n8n-code-javascript

Write JavaScript in n8n Code nodes for data transformation and API calls.

Updated Nov 29, 2025
One-click install
npx skills add https://github.com/thimslugga/agent-skills --skill n8n-code-javascript-thimslugga
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: n8n-code-javascript
Source: https://github.com/thimslugga/agent-skills/tree/main/skills/development/n8n/n8n-code-javascript
Command: npx skills add https://github.com/thimslugga/agent-skills --skill n8n-code-javascript-thimslugga

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Writing custom JavaScript in n8n Code nodes can be error-prone and repetitive, especially when handling data access patterns, webhook structures, API calls, and error scenarios.

Core Features & Use Cases

  • Data access with $input.all(), $input.first(), and $input.item, plus references through $node.
  • Two execution modes: Run Once for All Items and Run Once for Each Item, with guidance on when to choose each.
  • Built-in utilities like $helpers.httpRequest(), DateTime (Luxon), and $jmespath() for API integration, data transformation, and validation.
  • Real-world patterns include batch processing, per-item logic, and robust error handling across workflows.

Quick Start

Process all input items in a single run and return the transformed results as an array of {json: ...} objects.

Frequently Asked Questions about n8n-code-javascript

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I write JavaScript in n8n Code nodes to transform data correctly?▼

JavaScript in n8n Code nodes supports built-in utilities like $helpers.httpRequest() for API interactions, Luxon DateTime for date formatting, and $jmespath() for data validation. These built-ins eliminate external dependencies during data transformation.

When should I use Run Once for All Items vs Run Once for Each Item in n8n?▼

n8n Code nodes support webhook handling and API calls through built-in utilities like $helpers.httpRequest(). You combine these with error handling patterns and safe data access via $input.item to process webhook payloads reliably.

Why does my n8n Code node return an error when processing input items?▼

n8n Code node errors often occur when JavaScript fails to return the correct format of an array containing {json: ...} objects. Enforcing safe data access patterns and proper return structures prevents these execution failures.

Does n8n support Luxon DateTime and $jmespath inside Code nodes?▼

Error handling in n8n Code nodes involves wrapping JavaScript logic in try-catch structures and validating data access patterns. This ensures robust workflow automation when processing per-item logic or batch API interactions.