_snippets/data/data-mapping/item-linking-node-creators.md

/// note | Programmatic-style nodes only
This guidance applies to programmatic-style nodes. If you're using declarative style, n8n handles paired items for you automatically.
///

Use n8n's item linking to access data from items that precede the current item. n8n needs to know which input item a given output item comes from. If this information is missing, expressions in other nodes may break. As a node developer, you must ensure any items returned by your node support this. 

This applies to programmatic nodes (including trigger nodes). You don't need to consider item linking when building a declarative-style node. Refer to [Choose your node building approach](/integrations/creating-nodes/plan/choose-node-method.md) for more information on node styles.

Start by reading [Item linking concepts](/data/data-mapping/data-item-linking/item-linking-concepts.md), which provides a conceptual overview of item linking, and details of the scenarios where n8n can handle the linking automatically.

If you need to handle item linking manually, do this by setting `pairedItem` on each item your node returns:

```typescript
// Use the pairedItem information of the incoming item
newItem = {
	"json": { . . . },
	"pairedItem": {
		"item": item.pairedItem,
		// Optional: choose the input to use
		// Set this if your node combines multiple inputs
		"input": 0
};

// Or set the index manually
newItem = {
		"json": { . . . }
		"pairedItem": {
			"item": i,
			// Optional: choose the input to use
			// Set this if your node combines multiple inputs
			"input": 0
		},
};
```