diff --git a/updater/include/updater/simulator_runtime.h b/updater/include/updater/simulator_runtime.h
new file mode 100644
index 0000000..93fa2a4
--- /dev/null
+++ b/updater/include/updater/simulator_runtime.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#pragma once
+
+#include <map>
+#include <memory>
+#include <string>
+#include <string_view>
+#include <utility>
+#include <vector>
+
+#include "edify/updater_runtime_interface.h"
+#include "updater/target_files.h"
+
+class SimulatorRuntime : public UpdaterRuntimeInterface {
+ public:
+  explicit SimulatorRuntime(TargetFiles* source) : source_(source) {}
+
+  bool IsSimulator() const override {
+    return true;
+  }
+
+  std::string GetProperty(const std::string_view key,
+                          const std::string_view default_value) const override;
+
+  int Mount(const std::string_view location, const std::string_view mount_point,
+            const std::string_view fs_type, const std::string_view mount_options) override;
+  bool IsMounted(const std::string_view mount_point) const override;
+  std::pair<bool, int> Unmount(const std::string_view mount_point) override;
+
+  bool ReadFileToString(const std::string_view filename, std::string* content) const override;
+  bool WriteStringToFile(const std::string_view content,
+                         const std::string_view filename) const override;
+
+  int WipeBlockDevice(const std::string_view filename, size_t len) const override;
+  int RunProgram(const std::vector<std::string>& args, bool is_vfork) const override;
+  int Tune2Fs(const std::vector<std::string>& args) const override;
+
+ private:
+  std::string FindBlockDeviceName(const std::string_view name) const override;
+
+  TargetFiles* source_;
+  std::map<std::string, std::string, std::less<>> mounted_partitions_;
+};
diff --git a/updater/include/updater/target_files.h b/updater/include/updater/target_files.h
new file mode 100644
index 0000000..9ef1a5b
--- /dev/null
+++ b/updater/include/updater/target_files.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#pragma once
+
+#include <string>
+
+// This class parses a given target file for the build properties and image files. Then it creates
+// and maintains the temporary files to simulate the block devices on host.
+class TargetFiles {
+ public:
+  TargetFiles(std::string path, std::string work_dir)
+      : path_(std::move(path)), work_dir_(std::move(work_dir)) {}
+
+  std::string GetProperty(const std::string_view key, const std::string_view default_value) const;
+
+  std::string FindBlockDeviceName(const std::string_view name) const;
+
+ private:
+  std::string path_;  // Path to the target file.
+
+  std::string work_dir_;  // A temporary directory to store the extracted image files
+};