n8n JavaScript?

n8n provides the Luxon library via the DateTime object, allowing you to easily format, parse, and perform arithmetic on dates without external dependencies.

n8n JavaScript Code Assistant

Name: n8n JavaScript Code Assistant
Author: echoleesong

byecholeesong

Productivity & Workflow

Optimizes JavaScript development in n8n Code nodes by providing expert patterns for data transformation, built-in helpers, and execution modes.

About

This skill provides comprehensive guidance for developers writing JavaScript within n8n's Code nodes, ensuring correct data access and return formats. It helps users navigate the nuances of 'Run Once for All Items' versus 'Run Once for Each Item' modes, provides patterns for complex data transformations, and clarifies the specific structure of webhook payloads. By incorporating built-in helpers like Luxon for date manipulation and JMESPath for JSON querying, this skill enables the creation of robust, efficient n8n workflows while preventing common runtime errors like incorrect return structures or missing null checks.

Key Features

Expert guidance on 'Run Once for All Items' vs. 'Run Once for Each Item' modes
Troubleshooting for common mistakes like webhook body nesting and loop processing
Strict enforcement of n8n return formats to prevent workflow execution failures
Standardized data access patterns for $input.all(), $input.first(), and $node
Tutorials for built-in helpers including $helpers.httpRequest() and Luxon (DateTime)
0 GitHub stars

Use Cases

Aggregating data across multiple workflow items for batch processing or reporting
Transforming and normalizing complex JSON structures from API responses
Implementing custom validation logic and date arithmetic within automation steps

About

Key Features

Expert guidance on 'Run Once for All Items' vs. 'Run Once for Each Item' modes
Troubleshooting for common mistakes like webhook body nesting and loop processing
Strict enforcement of n8n return formats to prevent workflow execution failures
Standardized data access patterns for $input.all(), $input.first(), and $node
Tutorials for built-in helpers including $helpers.httpRequest() and Luxon (DateTime)
0 GitHub stars

Use Cases

Aggregating data across multiple workflow items for batch processing or reporting
Transforming and normalizing complex JSON structures from API responses
Implementing custom validation logic and date arithmetic within automation steps