diff --git a/src/com/android/server/telecom/Call.java b/src/com/android/server/telecom/Call.java
index b88711e..2a65afe 100644
--- a/src/com/android/server/telecom/Call.java
+++ b/src/com/android/server/telecom/Call.java
@@ -29,9 +29,11 @@
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Looper;
+import android.os.OutcomeReceiver;
 import android.os.ParcelFileDescriptor;
 import android.os.Parcelable;
 import android.os.RemoteException;
+import android.os.ResultReceiver;
 import android.os.SystemClock;
 import android.os.Trace;
 import android.os.UserHandle;
@@ -92,7 +94,6 @@
  *  from the time the call intent was received by Telecom (vs. the time the call was
  *  connected etc).
  */
-@VisibleForTesting
 public class Call implements CreateConnectionResponse, EventManager.Loggable,
         ConnectionServiceFocusManager.CallFocus {
     public final static String CALL_ID_UNKNOWN = "-1";
@@ -381,6 +382,8 @@
      */
     private ConnectionServiceWrapper mConnectionService;
 
+    private TransactionalServiceWrapper mTransactionalService;
+
     private boolean mIsEmergencyCall;
 
     // The Call is considered an emergency call for testing, but will not actually connect to
@@ -529,6 +532,8 @@
      */
     private boolean mIsSelfManaged = false;
 
+    private boolean mIsTransactionalCall = false;
+
     /**
      * Indicates whether the {@link PhoneAccount} associated with an self-managed call want to
      * expose the call to an {@link android.telecom.InCallService} which declares the metadata
@@ -1038,7 +1043,7 @@
 
     @Override
     public ConnectionServiceFocusManager.ConnectionServiceFocus getConnectionServiceWrapper() {
-        return mConnectionService;
+        return (!mIsTransactionalCall ? mConnectionService : mTransactionalService);
     }
 
     @VisibleForTesting
@@ -1767,6 +1772,25 @@
         setConnectionProperties(getConnectionProperties());
     }
 
+    public boolean isTransactionalCall() {
+        return mIsTransactionalCall;
+    }
+
+    public void setIsTransactionalCall(boolean isTransactionalCall) {
+        mIsTransactionalCall = isTransactionalCall;
+
+        // Connection properties will add/remove the PROPERTY_SELF_MANAGED.
+        setConnectionProperties(getConnectionProperties());
+    }
+
+    public void setTransactionServiceWrapper(TransactionalServiceWrapper service) {
+        mTransactionalService = service;
+    }
+
+    public TransactionalServiceWrapper getTransactionServiceWrapper() {
+        return mTransactionalService;
+    }
+
     public boolean visibleToInCallService() {
         return mVisibleToInCallService;
     }
@@ -2044,8 +2068,10 @@
                     createRttStreams();
                     // Call startRtt to pass the RTT pipes down to the connection service.
                     // They already turned on the RTT property so no request should be sent.
-                    mConnectionService.startRtt(this,
-                            getInCallToCsRttPipeForCs(), getCsToInCallRttPipeForCs());
+                    if (mConnectionService != null) {
+                        mConnectionService.startRtt(this,
+                                getInCallToCsRttPipeForCs(), getCsToInCallRttPipeForCs());
+                    }
                     mWasEverRtt = true;
                     if (isEmergencyCall()) {
                         mCallsManager.mute(false);
@@ -2146,7 +2172,6 @@
         return mConferenceLevelActiveCall;
     }
 
-    @VisibleForTesting
     public ConnectionServiceWrapper getConnectionService() {
         return mConnectionService;
     }
@@ -2462,7 +2487,10 @@
                 // Override the disconnect cause to MISSED
                 setOverrideDisconnectCauseCode(new DisconnectCause(DisconnectCause.MISSED));
             }
-            if (mConnectionService == null) {
+            if (mTransactionalService != null) {
+                mTransactionalService.onDisconnect(this, getDisconnectCause());
+                Log.i(this, "Send Disconnect to transactional service for call");
+            } else if (mConnectionService == null) {
                 Log.e(this, new Exception(), "disconnect() request on a call without a"
                         + " connection service.");
             } else {
@@ -2531,6 +2559,8 @@
             // {@link ConnectionServiceAdapter#setActive} and other set* methods.
             if (mConnectionService != null) {
                 mConnectionService.answer(this, videoState);
+            } else if (mTransactionalService != null) {
+                mTransactionalService.onAnswer(this, videoState);
             } else {
                 Log.e(this, new NullPointerException(),
                         "answer call failed due to null CS callId=%s", getId());
@@ -2622,7 +2652,9 @@
             // ringing. Since the call is already active on the connectionservice side, we want to
             // hangup, not reject.
             setOverrideDisconnectCauseCode(new DisconnectCause(DisconnectCause.REJECTED));
-            if (mConnectionService != null) {
+            if (mTransactionalService != null) {
+                mTransactionalService.onReject(this, DisconnectCause.REJECTED);
+            } else if (mConnectionService != null) {
                 mConnectionService.disconnect(this);
             } else {
                 Log.e(this, new NullPointerException(),
@@ -2633,7 +2665,9 @@
             // Ensure video state history tracks video state at time of rejection.
             mVideoStateHistory |= mVideoState;
 
-            if (mConnectionService != null) {
+            if (mTransactionalService != null) {
+                mTransactionalService.onReject(this, DisconnectCause.REJECTED);
+            } else if (mConnectionService != null) {
                 mConnectionService.reject(this, rejectWithMessage, textMessage);
             } else {
                 Log.e(this, new NullPointerException(),
@@ -2654,7 +2688,9 @@
             // hangup, not reject.
             // Since its simulated reason we can't pass along the reject reason.
             setOverrideDisconnectCauseCode(new DisconnectCause(DisconnectCause.REJECTED));
-            if (mConnectionService != null) {
+            if (mTransactionalService != null) {
+                mTransactionalService.onReject(this, DisconnectCause.REJECTED);
+            } else if (mConnectionService != null) {
                 mConnectionService.disconnect(this);
             } else {
                 Log.e(this, new NullPointerException(),
@@ -2664,8 +2700,9 @@
         } else if (isRinging("reject") || isAnswered("reject")) {
             // Ensure video state history tracks video state at time of rejection.
             mVideoStateHistory |= mVideoState;
-
-            if (mConnectionService != null) {
+            if (mTransactionalService != null) {
+                mTransactionalService.onReject(this, rejectReason);
+            } else if (mConnectionService != null) {
                 mConnectionService.rejectWithReason(this, rejectReason);
             } else {
                 Log.e(this, new NullPointerException(),
@@ -2684,7 +2721,9 @@
     @VisibleForTesting
     public void transfer(Uri number, boolean isConfirmationRequired) {
         if (mState == CallState.ACTIVE || mState == CallState.ON_HOLD) {
-            if (mConnectionService != null) {
+            if (mTransactionalService != null) {
+                Log.i(this, "transfer: called on TransactionalService. doing nothing");
+            } else if (mConnectionService != null) {
                 mConnectionService.transfer(this, number, isConfirmationRequired);
             } else {
                 Log.e(this, new NullPointerException(),
@@ -2704,7 +2743,9 @@
     public void transfer(Call otherCall) {
         if (mState == CallState.ACTIVE &&
                 (otherCall != null && otherCall.getState() == CallState.ON_HOLD)) {
-            if (mConnectionService != null) {
+            if (mTransactionalService != null) {
+                Log.i(this, "transfer: called on TransactionalService. doing nothing");
+            } else if (mConnectionService != null) {
                 mConnectionService.transfer(this, otherCall);
             } else {
                 Log.e(this, new NullPointerException(),
@@ -2724,7 +2765,9 @@
 
     public void hold(String reason) {
         if (mState == CallState.ACTIVE) {
-            if (mConnectionService != null) {
+            if (mTransactionalService != null) {
+                mTransactionalService.onSetInactive(this);
+            } else if (mConnectionService != null) {
                 mConnectionService.hold(this);
             } else {
                 Log.e(this, new NullPointerException(),
@@ -2744,7 +2787,9 @@
 
     public void unhold(String reason) {
         if (mState == CallState.ON_HOLD) {
-            if (mConnectionService != null) {
+            if (mTransactionalService != null){
+                mTransactionalService.onSetActive(this);
+            } else if (mConnectionService != null){
                 mConnectionService.unhold(this);
             } else {
                 Log.e(this, new NullPointerException(),
@@ -2769,7 +2814,6 @@
         }
     }
 
-    @VisibleForTesting
     public boolean isActive() {
         return mState == CallState.ACTIVE;
     }
@@ -2835,7 +2879,9 @@
 
         // If the change originated from an InCallService, notify the connection service.
         if (source == SOURCE_INCALL_SERVICE) {
-            if (mConnectionService != null) {
+            if (mTransactionalService != null) {
+                Log.i(this, "putExtras: called on TransactionalService. doing nothing");
+            } else if (mConnectionService != null) {
                 mConnectionService.onExtrasChanged(this, mExtras);
             } else {
                 Log.e(this, new NullPointerException(),
@@ -2870,7 +2916,9 @@
 
         // If the change originated from an InCallService, notify the connection service.
         if (source == SOURCE_INCALL_SERVICE) {
-            if (mConnectionService != null) {
+            if (mTransactionalService != null) {
+                Log.i(this, "removeExtras: called on TransactionalService. doing nothing");
+            } else if (mConnectionService != null) {
                 mConnectionService.onExtrasChanged(this, mExtras);
             } else {
                 Log.e(this, new NullPointerException(),
@@ -2924,7 +2972,9 @@
     }
 
     void postDialContinue(boolean proceed) {
-        if (mConnectionService != null) {
+        if (mTransactionalService != null) {
+            Log.i(this, "postDialContinue: called on TransactionalService. doing nothing");
+        } else if (mConnectionService != null) {
             mConnectionService.onPostDialContinue(this, proceed);
         } else {
             Log.e(this, new NullPointerException(),
@@ -2933,7 +2983,9 @@
     }
 
     void conferenceWith(Call otherCall) {
-        if (mConnectionService == null) {
+        if (mTransactionalService != null) {
+            Log.i(this, "conferenceWith: called on TransactionalService. doing nothing");
+        } else if (mConnectionService == null) {
             Log.w(this, "conference requested on a call without a connection service.");
         } else {
             Log.addEvent(this, LogUtils.Events.CONFERENCE_WITH, otherCall);
@@ -2942,7 +2994,9 @@
     }
 
     void splitFromConference() {
-        if (mConnectionService == null) {
+        if (mTransactionalService != null) {
+            Log.i(this, "splitFromConference: called on TransactionalService. doing nothing");
+        } else if (mConnectionService == null) {
             Log.w(this, "splitting from conference call without a connection service");
         } else {
             Log.addEvent(this, LogUtils.Events.SPLIT_FROM_CONFERENCE);
@@ -2952,7 +3006,9 @@
 
     @VisibleForTesting
     public void mergeConference() {
-        if (mConnectionService == null) {
+        if (mTransactionalService != null) {
+            Log.i(this, "mergeConference: called on TransactionalService. doing nothing");
+        } else if (mConnectionService == null) {
             Log.w(this, "merging conference calls without a connection service.");
         } else if (can(Connection.CAPABILITY_MERGE_CONFERENCE)) {
             Log.addEvent(this, LogUtils.Events.CONFERENCE_WITH);
@@ -2963,7 +3019,9 @@
 
     @VisibleForTesting
     public void swapConference() {
-        if (mConnectionService == null) {
+        if (mTransactionalService != null) {
+            Log.i(this, "swapConference: called on TransactionalService. doing nothing");
+        } else if (mConnectionService == null) {
             Log.w(this, "swapping conference calls without a connection service.");
         } else if (can(Connection.CAPABILITY_SWAP_CONFERENCE)) {
             Log.addEvent(this, LogUtils.Events.SWAP);
@@ -2989,7 +3047,9 @@
     }
 
     public void addConferenceParticipants(List<Uri> participants) {
-        if (mConnectionService == null) {
+        if (mTransactionalService != null) {
+            Log.i(this, "addConferenceParticipants: called on TransactionalService. doing nothing");
+        } else if (mConnectionService == null) {
             Log.w(this, "adding conference participants without a connection service.");
         } else if (can(Connection.CAPABILITY_ADD_PARTICIPANT)) {
             Log.addEvent(this, LogUtils.Events.ADD_PARTICIPANT);
@@ -3017,6 +3077,11 @@
      * If there is an ongoing emergency call, pull requests are also ignored.
      */
     public void pullExternalCall() {
+        if (mTransactionalService != null) {
+            Log.i(this, "transfer: called on TransactionalService. doing nothing");
+            return;
+        }
+
         if (mConnectionService == null) {
             Log.w(this, "pulling a call without a connection service.");
         }
@@ -3064,7 +3129,9 @@
      * @param extras Associated extras.
      */
     public void sendCallEvent(String event, int targetSdkVer, Bundle extras) {
-        if (mConnectionService != null) {
+        if (mTransactionalService != null) {
+            Log.i(this, "sendCallEvent: called on TransactionalService. doing nothing");
+        } else if (mConnectionService != null) {
             if (android.telecom.Call.EVENT_REQUEST_HANDOVER.equals(event)) {
                 if (targetSdkVer > Build.VERSION_CODES.P) {
                     Log.e(this, new Exception(), "sendCallEvent failed. Use public api handoverTo" +
@@ -3497,7 +3564,9 @@
     }
 
     public void stopRtt() {
-        if (mConnectionService != null) {
+        if (mTransactionalService != null) {
+            Log.i(this, "stopRtt: called on TransactionalService. doing nothing");
+        } else if (mConnectionService != null) {
             mConnectionService.stopRtt(this);
         } else {
             // If this gets called by the in-call app before the connection service is set, we'll
@@ -3507,6 +3576,10 @@
     }
 
     public void sendRttRequest() {
+        if (mTransactionalService != null) {
+            Log.i(this, "sendRttRequest: called on TransactionalService. doing nothing");
+            return;
+        }
         createRttStreams();
         mConnectionService.startRtt(this, getInCallToCsRttPipeForCs(), getCsToInCallRttPipeForCs());
     }
@@ -3556,6 +3629,10 @@
             Log.w(this, "Response ID %d does not match expected %d", id, mPendingRttRequestId);
             return;
         }
+        if (mTransactionalService != null) {
+            Log.i(this, "handleRttRequestResponse: called on TransactionalService. doing nothing");
+            return;
+        }
         if (accept) {
             createRttStreams();
             Log.i(this, "RTT request %d accepted.", id);
@@ -4223,6 +4300,11 @@
     }
 
     public void maybeOnInCallServiceTrackingChanged(boolean isTracking, boolean hasUi) {
+        if (mTransactionalService != null) {
+            Log.i(this,
+                    "maybeOnInCallServiceTrackingChanged: called on TransactionalService");
+            return;
+        }
         if (mConnectionService == null) {
             Log.w(this, "maybeOnInCallServiceTrackingChanged() request on a call"
                     + " without a connection service.");
diff --git a/src/com/android/server/telecom/CallAudioRouteStateMachine.java b/src/com/android/server/telecom/CallAudioRouteStateMachine.java
index bf81cc9..0daa254 100644
--- a/src/com/android/server/telecom/CallAudioRouteStateMachine.java
+++ b/src/com/android/server/telecom/CallAudioRouteStateMachine.java
@@ -1775,7 +1775,12 @@
         Set<Call> calls = mCallsManager.getTrackedCalls();
         for (Call call : calls) {
             if (call != null && call.getConnectionService() != null) {
-                call.getConnectionService().onCallAudioStateChanged(call, newCallAudioState);
+                if (call.isTransactionalCall() && call.getTransactionServiceWrapper() != null) {
+                    call.getTransactionServiceWrapper().onCallAudioStateChanged(call,
+                            newCallAudioState);
+                } else {
+                    call.getConnectionService().onCallAudioStateChanged(call, newCallAudioState);
+                }
             }
         }
     }
diff --git a/src/com/android/server/telecom/CallsManager.java b/src/com/android/server/telecom/CallsManager.java
index 75b3864..e5ed4fc 100755
--- a/src/com/android/server/telecom/CallsManager.java
+++ b/src/com/android/server/telecom/CallsManager.java
@@ -64,6 +64,7 @@
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.os.Looper;
+import android.os.OutcomeReceiver;
 import android.os.PersistableBundle;
 import android.os.Process;
 import android.os.ResultReceiver;
@@ -77,8 +78,10 @@
 import android.provider.CallLog.Calls;
 import android.provider.Settings;
 import android.sysprop.TelephonyProperties;
+import android.telecom.CallAttributes;
 import android.telecom.CallAudioState;
 import android.telecom.CallEndpoint;
+import android.telecom.CallException;
 import android.telecom.CallScreeningService;
 import android.telecom.CallerInfo;
 import android.telecom.Conference;
@@ -159,7 +162,6 @@
  * access from other packages specifically refraining from passing the CallsManager instance
  * beyond the com.android.server.telecom package boundary.
  */
-@VisibleForTesting
 public class CallsManager extends Call.ListenerBase
         implements VideoProviderProxy.Listener, CallFilterResultCallback, CurrentUserProxy {
 
@@ -1149,7 +1151,6 @@
         }
     }
 
-    @VisibleForTesting
     public Call getForegroundCall() {
         if (mCallAudioManager == null) {
             // Happens when getForegroundCall is called before full initialization.
@@ -1289,7 +1290,7 @@
         processIncomingCallIntent(phoneAccountHandle, extras, false);
     }
 
-    void processIncomingCallIntent(PhoneAccountHandle phoneAccountHandle, Bundle extras,
+    public Call processIncomingCallIntent(PhoneAccountHandle phoneAccountHandle, Bundle extras,
         boolean isConference) {
         Log.d(this, "processIncomingCallIntent");
         boolean isHandover = extras.getBoolean(TelecomManager.EXTRA_IS_HANDOVER);
@@ -1299,7 +1300,7 @@
             handle = extras.getParcelable(TelephonyManager.EXTRA_INCOMING_NUMBER);
         }
         Call call = new Call(
-                getNextCallId(),
+                generateNextCallId(extras),
                 mContext,
                 this,
                 mLock,
@@ -1315,6 +1316,15 @@
                 mClockProxy,
                 mToastFactory);
 
+        // set properties for transactional call
+        if (extras.containsKey(TelecomManager.TRANSACTION_CALL_ID_KEY)) {
+            call.setIsTransactionalCall(true);
+            call.setConnectionCapabilities(
+                    extras.getInt(CallAttributes.CALL_CAPABILITIES_KEY,
+                            CallAttributes.SUPPORTS_SET_INACTIVE), true);
+            call.setTargetPhoneAccount(phoneAccountHandle);
+        }
+
         // Ensure new calls related to self-managed calls/connections are set as such.  This will
         // be overridden when the actual connection is returned in startCreateConnection, however
         // doing this now ensures the logs and any other logic will treat this call as self-managed
@@ -1459,9 +1469,15 @@
             } else {
                 notifyCreateConnectionFailed(phoneAccountHandle, call);
             }
+        } else if (call.isTransactionalCall()) {
+            // transactional calls should skip Call#startCreateConnection below
+            // as that is meant for Call objects with a ConnectionServiceWrapper
+            call.setState(CallState.RINGING, "explicitly set new incoming to ringing");
+            addCall(call);
         } else {
             call.startCreateConnection(mPhoneAccountRegistrar);
         }
+        return call;
     }
 
     void addNewUnknownCall(PhoneAccountHandle phoneAccountHandle, Bundle extras) {
@@ -1552,6 +1568,14 @@
                 originalIntent, callingPackage, false);
     }
 
+    private String generateNextCallId(Bundle extras) {
+        if (extras != null && extras.containsKey(TelecomManager.TRANSACTION_CALL_ID_KEY)) {
+            return extras.getString(TelecomManager.TRANSACTION_CALL_ID_KEY);
+        } else {
+            return getNextCallId();
+        }
+    }
+
     private CompletableFuture<Call> startOutgoingCall(List<Uri> participants,
             PhoneAccountHandle requestedAccountHandle,
             Bundle extras, UserHandle initiatingUser, Intent originalIntent,
@@ -1578,7 +1602,7 @@
         // Create a call with original handle. The handle may be changed when the call is attached
         // to a connection service, but in most cases will remain the same.
         if (call == null) {
-            call = new Call(getNextCallId(), mContext,
+            call = new Call(generateNextCallId(extras), mContext,
                     this,
                     mLock,
                     mConnectionServiceRepository,
@@ -1593,6 +1617,15 @@
                     isConference, /* isConference */
                     mClockProxy,
                     mToastFactory);
+
+            if (extras.containsKey(TelecomManager.TRANSACTION_CALL_ID_KEY)) {
+                call.setIsTransactionalCall(true);
+                call.setConnectionCapabilities(
+                        extras.getInt(CallAttributes.CALL_CAPABILITIES_KEY,
+                                CallAttributes.SUPPORTS_SET_INACTIVE), true);
+                call.setTargetPhoneAccount(requestedAccountHandle);
+            }
+
             call.initAnalytics(callingPackage, creationLogs.toString());
 
             // Ensure new calls related to self-managed calls/connections are set as such.  This
@@ -2502,6 +2535,10 @@
     public void answerCall(Call call, int videoState) {
         if (!mCalls.contains(call)) {
             Log.i(this, "Request to answer a non-existent call %s", call);
+        } else if (call.isTransactionalCall()) {
+            // InCallAdapter is requesting to answer the given transactioanl call. Must get an ack
+            // from the client via a transaction before answering.
+            call.answer(videoState);
         } else {
             // Hold or disconnect the active call and request call focus for the incoming call.
             Call activeCall = (Call) mConnectionSvrFocusMgr.getCurrentFocusCall();
@@ -3203,6 +3240,45 @@
         return false;
     }
 
+    // attempt to hold the requested call and complete the callback on the result
+    public void transactionHoldPotentialActiveCallForNewCall(Call newCall,
+            OutcomeReceiver<Boolean, CallException> callback) {
+        Call activeCall = (Call) mConnectionSvrFocusMgr.getCurrentFocusCall();
+        Log.i(this, "transactionHoldPotentialActiveCallForNewCall: "
+                + "newCall=[%s], activeCall=[%s]", newCall, activeCall);
+
+        // early exit if there is no need to hold an active call
+        if (activeCall == null || activeCall == newCall) {
+            Log.i(this, "transactionHoldPotentialActiveCallForNewCall:"
+                    + " no need to hold activeCall");
+            callback.onResult(true);
+            return;
+        }
+
+        // before attempting CallsManager#holdActiveCallForNewCall(Call), check if it'll fail early
+        if (!canHold(activeCall) &&
+                !(supportsHold(activeCall) && areFromSameSource(activeCall, newCall))) {
+            Log.i(this, "transactionHoldPotentialActiveCallForNewCall: "
+                    + "conditions show the call cannot be held.");
+            callback.onError(new CallException("call does not support hold",
+                    CallException.CODE_CANNOT_HOLD_CURRENT_ACTIVE_CALL));
+            return;
+        }
+
+        // attempt to hold the active call
+        if (!holdActiveCallForNewCall(newCall)) {
+            Log.i(this, "transactionHoldPotentialActiveCallForNewCall: "
+                    + "attempted to hold call but failed.");
+            callback.onError(new CallException("cannot hold active call failed",
+                    CallException.CODE_CANNOT_HOLD_CURRENT_ACTIVE_CALL));
+            return;
+        }
+
+        // officially mark the activeCall as held
+        markCallAsOnHold(activeCall);
+        callback.onResult(true);
+    }
+
     @VisibleForTesting
     public void markCallAsActive(Call call) {
         Log.i(this, "markCallAsActive, isSelfManaged: " + call.isSelfManaged());
@@ -3237,7 +3313,6 @@
         }
     }
 
-    @VisibleForTesting
     public void markCallAsOnHold(Call call) {
         setCallState(call, CallState.ON_HOLD, "on-hold set explicitly");
     }
@@ -3248,7 +3323,6 @@
      *
      * @param disconnectCause The disconnect cause, see {@link android.telecom.DisconnectCause}.
      */
-    @VisibleForTesting
     public void markCallAsDisconnected(Call call, DisconnectCause disconnectCause) {
         int oldState = call.getState();
         if (call.getState() == CallState.SIMULATED_RINGING
@@ -3318,7 +3392,7 @@
     /**
      * Removes an existing disconnected call, and notifies the in-call app.
      */
-    void markCallAsRemoved(Call call) {
+    public void markCallAsRemoved(Call call) {
         if (call.isDisconnectHandledViaFuture()) {
             Log.i(this, "markCallAsRemoved; callid=%s, postingToFuture.", call.getId());
             // A future is being used due to a CallDiagnosticService handling the call.  We will
@@ -3795,6 +3869,10 @@
      */
     @VisibleForTesting
     public void addCall(Call call) {
+        if (mCalls.contains(call)) {
+            Log.i(this, "addCall(%s) is already added");
+            return;
+        }
         Trace.beginSection("addCall");
         Log.i(this, "addCall(%s)", call);
         call.addListener(this);
@@ -3827,6 +3905,11 @@
         Trace.beginSection("removeCall");
         Log.v(this, "removeCall(%s)", call);
 
+        if (call.isTransactionalCall() && call.getTransactionServiceWrapper() != null) {
+            // remove call from wrappers
+            call.getTransactionServiceWrapper().removeCallFromWrappers(call);
+        }
+
         call.setParentAndChildCall(null);  // clean up parent relationship before destroying.
         call.removeListener(this);
         call.clearConnectionService();
@@ -5492,8 +5575,10 @@
         return mConnectionSvrFocusMgr;
     }
 
-    private boolean canHold(Call call) {
-        return call.can(Connection.CAPABILITY_HOLD) && call.getState() != CallState.DIALING;
+    @VisibleForTesting
+    public boolean canHold(Call call) {
+        return ((call.isTransactionalCall() && call.can(Connection.CAPABILITY_SUPPORT_HOLD)) ||
+                call.can(Connection.CAPABILITY_HOLD)) && call.getState() != CallState.DIALING;
     }
 
     private boolean supportsHold(Call call) {
@@ -5601,6 +5686,59 @@
         }
     }
 
+    // driver method to create and execute a new TransactionalFocusRequestCallback
+    public void transactionRequestNewFocusCall(Call call,
+            OutcomeReceiver<Boolean, CallException> callback) {
+        Log.d(this, "transactionRequestNewFocusCall");
+        PendingAction pendingAction = new ActionSetCallState(call, CallState.ACTIVE,
+                "transactional ActionSetCallState");
+        mConnectionSvrFocusMgr
+                .requestFocus(call,
+                        new TransactionalFocusRequestCallback(pendingAction, call, callback));
+    }
+
+    // request a new call focus and ensure the request was successful
+    @VisibleForTesting(visibility = VisibleForTesting.Visibility.PACKAGE)
+    public class TransactionalFocusRequestCallback implements
+            ConnectionServiceFocusManager.RequestFocusCallback {
+        private PendingAction mPendingAction;
+        @NonNull
+        private Call mTargetCallFocus;
+        private OutcomeReceiver<Boolean, CallException> mCallback;
+
+        TransactionalFocusRequestCallback(PendingAction pendingAction, @NonNull Call call,
+                OutcomeReceiver<Boolean, CallException> callback) {
+            mPendingAction = pendingAction;
+            mTargetCallFocus = call;
+            mCallback = callback;
+        }
+
+        @Override
+        public void onRequestFocusDone(ConnectionServiceFocusManager.CallFocus call) {
+            Call currentCallFocus = (Call) mConnectionSvrFocusMgr.getCurrentFocusCall();
+
+            if (currentCallFocus == null) {
+                Log.i(this, "TransactionalFocusRequestCallback: "
+                        + "currentCallFocus is null.");
+                mCallback.onError(new CallException("currentCallFocus is null",
+                        CallException.CODE_CALL_CANNOT_BE_SET_TO_ACTIVE));
+                return;
+            }
+
+            Log.i(this, "TransactionalFocusRequestCallback: targetId=[%s], "
+                    + "currentId=[%s]", mTargetCallFocus.getId(), currentCallFocus.getId());
+            if (!currentCallFocus.getId().equals(mTargetCallFocus.getId())) {
+                Log.i(this, "TransactionalFocusRequestCallback: "
+                        + "currentCallFocus is not equal to targetCallFocus.");
+                mCallback.onError(new CallException("current focus is not target focus",
+                        CallException.CODE_CALL_CANNOT_BE_SET_TO_ACTIVE));
+                return;
+            }
+            mPendingAction.performAction();
+            mCallback.onResult(true);
+        }
+    }
+
     public void resetConnectionTime(Call call) {
         call.setConnectTimeMillis(System.currentTimeMillis());
         call.setConnectElapsedTimeMillis(SystemClock.elapsedRealtime());
diff --git a/src/com/android/server/telecom/ConnectionServiceFocusManager.java b/src/com/android/server/telecom/ConnectionServiceFocusManager.java
index aa0a64f..8db98e9 100644
--- a/src/com/android/server/telecom/ConnectionServiceFocusManager.java
+++ b/src/com/android/server/telecom/ConnectionServiceFocusManager.java
@@ -154,7 +154,8 @@
     }
 
     private static final int[] PRIORITY_FOCUS_CALL_STATE = new int[] {
-            CallState.ACTIVE, CallState.CONNECTING, CallState.DIALING, CallState.AUDIO_PROCESSING
+            CallState.ACTIVE, CallState.CONNECTING, CallState.DIALING, CallState.AUDIO_PROCESSING,
+            CallState.RINGING
     };
 
     private static final int MSG_REQUEST_FOCUS = 1;
@@ -348,13 +349,14 @@
     public List<CallFocus> getAllCall() { return mCalls; }
 
     private void updateConnectionServiceFocus(ConnectionServiceFocus connSvrFocus) {
+        Log.i(this, "updateConnectionServiceFocus connSvr = %s", connSvrFocus);
         if (!Objects.equals(mCurrentFocus, connSvrFocus)) {
             if (connSvrFocus != null) {
                 connSvrFocus.setConnectionServiceFocusListener(mConnectionServiceFocusListener);
                 connSvrFocus.connectionServiceFocusGained();
             }
             mCurrentFocus = connSvrFocus;
-            Log.d(this, "updateConnectionServiceFocus connSvr = %s", connSvrFocus);
+            Log.i(this, "updateConnectionServiceFocus connSvr = %s", connSvrFocus);
         }
     }
 
@@ -362,6 +364,7 @@
         mCurrentFocusCall = null;
 
         if (mCurrentFocus == null) {
+            Log.d(this, "updateCurrentFocusCall: mCurrentFocus is null");
             return;
         }
 
diff --git a/src/com/android/server/telecom/PhoneAccountRegistrar.java b/src/com/android/server/telecom/PhoneAccountRegistrar.java
index db577bd..cb9e052 100644
--- a/src/com/android/server/telecom/PhoneAccountRegistrar.java
+++ b/src/com/android/server/telecom/PhoneAccountRegistrar.java
@@ -41,7 +41,6 @@
 import android.provider.Settings;
 import android.telecom.CallAudioState;
 import android.telecom.ConnectionService;
-import android.telecom.DefaultDialerManager;
 import android.telecom.Log;
 import android.telecom.PhoneAccount;
 import android.telecom.PhoneAccountHandle;
@@ -58,7 +57,6 @@
 
 // TODO: Needed for move to system service: import com.android.internal.R;
 import com.android.internal.annotations.VisibleForTesting;
-import com.android.internal.util.FastXmlSerializer;
 import com.android.internal.util.IndentingPrintWriter;
 import com.android.internal.util.XmlUtils;
 
@@ -66,7 +64,6 @@
 import org.xmlpull.v1.XmlPullParserException;
 import org.xmlpull.v1.XmlSerializer;
 
-import java.io.BufferedInputStream;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
@@ -85,12 +82,9 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
-import java.util.Optional;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CopyOnWriteArrayList;
-import java.util.stream.Collector;
 import java.util.stream.Collectors;
-import java.util.stream.Stream;
 
 /**
  * Handles writing and reading PhoneAccountHandle registration entries. This is a simple verbatim
@@ -859,7 +853,8 @@
     public void registerPhoneAccount(PhoneAccount account) {
         // Enforce the requirement that a connection service for a phone account has the correct
         // permission.
-        if (!phoneAccountRequiresBindPermission(account.getAccountHandle())) {
+        if (!hasTransactionalCallCapabilites(account) &&
+                !phoneAccountRequiresBindPermission(account.getAccountHandle())) {
             Log.w(this,
                     "Phone account %s does not have BIND_TELECOM_CONNECTION_SERVICE permission.",
                     account.getAccountHandle());
@@ -898,6 +893,15 @@
         boolean isEnabled = false;
         boolean isNewAccount;
 
+        // add self-managed capability for transactional accounts that are missing it
+        if (hasTransactionalCallCapabilites(account) &&
+                !account.hasCapabilities(PhoneAccount.CAPABILITY_SELF_MANAGED)) {
+            account = account.toBuilder()
+                    .setCapabilities(account.getCapabilities()
+                            | PhoneAccount.CAPABILITY_SELF_MANAGED)
+                    .build();
+        }
+
         PhoneAccount oldAccount = getPhoneAccountUnchecked(account.getAccountHandle());
         if (oldAccount != null) {
             enforceSelfManagedAccountUnmodified(account, oldAccount);
@@ -1196,6 +1200,11 @@
             Log.w(this, "phoneAccount %s not found", phoneAccountHandle.getComponentName());
             return false;
         }
+
+        if (hasTransactionalCallCapabilites(getPhoneAccountUnchecked(phoneAccountHandle))) {
+            return false;
+        }
+
         for (ResolveInfo resolveInfo : resolveInfos) {
             ServiceInfo serviceInfo = resolveInfo.serviceInfo;
             if (serviceInfo == null) {
@@ -1214,6 +1223,15 @@
         return true;
     }
 
+    @VisibleForTesting
+    public boolean hasTransactionalCallCapabilites(PhoneAccount phoneAccount) {
+        if (phoneAccount == null) {
+            return false;
+        }
+        return phoneAccount.hasCapabilities(
+                PhoneAccount.CAPABILITY_SUPPORTS_TRANSACTIONAL_OPERATIONS);
+    }
+
     //
     // Methods for retrieving PhoneAccounts and PhoneAccountHandles
     //
diff --git a/src/com/android/server/telecom/TelecomServiceImpl.java b/src/com/android/server/telecom/TelecomServiceImpl.java
index ab35043..d5f9f58 100644
--- a/src/com/android/server/telecom/TelecomServiceImpl.java
+++ b/src/com/android/server/telecom/TelecomServiceImpl.java
@@ -27,6 +27,10 @@
 import static android.Manifest.permission.REGISTER_SIM_SUBSCRIPTION;
 import static android.Manifest.permission.WRITE_SECURE_SETTINGS;
 import static android.Manifest.permission.MANAGE_OWN_CALLS;
+import static android.telecom.CallAttributes.DIRECTION_INCOMING;
+import static android.telecom.CallAttributes.DIRECTION_OUTGOING;
+import static android.telecom.TelecomManager.TELECOM_TRANSACTION_SUCCESS;
+import static android.telecom.CallException.CODE_ERROR_UNKNOWN;
 
 import android.Manifest;
 import android.app.ActivityManager;
@@ -47,10 +51,15 @@
 import android.os.Binder;
 import android.os.Build;
 import android.os.Bundle;
+import android.os.OutcomeReceiver;
 import android.os.Process;
+import android.os.RemoteException;
 import android.os.UserHandle;
 import android.provider.BlockedNumberContract;
 import android.provider.Settings;
+import android.telecom.CallAttributes;
+
+import android.telecom.CallException;
 import android.telecom.Log;
 import android.telecom.PhoneAccount;
 import android.telecom.PhoneAccountHandle;
@@ -62,10 +71,20 @@
 import android.text.TextUtils;
 import android.util.EventLog;
 
+import androidx.annotation.NonNull;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.telecom.ICallControl;
+import com.android.internal.telecom.ICallEventCallback;
 import com.android.internal.telecom.ITelecomService;
 import com.android.internal.util.IndentingPrintWriter;
 import com.android.server.telecom.components.UserCallIntentProcessorFactory;
 import com.android.server.telecom.settings.BlockedNumbersActivity;
+import com.android.server.telecom.voip.IncomingCallTransaction;
+import com.android.server.telecom.voip.OutgoingCallTransaction;
+import com.android.server.telecom.voip.TransactionManager;
+import com.android.server.telecom.voip.VoipCallTransaction;
+import com.android.server.telecom.voip.VoipCallTransactionResult;
 
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
@@ -112,12 +131,106 @@
         }
     }
 
+    private static final String TAG = "TelecomServiceImpl";
     private static final String TIME_LINE_ARG = "timeline";
     private static final int DEFAULT_VIDEO_STATE = -1;
     private static final String PERMISSION_HANDLE_CALL_INTENT =
             "android.permission.HANDLE_CALL_INTENT";
+    private static final String ADD_CALL_ERR_MSG = "Call could not be created or found. "
+            + "Retry operation.";
 
     private final ITelecomService.Stub mBinderImpl = new ITelecomService.Stub() {
+
+        @Override
+        public void addCall(CallAttributes callAttributes, ICallEventCallback callEventCallback,
+                String callId, String callingPackage) {
+            try {
+                Log.startSession("TSI.aC", Log.getPackageAbbreviation(callingPackage));
+                Log.i(TAG, "addCall: id=[%s], attributes=[%s]", callId, callAttributes);
+                PhoneAccountHandle handle = callAttributes.getPhoneAccountHandle();
+
+                // enforce permissions and arguments
+                enforcePermission(android.Manifest.permission.MANAGE_OWN_CALLS);
+                enforceUserHandleMatchesCaller(handle);
+                enforcePhoneAccountIsNotManaged(handle);// only allow self-managed packages (temp.)
+                enforcePhoneAccountIsRegisteredEnabled(handle, handle.getUserHandle());
+                enforceCallingPackage(callingPackage, "addCall");
+
+                VoipCallTransaction transaction = null;
+                // create transaction based on the call direction
+                switch (callAttributes.getDirection()) {
+                    case DIRECTION_OUTGOING:
+                        transaction = new OutgoingCallTransaction(callId, mContext, callAttributes,
+                                mCallsManager);
+                        break;
+                    case DIRECTION_INCOMING:
+                        transaction = new IncomingCallTransaction(callId, callAttributes,
+                                mCallsManager);
+                        break;
+                    default:
+                        throw new IllegalArgumentException(String.format("Invalid Call Direction. "
+                                        + "Was [%d] but should be within [%d,%d]",
+                                callAttributes.getDirection(), DIRECTION_INCOMING,
+                                DIRECTION_OUTGOING));
+                }
+
+                mTransactionManager.addTransaction(transaction, new OutcomeReceiver<>() {
+                    @Override
+                    public void onResult(VoipCallTransactionResult result) {
+                        Log.d(TAG, "addCall: onResult");
+                        Call call = result.getCall();
+
+                        if (call == null || !call.getId().equals(callId)) {
+                            Log.i(TAG, "addCall: onResult: call is null or id mismatch");
+                            onAddCallControl(callId, callEventCallback, null,
+                                    new CallException(ADD_CALL_ERR_MSG, CODE_ERROR_UNKNOWN));
+                            return;
+                        }
+
+                        TransactionalServiceWrapper serviceWrapper =
+                                mTransactionalServiceRepository
+                                        .addNewCallForTransactionalServiceWrapper(handle,
+                                                callEventCallback, mCallsManager, call);
+
+                        call.setTransactionServiceWrapper(serviceWrapper);
+                        ICallControl clientCallControl = serviceWrapper.getICallControl();
+
+                        if (clientCallControl == null) {
+                            throw new IllegalStateException("TransactionalServiceWrapper"
+                                    + "#ICallControl is null.");
+                        }
+
+                        // finally, send objects back to the client
+                        onAddCallControl(callId, callEventCallback, clientCallControl, null);
+                    }
+
+                    @Override
+                    public void onError(@NonNull CallException exception) {
+                        Log.d(TAG, "addCall: onError: e=[%s]", exception.toString());
+                        onAddCallControl(callId, callEventCallback, null, exception);
+                    }
+                });
+            } finally {
+                Log.endSession();
+            }
+        }
+
+        private void onAddCallControl(String callId, ICallEventCallback callEventCallback,
+                ICallControl callControl, CallException callException) {
+            try {
+                if (callException == null) {
+                    callEventCallback.onAddCallControl(callId, TELECOM_TRANSACTION_SUCCESS,
+                            callControl, null);
+                } else {
+                    callEventCallback.onAddCallControl(callId,
+                            CallException.CODE_ERROR_UNKNOWN,
+                            null, callException);
+                }
+            } catch (RemoteException remoteException) {
+                throw remoteException.rethrowAsRuntimeException();
+            }
+        }
+
         @Override
         public PhoneAccountHandle getDefaultOutgoingPhoneAccount(String uriScheme,
                 String callingPackage, String callingFeatureId) {
@@ -2255,6 +2368,8 @@
     private final SubscriptionManagerAdapter mSubscriptionManagerAdapter;
     private final SettingsSecureAdapter mSettingsSecureAdapter;
     private final TelecomSystem.SyncRoot mLock;
+    private TransactionManager mTransactionManager;
+    private final TransactionalServiceRepository mTransactionalServiceRepository;
 
     public TelecomServiceImpl(
             Context context,
@@ -2291,6 +2406,14 @@
                             defaultDialer);
             mContext.sendBroadcastAsUser(intent, UserHandle.of(userId));
         });
+
+        mTransactionManager = TransactionManager.getInstance();
+        mTransactionalServiceRepository = new TransactionalServiceRepository();
+    }
+
+    @VisibleForTesting
+    public void setTransactionManager(TransactionManager transactionManager){
+        mTransactionManager = transactionManager;
     }
 
     public ITelecomService.Stub getBinder() {
@@ -2403,6 +2526,29 @@
         }
     }
 
+    // Enforce that the PhoneAccountHandle is tied to a self-managed package and not managed (aka
+    // sim calling, etc.)
+    private void enforcePhoneAccountIsNotManaged(PhoneAccountHandle phoneAccountHandle) {
+        PhoneAccount phoneAccount = mPhoneAccountRegistrar.getPhoneAccount(phoneAccountHandle,
+                phoneAccountHandle.getUserHandle());
+        if (phoneAccount == null) {
+            throw new IllegalArgumentException("enforcePhoneAccountIsNotManaged:"
+                    + " phoneAccount is null");
+        }
+        if (phoneAccount.hasCapabilities(PhoneAccount.CAPABILITY_SIM_SUBSCRIPTION)) {
+            throw new IllegalArgumentException("enforcePhoneAccountIsNotManaged:"
+                    + " CAPABILITY_SIM_SUBSCRIPTION is not allowed");
+        }
+        if (phoneAccount.hasCapabilities(PhoneAccount.CAPABILITY_CALL_PROVIDER)) {
+            throw new IllegalArgumentException("enforcePhoneAccountIsNotManaged:"
+                    + " CAPABILITY_CALL_PROVIDER is not allowed");
+        }
+        if (phoneAccount.hasCapabilities(PhoneAccount.CAPABILITY_CONNECTION_MANAGER)) {
+            throw new IllegalArgumentException("enforcePhoneAccountIsNotManaged:"
+                    + " CAPABILITY_CONNECTION_MANAGER is not allowed");
+        }
+    }
+
     private void enforcePhoneAccountModificationForPackage(String packageName) {
         // TODO: Use a new telecomm permission for this instead of reusing modify.
 
diff --git a/src/com/android/server/telecom/TransactionalServiceRepository.java b/src/com/android/server/telecom/TransactionalServiceRepository.java
new file mode 100644
index 0000000..f84b934
--- /dev/null
+++ b/src/com/android/server/telecom/TransactionalServiceRepository.java
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.telecom;
+
+import android.telecom.PhoneAccountHandle;
+
+import com.android.internal.telecom.ICallEventCallback;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Tracks all TransactionalServiceWrappers that have an ongoing call. Removes wrappers that have no
+ * more calls.
+ */
+public class TransactionalServiceRepository {
+
+    private static final Map<PhoneAccountHandle, TransactionalServiceWrapper> lookupTable =
+            new HashMap<>();
+
+    public TransactionalServiceRepository() {
+    }
+
+    public TransactionalServiceWrapper addNewCallForTransactionalServiceWrapper
+            (PhoneAccountHandle phoneAccountHandle, ICallEventCallback callEventCallback,
+                    CallsManager callsManager, Call call) {
+
+        TransactionalServiceWrapper service = null;
+        if (!hasExistingServiceWrapper(phoneAccountHandle)) {
+            service = new TransactionalServiceWrapper(callEventCallback,
+                    callsManager, phoneAccountHandle, call, this);
+        } else {
+            service = getTransactionalServiceWrapper(phoneAccountHandle);
+            if (service == null) {
+                throw new IllegalStateException("service is null");
+            } else {
+                service.trackCall(call);
+            }
+        }
+
+        lookupTable.put(phoneAccountHandle, service);
+
+        return service;
+    }
+
+    public TransactionalServiceWrapper getTransactionalServiceWrapper(PhoneAccountHandle pah) {
+        return lookupTable.get(pah);
+    }
+
+    public boolean hasExistingServiceWrapper(PhoneAccountHandle pah) {
+        return lookupTable.containsKey(pah);
+    }
+
+    public boolean removeServiceWrapper(PhoneAccountHandle pah) {
+        if (!hasExistingServiceWrapper(pah)) {
+            return false;
+        }
+        lookupTable.remove(pah);
+        return true;
+    }
+
+}
diff --git a/src/com/android/server/telecom/TransactionalServiceWrapper.java b/src/com/android/server/telecom/TransactionalServiceWrapper.java
new file mode 100644
index 0000000..8caacb8
--- /dev/null
+++ b/src/com/android/server/telecom/TransactionalServiceWrapper.java
@@ -0,0 +1,483 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.telecom;
+
+import static android.telecom.TelecomManager.TELECOM_TRANSACTION_SUCCESS;
+import static android.telecom.CallException.CODE_CALL_IS_NOT_BEING_TRACKED;
+import static android.telecom.CallException.TRANSACTION_EXCEPTION_KEY;
+
+import android.content.ComponentName;
+import android.os.Bundle;
+import android.os.IBinder;
+import android.os.OutcomeReceiver;
+import android.os.RemoteException;
+import android.os.ResultReceiver;
+import android.telecom.CallAudioState;
+import android.telecom.CallException;
+import android.telecom.DisconnectCause;
+import android.telecom.PhoneAccountHandle;
+import android.telecom.Log;
+
+import androidx.annotation.VisibleForTesting;
+
+import com.android.internal.telecom.ICallControl;
+import com.android.internal.telecom.ICallEventCallback;
+import com.android.server.telecom.voip.CallEventCallbackAckTransaction;
+import com.android.server.telecom.voip.HoldCallTransaction;
+import com.android.server.telecom.voip.EndCallTransaction;
+import com.android.server.telecom.voip.SerialTransaction;
+import com.android.server.telecom.voip.TransactionManager;
+import com.android.server.telecom.voip.HoldActiveCallForNewCallTransaction;
+import com.android.server.telecom.voip.RequestFocusTransaction;
+import com.android.server.telecom.voip.VoipCallTransaction;
+import com.android.server.telecom.voip.VoipCallTransactionResult;
+
+import java.util.ArrayList;
+import java.util.Hashtable;
+import java.util.List;
+import java.util.Locale;
+
+/**
+ * Implements {@link android.telecom.CallEventCallback} and {@link android.telecom.CallControl}
+ * on a per-client basis which is tied to a {@link PhoneAccountHandle}
+ */
+public class TransactionalServiceWrapper implements
+        ConnectionServiceFocusManager.ConnectionServiceFocus, IBinder.DeathRecipient {
+    private static final String TAG = TransactionalServiceWrapper.class.getSimpleName();
+
+    // CallControl : Client (ex. voip app) --> Telecom
+    public static final String SET_ACTIVE = "SetActive";
+    public static final String SET_INACTIVE = "SetInactive";
+    public static final String REJECT = "Reject";
+    public static final String DISCONNECT = "Disconnect";
+
+    // CallEventCallback : Telecom --> Client (ex. voip app)
+    public static final String ON_SET_ACTIVE = "onSetActive";
+    public static final String ON_SET_INACTIVE = "onSetInactive";
+    public static final String ON_ANSWER = "onAnswer";
+    public static final String ON_REJECT = "onReject";
+    public static final String ON_DISCONNECT = "onDisconnect";
+
+    private final CallsManager mCallsManager;
+    private final ICallEventCallback mICallEventCallback;
+    private final PhoneAccountHandle mPhoneAccountHandle;
+    private final TransactionalServiceRepository mRepository;
+    private ConnectionServiceFocusManager.ConnectionServiceFocusListener mConnSvrFocusListener;
+    // init when constructor is called
+    private final Hashtable<String, Call> mTrackedCalls = new Hashtable<>();
+    private final Object mLock;
+    private final String mPackageName;
+    // needs to be non-final for testing
+    private TransactionManager mTransactionManager;
+
+    public TransactionalServiceWrapper(ICallEventCallback callEventCallback,
+            CallsManager callsManager, PhoneAccountHandle phoneAccountHandle, Call call,
+            TransactionalServiceRepository repo) {
+        // passed args
+        mICallEventCallback = callEventCallback;
+        mCallsManager = callsManager;
+        mPhoneAccountHandle = phoneAccountHandle;
+        mTrackedCalls.put(call.getId(), call); // service is now tracking its first call
+        mRepository = repo;
+        // init instance vars
+        mPackageName = phoneAccountHandle.getComponentName().getPackageName();
+        mTransactionManager = TransactionManager.getInstance();
+        mLock = new Object();
+    }
+
+    @VisibleForTesting
+    public void setTransactionManager(TransactionManager transactionManager) {
+        mTransactionManager = transactionManager;
+    }
+
+    public PhoneAccountHandle getPhoneAccountHandle() {
+        return mPhoneAccountHandle;
+    }
+
+    public void trackCall(Call call) {
+        synchronized (mLock) {
+            if (call != null) {
+                mTrackedCalls.put(call.getId(), call);
+            }
+        }
+    }
+    @VisibleForTesting
+    public boolean untrackCall(Call call) {
+        Call removedCall = null;
+        synchronized (mLock) {
+            if (call != null) {
+                removedCall = mTrackedCalls.remove(call.getId());
+                if (mTrackedCalls.size() == 0) {
+                    mRepository.removeServiceWrapper(mPhoneAccountHandle);
+                }
+            }
+        }
+        Log.i(TAG, "removedCall call=" + removedCall);
+        return removedCall != null;
+    }
+
+    @VisibleForTesting
+    public int getNumberOfTrackedCalls() {
+        int callCount = 0;
+        synchronized (mLock) {
+            callCount = mTrackedCalls.size();
+        }
+        return callCount;
+    }
+
+    @Override
+    public void binderDied() {
+        // remove all tacked calls from CallsManager && frameworks side
+        for (String id : mTrackedCalls.keySet()) {
+            Call call = mTrackedCalls.get(id);
+            mCallsManager.markCallAsDisconnected(call, new DisconnectCause(DisconnectCause.ERROR));
+            mCallsManager.removeCall(call);
+            // remove calls from Frameworks side
+            if (mICallEventCallback != null) {
+                try {
+                    mICallEventCallback.removeCallFromTransactionalServiceWrapper(call.getId());
+                } catch (RemoteException e) {
+                    // pass
+                }
+            }
+        }
+        mTrackedCalls.clear();
+    }
+
+    /***
+     *********************************************************************************************
+     **                        ICallControl: Client --> Server                                **
+     **********************************************************************************************
+     */
+    public final ICallControl mICallControl = new ICallControl.Stub() {
+        @Override
+        public void setActive(String callId, android.os.ResultReceiver callback)
+                throws RemoteException {
+            try {
+                Log.startSession("TSW.sA");
+                createTransactions(callId, callback, SET_ACTIVE, 0);
+            } finally {
+                Log.endSession();
+            }
+        }
+
+        @Override
+        public void setInactive(String callId, android.os.ResultReceiver callback)
+                throws RemoteException {
+            try {
+                Log.startSession("TSW.sI");
+                createTransactions(callId, callback, SET_INACTIVE, 0);
+            } finally {
+                Log.endSession();
+            }
+        }
+
+        @Override
+        public void disconnect(String callId, DisconnectCause disconnectCause,
+                android.os.ResultReceiver callback)
+                throws RemoteException {
+            try {
+                Log.startSession("TSW.d");
+                createTransactions(callId, callback, DISCONNECT, disconnectCause.getCode());
+            } finally {
+                Log.endSession();
+            }
+        }
+
+        @Override
+        public void rejectCall(String callId, android.os.ResultReceiver callback)
+                throws RemoteException {
+            try {
+                Log.startSession("TSW.rC");
+                createTransactions(callId, callback, REJECT,
+                        android.telecom.Call.REJECT_REASON_DECLINED);
+            } finally {
+                Log.endSession();
+            }
+        }
+
+        private void createTransactions(String callId, ResultReceiver callback, String action,
+                int code) {
+            Log.d(TAG, "createTransactions: callId=" + callId);
+            Call call = mTrackedCalls.get(callId);
+            if (call != null) {
+                switch (action) {
+                    case SET_ACTIVE:
+                        addTransactionsToManager(createSetActiveTransactions(call), callback);
+                        break;
+                    case REJECT:
+                    case DISCONNECT:
+                        addTransactionsToManager(new EndCallTransaction(mCallsManager,
+                                action.equals(DISCONNECT), code, call), callback);
+                        break;
+                    case SET_INACTIVE:
+                        addTransactionsToManager(
+                                new HoldCallTransaction(mCallsManager, call), callback);
+                        break;
+                }
+            } else {
+                Log.i(TAG, action + ": mCallsManager does not contain call with id=" + callId);
+                callback.send(CODE_CALL_IS_NOT_BEING_TRACKED, new Bundle());
+            }
+        }
+
+        private void addTransactionsToManager(VoipCallTransaction transaction,
+                ResultReceiver callback) {
+            Log.d(TAG, "addTransactionsToManager");
+
+            mTransactionManager.addTransaction(transaction, new OutcomeReceiver<>() {
+                @Override
+                public void onResult(VoipCallTransactionResult result) {
+                    Log.d(TAG, "addTransactionsToManager: onResult:");
+                    callback.send(TELECOM_TRANSACTION_SUCCESS, new Bundle());
+                }
+
+                @Override
+                public void onError(CallException exception) {
+                    Log.d(TAG, "addTransactionsToManager: onError");
+                    Bundle extras = new Bundle();
+                    extras.putParcelable(TRANSACTION_EXCEPTION_KEY, exception);
+                    callback.send(exception == null ? CallException.CODE_ERROR_UNKNOWN :
+                            exception.getCode(), extras);
+                }
+            });
+        }
+    };
+
+    public ICallControl getICallControl() {
+        return mICallControl;
+    }
+
+    /***
+     *********************************************************************************************
+     **                    ICallEventCallback: Server --> Client                                **
+     **********************************************************************************************
+     */
+
+    public void onSetActive(Call call) {
+        try {
+            Log.startSession("TSW.oSA");
+            Log.d(TAG, String.format(Locale.US, "onSetActive: callId=[%s]", call.getId()));
+            handleNewActiveCallCallbacks(call, ON_SET_ACTIVE, 0);
+        } finally {
+            Log.endSession();
+        }
+    }
+
+    public void onAnswer(Call call, int videoState) {
+        try {
+            Log.startSession("TSW.oA");
+            Log.d(TAG, String.format(Locale.US, "onAnswer: callId=[%s]", call.getId()));
+            handleNewActiveCallCallbacks(call, ON_ANSWER, videoState);
+        } finally {
+            Log.endSession();
+        }
+    }
+
+    // need to create multiple transactions for onSetActive and onAnswer which both seek to set
+    // the call to active
+    private void handleNewActiveCallCallbacks(Call call, String action, int videoState) {
+        // save CallsManager state before sending client state changes
+        Call foregroundCallBeforeSwap = mCallsManager.getForegroundCall();
+        boolean wasActive = foregroundCallBeforeSwap != null && foregroundCallBeforeSwap.isActive();
+
+        // create 3 serial transactions:
+        // -- hold active
+        // -- set newCall as active
+        // -- ack from client
+        SerialTransaction serialTransactions = createSetActiveTransactions(call);
+        serialTransactions.appendTransaction(
+                new CallEventCallbackAckTransaction(mICallEventCallback,
+                        action, call.getId(), videoState));
+
+        // do CallsManager workload before asking client and
+        //   reset CallsManager state if client does NOT ack
+        mTransactionManager.addTransaction(serialTransactions, new OutcomeReceiver<>() {
+            @Override
+            public void onResult(VoipCallTransactionResult result) {
+                Log.i(TAG, String.format(Locale.US,
+                        "%s: onResult: callId=[%s]", action, call.getId()));
+            }
+
+            @Override
+            public void onError(CallException exception) {
+                maybeResetForegroundCall(foregroundCallBeforeSwap, wasActive);
+            }
+        });
+    }
+
+
+    public void onSetInactive(Call call) {
+        try {
+            Log.startSession("TSW.oSI");
+            Log.i(TAG, String.format(Locale.US, "onSetInactive: callId=[%s]", call.getId()));
+            mTransactionManager.addTransaction(
+                    new CallEventCallbackAckTransaction(mICallEventCallback,
+                            ON_SET_INACTIVE, call.getId(), 0), new OutcomeReceiver<>() {
+                        @Override
+                        public void onResult(VoipCallTransactionResult result) {
+                            mCallsManager.markCallAsOnHold(call);
+                        }
+                        @Override
+                        public void onError(CallException exception) {
+                            Log.i(TAG, "onSetInactive: onError: with e=[%e]", exception);
+                        }
+                    });
+        } finally {
+            Log.endSession();
+        }
+    }
+
+    public void onDisconnect(Call call, DisconnectCause cause) {
+        try {
+            Log.startSession("TSW.oD");
+            Log.d(TAG, String.format(Locale.US, "onDisconnect: callId=[%s]", call.getId()));
+
+            mTransactionManager.addTransaction(
+                    new CallEventCallbackAckTransaction(mICallEventCallback, ON_DISCONNECT,
+                            call.getId(), 0), new OutcomeReceiver<>() {
+                        @Override
+                        public void onResult(VoipCallTransactionResult result) {
+                            removeCallFromCallsManager(call, cause);
+                        }
+
+                        @Override
+                        public void onError(CallException exception) {
+                            removeCallFromCallsManager(call, cause);
+                        }
+                    }
+            );
+        } finally {
+            Log.endSession();
+        }
+    }
+
+    public void onReject(Call call, @android.telecom.Call.RejectReason int rejectReason) {
+        try {
+            Log.startSession("TSW.oR");
+            Log.d(TAG, String.format(Locale.US, "onReject: callId=[%s]", call.getId()));
+
+            mTransactionManager.addTransaction(
+                    new CallEventCallbackAckTransaction(mICallEventCallback, ON_REJECT,
+                            call.getId(), 0), new OutcomeReceiver<>() {
+                        @Override
+                        public void onResult(VoipCallTransactionResult result) {
+                            removeCallFromCallsManager(call,
+                                    new DisconnectCause(DisconnectCause.REJECTED));
+                        }
+
+                        @Override
+                        public void onError(CallException exception) {
+                            removeCallFromCallsManager(call,
+                                    new DisconnectCause(DisconnectCause.REJECTED));
+                        }
+                    }
+            );
+        } finally {
+            Log.endSession();
+        }
+    }
+
+    // TODO:: replace with onCallEndpointChanged when CLs are merged
+    public void onCallAudioStateChanged(Call call, CallAudioState callAudioState) {
+        if (call != null) {
+            try {
+                mICallEventCallback.onCallAudioStateChanged(call.getId(), callAudioState);
+            } catch (RemoteException e) {
+            }
+        }
+    }
+
+    public void removeCallFromWrappers(Call call) {
+        if (call != null) {
+            try {
+                // remove the call from frameworks wrapper (client side)
+                mICallEventCallback.removeCallFromTransactionalServiceWrapper(call.getId());
+                // remove the call from this class/wrapper (server side)
+                untrackCall(call);
+            } catch (RemoteException e) {
+            }
+        }
+    }
+
+    /***
+     *********************************************************************************************
+     **                                Helpers                                                  **
+     **********************************************************************************************
+     */
+    private void maybeResetForegroundCall(Call foregroundCallBeforeSwap, boolean wasActive) {
+        if (foregroundCallBeforeSwap == null) {
+            return;
+        }
+        if (wasActive && !foregroundCallBeforeSwap.isActive()) {
+            mCallsManager.markCallAsActive(foregroundCallBeforeSwap);
+        }
+    }
+
+    private void removeCallFromCallsManager(Call call, DisconnectCause cause) {
+        if (cause.getCode() != DisconnectCause.REJECTED) {
+            mCallsManager.markCallAsDisconnected(call, cause);
+        }
+        mCallsManager.removeCall(call);
+    }
+
+    private SerialTransaction createSetActiveTransactions(Call call) {
+        // create list for multiple transactions
+        List<VoipCallTransaction> transactions = new ArrayList<>();
+
+        // add t1. hold potential active call
+        transactions.add(new HoldActiveCallForNewCallTransaction(mCallsManager, call));
+
+        // add t2. answer current call
+        transactions.add(new RequestFocusTransaction(mCallsManager, call));
+
+        // send off to Transaction Manager to process
+        return new SerialTransaction(transactions);
+    }
+
+    /***
+     *********************************************************************************************
+     **                    FocusManager                                                       **
+     **********************************************************************************************
+     */
+
+    @Override
+    public void connectionServiceFocusLost() {
+        if (mConnSvrFocusListener != null) {
+            mConnSvrFocusListener.onConnectionServiceReleased(this);
+        }
+        Log.i(TAG, String.format(Locale.US, "connectionServiceFocusLost for package=[%s]",
+                mPackageName));
+    }
+
+    @Override
+    public void connectionServiceFocusGained() {
+        Log.i(TAG, String.format(Locale.US, "connectionServiceFocusGained for package=[%s]",
+                mPackageName));
+    }
+
+    @Override
+    public void setConnectionServiceFocusListener(
+            ConnectionServiceFocusManager.ConnectionServiceFocusListener listener) {
+        mConnSvrFocusListener = listener;
+    }
+
+    @Override
+    public ComponentName getComponentName() {
+        return mPhoneAccountHandle.getComponentName();
+    }
+}
diff --git a/src/com/android/server/telecom/voip/CallEventCallbackAckTransaction.java b/src/com/android/server/telecom/voip/CallEventCallbackAckTransaction.java
new file mode 100644
index 0000000..5ff4c8d
--- /dev/null
+++ b/src/com/android/server/telecom/voip/CallEventCallbackAckTransaction.java
@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.telecom.voip;
+
+import static android.telecom.TelecomManager.TELECOM_TRANSACTION_SUCCESS;
+import static android.telecom.CallException.CODE_OPERATION_TIMED_OUT;
+
+import android.os.Bundle;
+import android.os.RemoteException;
+import android.os.ResultReceiver;
+import android.util.Log;
+
+import com.android.internal.telecom.ICallEventCallback;
+import com.android.server.telecom.TransactionalServiceWrapper;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionStage;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * SRP: using the ICallEventCallback binder, reach out to the client for the pending call event and
+ * get an acknowledgement that the call event can be completed.
+ */
+public class CallEventCallbackAckTransaction extends VoipCallTransaction {
+    private static final String TAG = CallEventCallbackAckTransaction.class.getSimpleName();
+    private final ICallEventCallback mICallEventCallback;
+    private final String mAction;
+    private final String mCallId;
+    private final int mVideoState;
+    private final VoipCallTransactionResult TRANSACTION_FAILED = new VoipCallTransactionResult(
+            CODE_OPERATION_TIMED_OUT, "failed to complete the operation before timeout");
+
+    private static class AckResultReceiver extends ResultReceiver {
+        CountDownLatch mCountDownLatch;
+
+        public AckResultReceiver(CountDownLatch latch) {
+            super(null);
+            mCountDownLatch = latch;
+        }
+
+        @Override
+        protected void onReceiveResult(int resultCode, Bundle resultData) {
+            if (resultCode == TELECOM_TRANSACTION_SUCCESS) {
+                mCountDownLatch.countDown();
+            }
+        }
+    }
+
+    public CallEventCallbackAckTransaction(ICallEventCallback service, String action, String callId,
+            int videoState) {
+        mICallEventCallback = service;
+        mAction = action;
+        mCallId = callId;
+        mVideoState = videoState;
+    }
+
+
+    @Override
+    public CompletionStage<VoipCallTransactionResult> processTransaction(Void v) {
+        Log.d(TAG, "processTransaction");
+        CountDownLatch latch = new CountDownLatch(1);
+        ResultReceiver receiver = new AckResultReceiver(latch);
+
+        try {
+            switch (mAction) {
+                case TransactionalServiceWrapper.ON_SET_INACTIVE:
+                    mICallEventCallback.onSetInactive(mCallId, receiver);
+                    break;
+                case TransactionalServiceWrapper.ON_DISCONNECT:
+                    mICallEventCallback.onDisconnect(mCallId, receiver);
+                    break;
+                case TransactionalServiceWrapper.ON_REJECT:
+                    mICallEventCallback.onReject(mCallId, receiver);
+                    break;
+                case TransactionalServiceWrapper.ON_SET_ACTIVE:
+                    mICallEventCallback.onSetActive(mCallId, receiver);
+                    break;
+                case TransactionalServiceWrapper.ON_ANSWER:
+                    mICallEventCallback.onAnswer(mCallId, mVideoState, receiver);
+                    break;
+            }
+        } catch (RemoteException remoteException) {
+            return CompletableFuture.completedFuture(TRANSACTION_FAILED);
+        }
+
+        try {
+            // wait for the client to ack that CallEventCallback
+            boolean success = latch.await(VoipCallTransaction.TIMEOUT_LIMIT, TimeUnit.MILLISECONDS);
+            if (!success) {
+                // client send onError and failed to complete transaction
+                return CompletableFuture.completedFuture(TRANSACTION_FAILED);
+            } else {
+                // success
+                return CompletableFuture.completedFuture(
+                        new VoipCallTransactionResult(VoipCallTransactionResult.RESULT_SUCCEED,
+                                "success"));
+            }
+        } catch (InterruptedException ie) {
+            return CompletableFuture.completedFuture(TRANSACTION_FAILED);
+        }
+    }
+}
diff --git a/src/com/android/server/telecom/voip/EndCallTransaction.java b/src/com/android/server/telecom/voip/EndCallTransaction.java
new file mode 100644
index 0000000..9b738b3
--- /dev/null
+++ b/src/com/android/server/telecom/voip/EndCallTransaction.java
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.telecom.voip;
+
+import android.telecom.DisconnectCause;
+import android.util.Log;
+
+import com.android.server.telecom.Call;
+import com.android.server.telecom.CallsManager;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionStage;
+
+/**
+ * This transaction should only be created for a CallControl action.
+ */
+public class EndCallTransaction extends VoipCallTransaction {
+    private static final String TAG = EndCallTransaction.class.getSimpleName();
+    private final CallsManager mCallsManager;
+    private final boolean mIsDisconnect;
+    private final int mCode;
+    private final Call mCall;
+
+    public EndCallTransaction(CallsManager callsManager, boolean isDisconnect, int code,
+            Call call) {
+        mCallsManager = callsManager;
+        mIsDisconnect = isDisconnect;
+        mCode = code;
+        mCall = call;
+    }
+
+    @Override
+    public CompletionStage<VoipCallTransactionResult> processTransaction(Void v) {
+        Log.d(TAG, String.format("processTransaction: isDisconnect=[%b]", mIsDisconnect));
+
+        if (mIsDisconnect) {
+            mCallsManager.markCallAsDisconnected(mCall, new DisconnectCause(mCode));
+        } else {
+            mCallsManager.rejectCall(mCall, mCode);
+        }
+        mCallsManager.markCallAsRemoved(mCall);
+
+        return CompletableFuture.completedFuture(
+                new VoipCallTransactionResult(VoipCallTransactionResult.RESULT_SUCCEED,
+                        "endCallTransaction complete"));
+    }
+}
diff --git a/src/com/android/server/telecom/voip/HoldActiveCallForNewCallTransaction.java b/src/com/android/server/telecom/voip/HoldActiveCallForNewCallTransaction.java
new file mode 100644
index 0000000..c42cb07
--- /dev/null
+++ b/src/com/android/server/telecom/voip/HoldActiveCallForNewCallTransaction.java
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.telecom.voip;
+
+import android.os.OutcomeReceiver;
+import android.telecom.CallException;
+import android.util.Log;
+
+import com.android.server.telecom.Call;
+import com.android.server.telecom.CallsManager;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionStage;
+
+public class HoldActiveCallForNewCallTransaction extends VoipCallTransaction {
+
+    private static final String TAG = HoldActiveCallForNewCallTransaction.class.getSimpleName();
+    private final CallsManager mCallsManager;
+    private final Call mCall;
+
+    public HoldActiveCallForNewCallTransaction(CallsManager callsManager, Call call) {
+        mCallsManager = callsManager;
+        mCall = call;
+    }
+
+    @Override
+    public CompletionStage<VoipCallTransactionResult> processTransaction(Void v) {
+        Log.d(TAG, "processTransaction");
+        CompletableFuture<VoipCallTransactionResult> future = new CompletableFuture<>();
+
+        mCallsManager.transactionHoldPotentialActiveCallForNewCall(mCall, new OutcomeReceiver<>() {
+            @Override
+            public void onResult(Boolean result) {
+                Log.d(TAG, "processTransaction: onResult");
+                future.complete(new VoipCallTransactionResult(
+                        VoipCallTransactionResult.RESULT_SUCCEED, null));
+            }
+
+            @Override
+            public void onError(CallException exception) {
+                Log.d(TAG, "processTransaction: onError");
+                future.complete(new VoipCallTransactionResult(
+                        VoipCallTransactionResult.RESULT_FAILED, null));
+            }
+        });
+
+        return future;
+    }
+}
diff --git a/src/com/android/server/telecom/voip/HoldCallTransaction.java b/src/com/android/server/telecom/voip/HoldCallTransaction.java
new file mode 100644
index 0000000..530727a
--- /dev/null
+++ b/src/com/android/server/telecom/voip/HoldCallTransaction.java
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.telecom.voip;
+
+import android.util.Log;
+
+import com.android.server.telecom.Call;
+import com.android.server.telecom.CallsManager;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionStage;
+
+public class HoldCallTransaction extends VoipCallTransaction {
+
+    private static final String TAG = HoldCallTransaction.class.getSimpleName();
+    private final CallsManager mCallsManager;
+    private final Call mCall;
+
+    public HoldCallTransaction(CallsManager callsManager, Call call) {
+        mCallsManager = callsManager;
+        mCall = call;
+    }
+
+    @Override
+    public CompletionStage<VoipCallTransactionResult> processTransaction(Void v) {
+        Log.d(TAG, "processTransaction");
+
+        mCallsManager.markCallAsOnHold(mCall);
+
+        return CompletableFuture.completedFuture(
+                new VoipCallTransactionResult(VoipCallTransactionResult.RESULT_SUCCEED,
+                        "holdCallTransaction complete"));
+    }
+}
diff --git a/src/com/android/server/telecom/voip/IncomingCallTransaction.java b/src/com/android/server/telecom/voip/IncomingCallTransaction.java
new file mode 100644
index 0000000..7bb9736
--- /dev/null
+++ b/src/com/android/server/telecom/voip/IncomingCallTransaction.java
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.telecom.voip;
+
+import static android.telecom.CallAttributes.CALL_CAPABILITIES_KEY;
+
+import android.os.Bundle;
+import android.telecom.CallAttributes;
+import android.telecom.CallControl;
+import android.telecom.CallException;
+import android.telecom.TelecomManager;
+import android.util.Log;
+
+import com.android.server.telecom.Call;
+import com.android.server.telecom.CallsManager;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionStage;
+
+public class IncomingCallTransaction extends VoipCallTransaction {
+
+    private static final String TAG = IncomingCallTransaction.class.getSimpleName();
+    private final String mCallId;
+    private final CallAttributes mCallAttributes;
+    private final CallsManager mCallsManager;
+
+    public IncomingCallTransaction(String callId, CallAttributes callAttributes,
+            CallsManager callsManager) {
+        mCallId = callId;
+        mCallAttributes = callAttributes;
+        mCallsManager = callsManager;
+    }
+
+    @Override
+    public CompletionStage<VoipCallTransactionResult> processTransaction(Void v) {
+        Log.d(TAG, "processTransaction");
+
+        if (mCallsManager.isIncomingCallPermitted(mCallAttributes.getPhoneAccountHandle())) {
+            Log.d(TAG, "processTransaction: incoming call permitted");
+
+            Call call = mCallsManager.processIncomingCallIntent(
+                    mCallAttributes.getPhoneAccountHandle(),
+                    generateExtras(mCallAttributes), false);
+
+            return CompletableFuture.completedFuture(
+                    new VoipCallTransactionResult(
+                            VoipCallTransactionResult.RESULT_SUCCEED, call, "success"));
+        } else {
+            Log.d(TAG, "processTransaction: incoming call is not permitted at this time");
+
+            return CompletableFuture.completedFuture(
+                    new VoipCallTransactionResult(
+                            CallException.CODE_CALL_NOT_PERMITTED_AT_PRESENT_TIME,
+                            "incoming call not permitted at the current time"));
+        }
+    }
+
+    private Bundle generateExtras(CallAttributes callAttributes){
+        Bundle extras = new Bundle();
+        extras.putString(TelecomManager.TRANSACTION_CALL_ID_KEY, mCallId);
+        extras.putInt(CALL_CAPABILITIES_KEY, callAttributes.getCallCapabilities());
+        extras.putInt(TelecomManager.EXTRA_INCOMING_VIDEO_STATE, callAttributes.getCallType());
+        return extras;
+    }
+}
diff --git a/src/com/android/server/telecom/voip/OutgoingCallTransaction.java b/src/com/android/server/telecom/voip/OutgoingCallTransaction.java
new file mode 100644
index 0000000..169fc48
--- /dev/null
+++ b/src/com/android/server/telecom/voip/OutgoingCallTransaction.java
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.telecom.voip;
+
+import static android.Manifest.permission.CALL_PRIVILEGED;
+import static android.telecom.CallAttributes.CALL_CAPABILITIES_KEY;
+import static android.telecom.CallException.CODE_CALL_NOT_PERMITTED_AT_PRESENT_TIME;
+
+import android.content.Context;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.os.Bundle;
+import android.telecom.CallAttributes;
+import android.telecom.TelecomManager;
+import android.util.Log;
+
+import com.android.server.telecom.Call;
+import com.android.server.telecom.CallsManager;
+import com.android.server.telecom.LoggedHandlerExecutor;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionStage;
+
+public class OutgoingCallTransaction extends VoipCallTransaction {
+
+    private static final String TAG = OutgoingCallTransaction.class.getSimpleName();
+    private final String mCallId;
+    private final Context mContext;
+    private final String mCallingPackage;
+    private final CallAttributes mCallAttributes;
+    private final CallsManager mCallsManager;
+
+    public OutgoingCallTransaction(String callId, Context context, CallAttributes callAttributes,
+            CallsManager callsManager) {
+        mCallId = callId;
+        mContext = context;
+        mCallingPackage = mContext.getOpPackageName();
+        mCallAttributes = callAttributes;
+        mCallsManager = callsManager;
+    }
+
+    @Override
+    public CompletionStage<VoipCallTransactionResult> processTransaction(Void v) {
+        Log.d(TAG, "processTransaction");
+
+        final boolean hasCallPrivilegedPermission = mContext.checkCallingPermission(
+                CALL_PRIVILEGED) == PackageManager.PERMISSION_GRANTED;
+
+        final Intent intent = new Intent(hasCallPrivilegedPermission ?
+                Intent.ACTION_CALL_PRIVILEGED : Intent.ACTION_CALL, mCallAttributes.getAddress());
+
+        if (mCallsManager.isOutgoingCallPermitted(mCallAttributes.getPhoneAccountHandle())) {
+            Log.d(TAG, "processTransaction: outgoing call permitted");
+
+            CompletableFuture<Call> callFuture =
+                    mCallsManager.startOutgoingCall(mCallAttributes.getAddress(),
+                            mCallAttributes.getPhoneAccountHandle(),
+                            generateExtras(mCallAttributes),
+                            mCallAttributes.getPhoneAccountHandle().getUserHandle(),
+                            intent,
+                            mCallingPackage);
+
+            if (callFuture == null) {
+                return CompletableFuture.completedFuture(
+                        new VoipCallTransactionResult(
+                                CODE_CALL_NOT_PERMITTED_AT_PRESENT_TIME,
+                                "incoming call not permitted at the current time"));
+            }
+            CompletionStage<VoipCallTransactionResult> result = callFuture.thenComposeAsync(
+                    (call) -> {
+
+                        Log.d(TAG, "processTransaction: completing future");
+
+                        if (call == null) {
+                            Log.d(TAG, "processTransaction: call is null");
+                            return CompletableFuture.completedFuture(
+                                    new VoipCallTransactionResult(
+                                            CODE_CALL_NOT_PERMITTED_AT_PRESENT_TIME,
+                                            "call could not be created at this time"));
+                        } else {
+                            Log.d(TAG, "processTransaction: call done. id=" + call.getId());
+                        }
+
+                        return CompletableFuture.completedFuture(
+                                new VoipCallTransactionResult(
+                                        VoipCallTransactionResult.RESULT_SUCCEED,
+                                        call, null));
+                    }
+                    , new LoggedHandlerExecutor(mHandler, "OCT.pT", null));
+
+            return result;
+        } else {
+            return CompletableFuture.completedFuture(
+                    new VoipCallTransactionResult(
+                            CODE_CALL_NOT_PERMITTED_AT_PRESENT_TIME,
+                            "incoming call not permitted at the current time"));
+
+        }
+    }
+
+    private Bundle generateExtras(CallAttributes callAttributes){
+        Bundle extras = new Bundle();
+        extras.setDefusable(true);
+        extras.putString(TelecomManager.TRANSACTION_CALL_ID_KEY, mCallId);
+        extras.putInt(CALL_CAPABILITIES_KEY, callAttributes.getCallCapabilities());
+        extras.putInt(TelecomManager.EXTRA_START_CALL_WITH_VIDEO_STATE,
+                callAttributes.getCallType());
+        return extras;
+    }
+}
diff --git a/src/com/android/server/telecom/voip/RequestFocusTransaction.java b/src/com/android/server/telecom/voip/RequestFocusTransaction.java
new file mode 100644
index 0000000..210bd37
--- /dev/null
+++ b/src/com/android/server/telecom/voip/RequestFocusTransaction.java
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.telecom.voip;
+
+import android.os.OutcomeReceiver;
+import android.telecom.CallException;
+import android.util.Log;
+
+import com.android.server.telecom.Call;
+import com.android.server.telecom.CallsManager;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionStage;
+
+public class RequestFocusTransaction extends VoipCallTransaction {
+
+    private static final String TAG = RequestFocusTransaction.class.getSimpleName();
+    private final CallsManager mCallsManager;
+    private final Call mCall;
+
+    public RequestFocusTransaction(CallsManager callsManager, Call call) {
+        mCallsManager = callsManager;
+        mCall = call;
+    }
+
+    @Override
+    public CompletionStage<VoipCallTransactionResult> processTransaction(Void v) {
+        Log.d(TAG, "processTransaction");
+        CompletableFuture<VoipCallTransactionResult> future = new CompletableFuture<>();
+
+        mCallsManager.transactionRequestNewFocusCall(mCall, new OutcomeReceiver<>() {
+            @Override
+            public void onResult(Boolean result) {
+                Log.d(TAG, "processTransaction: onResult");
+                future.complete(new VoipCallTransactionResult(
+                        VoipCallTransactionResult.RESULT_SUCCEED, null));
+            }
+
+            @Override
+            public void onError(CallException exception) {
+                Log.d(TAG, "processTransaction: onError");
+
+                future.complete(new VoipCallTransactionResult(
+                        VoipCallTransactionResult.RESULT_FAILED, null));
+            }
+        });
+
+        return future;
+    }
+}
\ No newline at end of file
diff --git a/src/com/android/server/telecom/voip/SerialTransaction.java b/src/com/android/server/telecom/voip/SerialTransaction.java
index 9fe547c..87bc9ec 100644
--- a/src/com/android/server/telecom/voip/SerialTransaction.java
+++ b/src/com/android/server/telecom/voip/SerialTransaction.java
@@ -26,6 +26,10 @@
         super(subTransactions);
     }
 
+    public void appendTransaction(VoipCallTransaction transaction){
+        mSubTransactions.add(transaction);
+    }
+
     @Override
     public void start() {
         // post timeout work
diff --git a/src/com/android/server/telecom/voip/TransactionManager.java b/src/com/android/server/telecom/voip/TransactionManager.java
index 27e8069..a0955c8 100644
--- a/src/com/android/server/telecom/voip/TransactionManager.java
+++ b/src/com/android/server/telecom/voip/TransactionManager.java
@@ -17,6 +17,9 @@
 package com.android.server.telecom.voip;
 
 import android.os.OutcomeReceiver;
+import android.telecom.TelecomManager;
+import android.telecom.CallException;
+import android.util.Log;
 
 import com.android.internal.annotations.VisibleForTesting;
 
@@ -38,7 +41,6 @@
     private TransactionManager() {
         mTransactions = new ArrayDeque<>();
         mCurrentTransaction = null;
-
     }
 
     public static TransactionManager getInstance() {
@@ -56,24 +58,27 @@
     }
 
     public void addTransaction(VoipCallTransaction transaction,
-            OutcomeReceiver<VoipCallTransactionResult, Exception> receiver) {
+            OutcomeReceiver<VoipCallTransactionResult, CallException> receiver) {
         synchronized (sLock) {
             mTransactions.add(transaction);
             transaction.setCompleteListener(new TransactionCompleteListener() {
                 @Override
                 public void onTransactionCompleted(VoipCallTransactionResult result,
-                        String transactionName) {
-                    if (result.getResult() == 0
-                        /* TODO: change this to static value in TelecomManager */) {
+                        String transactionName){
+                    Log.i(TAG, String.format("transaction completed: with result=[%d]",
+                            result.getResult()));
+                    if (result.getResult() == TelecomManager.TELECOM_TRANSACTION_SUCCESS) {
                         receiver.onResult(result);
                     } else {
-                        receiver.onError(new Exception());
+                        receiver.onError(
+                                new CallException(result.getMessage(),
+                                        result.getResult()));
                     }
                     finishTransaction();
                 }
 
                 @Override
-                public void onTransactionTimeout(String transactionName) {
+                public void onTransactionTimeout(String transactionName){
                     receiver.onResult(new VoipCallTransactionResult(
                             VoipCallTransactionResult.RESULT_FAILED, transactionName + " timeout"));
                     finishTransaction();
diff --git a/src/com/android/server/telecom/voip/VoipCallTransactionResult.java b/src/com/android/server/telecom/voip/VoipCallTransactionResult.java
index c610e06..2916fc6 100644
--- a/src/com/android/server/telecom/voip/VoipCallTransactionResult.java
+++ b/src/com/android/server/telecom/voip/VoipCallTransactionResult.java
@@ -47,6 +47,10 @@
         return mMessage;
     }
 
+    public Call getCall(){
+        return mCall;
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;
@@ -59,4 +63,15 @@
     public int hashCode() {
         return Objects.hash(mResult, mMessage);
     }
+
+    @Override
+    public String toString() {
+        return new StringBuilder().
+                append("{ VoipCallTransactionResult: [mResult: ").
+                append(mResult).
+                append("], [mCall: ").
+                append(mCall.toString()).
+                append("], [mMessage=").
+                append(mMessage).append("]  }").toString();
+    }
 }
diff --git a/testapps/transactionalVoipApp/Android.bp b/testapps/transactionalVoipApp/Android.bp
new file mode 100644
index 0000000..68089e2
--- /dev/null
+++ b/testapps/transactionalVoipApp/Android.bp
@@ -0,0 +1,28 @@
+//
+// Copyright (C) 2022 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package {
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+android_test {
+    name: "transactionalVoipApp",
+    static_libs: [
+        "androidx.legacy_legacy-support-v4",
+        "guava",
+    ],
+    srcs: ["src/**/*.java"],
+}
diff --git a/testapps/transactionalVoipApp/AndroidManifest.xml b/testapps/transactionalVoipApp/AndroidManifest.xml
new file mode 100644
index 0000000..d0aa50b
--- /dev/null
+++ b/testapps/transactionalVoipApp/AndroidManifest.xml
@@ -0,0 +1,39 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2019 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+     coreApp="true"
+     package="com.android.server.telecom.transactionalVoipApp">
+
+    <uses-sdk android:minSdkVersion="28"
+         android:targetSdkVersion="33"/>
+
+    <uses-permission android:name="android.permission.MANAGE_OWN_CALLS" />
+
+    <application android:label="Transactional Voip">
+        <uses-library android:name="android.test.runner"/>
+
+        <activity android:name="com.android.server.telecom.transactionalVoipApp.VoipAppMainActivity"
+                  android:exported="true"
+                  android:label="Transactional Voip">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+
+    </application>
+</manifest>
diff --git a/testapps/transactionalVoipApp/res/drawable-hdpi/ic_android_black_24dp.png b/testapps/transactionalVoipApp/res/drawable-hdpi/ic_android_black_24dp.png
new file mode 100644
index 0000000..ed3ee45
--- /dev/null
+++ b/testapps/transactionalVoipApp/res/drawable-hdpi/ic_android_black_24dp.png
Binary files differ
diff --git a/testapps/transactionalVoipApp/res/drawable-mdpi/ic_android_black_24dp.png b/testapps/transactionalVoipApp/res/drawable-mdpi/ic_android_black_24dp.png
new file mode 100644
index 0000000..a4add51
--- /dev/null
+++ b/testapps/transactionalVoipApp/res/drawable-mdpi/ic_android_black_24dp.png
Binary files differ
diff --git a/testapps/transactionalVoipApp/res/drawable-xhdpi/ic_android_black_24dp.png b/testapps/transactionalVoipApp/res/drawable-xhdpi/ic_android_black_24dp.png
new file mode 100644
index 0000000..41558f2
--- /dev/null
+++ b/testapps/transactionalVoipApp/res/drawable-xhdpi/ic_android_black_24dp.png
Binary files differ
diff --git a/testapps/transactionalVoipApp/res/drawable-xxhdpi/ic_android_black_24dp.png b/testapps/transactionalVoipApp/res/drawable-xxhdpi/ic_android_black_24dp.png
new file mode 100644
index 0000000..6006b12
--- /dev/null
+++ b/testapps/transactionalVoipApp/res/drawable-xxhdpi/ic_android_black_24dp.png
Binary files differ
diff --git a/testapps/transactionalVoipApp/res/drawable-xxxhdpi/ic_android_black_24dp.png b/testapps/transactionalVoipApp/res/drawable-xxxhdpi/ic_android_black_24dp.png
new file mode 100644
index 0000000..4f935bf
--- /dev/null
+++ b/testapps/transactionalVoipApp/res/drawable-xxxhdpi/ic_android_black_24dp.png
Binary files differ
diff --git a/testapps/transactionalVoipApp/res/layout/main_activity.xml b/testapps/transactionalVoipApp/res/layout/main_activity.xml
new file mode 100644
index 0000000..86d8e20
--- /dev/null
+++ b/testapps/transactionalVoipApp/res/layout/main_activity.xml
@@ -0,0 +1,90 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (C) 2022 The Android Open Source Project
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~      http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical">
+
+    <TextView
+        android:id="@+id/title"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:text="@string/app_name"/>
+
+    <LinearLayout
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:orientation="vertical">
+
+        <Button
+            android:id="@+id/registerButton"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="@string/register_phone_account"/>
+
+        <ToggleButton
+            android:id="@+id/callDirectionButton"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:textOff="@string/direction_outgoing"
+            android:textOn="@string/direction_incoming"
+        />
+
+        <LinearLayout
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:orientation="horizontal">
+            <Button
+                android:id="@+id/add_call_1_button"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/add_call_1"/>
+
+            <Button
+                android:id="@+id/disconnect_call_1_button"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/disconnect_call_1"/>
+        </LinearLayout>
+
+        <LinearLayout
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:orientation="horizontal">
+
+            <Button
+                android:id="@+id/add_call_2_button"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/add_call_2"/>
+
+            <Button
+                android:id="@+id/set_call_2_active_button"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/set_call_active"/>
+
+            <Button
+                android:id="@+id/disconnect_call_2_button"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/disconnect_call_2"/>
+        </LinearLayout>
+    </LinearLayout>
+</LinearLayout>
diff --git a/testapps/transactionalVoipApp/res/values/strings.xml b/testapps/transactionalVoipApp/res/values/strings.xml
new file mode 100644
index 0000000..038adc1
--- /dev/null
+++ b/testapps/transactionalVoipApp/res/values/strings.xml
@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (C) 2022 The Android Open Source Project
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~      http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+
+<resources>
+    <string name="app_name">Transactional API test Activity</string>
+    <string name="register_phone_account">Register Phone Account</string>
+    <string name="direction_outgoing">outgoing</string>
+    <string name="direction_incoming">incoming</string>
+    <string name="add_call_1">add call 1</string>
+    <string name="disconnect_call_1">disconnect call 1</string>
+    <string name="add_call_2">add call 2</string>
+    <string name="set_call_active">set call 2 active</string>
+    <string name="disconnect_call_2">disconnect call 2</string>
+
+</resources>
\ No newline at end of file
diff --git a/testapps/transactionalVoipApp/src/com/android/server/telecom/transactionalVoipApp/MyVoipCall.java b/testapps/transactionalVoipApp/src/com/android/server/telecom/transactionalVoipApp/MyVoipCall.java
new file mode 100644
index 0000000..5244be8
--- /dev/null
+++ b/testapps/transactionalVoipApp/src/com/android/server/telecom/transactionalVoipApp/MyVoipCall.java
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.telecom.transactionalVoipApp;
+
+
+import android.telecom.CallAudioState;
+import android.telecom.CallControl;
+import android.telecom.CallEventCallback;
+import android.util.Log;
+
+import androidx.annotation.NonNull;
+
+import java.util.function.Consumer;
+
+public class MyVoipCall implements CallEventCallback {
+
+    private static final String TAG = "MyVoipCall";
+    private final String mCallId;
+    CallControl mCallControl;
+
+    MyVoipCall(String id) {
+        mCallId = id;
+    }
+
+    public void onAddCallControl(@NonNull CallControl callControl) {
+        mCallControl = callControl;
+    }
+
+    @Override
+    public void onSetActive(@NonNull Consumer<Boolean> wasCompleted) {
+        Log.i(TAG, String.format("onSetActive: callId=[%s]", mCallId));
+        wasCompleted.accept(Boolean.TRUE);
+    }
+
+    @Override
+    public void onSetInactive(@NonNull Consumer<Boolean> wasCompleted) {
+        Log.i(TAG, String.format("onSetInactive: callId=[%s]", mCallId));
+        wasCompleted.accept(Boolean.TRUE);
+    }
+
+    @Override
+    public void onAnswer(int videoState, @NonNull Consumer<Boolean> wasCompleted) {
+        Log.i(TAG, String.format("onAnswer: callId=[%s]", mCallId));
+        wasCompleted.accept(Boolean.TRUE);
+    }
+
+    @Override
+    public void onReject(@NonNull Consumer<Boolean> wasCompleted) {
+        Log.i(TAG, String.format("onReject: callId=[%s]", mCallId));
+        wasCompleted.accept(Boolean.TRUE);
+    }
+
+    @Override
+    public void onDisconnect(@NonNull Consumer<Boolean> wasCompleted) {
+        Log.i(TAG, String.format("onDisconnect: callId=[%s]", mCallId));
+        wasCompleted.accept(Boolean.TRUE);
+    }
+
+    @Override
+    public void onCallAudioStateChanged(@NonNull CallAudioState callAudioState) {
+        Log.i(TAG, String.format("onCallAudioStateChanged: state=[%s]", callAudioState.toString()));
+    }
+}
diff --git a/testapps/transactionalVoipApp/src/com/android/server/telecom/transactionalVoipApp/VoipAppMainActivity.java b/testapps/transactionalVoipApp/src/com/android/server/telecom/transactionalVoipApp/VoipAppMainActivity.java
new file mode 100644
index 0000000..775947b
--- /dev/null
+++ b/testapps/transactionalVoipApp/src/com/android/server/telecom/transactionalVoipApp/VoipAppMainActivity.java
@@ -0,0 +1,169 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.telecom.transactionalVoipApp;
+
+import static android.telecom.CallAttributes.DIRECTION_INCOMING;
+import static android.telecom.CallAttributes.DIRECTION_OUTGOING;
+
+import android.app.Activity;
+import android.content.ComponentName;
+import android.net.Uri;
+import android.os.Bundle;
+import android.os.OutcomeReceiver;
+import android.telecom.CallAttributes;
+import android.telecom.CallControl;
+import android.telecom.CallException;
+import android.telecom.DisconnectCause;
+import android.telecom.PhoneAccount;
+import android.telecom.PhoneAccountHandle;
+import android.telecom.TelecomManager;
+import android.util.Log;
+import android.view.View;
+import android.widget.ToggleButton;
+
+public class VoipAppMainActivity extends Activity {
+
+    private static final String TAG = "VoipAppMainActivity";
+    private static TelecomManager mTelecomManager;
+    private MyVoipCall mCall1;
+    private MyVoipCall mCall2;
+    private ToggleButton mCallDirectionButton;
+
+    PhoneAccountHandle handle = new PhoneAccountHandle(
+            new ComponentName("com.android.server.telecom.transactionalVoipApp",
+                    "com.android.server.telecom.transactionalVoipApp.VoipAppMainActivity"), "123");
+
+    PhoneAccount mPhoneAccount = PhoneAccount.builder(handle, "test label")
+            .setCapabilities(PhoneAccount.CAPABILITY_SELF_MANAGED |
+                    PhoneAccount.CAPABILITY_SUPPORTS_TRANSACTIONAL_OPERATIONS).build();
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.main_activity);
+
+        mTelecomManager = getSystemService(TelecomManager.class);
+        mCallDirectionButton = findViewById(R.id.callDirectionButton);
+
+        // register account
+        findViewById(R.id.registerButton).setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                mTelecomManager.registerPhoneAccount(mPhoneAccount);
+            }
+        });
+
+        // call 1 buttons
+        findViewById(R.id.add_call_1_button).setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                Bundle extras = new Bundle();
+                extras.putString("testKey", "testValue");
+                mCall1 = new MyVoipCall("1");
+                addCall(mCall1, true);
+            }
+        });
+
+        findViewById(R.id.disconnect_call_1_button).setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                disconnectCall(mCall1);
+            }
+        });
+
+
+        //call 2 buttons
+        findViewById(R.id.add_call_2_button).setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                Bundle extras = new Bundle();
+                extras.putString("call2extraKey", "call2Value");
+                mCall2 = new MyVoipCall("2");
+                addCall(mCall2, false);
+            }
+        });
+
+        findViewById(R.id.set_call_2_active_button).setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                setCallActive(mCall2);
+            }
+        });
+
+        findViewById(R.id.disconnect_call_2_button).setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                disconnectCall(mCall2);
+            }
+        });
+    }
+
+    private void addCall(MyVoipCall call, boolean setActive) {
+        int direction = (mCallDirectionButton.isChecked() ? DIRECTION_INCOMING
+                : DIRECTION_OUTGOING);
+
+        CallAttributes callAttributes = new CallAttributes.Builder(handle, direction, "Alan Turing",
+                Uri.fromParts("tel", "abc", "123")).build();
+
+        mTelecomManager.addCall(callAttributes, Runnable::run,
+                new OutcomeReceiver<CallControl, CallException>() {
+                    @Override
+                    public void onResult(CallControl callControl) {
+                        Log.i(TAG, "addCall: onResult: callback fired");
+                        call.onAddCallControl(callControl);
+                        if (setActive) {
+                            setCallActive(call);
+                        }
+                    }
+
+                    @Override
+                    public void onError(CallException exception) {
+
+                    }
+                },
+                call);
+    }
+
+    private void setCallActive(MyVoipCall call) {
+        call.mCallControl.setActive(Runnable::run, new OutcomeReceiver<Void, CallException>() {
+            @Override
+            public void onResult(Void result) {
+                Log.i(TAG, "setCallActive: onResult");
+            }
+
+            @Override
+            public void onError(CallException exception) {
+                Log.i(TAG, "setCallActive: onError");
+            }
+        });
+    }
+
+    private void disconnectCall(MyVoipCall call) {
+        call.mCallControl.disconnect(new DisconnectCause(DisconnectCause.LOCAL), Runnable::run,
+                new OutcomeReceiver<Void, CallException>() {
+                    @Override
+                    public void onResult(Void result) {
+                        Log.i(TAG, "disconnectCall: onResult");
+                    }
+
+                    @Override
+                    public void onError(CallException exception) {
+                        Log.i(TAG, "disconnectCall: onError");
+                    }
+                });
+    }
+}
diff --git a/tests/AndroidManifest.xml b/tests/AndroidManifest.xml
index e8c69d4..d9756fa 100644
--- a/tests/AndroidManifest.xml
+++ b/tests/AndroidManifest.xml
@@ -21,13 +21,13 @@
 
     <uses-sdk
         android:minSdkVersion="23"
-        android:targetSdkVersion="23" />
+        android:targetSdkVersion="33" />
 
     <!-- TODO: Needed because we call BluetoothAdapter.getDefaultAdapter() statically, and
          BluetoothAdapter is a final class. -->
     <uses-permission android:name="android.permission.BLUETOOTH" />
+    <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
     <uses-permission android:name="android.permission.BLUETOOTH_PRIVILEGED" />
-
     <!-- TODO: Needed because we call ActivityManager.getCurrentUser() statically. -->
     <uses-permission android:name="android.permission.INTERACT_ACROSS_USERS" />
     <uses-permission android:name="android.permission.INTERACT_ACROSS_USERS_FULL" />
diff --git a/tests/src/com/android/server/telecom/tests/CallAttributesTests.java b/tests/src/com/android/server/telecom/tests/CallAttributesTests.java
new file mode 100644
index 0000000..acb913e
--- /dev/null
+++ b/tests/src/com/android/server/telecom/tests/CallAttributesTests.java
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.telecom.tests;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThrows;
+import static org.mockito.Mockito.isA;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import android.content.ComponentName;
+import android.net.Uri;
+import android.os.Parcel;
+import android.telecom.CallAttributes;
+import android.telecom.PhoneAccountHandle;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+public class CallAttributesTests extends TelecomTestCase {
+
+    private static final PhoneAccountHandle mHandle = new PhoneAccountHandle(
+            new ComponentName("foo", "bar"), "1");
+    private static final String TEST_NAME = "Larry Page";
+    private static final Uri TEST_URI = Uri.fromParts("tel", "abc", "123");
+    @Mock private Parcel mParcel;
+
+    @Override
+    @Before
+    public void setUp() throws Exception {
+        super.setUp();
+        MockitoAnnotations.initMocks(this);
+    }
+
+    @Override
+    @After
+    public void tearDown() throws Exception {
+        super.tearDown();
+    }
+
+    @Test
+    public void testRequiredAttributes() {
+        CallAttributes callAttributes = new CallAttributes.Builder(mHandle,
+                CallAttributes.DIRECTION_OUTGOING, TEST_NAME, TEST_URI).build();
+
+        assertEquals(CallAttributes.DIRECTION_OUTGOING, callAttributes.getDirection());
+        assertEquals(mHandle, callAttributes.getPhoneAccountHandle());
+    }
+
+    @Test
+    public void testInvalidDirectionAttributes() {
+        assertThrows(IllegalArgumentException.class, () ->
+                new CallAttributes.Builder(mHandle, -1, TEST_NAME, TEST_URI).build()
+        );
+    }
+
+    @Test
+    public void testInvalidCallType() {
+        assertThrows(IllegalArgumentException.class, () ->
+                new CallAttributes.Builder(mHandle, CallAttributes.DIRECTION_OUTGOING,
+                        TEST_NAME, TEST_URI).setCallType(-1).build()
+        );
+    }
+
+    @Test
+    public void testOptionalAttributes() {
+        CallAttributes callAttributes = new CallAttributes.Builder(mHandle,
+                CallAttributes.DIRECTION_OUTGOING, TEST_NAME, TEST_URI)
+                .setCallCapabilities(CallAttributes.SUPPORTS_SET_INACTIVE)
+                .setCallType(CallAttributes.AUDIO_CALL)
+                .build();
+
+        assertEquals(CallAttributes.DIRECTION_OUTGOING, callAttributes.getDirection());
+        assertEquals(mHandle, callAttributes.getPhoneAccountHandle());
+        assertEquals(CallAttributes.SUPPORTS_SET_INACTIVE, callAttributes.getCallCapabilities());
+        assertEquals(CallAttributes.AUDIO_CALL, callAttributes.getCallType());
+        assertEquals(TEST_URI, callAttributes.getAddress());
+        assertEquals(TEST_NAME, callAttributes.getDisplayName());
+    }
+
+    @Test
+    public void testDescribeContents() {
+        CallAttributes callAttributes = new CallAttributes.Builder(mHandle,
+                CallAttributes.DIRECTION_OUTGOING, TEST_NAME, TEST_URI).build();
+
+        assertEquals(0, callAttributes.describeContents());
+    }
+
+    @Test
+    public void testWriteToParcel() {
+        // GIVEN
+        CallAttributes callAttributes = new CallAttributes.Builder(mHandle,
+                CallAttributes.DIRECTION_OUTGOING, TEST_NAME, TEST_URI)
+                .setCallCapabilities(CallAttributes.SUPPORTS_SET_INACTIVE)
+                .setCallType(CallAttributes.AUDIO_CALL)
+                .build();
+
+        // WHEN
+        callAttributes.writeToParcel(mParcel, 0);
+
+        // THEN
+        verify(mParcel, times(1))
+                .writeParcelable(isA(PhoneAccountHandle.class), isA(Integer.class));
+        verify(mParcel, times(1)).writeCharSequence(isA(CharSequence.class));
+        verify(mParcel, times(1))
+                .writeParcelable(isA(Uri.class), isA(Integer.class));
+        verify(mParcel, times(3)).writeInt(isA(Integer.class));
+    }
+}
diff --git a/tests/src/com/android/server/telecom/tests/CallControlTest.java b/tests/src/com/android/server/telecom/tests/CallControlTest.java
new file mode 100644
index 0000000..279fcc8
--- /dev/null
+++ b/tests/src/com/android/server/telecom/tests/CallControlTest.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.telecom.tests;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThrows;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import android.content.ComponentName;
+import android.os.OutcomeReceiver;
+import android.telecom.CallControl;
+import android.telecom.CallException;
+import android.telecom.PhoneAccountHandle;
+
+import com.android.internal.telecom.ClientTransactionalServiceRepository;
+import com.android.internal.telecom.ICallControl;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.util.UUID;
+
+public class CallControlTest extends TelecomTestCase {
+
+    private static final PhoneAccountHandle mHandle = new PhoneAccountHandle(
+            new ComponentName("foo", "bar"), "1");
+
+    @Mock
+    private ICallControl mICallControl;
+    @Mock
+    private ClientTransactionalServiceRepository mRepository;
+    private static final String CALL_ID_1 = UUID.randomUUID().toString();
+
+    @Override
+    @Before
+    public void setUp() throws Exception {
+        super.setUp();
+        MockitoAnnotations.initMocks(this);
+    }
+
+    @Override
+    @After
+    public void tearDown() throws Exception {
+        super.tearDown();
+    }
+
+    @Test
+    public void testGetCallId() {
+        CallControl control = new CallControl(CALL_ID_1, mICallControl, mRepository, mHandle);
+        assertEquals(CALL_ID_1, control.getCallId().toString());
+    }
+
+    @Test
+    public void testCallControlHitsIllegalStateException() {
+        CallControl control = new CallControl(CALL_ID_1, null, mRepository, mHandle);
+        assertThrows(IllegalStateException.class, () ->
+                control.setInactive(Runnable::run, result -> {
+                }));
+    }
+
+    @Test
+    public void testClose() {
+        // GIVEN
+        CallControl control = new CallControl(CALL_ID_1, mICallControl, mRepository, mHandle);
+
+        // WHEN
+        control.close();
+
+        // THEN
+        verify(mRepository, times(1))
+                .removeCallFromServiceWrapper(mHandle, CALL_ID_1);
+    }
+}
diff --git a/tests/src/com/android/server/telecom/tests/CallExceptionTests.java b/tests/src/com/android/server/telecom/tests/CallExceptionTests.java
new file mode 100644
index 0000000..3f8336d
--- /dev/null
+++ b/tests/src/com/android/server/telecom/tests/CallExceptionTests.java
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.telecom.tests;
+
+import static android.telecom.CallException.CODE_CALL_CANNOT_BE_SET_TO_ACTIVE;
+
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.isA;
+import static org.junit.Assert.assertEquals;
+
+import android.os.Parcel;
+import android.telecom.CallException;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+public class CallExceptionTests extends TelecomTestCase {
+
+    @Mock private Parcel mParcel;
+
+    @Override
+    @Before
+    public void setUp() throws Exception {
+        super.setUp();
+        MockitoAnnotations.initMocks(this);
+    }
+
+    @Override
+    @After
+    public void tearDown() throws Exception {
+        super.tearDown();
+    }
+
+    @Test
+    public void testSimpleException() {
+        String message = "test message";
+        CallException exception = new CallException(message);
+        assertTrue(exception.getMessage().contains(message));
+        assertEquals(CallException.CODE_ERROR_UNKNOWN, exception.getCode());
+    }
+
+    @Test
+    public void testExceptionWithCode() {
+        String message = "test message";
+        CallException exception = new CallException(message, CODE_CALL_CANNOT_BE_SET_TO_ACTIVE);
+        assertTrue(exception.getMessage().contains(message));
+        assertEquals(CODE_CALL_CANNOT_BE_SET_TO_ACTIVE, exception.getCode());
+    }
+
+    @Test
+    public void testDescribeContents() {
+        String message = "test message";
+        CallException exception = new CallException(message);
+        assertEquals(0, exception.describeContents());
+    }
+
+    @Test
+    public void testWriteToParcel() {
+        // GIVEN
+        String message = "test message";
+        CallException exception = new CallException(message);
+
+        // WHEN
+        exception.writeToParcel(mParcel, 0);
+
+        // THEN
+        verify(mParcel, times(1)).writeString8(isA(String.class));
+        verify(mParcel, times(1)).writeInt(isA(Integer.class));
+    }
+}
diff --git a/tests/src/com/android/server/telecom/tests/CallTest.java b/tests/src/com/android/server/telecom/tests/CallTest.java
index 0492f0a..a7619ad 100644
--- a/tests/src/com/android/server/telecom/tests/CallTest.java
+++ b/tests/src/com/android/server/telecom/tests/CallTest.java
@@ -18,15 +18,18 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.atLeastOnce;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.timeout;
+import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
 import static org.mockito.Mockito.verifyZeroInteractions;
@@ -54,6 +57,7 @@
 import com.android.server.telecom.PhoneAccountRegistrar;
 import com.android.server.telecom.PhoneNumberUtilsAdapter;
 import com.android.server.telecom.TelecomSystem;
+import com.android.server.telecom.TransactionalServiceWrapper;
 import com.android.server.telecom.ui.ToastFactory;
 
 import org.junit.After;
@@ -87,6 +91,7 @@
     @Mock private Toast mMockToast;
     @Mock private PhoneNumberUtilsAdapter mMockPhoneNumberUtilsAdapter;
     @Mock private ConnectionServiceWrapper mMockConnectionService;
+    @Mock private TransactionalServiceWrapper mMockTransactionalService;
 
     private final TelecomSystem.SyncRoot mLock = new TelecomSystem.SyncRoot() { };
 
@@ -372,4 +377,87 @@
         assertTrue(call.wasDndCheckComputedForCall());
         assertTrue(call.isCallSuppressedByDoNotDisturb());
     }
+
+    @Test
+    public void testGetConnectionServiceWrapper() {
+        Call call = new Call(
+                "1", /* callId */
+                mContext,
+                mMockCallsManager,
+                mLock,
+                null /* ConnectionServiceRepository */,
+                mMockPhoneNumberUtilsAdapter,
+                TEST_ADDRESS,
+                null /* GatewayInfo */,
+                null /* connectionManagerPhoneAccountHandle */,
+                SIM_1_HANDLE,
+                Call.CALL_DIRECTION_UNDEFINED,
+                false /* shouldAttachToExistingConnection*/,
+                true /* isConference */,
+                mMockClockProxy,
+                mMockToastProxy);
+
+        assertNull(call.getConnectionServiceWrapper());
+        assertFalse(call.isTransactionalCall());
+        call.setConnectionService(mMockConnectionService);
+        assertEquals(mMockConnectionService, call.getConnectionServiceWrapper());
+        call.setIsTransactionalCall(true);
+        assertTrue(call.isTransactionalCall());
+        assertNull(call.getConnectionServiceWrapper());
+        call.setTransactionServiceWrapper(mMockTransactionalService);
+        assertEquals(mMockTransactionalService, call.getTransactionServiceWrapper());
+    }
+
+    @Test
+    public void testCallEventCallbacksWereCalled() {
+        Call call = new Call(
+                "1", /* callId */
+                mContext,
+                mMockCallsManager,
+                mLock,
+                null /* ConnectionServiceRepository */,
+                mMockPhoneNumberUtilsAdapter,
+                TEST_ADDRESS,
+                null /* GatewayInfo */,
+                null /* connectionManagerPhoneAccountHandle */,
+                SIM_1_HANDLE,
+                Call.CALL_DIRECTION_UNDEFINED,
+                false /* shouldAttachToExistingConnection*/,
+                true /* isConference */,
+                mMockClockProxy,
+                mMockToastProxy);
+
+        // setup
+        call.setIsTransactionalCall(true);
+        assertTrue(call.isTransactionalCall());
+        assertNull(call.getConnectionServiceWrapper());
+        call.setTransactionServiceWrapper(mMockTransactionalService);
+        assertEquals(mMockTransactionalService, call.getTransactionServiceWrapper());
+
+        // assert CallEventCallback#onSetInactive is called
+        call.setState(CallState.ACTIVE, "test");
+        call.hold();
+        verify(mMockTransactionalService, times(1)).onSetInactive(call);
+
+        // assert CallEventCallback#onSetActive is called
+        call.setState(CallState.ON_HOLD, "test");
+        call.unhold();
+        verify(mMockTransactionalService, times(1)).onSetActive(call);
+
+        // assert CallEventCallback#onAnswer is called
+        call.setState(CallState.RINGING, "test");
+        call.answer(0);
+        verify(mMockTransactionalService, times(1)).onAnswer(call, 0);
+
+        // assert CallEventCallback#onReject is called
+        call.setState(CallState.RINGING, "test");
+        call.reject(0);
+        verify(mMockTransactionalService, times(1)).onReject(call, 0);
+
+        // assert CallEventCallback#onDisconnect is called
+        call.setState(CallState.ACTIVE, "test");
+        call.disconnect();
+        verify(mMockTransactionalService, times(1)).onDisconnect(call,
+                call.getDisconnectCause());
+    }
 }
diff --git a/tests/src/com/android/server/telecom/tests/CallsManagerTest.java b/tests/src/com/android/server/telecom/tests/CallsManagerTest.java
index 8fe64e2..59efb56 100644
--- a/tests/src/com/android/server/telecom/tests/CallsManagerTest.java
+++ b/tests/src/com/android/server/telecom/tests/CallsManagerTest.java
@@ -50,6 +50,7 @@
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Looper;
+import android.os.OutcomeReceiver;
 import android.os.Process;
 import android.os.SystemClock;
 import android.os.UserHandle;
@@ -60,6 +61,7 @@
 import android.telecom.PhoneAccount;
 import android.telecom.PhoneAccountHandle;
 import android.telecom.TelecomManager;
+import android.telecom.CallException;
 import android.telecom.VideoProfile;
 import android.telephony.TelephonyManager;
 import android.test.suitebuilder.annotation.MediumTest;
@@ -122,7 +124,6 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.CompletableFuture;
@@ -1774,6 +1775,88 @@
         assertTrue(argumentCaptor.getValue().contains("Unavailable phoneAccountHandle"));
     }
 
+    public class LatchedOutcomeReceiver implements OutcomeReceiver<Boolean,
+            CallException> {
+        CountDownLatch mCountDownLatch;
+        Boolean mIsOnResultExpected;
+
+        public LatchedOutcomeReceiver(CountDownLatch latch, boolean isOnResultExpected){
+            mCountDownLatch = latch;
+            mIsOnResultExpected = isOnResultExpected;
+        }
+
+        @Override
+        public void onResult(Boolean result) {
+            if(mIsOnResultExpected) {
+                mCountDownLatch.countDown();
+            }
+        }
+
+        @Override
+        public void onError(CallException error) {
+            OutcomeReceiver.super.onError(error);
+            if(!mIsOnResultExpected){
+                mCountDownLatch.countDown();
+            }
+        }
+    }
+
+    @SmallTest
+    @Test
+    public void testCanHold() {
+        Call newCall = addSpyCall();
+        when(newCall.isTransactionalCall()).thenReturn(true);
+        when(newCall.can(Connection.CAPABILITY_SUPPORT_HOLD)).thenReturn(false);
+        assertFalse(mCallsManager.canHold(newCall));
+        when(newCall.can(Connection.CAPABILITY_SUPPORT_HOLD)).thenReturn(true);
+        assertTrue(mCallsManager.canHold(newCall));
+    }
+
+    @MediumTest
+    @Test
+    public void testHoldTransactional() throws Exception {
+        CountDownLatch latch = new CountDownLatch(1);
+        Call newCall = addSpyCall();
+
+        // case 1: no active call, no need to put the call on hold
+        when(mConnectionSvrFocusMgr.getCurrentFocusCall()).thenReturn(null);
+        mCallsManager.transactionHoldPotentialActiveCallForNewCall(newCall,
+                new LatchedOutcomeReceiver(latch, true));
+        waitForCountDownLatch(latch);
+
+        // case 2: active call == new call, no need to put the call on hold
+        latch = new CountDownLatch(1);
+        when(mConnectionSvrFocusMgr.getCurrentFocusCall()).thenReturn(newCall);
+        mCallsManager.transactionHoldPotentialActiveCallForNewCall(newCall,
+                new LatchedOutcomeReceiver(latch, true));
+        waitForCountDownLatch(latch);
+
+        // case 3: cannot hold current active call early check
+        Call cannotHoldCall = addSpyCall(SIM_1_HANDLE, null,
+                CallState.ACTIVE, 0, 0);
+        latch = new CountDownLatch(1);
+        when(mConnectionSvrFocusMgr.getCurrentFocusCall()).thenReturn(cannotHoldCall);
+        mCallsManager.transactionHoldPotentialActiveCallForNewCall(newCall,
+                new LatchedOutcomeReceiver(latch, false));
+        waitForCountDownLatch(latch);
+
+        // case 4: activeCall != newCall && canHold(activeCall)
+        Call canHoldCall = addSpyCall(SIM_1_HANDLE, null,
+                CallState.ACTIVE, Connection.CAPABILITY_HOLD, 0);
+        latch = new CountDownLatch(1);
+        when(mConnectionSvrFocusMgr.getCurrentFocusCall()).thenReturn(canHoldCall);
+        mCallsManager.transactionHoldPotentialActiveCallForNewCall(newCall,
+                new LatchedOutcomeReceiver(latch, true));
+        waitForCountDownLatch(latch);
+    }
+
+    public void waitForCountDownLatch(CountDownLatch latch) throws InterruptedException {
+            boolean success = latch.await(5000, TimeUnit.MILLISECONDS);
+            if (!success) {
+                fail("assertOnResultWasReceived success failed");
+            }
+    }
+
     private Call addSpyCall() {
         return addSpyCall(SIM_2_HANDLE, CallState.ACTIVE);
     }
diff --git a/tests/src/com/android/server/telecom/tests/PhoneAccountRegistrarTest.java b/tests/src/com/android/server/telecom/tests/PhoneAccountRegistrarTest.java
index 26f0f6d..efa83ea 100644
--- a/tests/src/com/android/server/telecom/tests/PhoneAccountRegistrarTest.java
+++ b/tests/src/com/android/server/telecom/tests/PhoneAccountRegistrarTest.java
@@ -684,6 +684,75 @@
         assertEquals(TEST_LABEL, registeredAccount.getLabel());
     }
 
+    @MediumTest
+    @Test
+    public void testSecurityExceptionIsThrownWhenSelfManagedLacksPermissions() {
+        PhoneAccountHandle handle = makeQuickAccountHandle(
+                new ComponentName("self", "managed"), "selfie1");
+
+        PhoneAccount accountWithoutCapability = new PhoneAccount.Builder(handle, "label")
+                .setCapabilities(PhoneAccount.CAPABILITY_SELF_MANAGED)
+                .build();
+
+        assertFalse(mRegistrar.hasTransactionalCallCapabilites(accountWithoutCapability));
+
+        try {
+            mRegistrar.registerPhoneAccount(accountWithoutCapability);
+            fail("should not be able to register account");
+        } catch (SecurityException securityException) {
+            // test pass
+        } finally {
+            mRegistrar.unregisterPhoneAccount(handle);
+        }
+    }
+
+    @MediumTest
+    @Test
+    public void testSelfManagedPhoneAccountWithTransactionalOperations() {
+        PhoneAccountHandle handle = makeQuickAccountHandle(
+                new ComponentName("self", "managed"), "selfie1");
+
+        PhoneAccount accountWithCapability = new PhoneAccount.Builder(handle, "label")
+                .setCapabilities(PhoneAccount.CAPABILITY_SELF_MANAGED |
+                        PhoneAccount.CAPABILITY_SUPPORTS_TRANSACTIONAL_OPERATIONS)
+                .build();
+
+        assertTrue(mRegistrar.hasTransactionalCallCapabilites(accountWithCapability));
+
+        try {
+            mRegistrar.registerPhoneAccount(accountWithCapability);
+            PhoneAccount registeredAccount = mRegistrar.getPhoneAccountUnchecked(handle);
+            assertEquals(TEST_LABEL, registeredAccount.getLabel().toString());
+        } finally {
+            mRegistrar.unregisterPhoneAccount(handle);
+        }
+    }
+
+    @MediumTest
+    @Test
+    public void testRegisterPhoneAccountAmendsSelfManagedCapabilityInternally() {
+        // GIVEN
+        PhoneAccountHandle handle = makeQuickAccountHandle(
+                new ComponentName("self", "managed"), "selfie1");
+        PhoneAccount accountWithCapability = new PhoneAccount.Builder(handle, "label")
+                .setCapabilities(
+                        PhoneAccount.CAPABILITY_SUPPORTS_TRANSACTIONAL_OPERATIONS)
+                .build();
+
+        assertTrue(mRegistrar.hasTransactionalCallCapabilites(accountWithCapability));
+
+        try {
+            // WHEN
+            mRegistrar.registerPhoneAccount(accountWithCapability);
+            PhoneAccount registeredAccount = mRegistrar.getPhoneAccountUnchecked(handle);
+            // THEN
+            assertEquals(PhoneAccount.CAPABILITY_SELF_MANAGED, (registeredAccount.getCapabilities()
+                    & PhoneAccount.CAPABILITY_SELF_MANAGED));
+        } finally {
+            mRegistrar.unregisterPhoneAccount(handle);
+        }
+    }
+
     /**
      * Tests to ensure that when registering a self-managed PhoneAccount, it cannot also be defined
      * as a call provider, connection manager, or sim subscription.
diff --git a/tests/src/com/android/server/telecom/tests/TelecomServiceImplTest.java b/tests/src/com/android/server/telecom/tests/TelecomServiceImplTest.java
index a5aa936..e8d4226 100644
--- a/tests/src/com/android/server/telecom/tests/TelecomServiceImplTest.java
+++ b/tests/src/com/android/server/telecom/tests/TelecomServiceImplTest.java
@@ -36,9 +36,11 @@
 import android.os.Binder;
 import android.os.Build;
 import android.os.Bundle;
+import android.os.OutcomeReceiver;
 import android.os.RemoteException;
 import android.os.UserHandle;
 import android.os.UserManager;
+import android.telecom.CallAttributes;
 import android.telecom.PhoneAccount;
 import android.telecom.PhoneAccountHandle;
 import android.telecom.TelecomManager;
@@ -46,6 +48,7 @@
 import android.telephony.TelephonyManager;
 import android.test.suitebuilder.annotation.SmallTest;
 
+import com.android.internal.telecom.ICallEventCallback;
 import com.android.internal.telecom.ITelecomService;
 import com.android.server.telecom.Call;
 import com.android.server.telecom.CallIntentProcessor;
@@ -57,6 +60,9 @@
 import com.android.server.telecom.TelecomSystem;
 import com.android.server.telecom.components.UserCallIntentProcessor;
 import com.android.server.telecom.components.UserCallIntentProcessorFactory;
+import com.android.server.telecom.voip.IncomingCallTransaction;
+import com.android.server.telecom.voip.OutgoingCallTransaction;
+import com.android.server.telecom.voip.TransactionManager;
 
 import org.junit.After;
 import org.junit.Before;
@@ -67,7 +73,6 @@
 import org.mockito.ArgumentMatcher;
 import org.mockito.Mock;
 
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 import java.util.concurrent.Executor;
@@ -95,14 +100,18 @@
 import static org.mockito.Mockito.doThrow;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.isA;
 import static org.mockito.Mockito.when;
 
 @RunWith(JUnit4.class)
 public class TelecomServiceImplTest extends TelecomTestCase {
 
     private static final String CALLING_PACKAGE = TelecomServiceImplTest.class.getPackageName();
+    private static final String TEST_NAME = "Alan Turing";
+    private static final Uri TEST_URI = Uri.fromParts("tel", "abc", "123");
     public static final String TEST_PACKAGE = "com.test";
     public static final String PACKAGE_NAME = "test";
 
@@ -176,6 +185,8 @@
     @Mock private UserCallIntentProcessor mUserCallIntentProcessor;
     private PackageManager mPackageManager;
     @Mock private ApplicationInfo mApplicationInfo;
+    @Mock private ICallEventCallback mICallEventCallback;
+    @Mock private TransactionManager mTransactionManager;
 
     private final TelecomSystem.SyncRoot mLock = new TelecomSystem.SyncRoot() { };
 
@@ -225,6 +236,7 @@
                 mSubscriptionManagerAdapter,
                 mSettingsSecureAdapter,
                 mLock);
+        telecomServiceImpl.setTransactionManager(mTransactionManager);
         mTSIBinder = telecomServiceImpl.getBinder();
         mComponentContextFixture.setTelecomManager(mTelecomManager);
         when(mTelecomManager.getDefaultDialerPackage()).thenReturn(DEFAULT_DIALER_PACKAGE);
@@ -356,6 +368,82 @@
                 .setUserSelectedOutgoingPhoneAccount(eq(TEL_PA_HANDLE_16), any(UserHandle.class));
     }
 
+    @Test
+    public void testAddCallWithOutgoingCall() throws RemoteException {
+        // GIVEN
+        CallAttributes mOutgoingCallAttributes = new CallAttributes.Builder(TEL_PA_HANDLE_CURRENT,
+                CallAttributes.DIRECTION_OUTGOING, TEST_NAME, TEST_URI)
+                .setCallType(CallAttributes.AUDIO_CALL)
+                .setCallCapabilities(CallAttributes.SUPPORTS_SET_INACTIVE)
+                .build();
+        PhoneAccount phoneAccount = makeMultiUserPhoneAccount(TEL_PA_HANDLE_CURRENT).build();
+        phoneAccount.setIsEnabled(true);
+
+        // WHEN
+        when(mFakePhoneAccountRegistrar.getPhoneAccountUnchecked(TEL_PA_HANDLE_CURRENT)).thenReturn(
+                phoneAccount);
+
+        doReturn(phoneAccount).when(mFakePhoneAccountRegistrar).getPhoneAccount(
+                eq(TEL_PA_HANDLE_CURRENT), any(UserHandle.class));
+
+        mTSIBinder.addCall(mOutgoingCallAttributes, mICallEventCallback, "1", CALLING_PACKAGE);
+
+        // THEN
+        verify(mTransactionManager, times(1))
+                .addTransaction(isA(OutgoingCallTransaction.class), isA(OutcomeReceiver.class));
+    }
+
+    @Test
+    public void testAddCallWithIncomingCall() throws RemoteException {
+        // GIVEN
+        CallAttributes mIncomingCallAttributes = new CallAttributes.Builder(TEL_PA_HANDLE_CURRENT,
+                CallAttributes.DIRECTION_INCOMING, TEST_NAME, TEST_URI)
+                .setCallType(CallAttributes.AUDIO_CALL)
+                .setCallCapabilities(CallAttributes.SUPPORTS_SET_INACTIVE)
+                .build();
+        PhoneAccount phoneAccount = makeMultiUserPhoneAccount(TEL_PA_HANDLE_CURRENT).build();
+        phoneAccount.setIsEnabled(true);
+
+        // WHEN
+        when(mFakePhoneAccountRegistrar.getPhoneAccountUnchecked(TEL_PA_HANDLE_CURRENT)).thenReturn(
+                phoneAccount);
+
+        doReturn(phoneAccount).when(mFakePhoneAccountRegistrar).getPhoneAccount(
+                eq(TEL_PA_HANDLE_CURRENT), any(UserHandle.class));
+
+        mTSIBinder.addCall(mIncomingCallAttributes, mICallEventCallback, "1", CALLING_PACKAGE);
+
+        // THEN
+        verify(mTransactionManager, times(1))
+                .addTransaction(isA(IncomingCallTransaction.class), isA(OutcomeReceiver.class));
+    }
+
+    @Test
+    public void testAddCallWithManagedPhoneAccount() throws RemoteException {
+        // GIVEN
+        CallAttributes attributes = new CallAttributes.Builder(TEL_PA_HANDLE_CURRENT,
+                CallAttributes.DIRECTION_OUTGOING, TEST_NAME, TEST_URI).build();
+        PhoneAccount phoneAccount = makeMultiUserPhoneAccount(TEL_PA_HANDLE_CURRENT)
+                .setCapabilities(PhoneAccount.CAPABILITY_SIM_SUBSCRIPTION)
+                .build();
+        phoneAccount.setIsEnabled(true);
+
+        // WHEN
+        when(mFakePhoneAccountRegistrar.getPhoneAccountUnchecked(TEL_PA_HANDLE_CURRENT)).thenReturn(
+                phoneAccount);
+
+        doReturn(phoneAccount).when(mFakePhoneAccountRegistrar).getPhoneAccount(
+                eq(TEL_PA_HANDLE_CURRENT), any(UserHandle.class));
+
+        // THEN
+        try {
+            mTSIBinder.addCall(attributes, mICallEventCallback, "1", CALLING_PACKAGE);
+            fail("should have thrown IllegalArgumentException");
+        } catch (IllegalArgumentException e) {
+            // pass
+        }
+    }
+
     @SmallTest
     @Test
     public void testSetUserSelectedOutgoingPhoneAccountFailure() throws RemoteException {
diff --git a/tests/src/com/android/server/telecom/tests/TransactionTests.java b/tests/src/com/android/server/telecom/tests/TransactionTests.java
new file mode 100644
index 0000000..9ae05eb
--- /dev/null
+++ b/tests/src/com/android/server/telecom/tests/TransactionTests.java
@@ -0,0 +1,268 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.telecom.tests;
+
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.isA;
+import static org.junit.Assert.assertEquals;
+import static org.mockito.ArgumentMatchers.nullable;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.doNothing;
+import static org.mockito.Mockito.when;
+
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.net.Uri;
+import android.os.Bundle;
+import android.os.OutcomeReceiver;
+import android.os.UserHandle;
+import android.telecom.CallAttributes;
+import android.telecom.DisconnectCause;
+import android.telecom.PhoneAccountHandle;
+
+import com.android.server.telecom.Call;
+import com.android.server.telecom.CallState;
+import com.android.server.telecom.CallerInfoLookupHelper;
+import com.android.server.telecom.CallsManager;
+import com.android.server.telecom.ClockProxy;
+import com.android.server.telecom.PhoneNumberUtilsAdapter;
+import com.android.server.telecom.TelecomSystem;
+import com.android.server.telecom.ui.ToastFactory;
+import com.android.server.telecom.voip.EndCallTransaction;
+import com.android.server.telecom.voip.HoldCallTransaction;
+import com.android.server.telecom.voip.IncomingCallTransaction;
+import com.android.server.telecom.voip.OutgoingCallTransaction;
+import com.android.server.telecom.voip.HoldActiveCallForNewCallTransaction;
+import com.android.server.telecom.voip.RequestFocusTransaction;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+
+
+public class TransactionTests extends TelecomTestCase {
+
+    private static final String CALL_ID_1 = "1";
+
+    private static final PhoneAccountHandle mHandle = new PhoneAccountHandle(
+            new ComponentName("foo", "bar"), "1");
+    private static final String TEST_NAME = "Sergey Brin";
+    private static final Uri TEST_URI = Uri.fromParts("tel", "abc", "123");
+
+    @Mock private Call mMockCall1;
+    @Mock private Context mMockContext;
+    @Mock private CallsManager mCallsManager;
+    @Mock private ToastFactory mToastFactory;
+    @Mock private ClockProxy mClockProxy;
+    @Mock private PhoneNumberUtilsAdapter mPhoneNumberUtilsAdapter;
+    @Mock private CallerInfoLookupHelper mCallerInfoLookupHelper;
+
+    private final TelecomSystem.SyncRoot mLock = new TelecomSystem.SyncRoot() {
+    };
+    private static final Uri TEST_ADDRESS = Uri.parse("tel:555-1212");
+
+    @Override
+    @Before
+    public void setUp() throws Exception {
+        super.setUp();
+        MockitoAnnotations.initMocks(this);
+        Mockito.when(mMockCall1.getId()).thenReturn(CALL_ID_1);
+    }
+
+    @Override
+    @After
+    public void tearDown() throws Exception {
+        super.tearDown();
+    }
+
+    @Test
+    public void testEndCallTransactionWithDisconnect() throws Exception {
+        // GIVEN
+        EndCallTransaction transaction =
+                new EndCallTransaction(mCallsManager, true, 0, mMockCall1);
+
+        // WHEN
+        transaction.processTransaction(null);
+
+        // THEN
+        verify(mCallsManager, times(1))
+                .markCallAsDisconnected(mMockCall1, new DisconnectCause(0));
+        verify(mCallsManager, never())
+                .rejectCall(mMockCall1, 0);
+        verify(mCallsManager, times(1))
+                .markCallAsRemoved(mMockCall1);
+    }
+
+    @Test
+    public void testEndCallTransactionWithReject() throws Exception {
+        // GIVEN
+        EndCallTransaction transaction =
+                new EndCallTransaction(mCallsManager, false, 0, mMockCall1);
+
+        // WHEN
+        transaction.processTransaction(null);
+
+        // THEN
+        verify(mCallsManager, never())
+                .markCallAsDisconnected(mMockCall1, new DisconnectCause(0));
+        verify(mCallsManager, times(1))
+                .rejectCall(mMockCall1, 0);
+        verify(mCallsManager, times(1))
+                .markCallAsRemoved(mMockCall1);
+    }
+
+    @Test
+    public void testHoldCallTransaction() throws Exception {
+        // GIVEN
+        Call spyCall = createSpyCall(null, CallState.ACTIVE, CALL_ID_1);
+
+        HoldCallTransaction transaction =
+                new HoldCallTransaction(mCallsManager, spyCall);
+
+        // WHEN
+        doAnswer(invocation -> {
+            Call call = invocation.getArgument(0);
+            call.setState(CallState.ON_HOLD, "manual set");
+            return null;
+        }).when(mCallsManager).markCallAsOnHold(spyCall);
+
+        transaction.processTransaction(null);
+
+        // THEN
+        verify(mCallsManager, times(1))
+                .markCallAsOnHold(spyCall);
+
+        assertEquals(CallState.ON_HOLD, spyCall.getState());
+    }
+
+    @Test
+    public void testTransactionalRequestFocus() throws Exception {
+        // GIVEN
+        RequestFocusTransaction transaction =
+                new RequestFocusTransaction(mCallsManager, mMockCall1);
+
+        // WHEN
+        transaction.processTransaction(null);
+
+        // THEN
+        verify(mCallsManager, times(1))
+                .transactionRequestNewFocusCall(eq(mMockCall1), isA(OutcomeReceiver.class));
+    }
+
+    @Test
+    public void testTransactionalHoldActiveCallForNewCall() throws Exception {
+        // GIVEN
+        HoldActiveCallForNewCallTransaction transaction =
+                new HoldActiveCallForNewCallTransaction(mCallsManager, mMockCall1);
+
+        // WHEN
+        transaction.processTransaction(null);
+
+        // THEN
+        verify(mCallsManager, times(1))
+                .transactionHoldPotentialActiveCallForNewCall(eq(mMockCall1),
+                        isA(OutcomeReceiver.class));
+    }
+
+    @Test
+    public void testOutgoingCallTransaction() throws Exception {
+        // GIVEN
+        CallAttributes callAttributes = new CallAttributes.Builder(mHandle,
+                CallAttributes.DIRECTION_OUTGOING, TEST_NAME, TEST_URI).build();
+
+        OutgoingCallTransaction transaction =
+                new OutgoingCallTransaction(CALL_ID_1, mMockContext, callAttributes, mCallsManager);
+
+        // WHEN
+        when(mMockContext.getOpPackageName()).thenReturn("testPackage");
+        when(mMockContext.checkCallingPermission(android.Manifest.permission.CALL_PRIVILEGED))
+                .thenReturn(PackageManager.PERMISSION_GRANTED);
+        when(mCallsManager.isOutgoingCallPermitted(callAttributes.getPhoneAccountHandle()))
+                .thenReturn(true);
+        transaction.processTransaction(null);
+
+        // THEN
+        verify(mCallsManager, times(1))
+                .startOutgoingCall(isA(Uri.class),
+                        isA(PhoneAccountHandle.class),
+                        isA(Bundle.class),
+                        isA(UserHandle.class),
+                        isA(Intent.class),
+                        nullable(String.class));
+    }
+
+    @Test
+    public void testIncomingCallTransaction() throws Exception {
+        // GIVEN
+        CallAttributes callAttributes = new CallAttributes.Builder(mHandle,
+                CallAttributes.DIRECTION_INCOMING, TEST_NAME, TEST_URI).build();
+
+        IncomingCallTransaction transaction =
+                new IncomingCallTransaction(CALL_ID_1, callAttributes, mCallsManager);
+
+        // WHEN
+        when(mCallsManager.isIncomingCallPermitted(callAttributes.getPhoneAccountHandle()))
+                .thenReturn(true);
+        transaction.processTransaction(null);
+
+        // THEN
+        verify(mCallsManager, times(1))
+                .processIncomingCallIntent(isA(PhoneAccountHandle.class),
+                        isA(Bundle.class),
+                        isA(Boolean.class));
+    }
+
+    private Call createSpyCall(PhoneAccountHandle targetPhoneAccount, int initialState, String id) {
+        when(mCallsManager.getCallerInfoLookupHelper()).thenReturn(mCallerInfoLookupHelper);
+
+        Call call = new Call(id,
+                mMockContext,
+                mCallsManager,
+                mLock, /* ConnectionServiceRepository */
+                null,
+                mPhoneNumberUtilsAdapter,
+                TEST_ADDRESS,
+                null /* GatewayInfo */,
+                null /* ConnectionManagerAccount */,
+                targetPhoneAccount,
+                Call.CALL_DIRECTION_INCOMING,
+                false /* shouldAttachToExistingConnection*/,
+                false /* isConference */,
+                mClockProxy,
+                mToastFactory);
+
+        Call callSpy = Mockito.spy(call);
+
+        callSpy.setState(initialState, "manual set in test");
+
+        // Mocks some methods to not call the real method.
+        doNothing().when(callSpy).unhold();
+        doNothing().when(callSpy).hold();
+        doNothing().when(callSpy).disconnect();
+
+        return callSpy;
+    }
+}
\ No newline at end of file
diff --git a/tests/src/com/android/server/telecom/tests/TransactionalServiceWrapperTest.java b/tests/src/com/android/server/telecom/tests/TransactionalServiceWrapperTest.java
new file mode 100644
index 0000000..1ea81e7
--- /dev/null
+++ b/tests/src/com/android/server/telecom/tests/TransactionalServiceWrapperTest.java
@@ -0,0 +1,180 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.telecom.tests;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.isA;
+
+
+import android.content.ComponentName;
+import android.os.OutcomeReceiver;
+import android.os.RemoteException;
+import android.os.ResultReceiver;
+import android.telecom.DisconnectCause;
+import android.telecom.PhoneAccountHandle;
+
+import com.android.internal.telecom.ICallControl;
+import com.android.internal.telecom.ICallEventCallback;
+import com.android.server.telecom.Call;
+import com.android.server.telecom.CallsManager;
+import com.android.server.telecom.TransactionalServiceRepository;
+import com.android.server.telecom.TransactionalServiceWrapper;
+import com.android.server.telecom.voip.EndCallTransaction;
+import com.android.server.telecom.voip.HoldCallTransaction;
+import com.android.server.telecom.voip.SerialTransaction;
+import com.android.server.telecom.voip.TransactionManager;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+
+@RunWith(JUnit4.class)
+public class TransactionalServiceWrapperTest extends TelecomTestCase {
+
+    private static final PhoneAccountHandle SERVICE_HANDLE = new PhoneAccountHandle(
+            ComponentName.unflattenFromString("com.foo/.Blah"), "Service1");
+
+    private static final String CALL_ID_1 = "1";
+    private static final String CALL_ID_2 = "2";
+
+    TransactionalServiceWrapper mTransactionalServiceWrapper;
+
+    @Mock private Call mMockCall1;
+    @Mock private Call mMockCall2;
+    @Mock private CallsManager mCallsManager;
+    @Mock private TransactionManager mTransactionManager;
+    @Mock private ICallEventCallback mCallEventCallback;
+    @Mock private TransactionalServiceRepository mRepository;
+
+    @Override
+    @Before
+    public void setUp() throws Exception {
+        super.setUp();
+        MockitoAnnotations.initMocks(this);
+        Mockito.when(mMockCall1.getId()).thenReturn(CALL_ID_1);
+        Mockito.when(mMockCall2.getId()).thenReturn(CALL_ID_2);
+
+        mTransactionalServiceWrapper = new TransactionalServiceWrapper(mCallEventCallback,
+                mCallsManager, SERVICE_HANDLE, mMockCall1, mRepository);
+
+        mTransactionalServiceWrapper.setTransactionManager(mTransactionManager);
+    }
+
+    @Override
+    @After
+    public void tearDown() throws Exception {
+        super.tearDown();
+    }
+
+    @Test
+    public void testTransactionalServiceWrapperStartState() throws Exception {
+        TransactionalServiceWrapper service =
+                new TransactionalServiceWrapper(mCallEventCallback,
+                        mCallsManager, SERVICE_HANDLE, mMockCall1, mRepository);
+
+        assertEquals(SERVICE_HANDLE, service.getPhoneAccountHandle());
+        assertEquals(1, service.getNumberOfTrackedCalls());
+    }
+
+    @Test
+    public void testTransactionalServiceWrapperCallCount() throws Exception {
+        TransactionalServiceWrapper service =
+                new TransactionalServiceWrapper(mCallEventCallback,
+                        mCallsManager, SERVICE_HANDLE, mMockCall1, mRepository);
+
+        assertEquals(1, service.getNumberOfTrackedCalls());
+        service.trackCall(mMockCall2);
+        assertEquals(2, service.getNumberOfTrackedCalls());
+
+        assertTrue(service.untrackCall(mMockCall2));
+        assertEquals(1, service.getNumberOfTrackedCalls());
+
+        assertTrue(service.untrackCall(mMockCall1));
+        assertFalse(service.untrackCall(mMockCall1));
+        assertEquals(0, service.getNumberOfTrackedCalls());
+    }
+
+    @Test
+    public void testCallControlSetActive() throws RemoteException {
+        // GIVEN
+        mTransactionalServiceWrapper.trackCall(mMockCall1);
+        //when(mCallsManager.getCallObjectFromCallId(CALL_ID_1)).thenReturn(mMockCall1);
+
+        // WHEN
+        ICallControl callControl = mTransactionalServiceWrapper.getICallControl();
+        callControl.setActive(CALL_ID_1, new ResultReceiver(null));
+
+        //THEN
+        verify(mTransactionManager, times(1))
+                .addTransaction(isA(SerialTransaction.class), isA(OutcomeReceiver.class));
+    }
+
+    @Test
+    public void testCallControlRejectCall() throws RemoteException {
+        // GIVEN
+        mTransactionalServiceWrapper.trackCall(mMockCall1);
+        //when(mCallsManager.getCallObjectFromCallId(CALL_ID_1)).thenReturn(mMockCall1);
+
+        // WHEN
+        ICallControl callControl = mTransactionalServiceWrapper.getICallControl();
+        callControl.rejectCall(CALL_ID_1, new ResultReceiver(null));
+
+        //THEN
+        verify(mTransactionManager, times(1))
+                .addTransaction(isA(EndCallTransaction.class), isA(OutcomeReceiver.class));
+    }
+
+    @Test
+    public void testCallControlDisconnectCall() throws RemoteException {
+        // GIVEN
+        mTransactionalServiceWrapper.trackCall(mMockCall1);
+        //when(mCallsManager.getCallObjectFromCallId(CALL_ID_1)).thenReturn(mMockCall1);
+
+        // WHEN
+        ICallControl callControl = mTransactionalServiceWrapper.getICallControl();
+        callControl.disconnect(CALL_ID_1, new DisconnectCause(DisconnectCause.LOCAL),
+                new ResultReceiver(null));
+
+        //THEN
+        verify(mTransactionManager, times(1))
+                .addTransaction(isA(EndCallTransaction.class), isA(OutcomeReceiver.class));
+    }
+
+    @Test
+    public void testCallControlSetInactive() throws RemoteException {
+        // GIVEN
+        mTransactionalServiceWrapper.trackCall(mMockCall1);
+        //when(mCallsManager.getCallObjectFromCallId(CALL_ID_1)).thenReturn(mMockCall1);
+
+        // WHEN
+        ICallControl callControl = mTransactionalServiceWrapper.getICallControl();
+        callControl.setInactive(CALL_ID_1, new ResultReceiver(null));
+
+        //THEN
+        verify(mTransactionManager, times(1))
+                .addTransaction(isA(HoldCallTransaction.class), isA(OutcomeReceiver.class));
+    }
+}
diff --git a/tests/src/com/android/server/telecom/tests/VoipCallTransactionTest.java b/tests/src/com/android/server/telecom/tests/VoipCallTransactionTest.java
index d57a163..58e4a77 100644
--- a/tests/src/com/android/server/telecom/tests/VoipCallTransactionTest.java
+++ b/tests/src/com/android/server/telecom/tests/VoipCallTransactionTest.java
@@ -20,6 +20,7 @@
 import static org.junit.Assert.assertTrue;
 
 import android.os.OutcomeReceiver;
+import android.telecom.CallException;
 import android.util.Log;
 
 import androidx.test.filters.SmallTest;
@@ -121,7 +122,7 @@
         subTransactions.add(t2);
         subTransactions.add(t3);
         CompletableFuture<VoipCallTransactionResult> resultFuture = new CompletableFuture<>();
-        OutcomeReceiver<VoipCallTransactionResult, Exception> outcomeReceiver =
+        OutcomeReceiver<VoipCallTransactionResult, CallException> outcomeReceiver =
                 resultFuture::complete;
         String expectedLog = "t1 success;\nt2 success;\nt3 success;\n";
         mTransactionManager.addTransaction(new SerialTransaction(subTransactions), outcomeReceiver);
@@ -145,15 +146,15 @@
         subTransactions.add(t2);
         subTransactions.add(t3);
         CompletableFuture<String> exceptionFuture = new CompletableFuture<>();
-        OutcomeReceiver<VoipCallTransactionResult, Exception> outcomeReceiver =
-                new OutcomeReceiver<VoipCallTransactionResult, Exception>() {
+        OutcomeReceiver<VoipCallTransactionResult, CallException> outcomeReceiver =
+                new OutcomeReceiver<VoipCallTransactionResult, CallException>() {
                     @Override
                     public void onResult(VoipCallTransactionResult result) {
 
                     }
 
                     @Override
-                    public void onError(Exception e) {
+                    public void onError(CallException e) {
                         exceptionFuture.complete(e.getMessage());
                     }
                 };
@@ -179,7 +180,7 @@
         subTransactions.add(t2);
         subTransactions.add(t3);
         CompletableFuture<VoipCallTransactionResult> resultFuture = new CompletableFuture<>();
-        OutcomeReceiver<VoipCallTransactionResult, Exception> outcomeReceiver =
+        OutcomeReceiver<VoipCallTransactionResult, CallException> outcomeReceiver =
                 resultFuture::complete;
         mTransactionManager.addTransaction(new ParallelTransaction(subTransactions),
                 outcomeReceiver);
@@ -206,15 +207,15 @@
         subTransactions.add(t2);
         subTransactions.add(t3);
         CompletableFuture<String> exceptionFuture = new CompletableFuture<>();
-        OutcomeReceiver<VoipCallTransactionResult, Exception> outcomeReceiver =
-                new OutcomeReceiver<VoipCallTransactionResult, Exception>() {
+        OutcomeReceiver<VoipCallTransactionResult, CallException> outcomeReceiver =
+                new OutcomeReceiver<VoipCallTransactionResult, CallException>() {
             @Override
             public void onResult(VoipCallTransactionResult result) {
 
             }
 
             @Override
-            public void onError(Exception e) {
+            public void onError(CallException e) {
                 exceptionFuture.complete(e.getMessage());
             }
         };
@@ -231,7 +232,7 @@
         VoipCallTransaction t = new TestVoipCallTransaction("t", 10000L,
                 TestVoipCallTransaction.SUCCESS);
         CompletableFuture<VoipCallTransactionResult> resultFuture = new CompletableFuture<>();
-        OutcomeReceiver<VoipCallTransactionResult, Exception> outcomeReceiver =
+        OutcomeReceiver<VoipCallTransactionResult, CallException> outcomeReceiver =
                 resultFuture::complete;
         mTransactionManager.addTransaction(t, outcomeReceiver);
         VoipCallTransactionResult result = resultFuture.get(7000L, TimeUnit.MILLISECONDS);