Why does my n8n Code node return an error even when the logic is correct?

n8n requires a specific return format: an array of objects where each object contains a 'json' property (e.g., return [{json: {data}}]). Returning a plain object or string will cause the node to fail.

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

Yes, you can use the built-in $helpers.httpRequest() function, which is an asynchronous helper available within the node's environment for making external requests.

How do I access data from a Webhook node in my code?

Webhook data is nested under the '.body' property. You must use $json.body.fieldName or $input.first().json.body to access the payload correctly.

How do I handle dates in n8n Code nodes?

n8n includes the Luxon library as 'DateTime'. You can use it directly for formatting, parsing, and arithmetic (e.g., DateTime.now().plus({days: 1})) without any imports.

Which execution mode should I use: 'All Items' or 'Each Item'?

Use 'Run Once for All Items' for 95% of cases. It is faster, allows for data aggregation, and lets you loop through all input data in a single execution.

n8n JavaScript Code Expert

Name: n8n JavaScript Code Expert
Author: ProfSynapse

byProfSynapse

•

生産性とワークフロー

Simplifies writing, debugging, and optimizing custom JavaScript within n8n Code nodes for seamless workflow automation.

This skill provides expert guidance for implementing custom logic in n8n automation workflows, bridging the gap between standard JavaScript and n8n's specific runtime environment. It offers specialized patterns for data access, transformation, and error handling, ensuring that developers follow the strict 'array of objects' return requirements. Whether you are managing complex webhook payloads, performing date arithmetic with the built-in Luxon library, or aggregating data from multiple nodes, this skill ensures your custom code is performant, reliable, and properly structured for production environments.

主な機能

0136 GitHub stars

02Optimized templates for 'Run Once for All Items' and 'Run Once for Each Item' modes

03Implementation patterns for built-in helpers including $helpers.httpRequest and Luxon

04Validation for mandatory n8n return formats to prevent execution failures

05Precise data access patterns for $input, $json, and $node syntax

06Detailed instruction for handling nested webhook body data structures

ユースケース

01Transforming and filtering large datasets before passing them to downstream nodes

02Normalizing date formats and timezones across different platforms using the DateTime helper

03Aggregating data from multiple sources like webhooks and external APIs into unified reports

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add profsynapse/pact-prompt n8n-code-javascript

For use in Claude.ai and ChatGPT

Download Skill