> For the complete documentation index, see [llms.txt](https://docs.n8n.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.n8n.io/build/work-with-data/reference-data/link-data-items/preserving-linking-in-the-code-node.md).

# Preserving linking in the Code node

When referencing a previous node you need to know which item to use. This is solved by item linking. Most nodes automatically link every output item to an input item, creating a chain of items that you can work back along to access previous items. For a deeper conceptual overview of this topic, refer to [Item linking concepts](/build/work-with-data/reference-data/link-data-items/how-items-link-through-workflows.md). This document focuses on practical usage examples.

When using the Code node, there are some scenarios where you need to manually supply item linking information if you want to be able to use `$("<node-name>").item` later in the workflow. All these scenarios only apply if you have more than one incoming item. n8n automatically handles item linking for single items.

These scenarios are when you:

* Add new items: the new items aren't linked to any input.
* Return new items.
* Want to manually control the item linking.

[n8n's automatic item linking](/build/work-with-data/reference-data/link-data-items/how-items-link-through-workflows.md) handles the other scenarios.

To control item linking, set `pairedItem` when returning data. For example, to link to the item at index 0:

```js
[
	{
		"json": {
			. . . 
		},
		// The index of the input item that generated this output item
		"pairedItem": 0
	}
]
```

#### `pairedItem` usage example <a href="#paireditem-usage-example" id="paireditem-usage-example"></a>

Take this input data:

```json
[
  {
    "id": "23423532",
    "name": "Jay Gatsby"
  },
  {
    "id": "23423533",
    "name": "José Arcadio Buendía"
  },
  {
    "id": "23423534",
    "name": "Max Sendak"
  },
  {
    "id": "23423535",
    "name": "Zaphod Beeblebrox"
  },
  {
    "id": "23423536",
    "name": "Edmund Pevensie"
  }
]
```

And use it to generate new items, containing just the name, along with a new piece of data:

```js
newItems = [];
for(let i=0; i<items.length; i++){
  newItems.push(
    {
    "json":
      {
        "name": items[i].json.name,
				"aBrandNewField": "New data for item " + i
      }
    }
  )
}

return newItems;
```

`newItems` is an array of items with no `pairedItem`. This means there's no way to trace back from these items to the items used to generate them.

Add the `pairedItem` object:

```js
newItems = [];
for(let i=0; i<items.length; i++){
  newItems.push(
    {
      "json":
        {
          "name": items[i].json.name,
					"aBrandNewField": "New data for item " + i
        },
      "pairedItem": i
    }    
  )
}
return newItems;
```

Each new item now links to the item used to create it.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.n8n.io/build/work-with-data/reference-data/link-data-items/preserving-linking-in-the-code-node.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.