diff --git a/Tethering/common/TetheringLib/Android.bp b/Tethering/common/TetheringLib/Android.bp
index b0ef153..e0adb34 100644
--- a/Tethering/common/TetheringLib/Android.bp
+++ b/Tethering/common/TetheringLib/Android.bp
@@ -19,7 +19,15 @@
     local_include_dir: "src",
     include_dirs: ["frameworks/base/core/java"], // For framework parcelables.
     srcs: [
-        "src/android/net/*.aidl",
+        // @JavaOnlyStableParcelable aidl declarations must not be listed here, as this would cause
+        // compilation to fail (b/148001843).
+        "src/android/net/IIntResultListener.aidl",
+        "src/android/net/ITetheringConnector.aidl",
+        "src/android/net/ITetheringEventCallback.aidl",
+        "src/android/net/TetheringCallbackStartedParcel.aidl",
+        "src/android/net/TetheringConfigurationParcel.aidl",
+        "src/android/net/TetheringRequestParcel.aidl",
+        "src/android/net/TetherStatesParcel.aidl",
     ],
     backend: {
         ndk: {
@@ -35,6 +43,7 @@
     name: "framework-tethering",
     sdk_version: "system_current",
     srcs: [
+        "src/android/net/TetheredClient.java",
         "src/android/net/TetheringManager.java",
         "src/android/net/TetheringConstants.java",
         ":framework-tethering-annotations",
@@ -63,6 +72,8 @@
 filegroup {
     name: "framework-tethering-srcs",
     srcs: [
+        "src/android/net/TetheredClient.aidl",
+        "src/android/net/TetheredClient.java",
         "src/android/net/TetheringManager.java",
         "src/android/net/TetheringConstants.java",
         "src/android/net/IIntResultListener.aidl",
diff --git a/Tethering/common/TetheringLib/src/android/net/TetheredClient.aidl b/Tethering/common/TetheringLib/src/android/net/TetheredClient.aidl
new file mode 100644
index 0000000..0b279b8
--- /dev/null
+++ b/Tethering/common/TetheringLib/src/android/net/TetheredClient.aidl
@@ -0,0 +1,18 @@
+/**
+ * Copyright (C) 2020 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 android.net;
+
+@JavaOnlyStableParcelable parcelable TetheredClient;
\ No newline at end of file
diff --git a/Tethering/common/TetheringLib/src/android/net/TetheredClient.java b/Tethering/common/TetheringLib/src/android/net/TetheredClient.java
new file mode 100644
index 0000000..6514688
--- /dev/null
+++ b/Tethering/common/TetheringLib/src/android/net/TetheredClient.java
@@ -0,0 +1,212 @@
+/*
+ * Copyright (C) 2020 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 android.net;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.SystemApi;
+import android.annotation.TestApi;
+import android.os.Parcel;
+import android.os.Parcelable;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * Information on a tethered downstream client.
+ * @hide
+ */
+@SystemApi
+@TestApi
+public final class TetheredClient implements Parcelable {
+    @NonNull
+    private final MacAddress mMacAddress;
+    @NonNull
+    private final List<AddressInfo> mAddresses;
+    // TODO: use an @IntDef here
+    private final int mTetheringType;
+
+    public TetheredClient(@NonNull MacAddress macAddress,
+            @NonNull Collection<AddressInfo> addresses, int tetheringType) {
+        mMacAddress = macAddress;
+        mAddresses = new ArrayList<>(addresses);
+        mTetheringType = tetheringType;
+    }
+
+    private TetheredClient(@NonNull Parcel in) {
+        this(in.readParcelable(null), in.createTypedArrayList(AddressInfo.CREATOR), in.readInt());
+    }
+
+    @Override
+    public void writeToParcel(@NonNull Parcel dest, int flags) {
+        dest.writeParcelable(mMacAddress, flags);
+        dest.writeTypedList(mAddresses);
+        dest.writeInt(mTetheringType);
+    }
+
+    @NonNull
+    public MacAddress getMacAddress() {
+        return mMacAddress;
+    }
+
+    @NonNull
+    public List<AddressInfo> getAddresses() {
+        return new ArrayList<>(mAddresses);
+    }
+
+    public int getTetheringType() {
+        return mTetheringType;
+    }
+
+    /**
+     * Return a new {@link TetheredClient} that has all the attributes of this instance, plus the
+     * {@link AddressInfo} of the provided {@link TetheredClient}.
+     *
+     * <p>Duplicate addresses are removed.
+     * @hide
+     */
+    public TetheredClient addAddresses(@NonNull TetheredClient other) {
+        final HashSet<AddressInfo> newAddresses = new HashSet<>(
+                mAddresses.size() + other.mAddresses.size());
+        newAddresses.addAll(mAddresses);
+        newAddresses.addAll(other.mAddresses);
+        return new TetheredClient(mMacAddress, newAddresses, mTetheringType);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(mMacAddress, mAddresses, mTetheringType);
+    }
+
+    @Override
+    public boolean equals(@Nullable Object obj) {
+        if (!(obj instanceof TetheredClient)) return false;
+        final TetheredClient other = (TetheredClient) obj;
+        return mMacAddress.equals(other.mMacAddress)
+                && mAddresses.equals(other.mAddresses)
+                && mTetheringType == other.mTetheringType;
+    }
+
+    /**
+     * Information on an lease assigned to a tethered client.
+     */
+    public static final class AddressInfo implements Parcelable {
+        @NonNull
+        private final LinkAddress mAddress;
+        @Nullable
+        private final String mHostname;
+        // TODO: use LinkAddress expiration time once it is supported
+        private final long mExpirationTime;
+
+        /** @hide */
+        public AddressInfo(@NonNull LinkAddress address, @Nullable String hostname) {
+            this(address, hostname, 0);
+        }
+
+        /** @hide */
+        public AddressInfo(@NonNull LinkAddress address, String hostname, long expirationTime) {
+            this.mAddress = address;
+            this.mHostname = hostname;
+            this.mExpirationTime = expirationTime;
+        }
+
+        private AddressInfo(Parcel in) {
+            this(in.readParcelable(null),  in.readString(), in.readLong());
+        }
+
+        @Override
+        public void writeToParcel(@NonNull Parcel dest, int flags) {
+            dest.writeParcelable(mAddress, flags);
+            dest.writeString(mHostname);
+            dest.writeLong(mExpirationTime);
+        }
+
+        @NonNull
+        public LinkAddress getAddress() {
+            return mAddress;
+        }
+
+        @Nullable
+        public String getHostname() {
+            return mHostname;
+        }
+
+        /** @hide TODO: use expiration time in LinkAddress */
+        public long getExpirationTime() {
+            return mExpirationTime;
+        }
+
+        @Override
+        public int describeContents() {
+            return 0;
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(mAddress, mHostname, mExpirationTime);
+        }
+
+        @Override
+        public boolean equals(@Nullable Object obj) {
+            if (!(obj instanceof AddressInfo)) return false;
+            final AddressInfo other = (AddressInfo) obj;
+            // Use .equals() for addresses as all changes, including address expiry changes,
+            // should be included.
+            return other.mAddress.equals(mAddress)
+                    && Objects.equals(mHostname, other.mHostname)
+                    && mExpirationTime == other.mExpirationTime;
+        }
+
+        @NonNull
+        public static final Creator<AddressInfo> CREATOR = new Creator<AddressInfo>() {
+            @NonNull
+            @Override
+            public AddressInfo createFromParcel(@NonNull Parcel in) {
+                return new AddressInfo(in);
+            }
+
+            @NonNull
+            @Override
+            public AddressInfo[] newArray(int size) {
+                return new AddressInfo[size];
+            }
+        };
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @NonNull
+    public static final Creator<TetheredClient> CREATOR = new Creator<TetheredClient>() {
+        @NonNull
+        @Override
+        public TetheredClient createFromParcel(@NonNull Parcel in) {
+            return new TetheredClient(in);
+        }
+
+        @NonNull
+        @Override
+        public TetheredClient[] newArray(int size) {
+            return new TetheredClient[size];
+        }
+    };
+}
diff --git a/Tethering/common/TetheringLib/src/android/net/TetheringManager.java b/Tethering/common/TetheringLib/src/android/net/TetheringManager.java
index 58bc4e7..8dacecc 100644
--- a/Tethering/common/TetheringLib/src/android/net/TetheringManager.java
+++ b/Tethering/common/TetheringLib/src/android/net/TetheringManager.java
@@ -31,6 +31,7 @@
 import android.util.Log;
 
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
@@ -653,6 +654,19 @@
          * @param error One of {@code TetheringManager#TETHER_ERROR_*}.
          */
         public void onError(@NonNull String ifName, int error) {}
+
+        /**
+         * Called when the list of tethered clients changes.
+         *
+         * <p>This callback provides best-effort information on connected clients based on state
+         * known to the system, however the list cannot be completely accurate (and should not be
+         * used for security purposes). For example, clients behind a bridge and using static IP
+         * assignments are not visible to the tethering device; or even when using DHCP, such
+         * clients may still be reported by this callback after disconnection as the system cannot
+         * determine if they are still connected.
+         * @param clients The new set of tethered clients; the collection is not ordered.
+         */
+        public void onClientsChanged(@NonNull Collection<TetheredClient> clients) {}
     }
 
     /**
diff --git a/Tethering/tests/unit/src/android/net/TetheredClientTest.kt b/Tethering/tests/unit/src/android/net/TetheredClientTest.kt
new file mode 100644
index 0000000..83c19ec
--- /dev/null
+++ b/Tethering/tests/unit/src/android/net/TetheredClientTest.kt
@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2020 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 android.net
+
+import android.net.InetAddresses.parseNumericAddress
+import android.net.TetheredClient.AddressInfo
+import android.net.TetheringManager.TETHERING_BLUETOOTH
+import android.net.TetheringManager.TETHERING_USB
+import androidx.test.filters.SmallTest
+import androidx.test.runner.AndroidJUnit4
+import com.android.testutils.assertParcelSane
+import org.junit.Test
+import org.junit.runner.RunWith
+import kotlin.test.assertEquals
+import kotlin.test.assertNotEquals
+
+private val TEST_MACADDR = MacAddress.fromBytes(byteArrayOf(12, 23, 34, 45, 56, 67))
+private val TEST_OTHER_MACADDR = MacAddress.fromBytes(byteArrayOf(23, 34, 45, 56, 67, 78))
+private val TEST_ADDR1 = LinkAddress(parseNumericAddress("192.168.113.3"), 24)
+private val TEST_ADDR2 = LinkAddress(parseNumericAddress("fe80::1:2:3"), 64)
+private val TEST_ADDRINFO1 = AddressInfo(TEST_ADDR1, "test_hostname")
+private val TEST_ADDRINFO2 = AddressInfo(TEST_ADDR2, null)
+
+@RunWith(AndroidJUnit4::class)
+@SmallTest
+class TetheredClientTest {
+    @Test
+    fun testParceling() {
+        assertParcelSane(makeTestClient(), fieldCount = 3)
+    }
+
+    @Test
+    fun testEquals() {
+        assertEquals(makeTestClient(), makeTestClient())
+
+        // Different mac address
+        assertNotEquals(makeTestClient(), TetheredClient(
+                TEST_OTHER_MACADDR,
+                listOf(TEST_ADDRINFO1, TEST_ADDRINFO2),
+                TETHERING_BLUETOOTH))
+
+        // Different hostname
+        assertNotEquals(makeTestClient(), TetheredClient(
+                TEST_MACADDR,
+                listOf(AddressInfo(TEST_ADDR1, "test_other_hostname"), TEST_ADDRINFO2),
+                TETHERING_BLUETOOTH))
+
+        // Null hostname
+        assertNotEquals(makeTestClient(), TetheredClient(
+                TEST_MACADDR,
+                listOf(AddressInfo(TEST_ADDR1, null), TEST_ADDRINFO2),
+                TETHERING_BLUETOOTH))
+
+        // Missing address
+        assertNotEquals(makeTestClient(), TetheredClient(
+                TEST_MACADDR,
+                listOf(TEST_ADDRINFO2),
+                TETHERING_BLUETOOTH))
+
+        // Different type
+        assertNotEquals(makeTestClient(), TetheredClient(
+                TEST_MACADDR,
+                listOf(TEST_ADDRINFO1, TEST_ADDRINFO2),
+                TETHERING_BLUETOOTH))
+    }
+
+    @Test
+    fun testAddAddresses() {
+        val client1 = TetheredClient(TEST_MACADDR, listOf(TEST_ADDRINFO1), TETHERING_USB)
+        val client2 = TetheredClient(TEST_OTHER_MACADDR, listOf(TEST_ADDRINFO2), TETHERING_USB)
+        assertEquals(TetheredClient(
+                TEST_MACADDR,
+                listOf(TEST_ADDRINFO1, TEST_ADDRINFO2),
+                TETHERING_USB), client1.addAddresses(client2))
+    }
+
+    private fun makeTestClient() = TetheredClient(
+            TEST_MACADDR,
+            listOf(TEST_ADDRINFO1, TEST_ADDRINFO2),
+            TETHERING_BLUETOOTH)
+}
\ No newline at end of file