n8n JavaScript Code Expert FAQs

Question 1

Why does my n8n Code node return an error even with valid JavaScript?

Accepted Answer

n8n requires a specific return structure: an array of objects where each object contains a 'json' key (e.g., return [{json: {data: 'value' }}]). This skill helps you format these correctly.

Question 2

How do I access data from previous nodes in n8n?

Accepted Answer

You should use the modern $input.all() to retrieve all items or $input.first() for a single item. This skill provides the correct syntax for various data access patterns.

Question 3

What is the difference between 'Run Once for All Items' and 'Run Once for Each Item'?

Accepted Answer

'All Items' executes once for the entire dataset, making it ideal for aggregation and filtering, while 'Each Item' runs separately for every record, which is useful for independent item processing.

Question 4

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

Accepted Answer

Yes, you can use the built-in $helpers.httpRequest() function. This skill provides syntax examples for making authenticated requests within your custom code.

Question 5

How do I handle webhook data in n8n Code nodes?

Accepted Answer

A common mistake is accessing webhook data directly; it is actually nested under $json.body. This skill includes specific patterns to handle this nesting correctly.

n8n JavaScript Code Expert

Key Features

Use Cases

n8n JavaScript Code Expert

Key Features

Use Cases