n8n-code-javascript

Use $input.all() to process all items as an array, $input.first() for a single item, or $input.item when running in Each Item mode. Access fields through the .json property, for example $input.first().json.fieldName.

The Code node 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 fields via $json.body.name or extract the body first with const data = $input.first().json.body.

No, expression syntax with double curly braces only works in other nodes like Set or IF. Inside Code nodes, write plain JavaScript such as $json.field, and 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 directly 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.