domains / families / agent-tooling / n8n-expression-syntax

n8n-expression-syntax

combined

Validate n8n expression syntax and fix common errors. Use when writing n8n expressions, using {{}} syntax, accessing $json/$node variables, troubleshooting expression errors, mapping data between nodes, or referencing webhook data in workflows. Use this skill whenever configuring node fields that reference data from previous nodes — expressions are how n8n passes data between nodes, and getting the syntax wrong is the most common source of workflow errors. Also use when asked whether a complex expression hurts performance. Validate n8n expression syntax and fix common errors. Use when writing n8n expressions, using {{}} syntax, accessing $json/$node variables, troubleshooting expression errors, or working with webhook data in workflows.

When to use

• You need to write or debug n8n expressions using `{{ ... }}` syntax.
• The task involves `$json`, `$node`, webhook payloads, or expression-related workflow errors.
• You want syntax-correct dynamic values inside n8n nodes and parameters.

When not to use

• Code nodes use **direct JavaScript access**, NOT expressions! ---
• Use this skill only when the task clearly matches the scope described above.
• Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
• Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.

Skill page

Conflict

The first copy is the substantive procedure: it defines the expression format, core variables, the critical webhook body structure, common patterns, and a detailed transform gatekeeper (expression vs IIFE vs Code node). The second copy is a thin wrapper that defers to a separate detailed guide, adds a risk label, and includes working examples and limitations, but it omits the core syntax rules and the transform gatekeeper. Crowning either one would hide a real alternative: the first has the deep reference, the second has the wrapper structure and examples.