What problem does it solve? Writing n8n expressions often leads to silent failures: missing curly braces, wrong webhook data paths, broken node references, and expressions mistakenly used inside Code nodes. This Skill provides the correct syntax rules, a catalog of 15 common mistakes with fixes, and real workflow examples so expressions resolve to actual values instead of literal text or undefined. ## Core Features & Use Cases - Syntax Validation Rules: Covers the {{ }} format, core variables ($json, $node, $now, $env), bracket notation for names with spaces, and case-sensitive node references. - Webhook Data Gotcha: Documents the critical rule that webhook payloads live under $json.body, the single most common source of undefined values. - Error Catalog & Examples: Includes COMMON_MISTAKES.md with 15 diagnosed errors and EXAMPLES.md with 10 working scenarios (webhook to Slack, HTTP to database, date formatting, array operations). - Use Case: When a Slack node shows "{{$json.name}}" as literal text or returns undefined from a webhook, use this Skill to identify the missing braces or the missing .body path and correct the expression. ## Quick Start Ask the AI to check why your n8n expression returns undefined or literal text, and have it rewrite the expression using correct {{ }} syntax and webhook .body paths.
