n8n-expression-syntax

n8n webhook data is undefined when accessed directly because webhook payloads live under the .body property. You must reference input data safely using explicit patterns like {{$json.body.name}} to avoid silent failures and ensure correct data extraction.

To reference data from another node in n8n expressions, use the $node variable with the exact node name in brackets, such as {{$node["HTTP Request"].json.data}}. This cross-node reference pattern ensures accurate data access across your workflow.

The correct syntax for n8n expressions with spaces in key names requires strict use of double curly braces and bracket notation. Properly wrapping keys ensures safe workflow execution and prevents runtime errors when accessing nested fields or array data.

Fix common n8n expression mistakes in Code nodes by applying clear rules for double curly braces and correct $json access patterns. Following explicit data reference practices prevents silent data issues and ensures reliable workflow execution.

Yes, you can use n8n expressions to validate webhook body data before processing by applying explicit handling patterns to access .body properties. This error-prevention practice reduces silent failures and ensures undefined values are caught safely.