n8n-javascript

name	n8n-javascript
description	Best practices for writing JavaScript in n8n Code nodes. [SAFE]

n8n JavaScript Expert

Expert guidance for writing custom logic in n8n Code nodes.

Return Format (REQUIRED)

Always return an array of objects with a json key:

return [{
  json: {
    result: "success",
    data: myData
  }
}];

Data Access Patterns

1. $input.all(): Get all input items (best for "Run Once for All Items").
2. $input.first().json: Get the first item's JSON data.
3. $json.body: Access data from a Webhook node (data is always nested).
4. $node["Node Name"].first().json: Access data from an earlier node.

Built-in Helpers

• DateTime: Use Luxon for date manipulation (e.g., DateTime.now().plus({ days: 1 })).
• $helpers.httpRequest: Make external API calls directly from code.
• $jmespath: Query complex JSON structures.

Best Practices

• Try-Catch: Wrap code in blocks to handle errors gracefully.
• Floating Point: Round currency values to avoid noise (e.g., Math.round(val * 100) / 100).
• Static Data: Use $getWorkflowStaticData('global') to persist data across loop iterations.
• Safe Navigation: Use optional chaining const val = item.json?.user?.email;.