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# start()

Starts running the session.

```
func start()
```

## Discussion

Use [`start()`](/documentation/WatchKit/WKExtendedRuntimeSession/start()) to begin a session. You must call this method while your app is running in the foreground.

You can’t use the [`start()`](/documentation/WatchKit/WKExtendedRuntimeSession/start()) method to set up a schedulable session (such as a smart alarm session). Call the [`start(at:)`](/documentation/WatchKit/WKExtendedRuntimeSession/start(at:)) method instead.

---

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