diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 83fbbcb44d546..5347c5b73ae92 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -7424,6 +7424,14 @@
                  android:permission="android.permission.BIND_JOB_SERVICE" >
         </service>
 
+        <service android:name="com.android.server.companion.datatransfer.contextsync.CallMetadataSyncInCallService"
+                 android:permission="android.permission.BIND_INCALL_SERVICE"
+                 android:exported="true">
+            <intent-filter>
+                <action android:name="android.telecom.InCallService"/>
+            </intent-filter>
+        </service>
+
         <provider
             android:name="com.android.server.textclassifier.IconsContentProvider"
             android:authorities="com.android.textclassifier.icons"
diff --git a/services/companion/java/com/android/server/companion/datatransfer/contextsync/CallMetadataSyncInCallService.java b/services/companion/java/com/android/server/companion/datatransfer/contextsync/CallMetadataSyncInCallService.java
new file mode 100644
index 0000000000000..7ea1e6cb7e3e5
--- /dev/null
+++ b/services/companion/java/com/android/server/companion/datatransfer/contextsync/CallMetadataSyncInCallService.java
@@ -0,0 +1,75 @@
+/*
+ * 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.companion.datatransfer.contextsync;
+
+import android.telecom.Call;
+import android.telecom.InCallService;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicLong;
+
+/** In-call service to sync call metadata across a user's devices. */
+public class CallMetadataSyncInCallService extends InCallService {
+
+    @VisibleForTesting
+    final Set<CrossDeviceCall> mCurrentCalls = new HashSet<>();
+
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        mCurrentCalls.addAll(getCalls().stream().map(CrossDeviceCall::new).toList());
+    }
+
+    @Override
+    public void onCallAdded(Call call) {
+        onCallAdded(new CrossDeviceCall(call));
+    }
+
+    @VisibleForTesting
+    void onCallAdded(CrossDeviceCall call) {
+        mCurrentCalls.add(call);
+    }
+
+    @Override
+    public void onCallRemoved(Call call) {
+        mCurrentCalls.removeIf(crossDeviceCall -> crossDeviceCall.getCall().equals(call));
+    }
+
+    /** Data holder for a telecom call and additional metadata. */
+    public static final class CrossDeviceCall {
+        private static final AtomicLong sNextId = new AtomicLong(1);
+
+        private final Call mCall;
+        private final long mId;
+
+        public CrossDeviceCall(Call call) {
+            mCall = call;
+            mId = sNextId.getAndIncrement();
+        }
+
+        public Call getCall() {
+            return mCall;
+        }
+
+        public long getId() {
+            return mId;
+        }
+    }
+}