What problem does it solve? Writing n8n expressions often leads to silent failures: literal text instead of values, undefined webhook fields, and broken node references. This Skill teaches correct {{ }} expression syntax and catalogs the 15 most common mistakes with fixes, including the critical webhook .body data structure gotcha. ## Core Features & Use Cases - Syntax Validation Rules: Covers the core variables ($json, $node, $now, $env), bracket notation for names with spaces, and case-sensitive node references. - Error Catalog: 15 documented mistakes with wrong/correct examples, a quick-reference fix table, and a step-by-step debugging process. - Real Workflow Examples: 10 working examples including webhook-to-Slack, HTTP-to-database, date formatting, array operations, and conditional logic. - Use Case: A user builds a webhook-to-Slack workflow but sees "undefined" for submitted form fields; the Skill identifies that webhook data lives under $json.body and provides the corrected expression. ## Quick Start Ask the AI to check why your n8n expression {{$json.name}} returns undefined in a webhook workflow and show the corrected syntax.
