n8n-code-javascript

Access input data with $input.all() or $input.first(), process it with standard JavaScript, and return an array of objects wrapped in a json property like [{json: {field: value}}]. Choose "Run Once for All Items" mode for most use cases.

Run Once for All Items executes the code once with access to all items via $input.all(), ideal for aggregation and batch processing. Run Once for Each Item executes separately per item via $input.item, suited for independent per-item operations.

Webhook data in n8n is nested under the body property, so $json.email returns undefined. Access webhook fields with $json.body.email or $input.first().json.body instead.

Yes, use the built-in $helpers.httpRequest() method with method, url, and headers options. Wrap the call in try-catch to handle request failures and return errors in the standard [{json: ...}] format.

Avoid the Code node for simple field mapping, basic filtering, or simple conditionals. Use the Set node for mapping, the Filter node for filtering, and IF or Switch nodes for conditionals instead.