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.
Expert guide for writing correct n8n expressions in workflows.
{{ ... }} syntax.$json, $node, webhook payloads, or expression-related workflow errors.All dynamic content in n8n uses double curly braces:
{{expression}}
Examples:
✅ {{$json.email}}
✅ {{$json.body.name}}
✅ {{$node["HTTP Request"].json.data}}
❌ $json.email (no braces - treated as literal text)
❌ {$json.email} (single braces - invalid)
Access data from the current node:
{{$json.fieldName}}
{{$json['field with spaces']}}
{{$json.nested.property}}
{{$json.items[0].name}}
Access data from any previous node:
{{$node["Node Name"].json.fieldName}}
{{$node["HTTP Request"].json.data}}
{{$node["Webhook"].json.body.email}}
Important:
Access current date/time:
{{$now}}
{{$now.toFormat('yyyy-MM-dd')}}
{{$now.toFormat('HH:mm:ss')}}
{{$now.plus({days: 7})}}
Access environment variables:
{{$env.API_KEY}}
{{$env.DATABASE_URL}}
Most Common Mistake: Webhook data is NOT at the root!
{
"headers": {...},
"params": {...},
"query": {...},
"body": { // ⚠️ USER DATA IS HERE!
"name": "John",
"email": "[email protected]",
"message": "Hello"
}
}
❌ WRONG: {{$json.name}}
❌ WRONG: {{$json.email}}
✅ CORRECT: {{$json.body.name}}
✅ CORRECT: {{$json.body.email}}
✅ CORRECT: {{$json.body.message}}
Why: Webhook node wraps incoming data under .body property to preserve headers, params, and query parameters.
// Simple nesting
{{$json.user.email}}
// Array access
{{$json.data[0].name}}
{{$json.items[0].id}}
// Bracket notation for spaces
{{$json['field name']}}
{{$json['user data']['first name']}}
// Node without spaces
{{$node["Set"].json.value}}
// Node with spaces (common!)
{{$node["HTTP Request"].json.data}}
{{$node["Respond to Webhook"].json.message}}
// Webhook node
{{$node["Webhook"].json.body.email}}
// Concatenation (automatic)
Hello {{$json.body.name}}!
// In URLs