---
title: startRunning()
framework: avfoundation
role: symbol
role_heading: Instance Method
path: avfoundation/avcapturesession/startrunning()
---

# startRunning()

Starts the flow of data through the capture pipeline.

## Declaration

```swift
func startRunning()
```

## Mentioned in

Setting up a capture session

## Discussion

Discussion Call this method to start the flow of data from the capture session’s inputs to its outputs. This method is synchronous and blocks until the session starts running or it fails, which it reports by posting an runtimeErrorNotification notification.

## See Also

### Managing the session life cycle

- [stopRunning()](avfoundation/avcapturesession/stoprunning().md)