ba-n8n-expression-syntax

Identify and fix incorrect n8n expressions for predictable workflow data access.

Updated Apr 12, 2026
One-click install
npx skills add https://github.com/clovernguyen1010-ship-it/Clover_Nguyen --skill ba-n8n-expression-syntax-clovernguyen1010-ship-it
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: ba-n8n-expression-syntax
Source: https://github.com/clovernguyen1010-ship-it/Clover_Nguyen/tree/main/.agent/skills/ba-n8n-expression-syntax
Command: npx skills add https://github.com/clovernguyen1010-ship-it/Clover_Nguyen --skill ba-n8n-expression-syntax-clovernguyen1010-ship-it

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

n8n expression syntax is error-prone and often leads to incorrect data extraction, especially with webhook payloads and cross-node references. This guide teaches correct usage and common fixes.

Core Features & Use Cases

  • Clear guidance on using {{ }} expressions with $json, $node, and $now.
  • Troubleshooting patterns for webhook data structure and node references.
  • Real-world examples illustrating common mistakes and their fixes.

Quick Start

Review your current workflow and apply the correct expression patterns to validate data extraction.

Frequently Asked Questions about ba-n8n-expression-syntax

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
Why does my n8n webhook expression return undefined or empty data?▼

n8n webhook expressions return undefined when the payload is accessed incorrectly. You must use the .body property within your $json expression to properly extract incoming webhook data.

How do I fix n8n expression syntax errors with spaces and arrays?▼

To fix n8n expression syntax errors, ensure your {{ }} expressions are formatted correctly. Common mistakes involve improper spacing and incorrect array indexing, which disrupt predictable data access.

How do I correctly reference data from previous nodes using n8n expressions?▼

To reference data from previous nodes in n8n expressions, use the $node variable with proper quoting and exact casing. This enforces correct cross-node data retrieval and prevents referencing errors.

What is the correct syntax for n8n expressions using $json and $now?▼

The correct syntax for n8n expressions requires wrapping variables like $json and $now in double curly braces {{ }}. This ensures the workflow automation platform properly evaluates and injects the data.

How do I troubleshoot incorrect data extraction in n8n workflow automation?▼

To troubleshoot incorrect data extraction in n8n workflow automation, validate your {{ }} expressions, ensure .body is used for webhook payloads, and check $node references for casing and quoting errors.