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# sessionWatchStateDidChange(_:)

Indicates a change to the counterpart’s information.

```
optional func sessionWatchStateDidChange(_ session: WCSession)
```

## Parameters

`session`

The session object whose state changed.

## Discussion

The session object calls this method when the value in the [`isPaired`](/documentation/WatchConnectivity/WCSession/isPaired), [`isWatchAppInstalled`](/documentation/WatchConnectivity/WCSession/isWatchAppInstalled), [`isComplicationEnabled`](/documentation/WatchConnectivity/WCSession/isComplicationEnabled), or [`watchDirectoryURL`](/documentation/WatchConnectivity/WCSession/watchDirectoryURL) properties of the [`WCSession`](/documentation/WatchConnectivity/WCSession) object changes. Use this state to update the state of your iOS app. For example, when the complication is disabled, make a note of that fact and do not send any more data updates for the complication.

---

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