diff --git a/lz4diff/lz4diff.h b/lz4diff/lz4diff.h
new file mode 100644
index 0000000..a1a1b9b
--- /dev/null
+++ b/lz4diff/lz4diff.h
@@ -0,0 +1,47 @@
+//
+// Copyright (C) 2021 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.
+//
+
+#ifndef UPDATE_ENGINE_LZ4DIFF_LZ4DIFF_H_
+#define UPDATE_ENGINE_LZ4DIFF_LZ4DIFF_H_
+
+#include <vector>
+#include <string_view>
+
+#include "lz4diff/lz4diff.pb.h"
+#include "update_engine/lz4diff/lz4diff_format.h"
+#include "update_engine/update_metadata.pb.h"
+
+namespace chromeos_update_engine {
+
+bool Lz4Diff(std::string_view src,
+             std::string_view dst,
+             const CompressedFile& src_file_info,
+             const CompressedFile& dst_file_info,
+             const bool zero_padding_enabled,
+             Blob* output,
+             InstallOperation::Type* op_type = nullptr) noexcept;
+
+bool Lz4Diff(const Blob& src,
+             const Blob& dst,
+             const CompressedFile& src_file_info,
+             const CompressedFile& dst_file_info,
+             const bool zero_padding_enabled,
+             Blob* output,
+             InstallOperation::Type* op_type = nullptr) noexcept;
+
+}  // namespace chromeos_update_engine
+
+#endif