# DatasetsManager

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

The `DatasetsManager` class provides the public API for managing datasets, including CRUD operations and cross-dataset experiment comparisons. Access it via `mastra.datasets`.

## Usage examples

### Create and list datasets

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

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

// Create a dataset
const dataset = await mastra.datasets.create({
  name: "QA pairs",
  description: "Question-answer evaluation set",
});

// List all datasets
const { datasets } = await mastra.datasets.list();
```

### Get and delete a dataset

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

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

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

// Delete by ID
await mastra.datasets.delete({ id: "dataset-id" });
```

### Get experiment

Retrieves a specific experiment (run) by ID. Unlike `dataset.getExperiment()`, this works across all datasets without needing a dataset reference first.

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

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

// Get experiment directly without knowing the dataset
const experiment = await mastra.datasets.getExperiment({
  experimentId: "exp-id",
});

console.log(`Dataset: ${experiment.datasetId}`);
console.log(`Status: ${experiment.status}`);
```

### Compare experiments

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

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

const comparison = await mastra.datasets.compareExperiments({
  experimentIds: ["exp-1", "exp-2"],
  baselineId: "exp-1",
});
```

## Access

`DatasetsManager` is not instantiated directly. Access it from a `Mastra` instance:

```typescript
const mastra = new Mastra({ /* storage config */ });
const datasetsManager = mastra.datasets;
```

## Related

- [Dataset class](https://mastra.ai/reference/datasets/dataset)
- [DatasetsManager.create()](https://mastra.ai/reference/datasets/create)
- [DatasetsManager.compareExperiments()](https://mastra.ai/reference/datasets/compareExperiments)