diff --git a/internal/base/BUILD b/internal/base/BUILD
index 7f8ae71f..6fc220dc 100644
--- a/internal/base/BUILD
+++ b/internal/base/BUILD
@@ -19,8 +19,6 @@ licenses(["notice"])
 
 cc_library(
     name = "base",
-    srcs = [
-    ],
     hdrs = [
         "observer_list.h",
     ],
@@ -28,6 +26,7 @@ cc_library(
         "//internal/account:__subpackages__",
         "//internal/platform:__subpackages__",
         "//internal/test:__pkg__",
+        "//location/nearby/sharing/lib:__subpackages__",
         "//sharing:__subpackages__",
     ],
     deps = [
diff --git a/internal/platform/BUILD b/internal/platform/BUILD
index 67f362f5..88e62b1f 100644
--- a/internal/platform/BUILD
+++ b/internal/platform/BUILD
@@ -332,7 +332,6 @@ cc_library(
         "//connections/implementation/flags:connections_flags",
         "//internal/base",
         "//internal/flags:nearby_flags",
-        "//internal/platform/implementation:account_manager",
         "//internal/platform/implementation:comm",
         "//internal/platform/implementation:platform",
         "//internal/platform/implementation:wifi_utils",
diff --git a/internal/platform/implementation/BUILD b/internal/platform/implementation/BUILD
index d9a63885..708acebc 100644
--- a/internal/platform/implementation/BUILD
+++ b/internal/platform/implementation/BUILD
@@ -17,69 +17,6 @@ load("@rules_cc//cc:cc_test.bzl", "cc_test")
 
 licenses(["notice"])
 
-cc_library(
-    name = "auth_status",
-    hdrs = ["auth_status.h"],
-    visibility = [
-        "//internal/auth:__pkg__",
-        "//internal/platform/implementation:__subpackages__",
-        "//location/nearby/cpp/sharing/clients/cpp:__subpackages__",
-    ],
-)
-
-cc_library(
-    name = "account_info",
-    hdrs = ["account_info.h"],
-    visibility = [
-        "//internal/auth:__pkg__",
-        "//internal/platform/implementation:__subpackages__",
-        "//location/nearby/cpp/sharing/clients/cpp:__subpackages__",
-    ],
-)
-
-cc_library(
-    name = "account_manager",
-    hdrs = ["account_manager.h"],
-    visibility = [
-        "//internal/account:__pkg__",
-        "//internal/platform:__pkg__",
-        "//internal/platform/implementation:__subpackages__",
-        "//internal/test:__subpackages__",
-        "//location/nearby/cpp/sharing/clients/cpp:__subpackages__",
-        "//location/nearby/sharing/lib:__subpackages__",
-        "//location/nearby/sharing/sdk/quick_share_server:__pkg__",
-        "//sharing:__subpackages__",
-    ],
-    deps = [
-        ":account_info",
-        ":signin_attempt",
-        "@com_google_absl//absl/functional:any_invocable",
-        "@com_google_absl//absl/status",
-        "@com_google_absl//absl/status:statusor",
-        "@com_google_absl//absl/strings:string_view",
-    ],
-)
-
-cc_library(
-    name = "signin_attempt",
-    hdrs = ["signin_attempt.h"],
-    visibility = [
-        "//internal/account:__pkg__",
-        "//internal/auth:__pkg__",
-        "//internal/platform/implementation:__subpackages__",
-        "//internal/test:__subpackages__",
-        "//location/nearby/cpp/sharing/clients/cpp:__subpackages__",
-        "//location/nearby/sharing/sdk/quick_share_server:__pkg__",
-        "//sharing:__subpackages__",
-    ],
-    deps = [
-        ":account_info",
-        ":auth_status",
-        "@com_google_absl//absl/functional:any_invocable",
-        "@com_google_absl//absl/strings:string_view",
-    ],
-)
-
 cc_library(
     name = "types",
     hdrs = [
diff --git a/internal/platform/implementation/account_info.h b/internal/platform/implementation/account_info.h
deleted file mode 100644
index 2cb48535..00000000
--- a/internal/platform/implementation/account_info.h
+++ /dev/null
@@ -1,35 +0,0 @@
-// Copyright 2024 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_INTERNAL_PLATFORM_IMPLEMENTATION_ACCOUNT_INFO_H_
-#define THIRD_PARTY_NEARBY_INTERNAL_PLATFORM_IMPLEMENTATION_ACCOUNT_INFO_H_
-
-#include <string>
-
-namespace nearby {
-
-// Describes a Nearby account. The account class will have more properties
-// and methods in the future based on the new feature added.
-struct AccountInfo {
-  std::string id;  // The unique identify of the account.
-  std::string display_name;
-  std::string family_name;
-  std::string given_name;
-  std::string picture_url;
-  std::string email;
-};
-
-}  // namespace nearby
-
-#endif  // THIRD_PARTY_NEARBY_INTERNAL_PLATFORM_IMPLEMENTATION_ACCOUNT_INFO_H_
diff --git a/internal/platform/implementation/account_manager.h b/internal/platform/implementation/account_manager.h
deleted file mode 100644
index 3ab62731..00000000
--- a/internal/platform/implementation/account_manager.h
+++ /dev/null
@@ -1,89 +0,0 @@
-// Copyright 2022 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_API_ACCOUNT_MANAGER_H_
-#define PLATFORM_API_ACCOUNT_MANAGER_H_
-
-#include <memory>
-#include <optional>
-#include <string>
-#include <utility>
-
-#include "absl/functional/any_invocable.h"
-#include "absl/status/status.h"
-#include "absl/status/statusor.h"
-#include "absl/strings/string_view.h"
-#include "internal/platform/implementation/account_info.h"
-#include "internal/platform/implementation/signin_attempt.h"
-
-namespace nearby {
-
-// AccountManager manages the accounts are used to access Nearby backend.
-// In current design, AccountManager only support one active account.
-class AccountManager {
- public:
-  using Account = AccountInfo;
-
-  // Observes the activity of the account manager.
-  class Observer {
-   public:
-    virtual ~Observer() = default;
-
-    virtual void OnLoginSucceeded(absl::string_view account_id) = 0;
-    // |credential_error| is true if the logout is due to critical auth error.
-    virtual void OnLogoutSucceeded(absl::string_view account_id,
-                                   bool credential_error) = 0;
-  };
-
-  virtual ~AccountManager() = default;
-
-  // Gets current active account. If no login user, return std::nullopt.
-  virtual std::optional<Account> GetCurrentAccount() = 0;
-
-  // Initializes the login process for a Google account from an oauth client.
-  // |client_id| GCP client_id of the client
-  // |client_secret| GCP client_secret of the client
-  // Returns a SigninAttempt object that can be used to complete the login
-  // process.
-  virtual std::unique_ptr<SigninAttempt> Login(
-      absl::string_view client_id, absl::string_view client_secret) = 0;
-
-  // Logs out current active account. |logout_callback| is called when logout is
-  // completed.
-  virtual void Logout(
-      absl::AnyInvocable<void(absl::Status)> logout_callback) = 0;
-
-  // Gets access token for the active account.
-  // |callback| is called with the access token or error status.
-  //
-  // Returns false if callback is null.
-  virtual bool GetAccessToken(
-      absl::AnyInvocable<void(absl::StatusOr<std::string>)> callback) = 0;
-
-  // Returns a pair containing the client id and client secret used in the most
-  // recent Login request.
-  // If no current user is logged in, returns empty string for both.
-  virtual std::pair<std::string, std::string> GetOAuthClientCredential() = 0;
-
-  virtual void AddObserver(Observer* observer) = 0;
-  virtual void RemoveObserver(Observer* observer) = 0;
-
-  virtual void SaveAccountPrefs(absl::string_view user_id,
-                                absl::string_view client_id,
-                                absl::string_view client_secret) = 0;
-};
-
-}  // namespace nearby
-
-#endif  // PLATFORM_API_ACCOUNT_MANAGER_H_
diff --git a/internal/platform/implementation/auth_status.h b/internal/platform/implementation/auth_status.h
deleted file mode 100644
index 00227836..00000000
--- a/internal/platform/implementation/auth_status.h
+++ /dev/null
@@ -1,88 +0,0 @@
-// Copyright 2024 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_INTERNAL_PLATFORM_IMPLEMENTATION_AUTH_STATUS_H_
-#define THIRD_PARTY_NEARBY_INTERNAL_PLATFORM_IMPLEMENTATION_AUTH_STATUS_H_
-
-namespace nearby {
-
-enum AuthStatus {
-  AUTH_STATUS_UNSPECIFIED = 0,
-  // Request completed successfully, the results should be in the correct order
-  // up to the given count.
-  SUCCESS = 1,
-
-  // Request encountered a generic error.
-  GENERIC_ERROR = 2,
-
-  // Request as specified is not supported.
-  UNSUPPORTED = 3,
-
-  // Request failed and should be retried soon.
-  TEMPORARILY_UNAVAILABLE = 4,
-
-  // Request failed due to an unavailable resource.
-  UNAVAILABLE_RESOURCE = 5,
-
-  // The request failed due to an invalid argument.
-  INVALID_ARGUMENT = 6,
-
-  // In case the status could not be retrieved.
-  UNKNOWN_STATUS = 7,
-
-  // Currently used as a way to signal an ETag mismatch.
-  PRECONDITION_FAILED = 8,
-
-  // Exclusively used to report when user did not consent to required scopes.
-  // Do NOT use this for another other scenarios.
-  PERMISSION_DENIED = 9,
-
-  // The resource exists, but the requested attribute of it does not.
-  MISSING_ATTRIBUTE = 10,
-
-  // The method was interrupted and the caller should exit the current unit of
-  // work immediately.
-  INTERRUPTED = 11,
-
-  // User signed in with an unexpected account.
-  SIGNED_IN_WITH_WRONG_ACCOUNT = 12,
-
-  // Used when data cannot be parsed properly.
-  PARSE_ERROR = 13,
-
-  // Used to report that the local HTTP server for receiving the authorization
-  // code cannot be created.
-  CANT_CREATE_AUTH_SERVER = 14,
-
-  // Used to report that the system browser for authenticating the user cannot
-  // be open.
-  CANT_OPEN_BROWSER_FOR_AUTH = 15,
-
-  // Used to report that the authorization code cannot be received.
-  CANT_RECEIVE_AUTH_CODE = 16,
-
-  // Used to report that the account is blocked (e.g. CAA).
-  ACCOUNT_BLOCKED = 17,
-
-  // Receiving the authorization code failed because it took longer than the
-  // timeout.
-  AUTH_CODE_TIMEOUT_EXCEEDED = 18,
-
-  // Used to report when user presses the cancel button during login process.
-  USER_CANCELED = 19,
-};
-
-}  // namespace nearby
-
-#endif  // THIRD_PARTY_NEARBY_INTERNAL_PLATFORM_IMPLEMENTATION_AUTH_STATUS_H_
diff --git a/internal/platform/implementation/signin_attempt.h b/internal/platform/implementation/signin_attempt.h
deleted file mode 100644
index aa631a54..00000000
--- a/internal/platform/implementation/signin_attempt.h
+++ /dev/null
@@ -1,48 +0,0 @@
-// Copyright 2024 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_INTERNAL_PLATFORM_IMPLEMENTATION_SIGNIN_ATTEMPT_H_
-#define THIRD_PARTY_NEARBY_INTERNAL_PLATFORM_IMPLEMENTATION_SIGNIN_ATTEMPT_H_
-
-#include <string>
-
-#include "absl/functional/any_invocable.h"
-#include "absl/strings/string_view.h"
-#include "internal/platform/implementation/account_info.h"
-#include "internal/platform/implementation/auth_status.h"
-
-namespace nearby {
-
-class SigninAttempt {
- public:
-  SigninAttempt() = default;
-  virtual ~SigninAttempt() = default;
-
-  // Starts a new sign-in attempt.
-  // `callback` is called with the status of the request, client_id,
-  // client_secret, and account_info if the request is successful. Returns the
-  // auth url if the request is successful.
-  virtual std::string Start(
-      absl::AnyInvocable<void(AuthStatus, absl::string_view, absl::string_view,
-                              const AccountInfo&)>
-          callback) = 0;
-
-  // Tears down the machinery set up to request auth tokens, including the HTTP
-  // server.
-  virtual void Close() = 0;
-};
-
-}  // namespace nearby
-
-#endif  // THIRD_PARTY_NEARBY_INTERNAL_PLATFORM_IMPLEMENTATION_SIGNIN_ATTEMPT_H_
diff --git a/internal/platform/tachyon_express_signaling_messenger.cc b/internal/platform/tachyon_express_signaling_messenger.cc
index fc93df70..6b07190a 100644
--- a/internal/platform/tachyon_express_signaling_messenger.cc
+++ b/internal/platform/tachyon_express_signaling_messenger.cc
@@ -35,7 +35,6 @@
 #include "internal/account/account_manager_impl.h"
 #include "internal/platform/byte_array.h"
 #include "internal/platform/count_down_latch.h"
-#include "internal/platform/implementation/account_manager.h"
 #include "internal/platform/implementation/webrtc.h"
 #include "internal/platform/logging.h"
 #include "internal/proto/messaging.grpc.pb.h"
diff --git a/internal/platform/tachyon_express_signaling_messenger.h b/internal/platform/tachyon_express_signaling_messenger.h
index 872f95b9..8f01bddd 100644
--- a/internal/platform/tachyon_express_signaling_messenger.h
+++ b/internal/platform/tachyon_express_signaling_messenger.h
@@ -22,6 +22,7 @@
 #include <memory>
 #include <string>
 
+#include "location/nearby/sharing/lib/account/account_manager.h"
 #include "absl/base/thread_annotations.h"
 #include "absl/functional/any_invocable.h"
 #include "absl/strings/string_view.h"
@@ -30,7 +31,6 @@
 #include "third_party/grpc/include/grpcpp/support/client_callback.h"
 #include "third_party/grpc/include/grpcpp/support/status.h"
 #include "internal/platform/byte_array.h"
-#include "internal/platform/implementation/account_manager.h"
 #include "internal/platform/implementation/webrtc.h"
 #include "internal/proto/messaging.grpc.pb.h"
 
@@ -94,7 +94,7 @@ class TachyonExpressSignalingMessenger : public api::WebRtcSignalingMessenger {
   std::unique_ptr<google::internal::communications::instantmessaging::v1::grpc::
                       Messaging::StubInterface>
       messaging_stub_;
-  AccountManager* const account_manager_;
+  nearby::sharing::AccountManager* const account_manager_;
   std::shared_ptr<ReceiveMessagesReader> reader_ = nullptr;
 };
 
diff --git a/internal/test/BUILD b/internal/test/BUILD
index da7d9bcf..589e9f35 100644
--- a/internal/test/BUILD
+++ b/internal/test/BUILD
@@ -17,36 +17,15 @@ load("@rules_cc//cc:cc_test.bzl", "cc_test")
 
 licenses(["notice"])
 
-cc_library(
-    name = "mocks",
-    testonly = 1,
-    hdrs = [
-        "mock_account_manager.h",
-        "mock_account_observer.h",
-    ],
-    visibility = ["//visibility:public"],
-    deps = [
-        "//internal/platform/implementation:account_manager",
-        "//internal/platform/implementation:signin_attempt",
-        "@com_google_absl//absl/functional:any_invocable",
-        "@com_google_absl//absl/status",
-        "@com_google_absl//absl/status:statusor",
-        "@com_google_absl//absl/strings:string_view",
-        "@com_google_googletest//:gtest_for_library_testonly",
-    ],
-)
-
 cc_library(
     name = "test",
     srcs = [
-        "fake_account_manager.cc",
         "fake_clock.cc",
         "fake_single_thread_executor.cc",
         "fake_task_runner.cc",
         "fake_timer.cc",
     ],
     hdrs = [
-        "fake_account_manager.h",
         "fake_clock.h",
         "fake_device_info.h",
         "fake_http_client.h",
@@ -60,20 +39,16 @@ cc_library(
     ],
     visibility = ["//visibility:public"],
     deps = [
-        "//internal/base",
         "//internal/base:file_path",
         "//internal/base:files",
         "//internal/network:types",
         "//internal/platform:comm",
         "//internal/platform:logging",
         "//internal/platform:types",
-        "//internal/platform/implementation:account_manager",
-        "//internal/platform/implementation:signin_attempt",
         "//internal/platform/implementation:types",
         "@com_google_absl//absl/base:core_headers",
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/functional:any_invocable",
-        "@com_google_absl//absl/log",
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/status:statusor",
         "@com_google_absl//absl/strings",
diff --git a/internal/test/fake_account_manager.cc b/internal/test/fake_account_manager.cc
deleted file mode 100644
index c6e919f8..00000000
--- a/internal/test/fake_account_manager.cc
+++ /dev/null
@@ -1,101 +0,0 @@
-// Copyright 2022 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_account_manager.h"
-
-#include <memory>
-#include <optional>
-#include <string>
-#include <utility>
-
-#include "absl/functional/any_invocable.h"
-#include "absl/status/status.h"
-#include "absl/status/statusor.h"
-#include "absl/strings/string_view.h"
-#include "internal/platform/implementation/account_manager.h"
-#include "internal/platform/implementation/signin_attempt.h"
-
-namespace nearby {
-
-std::optional<AccountManager::Account> FakeAccountManager::GetCurrentAccount() {
-  return account_;
-}
-
-std::unique_ptr<SigninAttempt> FakeAccountManager::Login(
-    absl::string_view client_id, absl::string_view client_secret) {
-  return nullptr;
-}
-
-void FakeAccountManager::Logout(
-    absl::AnyInvocable<void(absl::Status)> logout_callback) {
-  if (is_logout_success_) {
-    std::string account_id = account_->id;
-    SetAccount(std::nullopt);
-    NotifyLogout(account_id, /*credential_error=*/false);
-    // Invoke callback after all operations have been performed since test cases
-    // may rely on the callback for synchronization.
-    logout_callback(absl::OkStatus());
-    return;
-  }
-
-  logout_callback(absl::NotFoundError("No account login."));
-}
-
-bool FakeAccountManager::GetAccessToken(
-    absl::AnyInvocable<void(absl::StatusOr<std::string>)> callback) {
-  if (!callback) {
-    return false;
-  }
-  if (!account_.has_value()) {
-    callback(absl::UnavailableError("No current user."));
-    return true;
-  }
-  callback("FAKE_ACCESS_TOKEN");
-  return true;
-}
-
-std::pair<std::string, std::string>
-FakeAccountManager::GetOAuthClientCredential() {
-  return {"", ""};
-}
-
-void FakeAccountManager::SetAccount(std::optional<Account> account) {
-  account_ = account;
-}
-
-void FakeAccountManager::AddObserver(Observer* observer) {
-  observers_.AddObserver(observer);
-}
-
-void FakeAccountManager::RemoveObserver(Observer* observer) {
-  if (!observers_.HasObserver(observer)) {
-    return;
-  }
-  observers_.RemoveObserver(observer);
-}
-
-void FakeAccountManager::NotifyLogin(absl::string_view account_id) {
-  for (const auto& observer : observers_.GetObservers()) {
-    observer->OnLoginSucceeded(account_id);
-  }
-}
-
-void FakeAccountManager::NotifyLogout(absl::string_view account_id,
-                                      bool credential_error) {
-  for (const auto& observer : observers_.GetObservers()) {
-    observer->OnLogoutSucceeded(account_id, credential_error);
-  }
-}
-
-}  // namespace nearby
diff --git a/internal/test/fake_account_manager.h b/internal/test/fake_account_manager.h
deleted file mode 100644
index 346663cf..00000000
--- a/internal/test/fake_account_manager.h
+++ /dev/null
@@ -1,81 +0,0 @@
-// Copyright 2022 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_INTERNAL_TEST_FAKE_ACCOUNT_MANAGER_H_
-#define THIRD_PARTY_NEARBY_INTERNAL_TEST_FAKE_ACCOUNT_MANAGER_H_
-
-#include <memory>
-#include <optional>
-#include <string>
-#include <utility>
-
-#include "absl/functional/any_invocable.h"
-#include "absl/status/status.h"
-#include "absl/status/statusor.h"
-#include "absl/strings/string_view.h"
-#include "internal/base/observer_list.h"
-#include "internal/platform/implementation/account_manager.h"
-#include "internal/platform/implementation/signin_attempt.h"
-
-namespace nearby {
-
-// A fake implementation of FakeAccountManager, along with a fake
-// factory, to be used in tests.
-class FakeAccountManager : public AccountManager {
- public:
-  FakeAccountManager() = default;
-  ~FakeAccountManager() override = default;
-
-  std::optional<Account> GetCurrentAccount() override;
-
-  std::unique_ptr<SigninAttempt> Login(
-      absl::string_view client_id, absl::string_view client_secret) override;
-
-  void Logout(absl::AnyInvocable<void(absl::Status)> logout_callback) override;
-
-  bool GetAccessToken(
-      absl::AnyInvocable<void(absl::StatusOr<std::string>)> callback) override;
-  std::pair<std::string, std::string> GetOAuthClientCredential() override;
-  void AddObserver(Observer* observer) override;
-  void RemoveObserver(Observer* observer) override;
-
-  void SaveAccountPrefs(absl::string_view user_id, absl::string_view client_id,
-                        absl::string_view client_secret) override {}
-
-  // Methods to set API response.
-  void SetAccount(std::optional<Account> account);
-
-  void SetLogoutSuccess(bool is_logout_success) {
-    is_logout_success_ = is_logout_success;
-  }
-
-  void NotifyCredentialError() {
-    NotifyLogout(account_->id, /*credential_error=*/true);
-  }
-
-  void NotifyLogin(absl::string_view account_id);
-  void NotifyLogout(absl::string_view account_id, bool credential_error);
-
- private:
-  // Login will fail when account_ is empty.
-  std::optional<Account> account_;
-
-  // Logout will fail when is_logout_success_ is false;
-  bool is_logout_success_ = true;
-  nearby::ObserverList<Observer> observers_;
-};
-
-}  // namespace nearby
-
-#endif  // THIRD_PARTY_NEARBY_INTERNAL_TEST_FAKE_ACCOUNT_MANAGER_H_
diff --git a/internal/test/mock_account_manager.h b/internal/test/mock_account_manager.h
deleted file mode 100644
index 778aa7aa..00000000
--- a/internal/test/mock_account_manager.h
+++ /dev/null
@@ -1,57 +0,0 @@
-// Copyright 2024 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_INTERNAL_TEST_MOCK_ACCOUNT_MANAGER_H_
-#define THIRD_PARTY_NEARBY_INTERNAL_TEST_MOCK_ACCOUNT_MANAGER_H_
-
-#include <memory>
-#include <optional>
-#include <string>
-#include <utility>
-
-#include "gmock/gmock.h"
-#include "absl/functional/any_invocable.h"
-#include "absl/status/status.h"
-#include "absl/status/statusor.h"
-#include "absl/strings/string_view.h"
-#include "internal/platform/implementation/account_manager.h"
-#include "internal/platform/implementation/signin_attempt.h"
-
-namespace nearby {
-
-class MockAccountManager : public AccountManager {
- public:
-  MOCK_METHOD(std::optional<Account>, GetCurrentAccount, (), (override));
-  MOCK_METHOD(std::unique_ptr<SigninAttempt>, Login,
-              (absl::string_view client_id, absl::string_view client_secret),
-              (override));
-  MOCK_METHOD(void, Logout,
-              (absl::AnyInvocable<void(absl::Status)> logout_callback),
-              (override));
-  MOCK_METHOD(bool, GetAccessToken,
-              (absl::AnyInvocable<void(absl::StatusOr<std::string>)> callback),
-              (override));
-  MOCK_METHOD((std::pair<std::string, std::string>), GetOAuthClientCredential,
-              (), (override));
-  MOCK_METHOD(void, AddObserver, (Observer * observer), (override));
-  MOCK_METHOD(void, RemoveObserver, (Observer * observer), (override));
-  MOCK_METHOD(void, SaveAccountPrefs,
-              (absl::string_view user_id, absl::string_view client_id,
-               absl::string_view client_secret),
-              (override));
-};
-
-}  // namespace nearby
-
-#endif  // THIRD_PARTY_NEARBY_INTERNAL_TEST_MOCK_ACCOUNT_MANAGER_H_
diff --git a/internal/test/mock_account_observer.h b/internal/test/mock_account_observer.h
deleted file mode 100644
index bf4da0e6..00000000
--- a/internal/test/mock_account_observer.h
+++ /dev/null
@@ -1,38 +0,0 @@
-// Copyright 2024 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_INTERNAL_TEST_MOCK_ACCOUNT_OBSERVER_H_
-#define THIRD_PARTY_NEARBY_INTERNAL_TEST_MOCK_ACCOUNT_OBSERVER_H_
-
-#include "gmock/gmock.h"
-#include "absl/strings/string_view.h"
-#include "internal/platform/implementation/account_manager.h"
-
-namespace nearby {
-
-class MockAccountObserver : public AccountManager::Observer {
- public:
-  ~MockAccountObserver() override = default;
-
-  MOCK_METHOD(void, OnLoginSucceeded, (absl::string_view account_id),
-              (override));
-
-  MOCK_METHOD(void, OnLogoutSucceeded,
-              (absl::string_view account_id, bool credential_error),
-              (override));
-};
-
-}  // namespace nearby
-
-#endif  // THIRD_PARTY_NEARBY_INTERNAL_TEST_MOCK_ACCOUNT_OBSERVER_H_
diff --git a/sharing/BUILD b/sharing/BUILD
index 6aadfd1e..567b9948 100644
--- a/sharing/BUILD
+++ b/sharing/BUILD
@@ -382,8 +382,8 @@ cc_library(
         "//internal/platform:logging",
         "//internal/platform:mac_address",
         "//internal/platform:types",
-        "//internal/platform/implementation:account_manager",
         "//internal/platform/implementation:types",
+        "//location/nearby/sharing/lib/account:account_manager",
         "//location/nearby/sharing/lib/rpc:grpc_async_client_factory",
         "//location/nearby/sharing/lib/rpc:sharing_rpc_client",
         "//location/nearby/sharing/lib/sync:sync_manager",
@@ -631,9 +631,10 @@ cc_test(
         "//internal/base:files",
         "//internal/flags:nearby_flags",
         "//internal/platform/implementation:platform_impl",
-        "//internal/platform/implementation:signin_attempt",
         "//internal/test",
-        "//internal/test:mocks",
+        "//location/nearby/sharing/lib/account:fake_account_manager",
+        "//location/nearby/sharing/lib/account:mock_account_manager",
+        "//location/nearby/sharing/lib/account:signin_attempt",
         "//location/nearby/sharing/lib/rpc:fake_nearby_share_client",
         "//sharing/analytics",
         "//sharing/certificates",
diff --git a/sharing/certificates/BUILD b/sharing/certificates/BUILD
index f18cfbd8..0b2a6f1f 100644
--- a/sharing/certificates/BUILD
+++ b/sharing/certificates/BUILD
@@ -50,7 +50,7 @@ cc_library(
         "//internal/crypto_cros",
         "//internal/platform:mac_address",
         "//internal/platform:types",
-        "//internal/platform/implementation:account_manager",
+        "//location/nearby/sharing/lib/account:account_manager",
         "//location/nearby/sharing/lib/rpc:sharing_rpc_client",
         "//sharing/internal/api:platform",
         "//sharing/internal/base",
@@ -127,9 +127,9 @@ cc_test(
         "//google/nearby/identity/v1:resources_cc_proto",
         "//google/nearby/identity/v1:rpcs_cc_proto",
         "//internal/platform:mac_address",
-        "//internal/platform/implementation:account_manager",
         "//internal/platform/implementation:platform_impl",
-        "//internal/test",
+        "//location/nearby/sharing/lib/account:account_manager",
+        "//location/nearby/sharing/lib/account:fake_account_manager",
         "//location/nearby/sharing/lib/rpc:fake_nearby_share_client",
         "//sharing/common:enum",
         "//sharing/internal/api:mock_sharing_platform",
diff --git a/sharing/certificates/nearby_share_certificate_manager_impl.cc b/sharing/certificates/nearby_share_certificate_manager_impl.cc
index fe33848a..2fe80bb4 100644
--- a/sharing/certificates/nearby_share_certificate_manager_impl.cc
+++ b/sharing/certificates/nearby_share_certificate_manager_impl.cc
@@ -31,6 +31,7 @@
 #include "google/nearby/identity/v1/resources.pb.h"
 #include "google/nearby/identity/v1/rpcs.pb.h"
 #include "google/protobuf/timestamp.pb.h"
+#include "location/nearby/sharing/lib/account/account_manager.h"
 #include "location/nearby/sharing/lib/rpc/sharing_rpc_client.h"
 #include "absl/algorithm/algorithm.h"
 #include "absl/base/nullability.h"
@@ -44,7 +45,6 @@
 #include "absl/time/time.h"
 #include "absl/types/span.h"
 #include "internal/base/file_path.h"
-#include "internal/platform/implementation/account_manager.h"
 #include "internal/platform/mac_address.h"
 #include "sharing/certificates/common.h"
 #include "sharing/certificates/constants.h"
@@ -72,11 +72,9 @@
 #include "sharing/scheduling/nearby_share_scheduler_factory.h"
 #include "util/hash/highway_fingerprint.h"
 
-namespace nearby {
-namespace sharing {
+namespace nearby::sharing {
 namespace {
 
-using ::google::nearby::identity::v1::AccountInfo;
 using ::google::nearby::identity::v1::GetAccountInfoRequest;
 using ::google::nearby::identity::v1::GetAccountInfoResponse;
 using ::google::nearby::identity::v1::PerVisibilitySharedCredentials;
@@ -889,8 +887,8 @@ bool NearbyShareCertificateManagerImpl::UpdateAccountInfoInExecutor() {
           const auto& capabilities = response->account_info().capabilities();
           bool has_titanium_capability =
               (std::find(capabilities.begin(), capabilities.end(),
-                         AccountInfo::CAPABILITY_TITANIUM) !=
-               capabilities.end());
+                         google::nearby::identity::v1::AccountInfo::
+                             CAPABILITY_TITANIUM) != capabilities.end());
           preference_manager_.SetBoolean(PrefNames::kAdvancedProtectionEnabled,
                                          has_titanium_capability);
           LOG(INFO) << "GetAccountInfo succeeded, advanced protection enabled: "
@@ -904,5 +902,4 @@ bool NearbyShareCertificateManagerImpl::UpdateAccountInfoInExecutor() {
   return get_account_info_succeeded;
 }
 
-}  // namespace sharing
-}  // namespace nearby
+}  // namespace nearby::sharing
diff --git a/sharing/certificates/nearby_share_certificate_manager_impl.h b/sharing/certificates/nearby_share_certificate_manager_impl.h
index 20ad389d..f3ca9a58 100644
--- a/sharing/certificates/nearby_share_certificate_manager_impl.h
+++ b/sharing/certificates/nearby_share_certificate_manager_impl.h
@@ -23,13 +23,13 @@
 #include <utility>
 #include <vector>
 
+#include "location/nearby/sharing/lib/account/account_manager.h"
 #include "location/nearby/sharing/lib/rpc/sharing_rpc_client.h"
 #include "absl/base/nullability.h"
 #include "absl/functional/any_invocable.h"
 #include "absl/status/statusor.h"
 #include "absl/time/time.h"
 #include "internal/base/file_path.h"
-#include "internal/platform/implementation/account_manager.h"
 #include "internal/platform/task_runner.h"
 #include "sharing/certificates/nearby_share_certificate_manager.h"
 #include "sharing/certificates/nearby_share_certificate_storage.h"
@@ -43,8 +43,7 @@
 #include "sharing/proto/enums.pb.h"
 #include "sharing/proto/rpc_resources.pb.h"
 
-namespace nearby {
-namespace sharing {
+namespace nearby::sharing {
 
 class NearbyShareScheduler;
 
@@ -221,7 +220,6 @@ class NearbyShareCertificateManagerImpl
   std::unique_ptr<TaskRunner> executor_;
 };
 
-}  // namespace sharing
-}  // namespace nearby
+}  // namespace nearby::sharing
 
 #endif  // THIRD_PARTY_NEARBY_SHARING_CERTIFICATES_NEARBY_SHARE_CERTIFICATE_MANAGER_IMPL_H_
diff --git a/sharing/certificates/nearby_share_certificate_manager_impl_test.cc b/sharing/certificates/nearby_share_certificate_manager_impl_test.cc
index 796c91e0..5db57f16 100644
--- a/sharing/certificates/nearby_share_certificate_manager_impl_test.cc
+++ b/sharing/certificates/nearby_share_certificate_manager_impl_test.cc
@@ -27,6 +27,8 @@
 
 #include "google/nearby/identity/v1/resources.pb.h"
 #include "google/nearby/identity/v1/rpcs.pb.h"
+#include "location/nearby/sharing/lib/account/account_manager.h"
+#include "location/nearby/sharing/lib/account/fake_account_manager.h"
 #include "location/nearby/sharing/lib/rpc/fake_nearby_share_client.h"
 #include "gmock/gmock.h"
 #include "protobuf-matchers/protocol-buffer-matchers.h"
@@ -37,9 +39,7 @@
 #include "absl/strings/string_view.h"
 #include "absl/time/time.h"
 #include "absl/types/span.h"
-#include "internal/platform/implementation/account_manager.h"
 #include "internal/platform/mac_address.h"
-#include "internal/test/fake_account_manager.h"
 #include "sharing/certificates/constants.h"
 #include "sharing/certificates/fake_nearby_share_certificate_storage.h"
 #include "sharing/certificates/nearby_share_certificate_manager.h"
@@ -62,10 +62,8 @@
 #include "sharing/scheduling/fake_nearby_share_scheduler_factory.h"
 #include "sharing/scheduling/nearby_share_scheduler_factory.h"
 
-namespace nearby {
-namespace sharing {
+namespace nearby::sharing {
 namespace {
-using ::google::nearby::identity::v1::AccountInfo;
 using ::google::nearby::identity::v1::Device;
 using ::google::nearby::identity::v1::GetAccountInfoResponse;
 using ::google::nearby::identity::v1::PublishDeviceRequest;
@@ -958,7 +956,7 @@ TEST_F(NearbyShareCertificateManagerImplTest,
   Initialize();
   GetAccountInfoResponse response;
   response.mutable_account_info()->mutable_capabilities()->Add(
-      AccountInfo::CAPABILITY_TITANIUM);
+      google::nearby::identity::v1::AccountInfo::CAPABILITY_TITANIUM);
   identity_client_.SetGetAccountInfoResponse(response);
 
   account_info_update_scheduler_->InvokeRequestCallback();
@@ -990,7 +988,7 @@ TEST_F(NearbyShareCertificateManagerImplTest,
   preference_manager_.SetBoolean(PrefNames::kAdvancedProtectionEnabled, true);
   GetAccountInfoResponse response;
   response.mutable_account_info()->mutable_capabilities()->Add(
-      AccountInfo::CAPABILITY_UNSPECIFIED);
+      google::nearby::identity::v1::AccountInfo::CAPABILITY_UNSPECIFIED);
   identity_client_.SetGetAccountInfoResponse(response);
 
   account_info_update_scheduler_->InvokeRequestCallback();
@@ -1015,5 +1013,4 @@ TEST_F(NearbyShareCertificateManagerImplTest,
       PrefNames::kAdvancedProtectionEnabled, /*default_value=*/false));
 }
 
-}  // namespace sharing
-}  // namespace nearby
+}  // namespace nearby::sharing
diff --git a/sharing/contacts/BUILD b/sharing/contacts/BUILD
index 61b4807b..0d489e88 100644
--- a/sharing/contacts/BUILD
+++ b/sharing/contacts/BUILD
@@ -42,7 +42,7 @@ cc_library(
     deps = [
         ":contacts_interface",
         "//internal/platform:types",
-        "//internal/platform/implementation:account_manager",
+        "//location/nearby/sharing/lib/account:account_manager",
         "//location/nearby/sharing/lib/rpc:sharing_rpc_client",
         "//sharing/internal/public:logging",
         "//sharing/internal/public:types",
@@ -70,9 +70,9 @@ cc_test(
     ],
     deps = [
         ":contacts",
-        "//internal/platform/implementation:account_manager",
         "//internal/platform/implementation:platform_impl",
-        "//internal/test",
+        "//location/nearby/sharing/lib/account:account_manager",
+        "//location/nearby/sharing/lib/account:fake_account_manager",
         "//location/nearby/sharing/lib/rpc:fake_nearby_share_client",
         "//sharing/internal/test:nearby_test",
         "//sharing/local_device_data:test_support",
diff --git a/sharing/contacts/nearby_share_contact_manager_impl.cc b/sharing/contacts/nearby_share_contact_manager_impl.cc
index 37c9df39..b0f7834e 100644
--- a/sharing/contacts/nearby_share_contact_manager_impl.cc
+++ b/sharing/contacts/nearby_share_contact_manager_impl.cc
@@ -23,19 +23,18 @@
 #include <utility>
 #include <vector>
 
+#include "location/nearby/sharing/lib/account/account_manager.h"
 #include "location/nearby/sharing/lib/rpc/sharing_rpc_client.h"
 #include "absl/base/nullability.h"
 #include "absl/status/statusor.h"
 #include "absl/synchronization/notification.h"
-#include "internal/platform/implementation/account_manager.h"
 #include "sharing/contacts/nearby_share_contact_manager.h"
 #include "sharing/internal/public/context.h"
 #include "sharing/internal/public/logging.h"
 #include "sharing/proto/contact_rpc.pb.h"
 #include "sharing/proto/rpc_resources.pb.h"
 
-namespace nearby {
-namespace sharing {
+namespace nearby::sharing {
 namespace {
 
 using ::nearby::sharing::proto::ContactRecord;
@@ -148,5 +147,4 @@ void NearbyShareContactManagerImpl::GetContacts(ContactsCallback callback) {
   });
 }
 
-}  // namespace sharing
-}  // namespace nearby
+}  // namespace nearby::sharing
diff --git a/sharing/contacts/nearby_share_contact_manager_impl.h b/sharing/contacts/nearby_share_contact_manager_impl.h
index 43e23592..16d38f87 100644
--- a/sharing/contacts/nearby_share_contact_manager_impl.h
+++ b/sharing/contacts/nearby_share_contact_manager_impl.h
@@ -17,15 +17,14 @@
 
 #include <memory>
 
+#include "location/nearby/sharing/lib/account/account_manager.h"
 #include "location/nearby/sharing/lib/rpc/sharing_rpc_client.h"
 #include "absl/base/nullability.h"
-#include "internal/platform/implementation/account_manager.h"
 #include "internal/platform/task_runner.h"
 #include "sharing/contacts/nearby_share_contact_manager.h"
 #include "sharing/internal/public/context.h"
 
-namespace nearby {
-namespace sharing {
+namespace nearby::sharing {
 
 class NearbyShareContactManagerImpl : public NearbyShareContactManager {
  public:
@@ -45,7 +44,6 @@ class NearbyShareContactManagerImpl : public NearbyShareContactManager {
   std::unique_ptr<TaskRunner> executor_ = nullptr;
 };
 
-}  // namespace sharing
-}  // namespace nearby
+}  // namespace nearby::sharing
 
 #endif  // THIRD_PARTY_NEARBY_SHARING_CONTACTS_NEARBY_SHARE_CONTACT_MANAGER_IMPL_H_
diff --git a/sharing/contacts/nearby_share_contact_manager_impl_test.cc b/sharing/contacts/nearby_share_contact_manager_impl_test.cc
index b2c7da8f..837ceca3 100644
--- a/sharing/contacts/nearby_share_contact_manager_impl_test.cc
+++ b/sharing/contacts/nearby_share_contact_manager_impl_test.cc
@@ -21,11 +21,11 @@
 #include <string>
 #include <vector>
 
+#include "location/nearby/sharing/lib/account/account_manager.h"
+#include "location/nearby/sharing/lib/account/fake_account_manager.h"
 #include "location/nearby/sharing/lib/rpc/fake_nearby_share_client.h"
 #include "gtest/gtest.h"
 #include "absl/time/time.h"
-#include "internal/platform/implementation/account_manager.h"
-#include "internal/test/fake_account_manager.h"
 #include "sharing/internal/test/fake_context.h"
 #include "sharing/local_device_data/fake_nearby_share_local_device_data_manager.h"
 #include "sharing/proto/contact_rpc.pb.h"
diff --git a/sharing/internal/api/BUILD b/sharing/internal/api/BUILD
index 9fb16437..cbb62511 100644
--- a/sharing/internal/api/BUILD
+++ b/sharing/internal/api/BUILD
@@ -41,7 +41,7 @@ cc_library(
         "//internal/base:file_path",
         "//internal/platform:mac_address",
         "//internal/platform:types",
-        "//internal/platform/implementation:account_manager",
+        "//location/nearby/sharing/lib/account:account_manager",
         "//location/nearby/sharing/lib/sync:sync_binding_prefs_cc_proto",
         "//location/nearby/sharing/lib/sync:sync_config_prefs_cc_proto",
         "//sharing/proto:share_cc_proto",
@@ -71,7 +71,7 @@ cc_library(
         "//internal/base:file_path",
         "//internal/platform:mac_address",
         "//internal/platform:types",
-        "//internal/platform/implementation:account_manager",
+        "//location/nearby/sharing/lib/account:account_manager",
         "//sharing/analytics",
         "//sharing/internal/public:logging",
         "//sharing/proto:share_cc_proto",
diff --git a/sharing/internal/api/mock_sharing_platform.h b/sharing/internal/api/mock_sharing_platform.h
index b5b64e18..d9e5df2a 100644
--- a/sharing/internal/api/mock_sharing_platform.h
+++ b/sharing/internal/api/mock_sharing_platform.h
@@ -19,11 +19,11 @@
 #include <memory>
 #include <vector>
 
+#include "location/nearby/sharing/lib/account/account_manager.h"
 #include "gmock/gmock.h"
 #include "absl/strings/string_view.h"
 #include "internal/base/file_path.h"
 #include "internal/platform/device_info.h"
-#include "internal/platform/implementation/account_manager.h"
 #include "internal/platform/task_runner.h"
 #include "sharing/internal/api/app_info.h"
 #include "sharing/internal/api/bluetooth_adapter.h"
diff --git a/sharing/internal/api/sharing_platform.h b/sharing/internal/api/sharing_platform.h
index d5bab76a..a65ac38f 100644
--- a/sharing/internal/api/sharing_platform.h
+++ b/sharing/internal/api/sharing_platform.h
@@ -19,10 +19,10 @@
 #include <memory>
 #include <vector>
 
+#include "location/nearby/sharing/lib/account/account_manager.h"
 #include "absl/strings/string_view.h"
 #include "internal/base/file_path.h"
 #include "internal/platform/device_info.h"
-#include "internal/platform/implementation/account_manager.h"
 #include "internal/platform/task_runner.h"
 #include "sharing/internal/api/app_info.h"
 #include "sharing/internal/api/bluetooth_adapter.h"
diff --git a/sharing/local_device_data/BUILD b/sharing/local_device_data/BUILD
index 030085b3..3dbd73cb 100644
--- a/sharing/local_device_data/BUILD
+++ b/sharing/local_device_data/BUILD
@@ -31,8 +31,8 @@ cc_library(
     deps = [
         "//internal/base",
         "//internal/platform:types",
-        "//internal/platform/implementation:account_manager",
         "//internal/platform/implementation:types",
+        "//location/nearby/sharing/lib/account:account_manager",
         "//sharing/common:enum",
         "//sharing/internal/api:platform",
         "//sharing/internal/base:utf_utils",
@@ -68,9 +68,10 @@ cc_test(
     ],
     deps = [
         ":local_device_data",
-        "//internal/platform/implementation:account_manager",
         "//internal/platform/implementation:platform_impl",
         "//internal/test",
+        "//location/nearby/sharing/lib/account:account_manager",
+        "//location/nearby/sharing/lib/account:fake_account_manager",
         "//sharing/common",
         "//sharing/common:enum",
         "//sharing/internal/test:nearby_test",
diff --git a/sharing/local_device_data/nearby_share_local_device_data_manager_impl.cc b/sharing/local_device_data/nearby_share_local_device_data_manager_impl.cc
index 80f2ffbb..ad53f866 100644
--- a/sharing/local_device_data/nearby_share_local_device_data_manager_impl.cc
+++ b/sharing/local_device_data/nearby_share_local_device_data_manager_impl.cc
@@ -21,11 +21,11 @@
 #include <optional>
 #include <string>
 
+#include "location/nearby/sharing/lib/account/account_manager.h"
 #include "absl/memory/memory.h"
 #include "absl/strings/string_view.h"
 #include "absl/strings/substitute.h"
 #include "internal/platform/device_info.h"
-#include "internal/platform/implementation/account_manager.h"
 #include "internal/platform/implementation/device_info.h"
 #include "sharing/common/nearby_share_enums.h"
 #include "sharing/internal/api/preference_manager.h"
@@ -37,8 +37,7 @@
 #include "sharing/proto/rpc_resources.pb.h"
 #include "sharing/proto/timestamp.pb.h"
 
-namespace nearby {
-namespace sharing {
+namespace nearby::sharing {
 namespace {
 using ::nearby::api::DeviceInfo;
 using ::nearby::sharing::api::PreferenceManager;
@@ -164,5 +163,4 @@ std::string NearbyShareLocalDeviceDataManagerImpl::GetDefaultDeviceName()
   return absl::Substitute(kDefaultDeviceName, truncated_name, device_type);
 }
 
-}  // namespace sharing
-}  // namespace nearby
+}  // namespace nearby::sharing
diff --git a/sharing/local_device_data/nearby_share_local_device_data_manager_impl.h b/sharing/local_device_data/nearby_share_local_device_data_manager_impl.h
index 176b3b94..5231babb 100644
--- a/sharing/local_device_data/nearby_share_local_device_data_manager_impl.h
+++ b/sharing/local_device_data/nearby_share_local_device_data_manager_impl.h
@@ -18,9 +18,9 @@
 #include <memory>
 #include <string>
 
+#include "location/nearby/sharing/lib/account/account_manager.h"
 #include "absl/strings/string_view.h"
 #include "internal/platform/device_info.h"
-#include "internal/platform/implementation/account_manager.h"
 #include "sharing/common/nearby_share_enums.h"
 #include "sharing/internal/api/preference_manager.h"
 #include "sharing/local_device_data/nearby_share_local_device_data_manager.h"
diff --git a/sharing/local_device_data/nearby_share_local_device_data_manager_impl_test.cc b/sharing/local_device_data/nearby_share_local_device_data_manager_impl_test.cc
index ca3fcdad..047f7182 100644
--- a/sharing/local_device_data/nearby_share_local_device_data_manager_impl_test.cc
+++ b/sharing/local_device_data/nearby_share_local_device_data_manager_impl_test.cc
@@ -21,11 +21,11 @@
 #include <string>
 #include <vector>
 
+#include "location/nearby/sharing/lib/account/account_manager.h"
+#include "location/nearby/sharing/lib/account/fake_account_manager.h"
 #include "gtest/gtest.h"
 #include "absl/strings/string_view.h"
 #include "absl/strings/substitute.h"
-#include "internal/platform/implementation/account_manager.h"
-#include "internal/test/fake_account_manager.h"
 #include "internal/test/fake_device_info.h"
 #include "sharing/common/nearby_share_enums.h"
 #include "sharing/common/nearby_share_prefs.h"
@@ -118,7 +118,7 @@ class NearbyShareLocalDeviceDataManagerImplTest
 
  protected:
   nearby::FakePreferenceManager preference_manager_;
-  nearby::FakeAccountManager fake_account_manager_;
+  FakeAccountManager fake_account_manager_;
   nearby::FakeDeviceInfo fake_device_info_;
   std::vector<ObserverNotification> notifications_;
   std::unique_ptr<NearbyShareLocalDeviceDataManager> manager_;
diff --git a/sharing/nearby_sharing_service.h b/sharing/nearby_sharing_service.h
index 8d1f8a1a..f664367c 100644
--- a/sharing/nearby_sharing_service.h
+++ b/sharing/nearby_sharing_service.h
@@ -31,12 +31,9 @@
 #include "sharing/share_target_discovered_callback.h"
 #include "sharing/transfer_update_callback.h"
 
-namespace nearby {
+namespace nearby::sharing {
 
 class AccountManager;
-
-namespace sharing {
-
 class NearbyNotificationDelegate;
 class NearbyShareContactManager;
 
@@ -227,7 +224,6 @@ class NearbySharingService {
       uint16_t alternate_service_uuid) = 0;
 };
 
-}  // namespace sharing
-}  // namespace nearby
+}  // namespace nearby::sharing
 
 #endif  // THIRD_PARTY_NEARBY_SHARING_NEARBY_SHARING_SERVICE_H_
diff --git a/sharing/nearby_sharing_service_impl.cc b/sharing/nearby_sharing_service_impl.cc
index 7749dfda..2ceb0496 100644
--- a/sharing/nearby_sharing_service_impl.cc
+++ b/sharing/nearby_sharing_service_impl.cc
@@ -31,6 +31,7 @@
 #include <utility>
 #include <vector>
 
+#include "location/nearby/sharing/lib/account/account_manager.h"
 #include "location/nearby/sharing/lib/rpc/sharing_rpc_client.h"
 #include "absl/base/nullability.h"
 #include "absl/container/flat_hash_map.h"
@@ -48,7 +49,6 @@
 #include "internal/network/url.h"
 #include "internal/platform/clock.h"
 #include "internal/platform/device_info.h"
-#include "internal/platform/implementation/account_manager.h"
 #include "internal/platform/implementation/device_info.h"
 #include "internal/platform/task_runner.h"
 #include "proto/sharing_enums.pb.h"
diff --git a/sharing/nearby_sharing_service_impl.h b/sharing/nearby_sharing_service_impl.h
index 7b17c0e8..d93bc24e 100644
--- a/sharing/nearby_sharing_service_impl.h
+++ b/sharing/nearby_sharing_service_impl.h
@@ -27,6 +27,7 @@
 #include <tuple>
 #include <vector>
 
+#include "location/nearby/sharing/lib/account/account_manager.h"
 #include "location/nearby/sharing/lib/rpc/sharing_rpc_client.h"
 #include "location/nearby/sharing/lib/sync/sync_manager.h"
 #include "absl/base/nullability.h"
@@ -38,7 +39,6 @@
 #include "absl/types/span.h"
 #include "internal/platform/clock.h"
 #include "internal/platform/device_info.h"
-#include "internal/platform/implementation/account_manager.h"
 #include "internal/platform/task_runner.h"
 #include "proto/sharing_enums.pb.h"
 #include "sharing/advertisement.h"
@@ -90,7 +90,7 @@ class NearbySharingServiceImpl
     : public NearbySharingService,
       public NearbyShareSettings::Observer,
       public NearbyShareCertificateManager::Observer,
-      public ::nearby::AccountManager::Observer,
+      public AccountManager::Observer,
       public NearbyFastInitiation::Observer,
       public sharing::api::BluetoothAdapter::Observer,
       public NearbyConnectionsManager::IncomingConnectionListener,
diff --git a/sharing/nearby_sharing_service_impl_test.cc b/sharing/nearby_sharing_service_impl_test.cc
index a009f000..aaf1624c 100644
--- a/sharing/nearby_sharing_service_impl_test.cc
+++ b/sharing/nearby_sharing_service_impl_test.cc
@@ -30,6 +30,9 @@
 #include <utility>
 #include <vector>
 
+#include "location/nearby/sharing/lib/account/signin_attempt.h"
+#include "location/nearby/sharing/lib/account/fake_account_manager.h"
+#include "location/nearby/sharing/lib/account/mock_account_observer.h"
 #include "location/nearby/sharing/lib/rpc/fake_nearby_share_client.h"
 #include "gmock/gmock.h"
 #include "protobuf-matchers/protocol-buffer-matchers.h"
@@ -48,11 +51,8 @@
 #include "internal/base/file_path.h"
 #include "internal/base/files.h"
 #include "internal/flags/nearby_flags.h"
-#include "internal/platform/implementation/signin_attempt.h"
-#include "internal/test/fake_account_manager.h"
 #include "internal/test/fake_device_info.h"
 #include "internal/test/fake_task_runner.h"
-#include "internal/test/mock_account_observer.h"
 #include "sharing/advertisement.h"
 #include "sharing/advertisement_capabilities.h"
 #include "sharing/analytics/analytics_recorder.h"
@@ -1705,7 +1705,7 @@ TEST_F(NearbySharingServiceImplTest,
        ForegroundRegisterReceiveSurfaceIsAdvertisingAllContacts) {
   SetLanConnected(true);
   SetVisibility(DeviceVisibility::DEVICE_VISIBILITY_ALL_CONTACTS);
-  ::nearby::AccountManager::Account account;
+  AccountManager::Account account;
   account.id = kTestAccountId;
   account_manager().SetAccount(account);
   local_device_data_manager()->SetDeviceName(kDeviceName);
@@ -1759,7 +1759,7 @@ TEST_F(NearbySharingServiceImplTest,
        BackgroundRegisterReceiveSurfaceIsAdvertisingSelectedContacts) {
   SetLanConnected(true);
   SetVisibility(DeviceVisibility::DEVICE_VISIBILITY_SELECTED_CONTACTS);
-  ::nearby::AccountManager::Account account;
+  AccountManager::Account account;
   account.id = kTestAccountId;
   account_manager().SetAccount(account);
   SetVisibility(DeviceVisibility::DEVICE_VISIBILITY_ALL_CONTACTS);
@@ -4883,7 +4883,7 @@ TEST_F(NearbySharingServiceImplTest, RemoveIncomingPayloads) {
 
 TEST_F(NearbySharingServiceImplTest, NotifyLogoutSucceededWithCredentialError) {
   TestObserver observer(service_.get());
-  ::nearby::AccountManager::Account account;
+  AccountManager::Account account;
   account.id = kTestAccountId;
   account_manager().SetAccount(account);