# Token refresh

At initialization of the MOVE SDK valid credentials [MoveAuth](https://docs.movesdk.com/move-platform/~/changes/1lLi1pFRKkteajbXv0hC/sdk/models/moveauth) is required. The accessToken is only valid for a short period of time. With the refresh token, the MOVE SDK tries to get a new accessToken. This can be done as long as the refreshToken is valid. \
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As soon as it is not possible anymore to get a new accessToken, the host application will be notified via the *AuthStateUpdateListener* and the [MoveAuthState ](https://docs.movesdk.com/move-platform/~/changes/1lLi1pFRKkteajbXv0hC/sdk/models/moveauthstate)changes to *Expired.* When this happens, the host app is responsible to provide new [MoveAuth ](https://docs.movesdk.com/move-platform/~/changes/1lLi1pFRKkteajbXv0hC/sdk/models/moveauth)credentials and pass it to the MOVE SDK at initialization or via [updateAuth](https://docs.movesdk.com/move-platform/~/changes/1lLi1pFRKkteajbXv0hC/api-interface/android-1/android#update-authentication).\
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The MOVE SDK keeps collecting data and trips as long as the SDK remains in state Running. A token expiry will not stop the detection, but is unable to transmit any data.