n8n-code-javascript

Use $input.all() to process all items as an array, $input.first() for single-item operations, or $input.item in Run Once for Each Item mode. Access fields via the .json property, such as $input.first().json.fieldName.

Code nodes must return an array of objects where each object has a json property, in the format [{json: {...}}]. Returning a plain object or an array without the json wrapper causes validation errors.

Webhook node output nests the payload under a body property, so $json.name returns undefined. Access the data via $json.body.name or extract the body first before processing fields.

No, expression syntax with double curly braces only works in other nodes like Set or IF. Code nodes use plain JavaScript, so write $json.field directly or use template literals with backticks for string interpolation.

Use the built-in $helpers.httpRequest() function with method, url, headers, and body options. External npm packages like axios are not available, so this helper is the supported way to call APIs from code.

Use a Code node for complex transformations, multi-step logic, aggregations, or recursive operations. For simple field mapping, filtering, or conditionals, the Set, Filter, IF, or Switch nodes are more appropriate.