---
title: "sessionStarted(_:)"
framework: Accessory Transport Extension
role: symbol
role_heading: Instance Method
platforms: [iOS 27.3+]
path: "accessorytransportextension/accessoryfeatureruntimesessionhandler/sessionstarted(_:)"
---

# sessionStarted(_:)

Notifies the handler when its feature session starts.

## Declaration

```swift
func sessionStarted(_ session: Self.Session)
```

## Parameters

- `session`: The session that starts. Hold a weak reference to this parameter because the doc://com.apple.accessorytransportextension/documentation/AccessoryTransportExtension/AccessoryTransportSession/makeFeatureSession(_:) caller owns it.

## Mentioned in

Sending data to an accessory in the background

## Discussion

Discussion The system calls this method once the session activates and your app enrolls the feature.

## See Also

### Handling the session life cycle

- [sessionInvalidated(error:)](accessorytransportextension/accessoryfeatureruntimesessionhandler/sessioninvalidated(error:).md)