# dataset.addItem()

**Added in:** `@mastra/core@1.4.0`

Adds a single item to the dataset. Each item has an input, optional ground truth, and optional metadata.

## Usage example

```typescript
import { Mastra } from "@mastra/core";

const mastra = new Mastra({ /* storage config */ });

const dataset = await mastra.datasets.get({ id: "dataset-id" });

const item = await dataset.addItem({
  input: { question: "What is TypeScript?" },
  groundTruth: { answer: "A typed superset of JavaScript" },
  metadata: { source: "manual" },
});

console.log(item.id);
```

## Parameters

**input:** (`unknown`): Input data for the item.

**groundTruth?:** (`unknown`): Expected output or ground truth for scoring.

**metadata?:** (`Record<string, unknown>`): Arbitrary metadata for the item.

## Returns

**result:** (`Promise<DatasetItem>`): DatasetItemid:stringUnique identifier of the item.datasetId:stringID of the parent dataset.datasetVersion:numberDataset version when the item was created.input:unknownInput data.groundTruth?:unknownGround truth data.metadata?:Record\<string, unknown>Item metadata.createdAt:DateWhen the item was created.updatedAt:DateWhen the item was last updated.