diff --git a/base_updater.py b/base_updater.py
new file mode 100644
index 0000000..74b688d
--- /dev/null
+++ b/base_updater.py
@@ -0,0 +1,72 @@
+# Copyright (C) 2018 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Base class for all updaters."""
+
+from pathlib import Path
+
+import fileutils
+import metadata_pb2  # type: ignore
+
+
+class Updater:
+    """Base Updater that defines methods common for all updaters."""
+    def __init__(self, proj_path: Path, old_url: metadata_pb2.URL,
+                 old_ver: str) -> None:
+        self._proj_path = fileutils.get_absolute_project_path(proj_path)
+        self._old_url = old_url
+        self._old_ver = old_ver
+
+        self._new_url = metadata_pb2.URL()
+        self._new_url.CopyFrom(old_url)
+        self._new_ver = old_ver
+
+    def is_supported_url(self) -> bool:
+        """Returns whether the url is supported."""
+        raise NotImplementedError()
+
+    def check(self) -> None:
+        """Checks whether a new version is available."""
+        raise NotImplementedError()
+
+    def update(self) -> None:
+        """Updates the package.
+
+        Has to call check() before this function.
+        """
+        raise NotImplementedError()
+
+    @property
+    def project_path(self) -> Path:
+        """Gets absolute path to the project."""
+        return self._proj_path
+
+    @property
+    def current_version(self) -> str:
+        """Gets the current version."""
+        return self._old_ver
+
+    @property
+    def current_url(self) -> metadata_pb2.URL:
+        """Gets the current url."""
+        return self._old_url
+
+    @property
+    def latest_version(self) -> str:
+        """Gets latest version."""
+        return self._new_ver
+
+    @property
+    def latest_url(self) -> metadata_pb2.URL:
+        """Gets URL for latest version."""
+        return self._new_url