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diff --git a/src/buildtool/file_system/git_tree_utils.hpp b/src/buildtool/file_system/git_tree_utils.hpp
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+// Copyright 2025 Huawei Cloud Computing Technology Co., Ltd.
+//
+// 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 INCLUDED_SRC_BUILDTOOL_FILE_SYSTEM_GIT_TREE_UTILS_HPP
+#define INCLUDED_SRC_BUILDTOOL_FILE_SYSTEM_GIT_TREE_UTILS_HPP
+
+#include <optional>
+#include <string>
+
+#include "src/buildtool/file_system/git_cas.hpp"
+#include "src/buildtool/file_system/git_tree.hpp"
+#include "src/buildtool/storage/config.hpp"
+
+/// \brief Utility methods for validating GitTree instances
+namespace GitTreeUtils {
+
+/// \brief Read a GitTree from a Git repository and ensure (recursively) that it
+/// is free of upwards symlinks. Performs storage-based caching of all found
+/// valid tree hashes.
+/// \param storage_config   Storage instance for caching valid tree hashes.
+/// \param tree_id  Git identifier of the tree to read and validate.
+/// \param git_cas  Git repository providing the tree.
+/// \returns GitTree instance free of upwards symlinks, recursively, on success
+/// or nullopt on failure.
+[[nodiscard]] auto ReadValidGitCASTree(StorageConfig const& storage_config,
+                                       std::string const& tree_id,
+                                       GitCASPtr const& git_cas) noexcept
+    -> std::optional<GitTree>;
+
+/// \brief Validate a known GitTreeEntry pointing to a Git tree, by checking
+/// recursively that it is free of upwards symlinks. Performs storage-based
+/// caching of all found valid tree hashes.
+/// \param storage_config   Storage instance for caching valid tree hashes.
+/// \param GitTreeEntryPtr  Pointer to an existing GitTreeEntry.
+/// \returns Flag stating if tree is (recursively) free of upwards symlinks.
+/// \note This method is useful when one has fast (and preferably cached) access
+/// to a GitTree instance and direct reading from a repository is not desired.
+[[nodiscard]] auto IsGitTreeValid(StorageConfig const& storage_config,
+                                  GitTreeEntryPtr const& entry) noexcept
+    -> bool;
+
+}  // namespace GitTreeUtils
+
+#endif  // INCLUDED_SRC_BUILDTOOL_FILE_SYSTEM_GIT_TREE_UTILS_HPP