diff --git a/Package.resolved b/Package.resolved
index 5b233429..677a6086 100644
--- a/Package.resolved
+++ b/Package.resolved
@@ -3,10 +3,10 @@
     "pins": [
       {
         "package": "abseil",
-        "repositoryURL": "https://github.com/firebase/abseil-cpp-SwiftPM.git",
+        "repositoryURL": "https://github.com/bourdakos1/abseil-cpp-SwiftPM.git",
         "state": {
-          "branch": "main",
-          "revision": "06e7506b74bfc47c70f3353e2927ea3e2275230c",
+          "branch": "cxx17",
+          "revision": "a7042563d167160f56e614cd1e2a32616510d9ec",
           "version": null
         }
       },
@@ -22,4 +22,4 @@
     ]
   },
   "version": 1
-}
\ No newline at end of file
+}
diff --git a/Package.swift b/Package.swift
index b690d341..21e142b1 100644
--- a/Package.swift
+++ b/Package.swift
@@ -168,78 +168,40 @@ let package = Package(
         .headerSearchPath("smhasher/src/")
       ]
     ),
-    .target(
-      name: "securemessage",
-      dependencies: [
-        "protobuf",
-        .product(name: "openssl_grpc", package: "BoringSSL-GRPC"),
-      ],
-      path: "third_party/securemessage",
-      exclude: [
-        "securemessage/cmake",
-        "securemessage/cpp/src/securemessage/CMakeLists.txt",
-        "securemessage/cpp/test",
-        "securemessage/cpp/CMakeLists.txt",
-        "securemessage/cpp/Makefile",
-        "securemessage/cpp/README.md",
-        "securemessage/java",
-        "securemessage/js",
-        "securemessage/proto",
-        "securemessage/third_party",
-        "securemessage/CMakeLists.txt",
-        "securemessage/CONTRIBUTORS",
-        "securemessage/CONTRIBUTING.md",
-        "securemessage/LICENSE",
-        "securemessage/README.md",
-      ],
-      sources: [
-        "securemessage/cpp/src/securemessage",
-        "compiled_proto",
-      ],
-      publicHeadersPath: "include",
-      cSettings: [
-        .headerSearchPath("securemessage/cpp/include/"),
-        .headerSearchPath("compiled_proto/"),
-      ]
-    ),
     .target(
       name: "ukey2",
       dependencies: [
-        "securemessage",
         "protobuf",
         .product(name: "abseil", package: "abseil"),
+        .product(name: "openssl_grpc", package: "BoringSSL-GRPC"),
       ],
       path: "third_party/ukey2",
       exclude: [
-        "ukey2/cmake",
-        "ukey2/src/main/cpp/src/securegcm/CMakeLists.txt",
         "ukey2/src/main/cpp/src/securegcm/ukey2_shell.cc",
         "ukey2/src/main/cpp/test",
-        "ukey2/src/main/cpp/CMakeLists.txt",
         "ukey2/src/main/java",
         "ukey2/src/main/javatest",
         "ukey2/src/main/proto",
-        "ukey2/src/main/CMakeLists.txt",
         "ukey2/third_party",
         "ukey2/Android.bp",
         "ukey2/build.gradle",
-        "ukey2/CMakeLists.txt",
         "ukey2/CONTRIBUTING.md",
         "ukey2/LICENSE",
         "ukey2/MODULE_LICENSE_APACHE2",
         "ukey2/NOTICE",
         "ukey2/README",
         "ukey2/README.md",
-        "compiled_proto/proto/securemessage.pb.cc",
       ],
       sources: [
+        "ukey2/src/securemessage/src/securemessage",
         "ukey2/src/main/cpp/src/securegcm",
         "compiled_proto",
       ],
       publicHeadersPath: "include",
       cSettings: [
-        .headerSearchPath("ukey2/src/main/cpp/include/"),
+        .headerSearchPath("ukey2/"),
         .headerSearchPath("compiled_proto/"),
+        .headerSearchPath("compiled_proto/src/main/"),
       ]
     ),
     .target(
@@ -569,6 +531,7 @@ let package = Package(
         "internal/network/http_request_test.cc",
         "internal/network/http_client_impl_test.cc",
         "internal/network/http_status_code_test.cc",
+        "internal/test/google3_only/fake_authentication_manager_test.cc",
         "internal/test/fake_clock_test.cc",
         "internal/test/fake_timer_test.cc",
         "internal/test/fake_device_info_test.cc",
@@ -604,6 +567,8 @@ let package = Package(
       cSettings: [
         .headerSearchPath("./"),
         .headerSearchPath("compiled_proto/"),
+        .headerSearchPath("third_party/ukey2/ukey2/"),
+        .headerSearchPath("third_party/ukey2/compiled_proto/"),
         .define("NO_WEBRTC"),
         .define("NEARBY_SWIFTPM"),
       ]
diff --git a/WORKSPACE b/WORKSPACE
index b317f629..0fc42261 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -59,10 +59,10 @@ http_archive(
     urls = ["https://github.com/google/glog/archive/v0.4.0.tar.gz"],
 )
 
-new_local_repository(
+http_archive(
     name = "com_google_ukey2",
-    path = "./third_party/ukey2/ukey2",
-    build_file_content = _ALL_CONTENT,
+    strip_prefix = "ukey2-master",
+    urls = ["https://github.com/google/ukey2/archive/master.zip"],
 )
 
 http_archive(
diff --git a/connections/implementation/BUILD b/connections/implementation/BUILD
index e0b8c2cf..0e93ee0a 100644
--- a/connections/implementation/BUILD
+++ b/connections/implementation/BUILD
@@ -1,5 +1,3 @@
-load("@rules_foreign_cc//foreign_cc:defs.bzl", "cmake")
-
 # Copyright 2020 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -15,28 +13,6 @@ load("@rules_foreign_cc//foreign_cc:defs.bzl", "cmake")
 # limitations under the License.
 licenses(["notice"])
 
-cmake(
-    name = "ukey2",
-    env = {
-        "CC": "clang",
-        "CXX": "clang++",
-    },
-    generate_args = [
-        "-DBYPASS_TESTING=ON",  # Set the flags in CMakeLists.txt (ukey2 & its dependencies) here.
-        "-Dukey2_USE_LOCAL_ABSL=ON",
-        "-Dukey2_USE_LOCAL_PROTOBUF=ON",  # Add -DCMAKE_BUILD_TYPE=Debug for debugger & Valgrind
-    ],
-    lib_source = "@com_google_ukey2//:all_srcs",
-    out_static_libs = [
-        "libproto_device_to_device_messages_cc_proto.a",
-        "libproto_securegcm_cc_proto.a",
-        "libproto_securemessage_cc_proto.a",
-        "libproto_ukey_cc_proto.a",
-        "libsecuremessage.a",
-        "libukey2.a",
-    ],
-)
-
 cc_library(
     name = "internal",
     srcs = [
@@ -131,15 +107,13 @@ cc_library(
         "//location/nearby/cpp/sharing/implementation:__pkg__",
     ],
     deps = [
-        ":message_lite",
-        ":ukey2",
         "//connections:core_types",
         "//connections/implementation/analytics",
         "//connections/implementation/flags:connections_flags",
         "//connections/implementation/mediums",
         "//connections/implementation/mediums:utils",
-        "//connections/implementation/mediums/webrtc",
         "//connections/implementation/proto:offline_wire_formats_cc_proto",
+        "//connections/v3:v3_types",
         "//internal/analytics:event_logger",
         "//internal/flags:nearby_flags",
         "//internal/interop:device",
@@ -164,6 +138,7 @@ cc_library(
         "@com_google_absl//absl/strings:str_format",
         "@com_google_absl//absl/time",
         "@com_google_absl//absl/types:span",
+        "@com_google_ukey2//:ukey2",
     ],
 )
 
@@ -242,11 +217,11 @@ cc_test(
     deps = [
         ":internal",
         ":internal_test",
-        ":ukey2",
         "//connections:core_types",
         "//connections/implementation/flags:connections_flags",
         "//connections/implementation/mediums",
         "//connections/implementation/proto:offline_wire_formats_cc_proto",
+        "//connections/v3:v3_types",
         "//internal/analytics:event_logger",
         "//internal/flags:nearby_flags",
         "//internal/platform:base",
@@ -255,6 +230,7 @@ cc_test(
         "//internal/platform:test_util",
         "//internal/platform:types",
         "//internal/platform/implementation/g3",  # build_cleaner: keep
+        "//internal/test",
         "//proto:connections_enums_cc_proto",
         "@com_github_protobuf_matchers//protobuf-matchers",
         "@com_google_absl//absl/container:flat_hash_set",
@@ -265,5 +241,6 @@ cc_test(
         "@com_google_absl//absl/types:span",
         "@com_google_googletest//:gtest",
         "@com_google_googletest//:gtest_main",
+        "@com_google_ukey2//:ukey2",
     ],
 )
diff --git a/connections/implementation/client_proxy.cc b/connections/implementation/client_proxy.cc
index 15621b9d..17cb5dd0 100644
--- a/connections/implementation/client_proxy.cc
+++ b/connections/implementation/client_proxy.cc
@@ -27,6 +27,7 @@
 #include "absl/container/flat_hash_set.h"
 #include "absl/strings/escaping.h"
 #include "absl/strings/str_format.h"
+#include "connections/v3/connections_device_provider.h"
 #include "internal/analytics/event_logger.h"
 #include "internal/platform/error_code_recorder.h"
 #include "internal/platform/feature_flags.h"
@@ -70,11 +71,13 @@ std::int64_t ClientProxy::GetClientId() const { return client_id_; }
 
 std::string ClientProxy::GetLocalEndpointId() {
   MutexLock lock(&mutex_);
-  if (local_endpoint_id_.empty()) {
+  if (!local_endpoint_id_.empty()) {
+    return local_endpoint_id_;
+  }
+  if (device_provider_ == nullptr) {
     local_endpoint_id_ = GenerateLocalEndpointId();
-    NEARBY_LOGS(INFO) << "ClientProxy [Local Endpoint Generated]: client="
-                      << GetClientId()
-                      << "; endpoint_id=" << local_endpoint_id_;
+  } else {
+    local_endpoint_id_ = device_provider_->GetLocalDevice()->GetEndpointId();
   }
   return local_endpoint_id_;
 }
diff --git a/connections/implementation/client_proxy.h b/connections/implementation/client_proxy.h
index f3bc81bf..fbf2669f 100644
--- a/connections/implementation/client_proxy.h
+++ b/connections/implementation/client_proxy.h
@@ -20,6 +20,7 @@
 #include <memory>
 #include <optional>
 #include <string>
+#include <utility>
 #include <vector>
 
 #include "connections/advertising_options.h"
@@ -31,6 +32,7 @@
 #include "connections/strategy.h"
 #include "internal/analytics/event_logger.h"
 #include "internal/interop/device.h"
+#include "internal/interop/device_provider.h"
 #include "internal/platform/byte_array.h"
 #include "internal/platform/cancelable_alarm.h"
 #include "internal/platform/cancellation_flag.h"
@@ -206,6 +208,10 @@ class ClientProxy final {
       absl::string_view endpoint_id,
       const location::nearby::connections::OsInfo& remote_os_info);
 
+  void RegisterDeviceProvider(std::unique_ptr<NearbyDeviceProvider> provider) {
+    device_provider_ = std::move(provider);
+  }
+
  private:
   struct Connection {
     // Status: may be either:
@@ -282,7 +288,7 @@ class ClientProxy final {
   // Bluetooth Classic enabled. When high_visibility_mode_ is true, the endpoint
   // id is stable for 30s. When high_visibility_mode_ is false, the endpoint id
   // always rotates.
-  bool high_vis_mode_{false};
+  bool high_vis_mode_ = false;
   // Caches the endpoint id when it is in high visibility mode advertisement for
   // 30s. Currently, Nearby Connections keeps rotating endpoint id. The client
   // (Nearby Share) treats different endpoints as different receivers, duplicate
@@ -339,6 +345,7 @@ class ClientProxy final {
   std::unique_ptr<ErrorCodeRecorder> error_code_recorder_;
   // Local device OS information.
   location::nearby::connections::OsInfo local_os_info_;
+  std::unique_ptr<NearbyDeviceProvider> device_provider_;
 };
 
 }  // namespace connections
diff --git a/connections/implementation/client_proxy_test.cc b/connections/implementation/client_proxy_test.cc
index a8b28833..2e74c1f7 100644
--- a/connections/implementation/client_proxy_test.cc
+++ b/connections/implementation/client_proxy_test.cc
@@ -15,6 +15,7 @@
 #include "connections/implementation/client_proxy.h"
 
 #include <cstdio>
+#include <memory>
 #include <optional>
 #include <string>
 
@@ -28,6 +29,7 @@
 #include "absl/types/span.h"
 #include "connections/listeners.h"
 #include "connections/strategy.h"
+#include "connections/v3/connections_device_provider.h"
 #include "internal/analytics/event_logger.h"
 #include "internal/platform/byte_array.h"
 #include "internal/platform/feature_flags.h"
@@ -427,6 +429,16 @@ TEST_F(ClientProxyTest, GeneratedEndpointIdIsUnique) {
   EXPECT_NE(client1_.GetLocalEndpointId(), client2_.GetLocalEndpointId());
 }
 
+TEST_F(ClientProxyTest, GeneratedEndpointIdIsUniqueWithDeviceProvider) {
+  client1_.RegisterDeviceProvider(
+      std::make_unique<v3::ConnectionsDeviceProvider>(
+          v3::ConnectionsDeviceProvider("", {})));
+  client2_.RegisterDeviceProvider(
+      std::make_unique<v3::ConnectionsDeviceProvider>(
+          v3::ConnectionsDeviceProvider("", {})));
+  EXPECT_NE(client1_.GetLocalEndpointId(), client2_.GetLocalEndpointId());
+}
+
 TEST_F(ClientProxyTest, ResetClearsState) {
   client1_.Reset();
   EXPECT_FALSE(client1_.IsAdvertising());
diff --git a/connections/implementation/endpoint_manager.cc b/connections/implementation/endpoint_manager.cc
index 2233eab2..cd7ef40e 100644
--- a/connections/implementation/endpoint_manager.cc
+++ b/connections/implementation/endpoint_manager.cc
@@ -287,10 +287,16 @@ bool operator<(const EndpointManager::FrameProcessor& lhs,
 }
 
 EndpointManager::EndpointManager(EndpointChannelManager* manager)
-    : channel_manager_(manager) {}
+    : EndpointManager(manager, std::make_unique<SingleThreadExecutor>()) {}
+
+EndpointManager::EndpointManager(
+    EndpointChannelManager* manager,
+    std::unique_ptr<SingleThreadExecutor> serial_executor)
+    : channel_manager_(manager), serial_executor_(std::move(serial_executor)) {}
 
 EndpointManager::~EndpointManager() {
   NEARBY_LOG(INFO, "Initiating shutdown of EndpointManager.");
+  is_shutdown_ = true;
   analytics::ThroughputRecorderContainer::GetInstance().Shutdown();
   CountDownLatch latch(1);
   RunOnEndpointManagerThread("bring-down-endpoints", [this, &latch]() {
@@ -301,7 +307,7 @@ EndpointManager::~EndpointManager() {
   latch.Await();
 
   NEARBY_LOG(INFO, "Bringing down control thread");
-  serial_executor_.Shutdown();
+  serial_executor_->Shutdown();
   NEARBY_LOG(INFO, "EndpointManager is down");
 }
 
@@ -524,10 +530,48 @@ std::vector<std::string> EndpointManager::SendPayloadChunk(
 void EndpointManager::DiscardEndpoint(ClientProxy* client,
                                       const std::string& endpoint_id) {
   NEARBY_LOGS(VERBOSE) << "DiscardEndpoint for endpoint " << endpoint_id;
-  RunOnEndpointManagerThread("discard-endpoint", [this, client, endpoint_id]() {
-    RemoveEndpoint(client, endpoint_id,
-                   /*notify=*/client->IsConnectedToEndpoint(endpoint_id));
-  });
+  RunOnEndpointManagerThread(
+      "discard-endpoint", [this, client, endpoint_id]() {
+        // `ClientProxy` is destroyed before `EndpointManager` in
+        // `~NearbyConnections`, which means "discard-endpoint" needs to check
+        // if this task is being executing during `~EndpointManager` to
+        // prevent accessing an invalid `ClientProxy` pointer. There are two
+        // cases where "discard-endpoint" can be executed during destruction,
+        // both of which can safely use `is_shutdown_` to check if this is being
+        // executed during the destruction of the object:
+        //
+        // Case 1: "discard-endpoints" is posted to the thread before
+        // destruction, but not executed yet: `~EndpointManager` blocks on
+        // "bring-down-endpoints" and because the executor is a single thread
+        // executor, tasks are guaranteed to execute sequentially
+        // (see
+        // https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Executors.html#newSingleThreadExecutor--)
+        // and this means that the "discard-endpoints" will be executed before
+        // "bring-down-endpoints", blocking the destruction of `is_shutdown_`
+        // and therefore `is_shutdown_` is not garbage memory.
+        //
+        // Case 2: "discard-endpoints" is posted to the thread during
+        // destruction, after "bring-down-endpoints" is called: the executor
+        // will be destructed before `is_shutdown_` because of the ordering of
+        // `EndpointManager`'s member variables, and the executor's destructor
+        // blocks on running all pending tasks
+        // (see
+        // https://source.chromium.org/chromium/chromium/src/+/refs/heads/main:chrome/services/sharing/nearby/platform/scheduled_executor.cc;l=67;drc=e0e0d24aaa54727dc0a8bc4b159ccdf80d3f5d8d),
+        // which means that "discard-endpoints" will run during the destruction
+        // of `serial_executor_` and will still have access to a valid
+        // `is_shutdown_`.
+        //
+        // TODO(b/280653613): Develop a more robost solution to prevent
+        // accessing an already destroyed `ClientProxy` during destruction.
+        if (is_shutdown_) {
+          NEARBY_LOGS(VERBOSE)
+              << "DiscardEndpoint called during destruction, returning early.";
+          return;
+        }
+
+        RemoveEndpoint(client, endpoint_id,
+                       /*notify=*/client->IsConnectedToEndpoint(endpoint_id));
+      });
 }
 
 std::vector<std::string> EndpointManager::SendControlMessage(
@@ -698,7 +742,7 @@ void EndpointManager::EndpointState::StartEndpointKeepAliveManager(
 
 void EndpointManager::RunOnEndpointManagerThread(const std::string& name,
                                                  Runnable runnable) {
-  serial_executor_.Execute(name, std::move(runnable));
+  serial_executor_->Execute(name, std::move(runnable));
 }
 
 }  // namespace connections
diff --git a/connections/implementation/endpoint_manager.h b/connections/implementation/endpoint_manager.h
index 53c16bf0..7e7fdaae 100644
--- a/connections/implementation/endpoint_manager.h
+++ b/connections/implementation/endpoint_manager.h
@@ -153,6 +153,11 @@ class EndpointManager {
   // blocked here.
   void DiscardEndpoint(ClientProxy* client, const std::string& endpoint_id);
 
+ protected:
+  // For unit tests only to control executing tasks on the executor.
+  EndpointManager(EndpointChannelManager* manager,
+                  std::unique_ptr<SingleThreadExecutor> serial_executor);
+
  private:
   class EndpointState {
    public:
@@ -288,7 +293,18 @@ class EndpointManager {
   // We keep track of all registered channel endpoints here.
   absl::flat_hash_map<std::string, EndpointState> endpoints_;
 
-  SingleThreadExecutor serial_executor_;
+  // Indicates whether the destructor has been called yet. If `is_shutdown_`
+  // is true, assume any `ClientProxy` pointers are invalid, and should not
+  // be used.
+  //
+  // The ordering of these objects is important: `serial_executor_` must be
+  // destroyed before `is_shutdown_` because `serial_executor_` runs all
+  // pending tasks during it's destruction, and the "discard-endpoints"
+  // task checks `is_shutdown_` to prevent accessing an invalid `ClientProxy`
+  // pointer.
+  bool is_shutdown_ = false;
+
+  std::unique_ptr<SingleThreadExecutor> serial_executor_;
 };
 
 // Operator overloads when comparing FrameProcessor*.
diff --git a/connections/implementation/endpoint_manager_test.cc b/connections/implementation/endpoint_manager_test.cc
index df790c70..58c83162 100644
--- a/connections/implementation/endpoint_manager_test.cc
+++ b/connections/implementation/endpoint_manager_test.cc
@@ -34,6 +34,7 @@
 #include "internal/platform/count_down_latch.h"
 #include "internal/platform/exception.h"
 #include "internal/platform/logging.h"
+#include "internal/test/fake_single_thread_executor.h"
 #include "proto/connections_enums.pb.h"
 
 namespace nearby {
@@ -111,6 +112,13 @@ class MockFrameProcessor : public EndpointManager::FrameProcessor {
               (override));
 };
 
+class TestEndpointManager : public EndpointManager {
+ public:
+  TestEndpointManager(EndpointChannelManager* manager,
+                      std::unique_ptr<SingleThreadExecutor> serial_executor)
+      : EndpointManager(manager, std::move(serial_executor)) {}
+};
+
 class EndpointManagerTest : public ::testing::Test {
  protected:
   void RegisterEndpoint(std::unique_ptr<MockEndpointChannel> channel,
@@ -127,14 +135,15 @@ class EndpointManagerTest : public ::testing::Test {
     EXPECT_CALL(*channel, GetLastWriteTimestamp())
         .WillRepeatedly(Return(start_time_));
     EXPECT_CALL(mock_listener_.initiated_cb, Call).Times(1);
-    em_.RegisterEndpoint(&client_, endpoint_id_, info_, connection_options_,
-                         std::move(channel), listener_, connection_token);
+    em_.RegisterEndpoint(client_.get(), endpoint_id_, info_,
+                         connection_options_, std::move(channel), listener_,
+                         connection_token);
     if (should_close) {
       EXPECT_TRUE(done.Await(absl::Milliseconds(1000)).result());
     }
   }
 
-  ClientProxy client_;
+  std::unique_ptr<ClientProxy> client_ = std::make_unique<ClientProxy>();
   ConnectionOptions connection_options_{
       .keep_alive_interval_millis = 5000,
       .keep_alive_timeout_millis = 30000,
@@ -195,7 +204,7 @@ TEST_F(EndpointManagerTest, UnregisterEndpointCallsOnDisconnected) {
   // (IMO, it should be called as long as any connection callback was called
   // before. (in this case initiated_cb is called)).
   // Test captures current protocol behavior.
-  em_.UnregisterEndpoint(&client_, endpoint_id_);
+  em_.UnregisterEndpoint(client_.get(), endpoint_id_);
 }
 
 TEST_F(EndpointManagerTest, RegisterFrameProcessorWorks) {
@@ -250,7 +259,7 @@ TEST_F(EndpointManagerTest, UnregisterFrameProcessorWorks) {
   processors_.emplace_back(std::move(connect_request));
   // Endpoint will not send OnDisconnect notification to frame processor.
   RegisterEndpoint(std::move(endpoint_channel), false);
-  em_.UnregisterEndpoint(&client_, endpoint_id_);
+  em_.UnregisterEndpoint(client_.get(), endpoint_id_);
 }
 
 TEST_F(EndpointManagerTest, SendControlMessageWorks) {
@@ -286,7 +295,7 @@ TEST_F(EndpointManagerTest, SendControlMessageWorks) {
       em_.SendControlMessage(header, control, std::vector{endpoint_id_});
   EXPECT_EQ(failed_ids, std::vector<std::string>{});
   NEARBY_LOG(INFO, "Will unregister endpoint now");
-  em_.UnregisterEndpoint(&client_, endpoint_id_);
+  em_.UnregisterEndpoint(client_.get(), endpoint_id_);
   NEARBY_LOG(INFO, "Will call destructors now");
 }
 
@@ -301,6 +310,48 @@ TEST_F(EndpointManagerTest, SingleReadOnInvalidPayload) {
   RegisterEndpoint(std::move(endpoint_channel));
 }
 
+// Regression test for b/278729669.
+//
+// During the destruction of NearbyConnections, Core (which owns ClientProxy)
+// is destructed before ServiceController (which owns EndpointManager), which
+// means any pending tasks on the EndpointManager than use ClientProxy will
+// be using garbage memory, and cause crashes. This test enforces the fix.
+TEST_F(EndpointManagerTest, DisconnectEndpointDuringDestruction) {
+  // This test uses a `FakeSingleThreadExecutor` in order to control when
+  // tasks are executed in order to simulate the scenario where
+  // `DiscardEndpoint` is posted to the executor before the EndpointManager
+  // is destructed, and executed during it's destruction.
+  std::unique_ptr<SingleThreadExecutor> serial_executor =
+      std::make_unique<FakeSingleThreadExecutor>();
+  FakeSingleThreadExecutor* fake_serial_executor =
+      static_cast<FakeSingleThreadExecutor*>(serial_executor.get());
+  std::unique_ptr<EndpointManager> endpoint_manager =
+      std::make_unique<TestEndpointManager>(&ecm_, std::move(serial_executor));
+
+  // DiscardEndpoint posts a task to the executor to run "discard-endpoint",
+  // however the `FakeSingleThreadExecutor` will not run this task
+  // immediately.
+  fake_serial_executor->SetRunExecutablesImmediately(
+      /*run_executables_immediately=*/false);
+  endpoint_manager->DiscardEndpoint(client_.get(), endpoint_id_);
+
+  // Simulate Core destruction of ClientProxy by destroying `client_`.
+  client_.reset();
+
+  // Simulate ServiceController destruction of EndpointManager by destroying
+  // `endpoint_manager`, and set the `FakeSingleThreadExecutor` to run
+  // executables on calls `Execute`. When `endpoint_manager` is destructed, it
+  // will block on calls to `Execute` to run all pending executables, notably
+  // "discard-endpoint" from above. However, "discard-endpoint" will have a
+  // reference to a destroyed ClientProxy.
+  //
+  // Expect no crash when "discard-endpoints" is executed during the
+  // destruction.
+  fake_serial_executor->SetRunExecutablesImmediately(
+      /*run_executables_immediately=*/true);
+  endpoint_manager.reset();
+}
+
 }  // namespace
 }  // namespace connections
 }  // namespace nearby
diff --git a/connections/implementation/flags/nearby_connections_feature_flags.h b/connections/implementation/flags/nearby_connections_feature_flags.h
index d18a9d72..dd9f3a47 100644
--- a/connections/implementation/flags/nearby_connections_feature_flags.h
+++ b/connections/implementation/flags/nearby_connections_feature_flags.h
@@ -37,8 +37,8 @@ constexpr auto kBlePeripheralLostTimeoutMillis =
     flags::Flag<int64_t>(kConfigPackage, "45411439", 12000);
 
 // LINT.ThenChange(
-//   //depot/google3/location/nearby/cpp/sharing/clients/windows/nearby_sharing_service_adapter_dart.h,
-//   //depot/google3/location/nearby/cpp/sharing/clients/windows/nearby_sharing_service_adapter_dart.cc,
+//   //depot/google3/location/nearby/cpp/sharing/clients/cpp/nearby_sharing_service_adapter_dart.h,
+//   //depot/google3/location/nearby/cpp/sharing/clients/cpp/nearby_sharing_service_adapter_dart.cc,
 //   //depot/google3/location/nearby/cpp/sharing/clients/dart/platform/lib/ffi_types.dart,
 //   //depot/google3/location/nearby/cpp/sharing/clients/dart/platform/lib/types/models.dart
 // )
diff --git a/fastpair/common/BUILD b/fastpair/common/BUILD
index b4235e89..ac60ad24 100644
--- a/fastpair/common/BUILD
+++ b/fastpair/common/BUILD
@@ -3,6 +3,7 @@ licenses(["notice"])
 cc_library(
     name = "common",
     srcs = [
+        "battery_notification.cc",
         "fast_pair_device.cc",
         "fast_pair_http_result.cc",
         "pair_failure.cc",
@@ -10,9 +11,11 @@ cc_library(
     ],
     hdrs = [
         "account_key.h",
+        "battery_notification.h",
         "constant.h",
         "fast_pair_device.h",
         "fast_pair_http_result.h",
+        "non_discoverable_advertisement.h",
         "pair_failure.h",
         "protocol.h",
     ],
@@ -21,6 +24,7 @@ cc_library(
     ],
     deps = [
         "//internal/crypto",
+        "//internal/platform:logging",
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/strings",
@@ -36,6 +40,7 @@ cc_test(
     shard_count = 16,
     deps = [
         ":common",
+        "//internal/platform/implementation/g3",  # build_cleaner: keep
         "@com_github_protobuf_matchers//protobuf-matchers",
         "@com_google_absl//absl/strings",
         "@com_google_googletest//:gtest_main",
@@ -51,6 +56,22 @@ cc_test(
     shard_count = 16,
     deps = [
         ":common",
+        "//internal/platform/implementation/g3",  # build_cleaner: keep
+        "@com_github_protobuf_matchers//protobuf-matchers",
+        "@com_google_googletest//:gtest_main",
+    ],
+)
+
+cc_test(
+    name = "battery_notification_test",
+    size = "small",
+    srcs = [
+        "battery_notification_test.cc",
+    ],
+    shard_count = 16,
+    deps = [
+        ":common",
+        "//internal/platform/implementation/g3",  # build_cleaner: keep
         "@com_github_protobuf_matchers//protobuf-matchers",
         "@com_google_googletest//:gtest_main",
     ],
diff --git a/fastpair/common/battery_notification.cc b/fastpair/common/battery_notification.cc
new file mode 100644
index 00000000..d46d6b86
--- /dev/null
+++ b/fastpair/common/battery_notification.cc
@@ -0,0 +1,86 @@
+// Copyright 2023 Google LLC
+//
+// 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
+//
+//     https://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.
+
+#include "fastpair/common/battery_notification.h"
+
+#include <optional>
+#include <utility>
+#include <vector>
+
+#include "fastpair/common/constant.h"
+#include "internal/platform/logging.h"
+
+namespace nearby {
+namespace fastpair {
+BatteryInfo::BatteryInfo(bool is_charging)
+    : is_charging(is_charging), percentage(std::nullopt) {}
+
+BatteryInfo::BatteryInfo(bool is_charging, int8_t percentage)
+    : is_charging(is_charging), percentage(percentage) {}
+
+// static
+BatteryInfo BatteryInfo::FromByte(uint8_t byte) {
+  // Battery value is in the form 0bSVVVVVVV.
+  // S = charging (0b1) or not (0b0).
+  // V = value, Ranges from 0-100, or 0bS1111111 if unknown.
+  bool is_charging = byte & kBatteryChargingMask;
+  uint8_t percentage = byte & kBatteryPercentageMask;
+  int8_t percentage_signed = static_cast<int8_t>(percentage);
+  if (percentage_signed < 0 || percentage_signed > 100) {
+    NEARBY_LOGS(INFO) << __func__ << "Invalid battery percentage.";
+    return BatteryInfo(is_charging);
+  }
+  return BatteryInfo(is_charging, percentage_signed);
+}
+
+uint8_t BatteryInfo::ToByte() const {
+  // Battery value is in the form 0bSVVVVVVV.
+  // S = charging (0b1) or not (0b0).
+  // V = value, Ranges from 0-100, or 1111111 if unknown.
+  if (!percentage) {
+    return is_charging ? kBatteryIsChargingByte : kBatteryNotChargingByte;
+  } else {
+    return percentage.value() | (is_charging ? kBatteryChargingMask : 0);
+  }
+}
+
+BatteryNotification::BatteryNotification(
+    Type type, const std::vector<BatteryInfo>& battery_infos)
+    : type(type), battery_infos(battery_infos) {}
+
+// static
+std::optional<BatteryNotification> BatteryNotification::FromBytes(
+    const std::vector<uint8_t>& bytes, Type type) {
+  if (bytes.size() == 1) {
+    // Single component device.
+    NEARBY_LOGS(INFO) << __func__ << " : Single component device.";
+    std::vector<BatteryInfo> battery_infos = {BatteryInfo::FromByte(bytes[0])};
+    return std::make_optional<BatteryNotification>(type, battery_infos);
+  } else if (bytes.size() == 3) {
+    // True wireless headset expecting 3 bytes - Left bud, Right bud and case.
+    NEARBY_LOGS(INFO) << __func__ << " : True wireless headset.";
+    std::vector<BatteryInfo> battery_infos = {
+        /* left bud info */ BatteryInfo::FromByte(bytes[0]),
+        /* right bud info */ BatteryInfo::FromByte(bytes[1]),
+        /* case info */ BatteryInfo::FromByte(bytes[2])};
+    return std::make_optional<BatteryNotification>(type, battery_infos);
+  }
+  NEARBY_LOGS(WARNING) << __func__
+                       << " : Unexpected battery notification length :"
+                       << bytes.size();
+  return std::nullopt;
+}
+
+}  // namespace fastpair
+}  // namespace nearby
diff --git a/fastpair/common/battery_notification.h b/fastpair/common/battery_notification.h
new file mode 100644
index 00000000..3c82060f
--- /dev/null
+++ b/fastpair/common/battery_notification.h
@@ -0,0 +1,66 @@
+// Copyright 2023 Google LLC
+//
+// 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
+//
+//     https://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.
+
+#ifndef THIRD_PARTY_NEARBY_FASTPAIR_COMMON_BATTERY_NOTIFICATION_H_
+#define THIRD_PARTY_NEARBY_FASTPAIR_COMMON_BATTERY_NOTIFICATION_H_
+
+#include <cstdint>
+#include <optional>
+#include <vector>
+
+namespace nearby {
+namespace fastpair {
+
+// Fast Pair battery information from notification. See
+// https://developers.google.com/nearby/fast-pair/spec#BatteryNotification
+struct BatteryInfo {
+  BatteryInfo() = default;
+  explicit BatteryInfo(bool is_charging);
+  BatteryInfo(bool is_charging, int8_t percentage);
+  ~BatteryInfo() = default;
+
+  static BatteryInfo FromByte(uint8_t byte);
+
+  uint8_t ToByte() const;
+
+  bool is_charging = false;
+  std::optional<int8_t> percentage;
+};
+
+// Fast Pair battery notification. See
+// https://developers.google.com/nearby/fast-pair/spec#BatteryNotification
+struct BatteryNotification {
+  // Represents if the provider wants to show an indication
+  // of the battery values
+  enum class Type {
+    kNone = 0,
+    kShowUi = 3, /* Show UI indication: 0b0011 */
+    kHideUi = 4, /* Hide UI indication: 0b0100 */
+  };
+
+  BatteryNotification() = default;
+  BatteryNotification(Type type, const std::vector<BatteryInfo>& battery_infos);
+  ~BatteryNotification() = default;
+
+  static std::optional<BatteryNotification> FromBytes(
+      const std::vector<uint8_t>& bytes, Type type);
+
+  Type type = Type::kNone;
+  std::vector<BatteryInfo> battery_infos;
+};
+
+}  // namespace fastpair
+}  // namespace nearby
+
+#endif  // THIRD_PARTY_NEARBY_FASTPAIR_COMMON_BATTERY_NOTIFICATION_H_
diff --git a/fastpair/common/battery_notification_test.cc b/fastpair/common/battery_notification_test.cc
new file mode 100644
index 00000000..48c86b60
--- /dev/null
+++ b/fastpair/common/battery_notification_test.cc
@@ -0,0 +1,152 @@
+// Copyright 2023 Google LLC
+//
+// 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
+//
+//     https://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.
+
+#include "fastpair/common/battery_notification.h"
+
+#include <cstdint>
+#include <vector>
+
+#include "gtest/gtest.h"
+
+namespace nearby {
+namespace fastpair {
+namespace {
+// Test data comes from:
+// https://developers.google.com/nearby/fast-pair/specifications/appendix/testcases#test_cases
+
+TEST(BatteryNotificationTest, TestBatteryInfo) {
+  // Tests default constructor
+  BatteryInfo battery_info_1;
+  EXPECT_FALSE(battery_info_1.is_charging);
+
+  // Tests Constructor with is_charging
+  BatteryInfo battery_info_2(true);
+  EXPECT_TRUE(battery_info_2.is_charging);
+  // Tests ToByte and FromByte
+  BatteryInfo battery_info_3 = BatteryInfo::FromByte(battery_info_2.ToByte());
+  EXPECT_TRUE(battery_info_3.is_charging);
+  EXPECT_FALSE(battery_info_3.percentage.has_value());
+
+  // Tests Constructor with is_charging and percentage value
+  BatteryInfo battery_info_4(true, 80);
+  EXPECT_TRUE(battery_info_4.is_charging);
+  EXPECT_EQ(battery_info_4.percentage.value(), 80);
+  // Tests ToByte and FromByte
+  BatteryInfo battery_info_5 = BatteryInfo::FromByte(battery_info_4.ToByte());
+  EXPECT_TRUE(battery_info_5.is_charging);
+  EXPECT_EQ(battery_info_5.percentage.value(), 80);
+
+  // Tests Constructor with is_charging and wrong percentage value
+  BatteryInfo battery_info_6(true, 110);
+  // Tests ToByte and FromByte
+  BatteryInfo battery_info_7 = BatteryInfo::FromByte(battery_info_6.ToByte());
+  EXPECT_TRUE(battery_info_7.is_charging);
+  EXPECT_FALSE(battery_info_7.percentage.has_value());
+
+  // Tests FromByte with battery percentage = 0
+  BatteryInfo battery_info_8 = BatteryInfo::FromByte(0);
+  EXPECT_FALSE(battery_info_8.is_charging);
+  EXPECT_EQ(battery_info_8.percentage.value(), 0);
+
+  BatteryInfo battery_info_10 = BatteryInfo::FromByte(0x80);
+  EXPECT_TRUE(battery_info_10.is_charging);
+  EXPECT_EQ(battery_info_10.percentage.value(), 0);
+
+  // Tests FromByte with battery percentage = 100
+  BatteryInfo battery_info_9 = BatteryInfo::FromByte(100);
+  EXPECT_FALSE(battery_info_9.is_charging);
+  EXPECT_EQ(battery_info_9.percentage.value(), 100);
+
+  BatteryInfo battery_info_11 = BatteryInfo::FromByte(0x80 | 100);
+  EXPECT_TRUE(battery_info_11.is_charging);
+  EXPECT_EQ(battery_info_11.percentage.value(), 100);
+
+  // Test battery with invalid battery percentage
+  BatteryInfo battery_info_12 = BatteryInfo::FromByte(0x7F);
+  EXPECT_FALSE(battery_info_12.is_charging);
+  EXPECT_FALSE(battery_info_12.percentage.has_value());
+
+  BatteryInfo battery_info_13 = BatteryInfo::FromByte(0xFF);
+  EXPECT_TRUE(battery_info_13.is_charging);
+  EXPECT_FALSE(battery_info_13.percentage.has_value());
+}
+
+TEST(BatteryNotificationTest, TestBatteryNotificationDefaultConstructor) {
+  // Tests default constructor
+  BatteryNotification battery_notification;
+  EXPECT_EQ(battery_notification.type, BatteryNotification::Type::kNone);
+  EXPECT_EQ(battery_notification.battery_infos.size(), 0);
+}
+
+TEST(BatteryNotificationTest, TestBatteryNotificationForSingleComponentDevice) {
+  std::vector<BatteryInfo> battery_infos = {BatteryInfo(false, 70)};
+  BatteryNotification battery_notification(BatteryNotification::Type::kShowUi,
+                                           battery_infos);
+  EXPECT_EQ(battery_notification.type, BatteryNotification::Type::kShowUi);
+  EXPECT_FALSE(battery_notification.battery_infos.at(0).is_charging);
+  EXPECT_EQ(battery_notification.battery_infos.at(0).percentage.value(), 70);
+}
+
+TEST(BatteryNotificationTest, TestBatteryNotificationForTrueWirelessHeadset) {
+  std::vector<BatteryInfo> battery_infos = {
+      BatteryInfo(false, 70), BatteryInfo(false, 80), BatteryInfo(true, 90)};
+  BatteryNotification battery_notification(BatteryNotification::Type::kShowUi,
+                                           battery_infos);
+  EXPECT_EQ(battery_notification.type, BatteryNotification::Type::kShowUi);
+  // Left bud
+  EXPECT_FALSE(battery_notification.battery_infos.at(0).is_charging);
+  EXPECT_EQ(battery_notification.battery_infos.at(0).percentage.value(), 70);
+  // Right bud
+  EXPECT_FALSE(battery_notification.battery_infos.at(1).is_charging);
+  EXPECT_EQ(battery_notification.battery_infos.at(1).percentage.value(), 80);
+  // Case
+  EXPECT_TRUE(battery_notification.battery_infos.at(2).is_charging);
+  EXPECT_EQ(battery_notification.battery_infos.at(2).percentage.value(), 90);
+}
+
+TEST(BatteryNotificationTest,
+     TestBatteryNotificationFromBytesForSingleComponentDevice) {
+  const std::vector<uint8_t> batteryData{0b01000000};
+  BatteryNotification battery_notification =
+      BatteryNotification::FromBytes(batteryData,
+                                     BatteryNotification::Type::kShowUi)
+          .value();
+  EXPECT_EQ(battery_notification.type, BatteryNotification::Type::kShowUi);
+  EXPECT_EQ(battery_notification.battery_infos.at(0).percentage.value(), 64);
+}
+
+TEST(BatteryNotificationTest,
+     TestBatteryNotificationFromBytesForTrueWirelessHeadset) {
+  const std::vector<uint8_t> batteryData{0b01000000, 0b01000000, 0b01000000};
+  BatteryNotification battery_notification =
+      BatteryNotification::FromBytes(batteryData,
+                                     BatteryNotification::Type::kShowUi)
+          .value();
+  EXPECT_EQ(battery_notification.type, BatteryNotification::Type::kShowUi);
+  EXPECT_EQ(battery_notification.battery_infos.at(0).percentage.value(), 64);
+  EXPECT_EQ(battery_notification.battery_infos.at(1).percentage.value(), 64);
+  EXPECT_EQ(battery_notification.battery_infos.at(2).percentage.value(), 64);
+}
+
+TEST(BatteryNotificationTest, TestBatteryNotificationFromWrongBytes) {
+  const std::vector<uint8_t> batteryDataWithWrongLenth{0b01000000, 0b01000000};
+  EXPECT_FALSE(
+      BatteryNotification::FromBytes(batteryDataWithWrongLenth,
+                                     BatteryNotification::Type::kShowUi)
+          .has_value());
+}
+}  // namespace
+
+}  // namespace fastpair
+}  // namespace nearby
diff --git a/fastpair/common/constant.h b/fastpair/common/constant.h
index d4614336..200eb0ac 100644
--- a/fastpair/common/constant.h
+++ b/fastpair/common/constant.h
@@ -24,7 +24,6 @@ namespace fastpair {
 constexpr char kServiceId[] = "Fast Pair";
 
 constexpr char kRfcommUuid[] = "df21fe2c-2515-4fdb-8886-f12c4d67927c";
-
 constexpr int kAccountKeySize = 16;
 
 // Key pair
@@ -60,6 +59,13 @@ constexpr uint8_t kAccountKeyStartByte = 0x04;
 constexpr uint8_t kKeyBasedPairingType = 0x00;
 constexpr uint8_t kInitialOrSubsequentFlags = 0x00;
 constexpr uint8_t kRetroactiveFlags = 0x10;
+
+// Battery Info
+constexpr int kBatteryChargingMask = 0b10000000;
+constexpr int kBatteryPercentageMask = 0b01111111;
+constexpr int kBatteryIsChargingByte = 0b11111111;
+constexpr int kBatteryNotChargingByte = 0b01111111;
+
 }  // namespace fastpair
 }  // namespace nearby
 
diff --git a/fastpair/common/non_discoverable_advertisement.h b/fastpair/common/non_discoverable_advertisement.h
new file mode 100644
index 00000000..a03fc421
--- /dev/null
+++ b/fastpair/common/non_discoverable_advertisement.h
@@ -0,0 +1,59 @@
+// Copyright 2023 Google LLC
+//
+// 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
+//
+//     https://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.
+
+#ifndef THIRD_PARTY_NEARBY_FASTPAIR_COMMON_NON_DISCOVERABLE_ADVERTISEMENT_H_
+#define THIRD_PARTY_NEARBY_FASTPAIR_COMMON_NON_DISCOVERABLE_ADVERTISEMENT_H_
+
+#include <cstdint>
+#include <optional>
+#include <utility>
+#include <vector>
+
+#include "fastpair/common/battery_notification.h"
+
+namespace nearby {
+namespace fastpair {
+
+// Fast Pair 'Not Discoverable' advertisement. See
+// https://developers.google.com/nearby/fast-pair/specifications/service/provider#AdvertisingWhenNotDiscoverable
+struct NonDiscoverableAdvertisement {
+  // Represents showing UI indication
+  enum class Type {
+    kShowUi = 0, /* Show UI indication: 0b0000*/
+    kNone = 1,
+    kHideUi = 2, /* Hide UI indication: 0b0010*/
+  };
+
+  NonDiscoverableAdvertisement() = default;
+  NonDiscoverableAdvertisement(
+      std::vector<uint8_t> account_key_filter, Type type,
+      std::vector<uint8_t> salt,
+      std::optional<BatteryNotification> battery_notification)
+      : account_key_filter(std::move(account_key_filter)),
+        type(type),
+        salt(std::move(salt)),
+        battery_notification(std::move(battery_notification)) {}
+
+  ~NonDiscoverableAdvertisement() = default;
+
+  std::vector<uint8_t> account_key_filter;
+  Type type = Type::kNone;
+  std::vector<uint8_t> salt;
+  std::optional<BatteryNotification> battery_notification;
+};
+
+}  // namespace fastpair
+}  // namespace nearby
+
+#endif  // THIRD_PARTY_NEARBY_FASTPAIR_COMMON_NON_DISCOVERABLE_ADVERTISEMENT_H_
diff --git a/internal/network/http_client_impl.cc b/internal/network/http_client_impl.cc
index ef74495a..a5dbacc1 100644
--- a/internal/network/http_client_impl.cc
+++ b/internal/network/http_client_impl.cc
@@ -38,7 +38,7 @@ void NearbyHttpClient::StartRequest(
   CleanThreads();
 
   std::future<void> http_thread = std::async(
-      std::launch::async, [&, request, callback = std::move(callback)]() {
+      std::launch::async, [=]() {
         NEARBY_LOGS(INFO) << __func__ << ": Start async request to url="
                           << request.GetUrl().GetUrlPath();
         absl::StatusOr<HttpResponse> response = InternalGetResponse(request);
diff --git a/internal/platform/implementation/g3/BUILD b/internal/platform/implementation/g3/BUILD
index 1d4b5f3b..79c8d9a7 100644
--- a/internal/platform/implementation/g3/BUILD
+++ b/internal/platform/implementation/g3/BUILD
@@ -36,7 +36,10 @@ cc_library(
         "single_thread_executor.h",
         "timer.h",
     ],
-    visibility = ["//location/nearby/cpp:__subpackages__"],
+    visibility = [
+        "//internal/test:__subpackages__",
+        "//location/nearby/cpp:__subpackages__",
+    ],
     deps = [
         ":preferences_repository",
         "//internal/platform:base",
diff --git a/internal/platform/single_thread_executor.h b/internal/platform/single_thread_executor.h
index 27a80f40..eb53bbee 100644
--- a/internal/platform/single_thread_executor.h
+++ b/internal/platform/single_thread_executor.h
@@ -24,7 +24,7 @@ namespace nearby {
 // queue.
 //
 // https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Executors.html#newSingleThreadExecutor--
-class ABSL_LOCKABLE SingleThreadExecutor final : public SubmittableExecutor {
+class ABSL_LOCKABLE SingleThreadExecutor : public SubmittableExecutor {
  public:
   using Platform = api::ImplementationPlatform;
   SingleThreadExecutor()
diff --git a/internal/platform/submittable_executor.h b/internal/platform/submittable_executor.h
index 47aa9e80..aba0375d 100644
--- a/internal/platform/submittable_executor.h
+++ b/internal/platform/submittable_executor.h
@@ -17,6 +17,7 @@
 
 #include <cstddef>
 #include <memory>
+#include <string>
 #include <utility>
 
 #include "absl/base/thread_annotations.h"
@@ -53,7 +54,7 @@ class ABSL_LOCKABLE SubmittableExecutor : public api::SubmittableExecutor,
     }
     return *this;
   }
-  void Execute(const std::string& name, Runnable&& runnable)
+  virtual void Execute(const std::string& name, Runnable&& runnable)
       ABSL_LOCKS_EXCLUDED(mutex_) {
     MutexLock lock(&mutex_);
     if (impl_)
diff --git a/internal/test/BUILD b/internal/test/BUILD
index dc5407b7..d843e66c 100644
--- a/internal/test/BUILD
+++ b/internal/test/BUILD
@@ -18,12 +18,14 @@ cc_library(
     name = "test",
     srcs = [
         "fake_clock.cc",
+        "fake_single_thread_executor.cc",
         "fake_task_runner.cc",
         "fake_timer.cc",
     ],
     hdrs = [
         "fake_clock.h",
         "fake_device_info.h",
+        "fake_single_thread_executor.h",
         "fake_task_runner.h",
         "fake_timer.h",
     ],
diff --git a/internal/test/fake_single_thread_executor.cc b/internal/test/fake_single_thread_executor.cc
new file mode 100644
index 00000000..dc50918a
--- /dev/null
+++ b/internal/test/fake_single_thread_executor.cc
@@ -0,0 +1,48 @@
+// Copyright 2023 Google LLC
+//
+// 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
+//
+//     https://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.
+
+#include "internal/test/fake_single_thread_executor.h"
+
+#include <string>
+#include <utility>
+#include <vector>
+
+namespace nearby {
+
+FakeSingleThreadExecutor::FakeSingleThreadExecutor() = default;
+
+FakeSingleThreadExecutor::~FakeSingleThreadExecutor() { DoShutdown(); }
+
+void FakeSingleThreadExecutor::Execute(const std::string& name,
+                                       Runnable&& runnable) {
+  runnables_.push_back(std::make_pair(name, std::move(runnable)));
+
+  if (!run_executables_immediately_) return;
+
+  RunAllExecutables();
+}
+
+void FakeSingleThreadExecutor::RunAllExecutables() {
+  // Because `SingleThreadExecutor` ensures sequencing, run all pending
+  // executables in order they were added to the vector.
+  for (auto& runnable_pair : runnables_) {
+    runnable_pair.second();
+  }
+
+  runnables_.clear();
+}
+
+void FakeSingleThreadExecutor::DoShutdown() { RunAllExecutables(); }
+
+}  // namespace nearby
diff --git a/internal/test/fake_single_thread_executor.h b/internal/test/fake_single_thread_executor.h
new file mode 100644
index 00000000..d9c86d35
--- /dev/null
+++ b/internal/test/fake_single_thread_executor.h
@@ -0,0 +1,52 @@
+// Copyright 2023 Google LLC
+//
+// 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
+//
+//     https://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.
+
+#ifndef PLATFORM_PUBLIC_FAKE_SINGLE_THREAD_EXECUTOR_H_
+#define PLATFORM_PUBLIC_FAKE_SINGLE_THREAD_EXECUTOR_H_
+
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "absl/base/thread_annotations.h"
+#include "internal/platform/single_thread_executor.h"
+
+namespace nearby {
+
+class ABSL_LOCKABLE FakeSingleThreadExecutor final
+    : public SingleThreadExecutor {
+ public:
+  FakeSingleThreadExecutor();
+  ~FakeSingleThreadExecutor() override;
+  FakeSingleThreadExecutor(FakeSingleThreadExecutor&&) = default;
+  FakeSingleThreadExecutor& operator=(FakeSingleThreadExecutor&&) = default;
+
+  void Execute(const std::string& name, Runnable&& runnable) override;
+
+  void SetRunExecutablesImmediately(bool run_executables_immediately) {
+    run_executables_immediately_ = run_executables_immediately;
+  }
+
+  void RunAllExecutables();
+
+ private:
+  void DoShutdown();
+
+  bool run_executables_immediately_ = false;
+  std::vector<std::pair<std::string, Runnable>> runnables_;
+};
+
+}  // namespace nearby
+
+#endif  // PLATFORM_PUBLIC_FAKE_SINGLE_THREAD_EXECUTOR_H_
diff --git a/presence/implementation/scan_manager.cc b/presence/implementation/scan_manager.cc
index 3d209e1c..6f35e49b 100644
--- a/presence/implementation/scan_manager.cc
+++ b/presence/implementation/scan_manager.cc
@@ -58,7 +58,6 @@ ScanSessionId ScanManager::StartScan(ScanRequest scan_request,
                         absl::Status ble_status) mutable {
                       start_scan_client(ble_status);
                     },
-                // TODO(b/256686710): Track known devices
                 .advertisement_found_cb =
                     [this, id](BlePeripheral& peripheral,
                                BleAdvertisementData data) {
diff --git a/third_party/absl b/third_party/absl
index b957f0cc..abe63eb9 160000
--- a/third_party/absl
+++ b/third_party/absl
@@ -1 +1 @@
-Subproject commit b957f0ccd00481cd4fd663d8320aa02ae0564f18
+Subproject commit abe63eb9bd1213c018bf82765ab747334d3b33d8
diff --git a/third_party/depot_tools b/third_party/depot_tools
index e1197f06..6316ac23 160000
--- a/third_party/depot_tools
+++ b/third_party/depot_tools
@@ -1 +1 @@
-Subproject commit e1197f06a8f45c0328d341b30e337d3a4b609716
+Subproject commit 6316ac234e70d983ae758e283ed6ac8d4d0cb36b
diff --git a/third_party/google-toolbox-for-mac/google-toolbox-for-mac b/third_party/google-toolbox-for-mac/google-toolbox-for-mac
index 33941504..1b2da5e6 160000
--- a/third_party/google-toolbox-for-mac/google-toolbox-for-mac
+++ b/third_party/google-toolbox-for-mac/google-toolbox-for-mac
@@ -1 +1 @@
-Subproject commit 339415048005a9eba957357a02459a977a2e3007
+Subproject commit 1b2da5e6e6b5edb1fa1427cc77e23f04069c04ad
diff --git a/third_party/gtest b/third_party/gtest
index d61d4d8e..d6fb5e3b 160000
--- a/third_party/gtest
+++ b/third_party/gtest
@@ -1 +1 @@
-Subproject commit d61d4d8e64c08a662055e82904bbf90e108a704f
+Subproject commit d6fb5e3bf76c0363d7519373a07c2435e57c1073
diff --git a/third_party/json/json b/third_party/json/json
index 6af826d0..bc889afb 160000
--- a/third_party/json/json
+++ b/third_party/json/json
@@ -1 +1 @@
-Subproject commit 6af826d0bdb55e4b69e3ad817576745335f243ca
+Subproject commit bc889afb4c5bf1c0d8ee29ef35eaaf4c8bef8a5d
diff --git a/third_party/mbedtls b/third_party/mbedtls
index 3e0418fe..ff7a3462 160000
--- a/third_party/mbedtls
+++ b/third_party/mbedtls
@@ -1 +1 @@
-Subproject commit 3e0418fe502b2a2194e118d362efdfc0e558be73
+Subproject commit ff7a3462017d1fafa823f6e081fc12802f96f29c
diff --git a/third_party/protobuf b/third_party/protobuf
index 4812107b..12f743d4 160000
--- a/third_party/protobuf
+++ b/third_party/protobuf
@@ -1 +1 @@
-Subproject commit 4812107b9d0fb9fdcca933766c237c38f2150379
+Subproject commit 12f743d4e7bc2a22918371a286e9ab09748b0f40
diff --git a/third_party/ukey2/compiled_proto/proto/device_to_device_messages.pb.cc b/third_party/ukey2/compiled_proto/src/main/proto/device_to_device_messages.pb.cc
similarity index 100%
rename from third_party/ukey2/compiled_proto/proto/device_to_device_messages.pb.cc
rename to third_party/ukey2/compiled_proto/src/main/proto/device_to_device_messages.pb.cc
diff --git a/third_party/ukey2/compiled_proto/proto/device_to_device_messages.pb.h b/third_party/ukey2/compiled_proto/src/main/proto/device_to_device_messages.pb.h
similarity index 100%
rename from third_party/ukey2/compiled_proto/proto/device_to_device_messages.pb.h
rename to third_party/ukey2/compiled_proto/src/main/proto/device_to_device_messages.pb.h
diff --git a/third_party/ukey2/compiled_proto/proto/passwordless_auth_payloads.pb.cc b/third_party/ukey2/compiled_proto/src/main/proto/passwordless_auth_payloads.pb.cc
similarity index 100%
rename from third_party/ukey2/compiled_proto/proto/passwordless_auth_payloads.pb.cc
rename to third_party/ukey2/compiled_proto/src/main/proto/passwordless_auth_payloads.pb.cc
diff --git a/third_party/ukey2/compiled_proto/proto/passwordless_auth_payloads.pb.h b/third_party/ukey2/compiled_proto/src/main/proto/passwordless_auth_payloads.pb.h
similarity index 100%
rename from third_party/ukey2/compiled_proto/proto/passwordless_auth_payloads.pb.h
rename to third_party/ukey2/compiled_proto/src/main/proto/passwordless_auth_payloads.pb.h
diff --git a/third_party/ukey2/compiled_proto/proto/proximity_payloads.pb.cc b/third_party/ukey2/compiled_proto/src/main/proto/proximity_payloads.pb.cc
similarity index 100%
rename from third_party/ukey2/compiled_proto/proto/proximity_payloads.pb.cc
rename to third_party/ukey2/compiled_proto/src/main/proto/proximity_payloads.pb.cc
diff --git a/third_party/ukey2/compiled_proto/proto/proximity_payloads.pb.h b/third_party/ukey2/compiled_proto/src/main/proto/proximity_payloads.pb.h
similarity index 100%
rename from third_party/ukey2/compiled_proto/proto/proximity_payloads.pb.h
rename to third_party/ukey2/compiled_proto/src/main/proto/proximity_payloads.pb.h
diff --git a/third_party/ukey2/compiled_proto/proto/securegcm.pb.cc b/third_party/ukey2/compiled_proto/src/main/proto/securegcm.pb.cc
similarity index 100%
rename from third_party/ukey2/compiled_proto/proto/securegcm.pb.cc
rename to third_party/ukey2/compiled_proto/src/main/proto/securegcm.pb.cc
diff --git a/third_party/ukey2/compiled_proto/proto/securegcm.pb.h b/third_party/ukey2/compiled_proto/src/main/proto/securegcm.pb.h
similarity index 100%
rename from third_party/ukey2/compiled_proto/proto/securegcm.pb.h
rename to third_party/ukey2/compiled_proto/src/main/proto/securegcm.pb.h
diff --git a/third_party/ukey2/compiled_proto/proto/securemessage.pb.cc b/third_party/ukey2/compiled_proto/src/main/proto/securemessage.pb.cc
similarity index 100%
rename from third_party/ukey2/compiled_proto/proto/securemessage.pb.cc
rename to third_party/ukey2/compiled_proto/src/main/proto/securemessage.pb.cc
diff --git a/third_party/ukey2/compiled_proto/proto/securemessage.pb.h b/third_party/ukey2/compiled_proto/src/main/proto/securemessage.pb.h
similarity index 100%
rename from third_party/ukey2/compiled_proto/proto/securemessage.pb.h
rename to third_party/ukey2/compiled_proto/src/main/proto/securemessage.pb.h
diff --git a/third_party/ukey2/compiled_proto/proto/ukey.pb.cc b/third_party/ukey2/compiled_proto/src/main/proto/ukey.pb.cc
similarity index 100%
rename from third_party/ukey2/compiled_proto/proto/ukey.pb.cc
rename to third_party/ukey2/compiled_proto/src/main/proto/ukey.pb.cc
diff --git a/third_party/ukey2/compiled_proto/proto/ukey.pb.h b/third_party/ukey2/compiled_proto/src/main/proto/ukey.pb.h
similarity index 100%
rename from third_party/ukey2/compiled_proto/proto/ukey.pb.h
rename to third_party/ukey2/compiled_proto/src/main/proto/ukey.pb.h
diff --git a/third_party/ukey2/ukey2 b/third_party/ukey2/ukey2
index c2436e55..03290b58 160000
--- a/third_party/ukey2/ukey2
+++ b/third_party/ukey2/ukey2
@@ -1 +1 @@
-Subproject commit c2436e55116964d88532080784f6ed496b0d11f9
+Subproject commit 03290b58d9f93cdd5c9f9f7a7f9e8efc640d0c40