# Class Index # Class Index *** ** * ** *** [Kotlin](https://developer.android.com/reference/kotlin/crossdevice/classes "View this page in Kotlin")\|Java These are all the API classes. See all[API packages](https://developer.android.com/reference/crossdevice/packages). [A](https://developer.android.com/reference/crossdevice/classes#letter_A)[C](https://developer.android.com/reference/crossdevice/classes#letter_C)[D](https://developer.android.com/reference/crossdevice/classes#letter_D)[E](https://developer.android.com/reference/crossdevice/classes#letter_E)[M](https://developer.android.com/reference/crossdevice/classes#letter_M)[O](https://developer.android.com/reference/crossdevice/classes#letter_O)[P](https://developer.android.com/reference/crossdevice/classes#letter_P)[R](https://developer.android.com/reference/crossdevice/classes#letter_R)[S](https://developer.android.com/reference/crossdevice/classes#letter_S)[T](https://developer.android.com/reference/crossdevice/classes#letter_T) ## A |----------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------| | [ApplicationSessionTag](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/ApplicationSessionTag) | An identifier that allows apps to differentiate between multiple types of sessions. | | [ApplicationSessionTagMatcher](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/ApplicationSessionTagMatcher) | Defines how two[ApplicationSessionTag](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/ApplicationSessionTag)should be matched. | ## C |---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------| | [ConnectionReceiver](https://developer.android.com/reference/com/google/ambient/crossdevice/connections/ConnectionReceiver) | Receiver callback for a[RemoteConnection](https://developer.android.com/reference/com/google/ambient/crossdevice/connections/RemoteConnection). | | [ConnectionType](https://developer.android.com/reference/com/google/ambient/crossdevice/connections/ConnectionType) | The type of the connection. | | [ConnectionsException](https://developer.android.com/reference/com/google/ambient/crossdevice/connections/ConnectionsException) | Exception for connections requests. | | [ConnectionsException.Companion](https://developer.android.com/reference/com/google/ambient/crossdevice/connections/ConnectionsException.Companion) | | | [ConnectionsException.ConnectionsErrorCode](https://developer.android.com/reference/com/google/ambient/crossdevice/connections/ConnectionsException.ConnectionsErrorCode) | | | [CrossDeviceException](https://developer.android.com/reference/com/google/ambient/crossdevice/CrossDeviceException) | Base exception type for Cross device APIs. | ## D |-------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [DeviceFilter](https://developer.android.com/reference/com/google/ambient/crossdevice/discovery/DeviceFilter) | A DeviceFilter is a restriction on which devices should be shown in a call to[Discovery.registerForResult](https://developer.android.com/reference/com/google/ambient/crossdevice/discovery/Discovery#registerForResult(androidx.activity.result.ActivityResultCaller,com.google.ambient.crossdevice.discovery.Discovery.OnDevicePickerResultListener)). | | [DeviceFilter.Companion](https://developer.android.com/reference/com/google/ambient/crossdevice/discovery/DeviceFilter.Companion) | | | [DevicePickerLauncher](https://developer.android.com/reference/com/google/ambient/crossdevice/discovery/DevicePickerLauncher) | A launcher to start a device discovery and show a dialog chooser to display available devices. | | [Discovery](https://developer.android.com/reference/com/google/ambient/crossdevice/discovery/Discovery) | Entry point for discovering devices. | | [Discovery.Companion](https://developer.android.com/reference/com/google/ambient/crossdevice/discovery/Discovery.Companion) | | | [Discovery.OnDevicePickerResultListener](https://developer.android.com/reference/com/google/ambient/crossdevice/discovery/Discovery.OnDevicePickerResultListener) | Interface to receive the result from the device picker, for use with[registerForResult](https://developer.android.com/reference/com/google/ambient/crossdevice/discovery/Discovery#registerForResult(androidx.activity.result.ActivityResultCaller,com.google.ambient.crossdevice.discovery.Discovery.OnDevicePickerResultListener)). | ## E |----------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [ExactSessionTagMatcher](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/ExactSessionTagMatcher) | An[ApplicationSessionTagMatcher](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/ApplicationSessionTagMatcher)that matches[ApplicationSessionTag](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/ApplicationSessionTag)objects when their[ApplicationSessionTag.sessionTag](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/ApplicationSessionTag#sessionTag())strings are the same. | ## M |------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [MatchEverythingSessionTagMatcher](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/MatchEverythingSessionTagMatcher) | An[ApplicationSessionTagMatcher](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/ApplicationSessionTagMatcher)that always returns true. | ## O |----------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------| | [OriginatingSession](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/OriginatingSession) | Describes a Session that is in the process of being transferred to another device. | | [OriginatingSessionStateCallback](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/OriginatingSessionStateCallback) | Clients of Sessions should implement`OriginatingSessionStateCallback`to receive notifications of Session state changes when transferring a Session. | ## P |--------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [Participant](https://developer.android.com/reference/com/google/ambient/crossdevice/Participant) | An opaque handle that represents a participant in a cross device experience. | | [PrimarySession](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/PrimarySession) | When a Session becomes shared with one or more devices, this interface represents the Primary device (the Session owner). | | [PrimarySessionStateCallback](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/PrimarySessionStateCallback) | Clients of Sessions should implement`PrimarySessionStateCallback`to receive notifications of Session state changes when acting as the Primary for a Shared Session. | ## R |------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------| | [ReceivingSession](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/ReceivingSession) | Describes a Session that is in the process of being transferred to another device. | | [ReceivingSessionStateCallback](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/ReceivingSessionStateCallback) | Clients of Sessions should implement`ReceivingSessionStateCallback`to receive notifications of Session state changes when transferring a Session. | | [RemoteConnection](https://developer.android.com/reference/com/google/ambient/crossdevice/connections/RemoteConnection) | A connection to a remote device, used for sending and receiving payloads. | ## S |--------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [SecondarySession](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/SecondarySession) | When a Session becomes shared with one or more devices, this interface represents a secondary device (a device that has joined an existing Session). | | [SecondarySessionStateCallback](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/SecondarySessionStateCallback) | Clients of Sessions should implement`SecondarySessionStateCallback`to receive notifications of Session state changes when acting as the Secondary for a shared Session. | | [SessionConnectionReceiver](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/SessionConnectionReceiver) | Receiver callback for a[SessionRemoteConnection](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/SessionRemoteConnection). | | [SessionException](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/SessionException) | Exception for session requests. | | [SessionException.Companion](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/SessionException.Companion) | | | [SessionException.SessionErrorCode](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/SessionException.SessionErrorCode) | | | [SessionId](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/SessionId) | An identifier that uniquely describes an individual Session. | | [SessionId.Companion](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/SessionId.Companion) | | | [SessionParticipant](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/SessionParticipant) | Represents an individual device that is participating in a Session. | | [SessionRemoteConnection](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/SessionRemoteConnection) | A connection to a remote device that is participating in a Session. | | [SessionStateCallback](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/SessionStateCallback) | Grants access to client-provided callbacks[OriginatingSessionStateCallback](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/OriginatingSessionStateCallback),[ReceivingSessionStateCallback](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/ReceivingSessionStateCallback),[PrimarySessionStateCallback](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/PrimarySessionStateCallback)and[SecondarySessionStateCallback](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/SecondarySessionStateCallback). | | [Sessions](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/Sessions) | Entry-point for creating and interacting with Sessions. | | [Sessions.Companion](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/Sessions.Companion) | | | [StartComponentRequest](https://developer.android.com/reference/com/google/ambient/crossdevice/wakeup/StartComponentRequest) | A request to wake up a specified component on another device, and optionally deliver additional information to it. | | [StartComponentRequest.Builder](https://developer.android.com/reference/com/google/ambient/crossdevice/wakeup/StartComponentRequest.Builder) | | ## T |------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------| | [TransferrableSession](https://developer.android.com/reference/com/google/ambient/crossdevice/sessions/TransferrableSession) | Describes methods that are common to both originating and receiving sides of a Session transfer. |