---
title: start()
framework: watchkit
role: symbol
role_heading: Instance Method
path: watchkit/wkextendedruntimesession/start()
---

# start()

Starts running the session.

## Declaration

```swift
func start()
```

## Mentioned in

Using extended runtime sessions

## Discussion

Discussion Use start() to begin a session. You must call this method while your app is running in the foreground. You can’t use the start() method to set up a schedulable session (such as a smart alarm session). Call the start(at:) method instead.

## See Also

### Managing the Session State

- [start(at:)](watchkit/wkextendedruntimesession/start(at:).md)
- [invalidate()](watchkit/wkextendedruntimesession/invalidate().md)
- [state](watchkit/wkextendedruntimesession/state.md)
- [WKExtendedRuntimeSessionState](watchkit/wkextendedruntimesessionstate.md)
- [expirationDate](watchkit/wkextendedruntimesession/expirationdate.md)
- [requestAutoLaunchAuthorizationStatus(completion:)](watchkit/wkextendedruntimesession/requestautolaunchauthorizationstatus(completion:).md)
- [WKExtendedRuntimeSessionAutoLaunchAuthorizationStatus](watchkit/wkextendedruntimesessionautolaunchauthorizationstatus.md)