diff --git a/src/otaclient/_types.py b/src/otaclient/_types.py
new file mode 100644
index 000000000..5d895e5c0
--- /dev/null
+++ b/src/otaclient/_types.py
@@ -0,0 +1,135 @@
+# Copyright 2022 TIER IV, INC. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""OTAClient internal used types."""
+
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from enum import Enum
+from typing import ClassVar, Optional
+
+from _otaclient_version import __version__
+from otaclient.configs.cfg import ecu_info
+from otaclient_common.typing import StrEnum
+
+#
+# ------ OTA status enums definitions ------ #
+#
+
+
+class OTAOperation(StrEnum):
+    UPDATE = "UPDATE"
+    ROLLBACK = "ROLLBACK"
+
+
+class OTAOperationResp(StrEnum):
+    ACCEPTED = "ACCEPTED"
+    BUSY = "BUSY"
+
+
+class UpdatePhase(StrEnum):
+    INITIALIZING = "INITIALIZING"
+    PROCESSING_METADATA = "PROCESSING_METADATA"
+    CALCULATING_DELTA = "CALCULATING_DELTA"
+    DOWNLOADING_OTA_FILES = "DOWNLOADING_OTA_FILES"
+    APPLYING_UPDATE = "APPLYING_UPDATE"
+    PROCESSING_POSTUPDATE = "PROCESSING_POSTUPDATE"
+    FINALIZING_UPDATE = "FINALIZING_UPDATE"
+
+
+class OTAStatus(StrEnum):
+    INITIALIZED = "INITIALIZED"
+    SUCCESS = "SUCCESS"
+    FAILURE = "FAILURE"
+    UPDATING = "UPDATING"
+    ROLLBACKING = "ROLLBACKING"
+    ROLLBACK_FAILURE = "ROLLBACK_FAILURE"
+
+
+class FailureType(StrEnum):
+    NO_FAILURE = "NO_FAILURE"
+    RECOVERABLE = "RECOVERABLE"
+    UNRECOVERABLE = "UNRECOVERABLE"
+
+
+#
+# ------ otaclient internal status report ------ #
+#
+
+
+@dataclass
+class UpdateMeta:
+    update_firmware_version: str = ""
+    image_size_uncompressed: int = 0
+    image_file_entries: int = 0
+    total_download_files_num: int = 0
+    total_download_files_size: int = 0
+    total_remove_files_num: int = 0
+
+
+@dataclass
+class UpdateProgress:
+    downloaded_files_num: int = 0
+    downloaded_bytes: int = 0
+    downloaded_files_size: int = 0
+    downloading_errors: int = 0
+    removed_files_num: int = 0
+    processed_files_num: int = 0
+    processed_files_size: int = 0
+
+
+@dataclass
+class UpdateTiming:
+    update_start_timestamp: int = 0  # in second
+    delta_generate_start_timestamp: int = 0  # in second
+    download_start_timestamp: int = 0  # in second
+    update_apply_start_timestamp: int = 0  # in second
+    post_update_start_timestamp: int = 0  # in second
+
+
+#
+# ------ otaclient internal IPC messages ------ #
+#
+
+
+@dataclass
+class OTAClientStatus:
+    """otaclient internal status definition."""
+
+    ecu_id: ClassVar[str] = ecu_info.ecu_id
+    otaclient_version: ClassVar[str] = __version__
+    firmware_version: str = ""
+
+    ota_status: OTAStatus = OTAStatus.INITIALIZED
+    session_id: str = ""
+    update_phase: UpdatePhase = UpdatePhase.INITIALIZING
+    update_meta: Optional[UpdateMeta] = None
+    update_progress: Optional[UpdateProgress] = None
+    update_timing: Optional[UpdateTiming] = None
+    failure_type: FailureType = FailureType.NO_FAILURE
+    failure_reason: str = ""
+
+
+@dataclass
+class UpdateRequestV2:
+    """Compatible with OTA API version 2."""
+
+    version: str
+    url_base: str
+    cookies_json: str
+
+
+class RollbackRequestV2:
+    """Compatbile with OTA API version 2."""