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# dataset.updateItem()

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

Updates an existing item in the dataset. Only the provided fields are updated. Updating an item creates a new version.

## Usage example

```typescript
import { Mastra } from '@mastra/core'

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

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

const updated = await dataset.updateItem({
  itemId: 'item-id',
  input: { question: 'What is TypeScript?' },
  groundTruth: { answer: 'A typed superset of JavaScript' },
  scorerIds: null,
  metadata: { reviewed: true },
})
```

## Parameters

**itemId** (`string`): ID of the item to update.

**input** (`unknown`): Updated input data.

**groundTruth** (`unknown`): Updated ground truth.

**expectedTrajectory** (`unknown`): Updated expected trajectory for trajectory scorers.

**toolMocks** (`DatasetItemToolMock[]`): Updated static tool mocks used during experiments. Each mock has toolName, args, output, and an optional matchArgs ('strict' | 'ignore').

**unmockedToolPolicy** (`'allow' | 'deny'`): Overrides how the experiment handles tool calls that are not declared in toolMocks.

**requestContext** (`Record<string, unknown>`): Updated request context applied when the item runs.

**scorerIds** (`string[] | null`): Scorer IDs that override dataset-attached scorers for this item. Use \[] to run no scorers, null to remove the override and restore dataset inheritance, or omit the field to preserve the current value.

**metadata** (`Record<string, unknown>`): Updated metadata.

**source** (`{ type: 'csv' | 'json' | 'trace' | 'llm' | 'experiment-result' | 'candidate-screener'; referenceId?: string }`): Updated provenance of the item.

## Returns

**result** (`Promise<DatasetItem>`): The updated dataset item. See dataset.addItem() for the item shape.