What problem does it solve?
Many n8n users write JavaScript in Code nodes incorrectly or inefficiently, causing runtime errors, malformed outputs, and fragile workflows. This Skill reduces onboarding friction and prevents common mistakes by teaching correct data access patterns, return formats, and safe handling of webhook and API data.
Core Features & Use Cases
- Mode selection guidance for choosing Run Once for All Items vs Run Once for Each Item and why it matters for performance.
- Data access patterns ($input.all(), $input.first(), $input.item, $node) with the critical webhook .body gotcha.
- Built-in helpers & examples: how to use $helpers.httpRequest, DateTime (Luxon), $jmespath, and $getWorkflowStaticData in real workflows.
- Error prevention: required return format, null-safety checks, unmatched-bracket avoidance, and the top error patterns with fixes.
- Production patterns: 10 reusable patterns for aggregation, parsing, ranking, Slack formatting, CRM transformation, and release parsing.
Quick Start
Use the n8n-code-javascript guidance to validate a Code node that aggregates webhook payloads, calls an external API with $helpers.httpRequest, and returns a properly formatted array of objects each containing a json property.
