# dataset.startExperimentAsync()

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

Starts an experiment asynchronously (fire-and-forget). Returns immediately with the experiment ID and a `'pending'` status. The experiment runs in the background.

## Usage example

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

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

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

// Start experiment without waiting
const { experimentId, status } = await dataset.startExperimentAsync({
  targetType: "agent",
  targetId: "my-agent",
  scorers: ["accuracy"],
});

console.log(`Experiment ${experimentId} started with status: ${status}`);

// Check progress later
const experiment = await dataset.getExperiment({ experimentId });
console.log(`Current status: ${experiment.status}`);
```

## Parameters

Takes the same `StartExperimentConfig` as [`dataset.startExperiment()`](https://mastra.ai/reference/datasets/startExperiment).

## Returns

**result:** (`Promise<object>`): objectexperimentId:stringUnique ID of the created experiment.status:'pending'Always \`'pending'\` since the experiment hasn't started executing yet.

## Related

- [dataset.startExperiment()](https://mastra.ai/reference/datasets/startExperiment)
- [dataset.getExperiment()](https://mastra.ai/reference/datasets/getExperiment)