n8n-expression-syntax

Write correct n8n expressions with double braces, proper variable syntax, and webhook data access patterns. Expert guide for writing correct n8n expressions in workflows. All dynamic content in n8n uses double curly braces : Examples : Access data from the current node: Access data from any previous node: Important : Access current date/time: Access environment variables: Warning : Some n8n instances have N8N_BLOCK_ENV_ACCESS_IN_NODE enabled, which blocks $env access entirely. If $env returns errors, use alternative approaches: Most Common Mistake : Webhook data is NOT at the root! Why : Webhook node wraps incoming data under .body property to preserve headers, params, and query parameters. Code nodes use direct JavaScript access , NOT expressions! Expressions must be wrapped in double curly braces. Field or node names with spaces, diacritics, or special characters require bracket notation : Node references are case-sensitive : Don't double-wrap expressions: For complete error catalog with fixes, see COMMON_MISTAKES.md For real workflow examples, see EXAMPLES.md Webhook receives : In Slack node text field : HTTP Request returns : In Email node (reference HTTP Request): "Cannot read property 'X' of undefined" → Parent object doesn't exist → Check your data path "X is not a function" → Trying to call method on non-function → Check variable type Expression shows as literal text →...