# Token refresh

At initialization of the MOVE SDK valid [MoveAuth](https://docs.movesdk.com/move-platform/sdk/models/moveauth) credentials is required. The `accessToken` is only valid for a short period of time. With the `refreshToken`, the MOVE SDK tries to get a new `accessToken`. This can be done as long as the `refreshToken` is valid. \
\
As soon as it is not possible anymore to get a new `accessToken`, the host application will be notified via the *AuthStateUpdateListener* ([Android](https://docs.movesdk.com/move-platform/api-interface/android/initialization#dolphinsdk.builderv1.1-initializationinitializationlistener-1) / [iOS](https://docs.movesdk.com/move-platform/api-interface/ios/setup#set-sdk-auth-state-listener) / [React](https://docs.movesdk.com/move-platform/api-interface/react-native/services#set-sdk-auth-state-listener)) and the [MoveAuthState ](https://docs.movesdk.com/move-platform/sdk/models/moveauthstate)changes to *Expired.* When this happens, the host app is responsible to provide new [MoveAuth ](https://docs.movesdk.com/move-platform/sdk/models/moveauth)credentials and pass it to the MOVE SDK at initialization or via `updateAuth` ([Android](https://docs.movesdk.com/move-platform/api-interface/android/services#update-authentication) / [iOS](https://docs.movesdk.com/move-platform/api-interface/ios/setup#update-authentication) / [React](https://docs.movesdk.com/move-platform/api-interface/react-native/services#update-authentication)).\
\
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 the MOVE SDK is unable to transmit any data.