diff --git a/res/fs_binary_msgpack1.png b/res/fs_binary_msgpack1.png
new file mode 100644
index 0000000..b536b20
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diff --git a/res/fs_binary_msgpack2.png b/res/fs_binary_msgpack2.png
new file mode 100644
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diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 5adca01..93cf2d6 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -23,3 +23,15 @@ target_link_libraries(solanaceae_message_fragment_store PUBLIC
 
 ########################################
 
+add_executable(convert_message_object_store
+	./convert_frag_to_obj.cpp
+)
+
+target_link_libraries(convert_message_object_store PUBLIC
+	solanaceae_object_store
+	solanaceae_object_store_backend_filesystem
+	solanaceae_message_fragment_store
+)
+
+########################################
+
diff --git a/src/convert_frag_to_obj.cpp b/src/convert_frag_to_obj.cpp
new file mode 100644
index 0000000..54746e5
--- /dev/null
+++ b/src/convert_frag_to_obj.cpp
@@ -0,0 +1,167 @@
+#include <solanaceae/object_store/object_store.hpp>
+#include <solanaceae/object_store/backends/filesystem_storage.hpp>
+#include <solanaceae/object_store/meta_components.hpp>
+#include <solanaceae/object_store/serializer_json.hpp>
+#include <solanaceae/message_fragment_store/message_fragment_store.hpp>
+#include <solanaceae/message3/message_serializer.hpp>
+
+#include <solanaceae/util/utils.hpp>
+
+#include <nlohmann/json.hpp>
+
+#include <filesystem>
+#include <iostream>
+
+#include <cassert>
+
+int main(int argc, const char** argv) {
+	if (argc != 3) {
+		std::cerr << "wrong paramter count, do " << argv[0] << " <input_folder> <output_folder>\n";
+		return 1;
+	}
+
+	if (!std::filesystem::is_directory(argv[1])) {
+		std::cerr << "input folder is no folder\n";
+	}
+
+	std::filesystem::create_directories(argv[2]);
+
+	// we are going to use 2 different OS for convineance, but could be done with 1 too
+	ObjectStore2 os_src;
+	ObjectStore2 os_dst;
+
+	backend::FilesystemStorage fsb_src(os_src, argv[1]);
+	backend::FilesystemStorage fsb_dst(os_dst, argv[2]);
+
+	Contact3Registry cr; // dummy
+	RegistryMessageModel rmm(cr); // dummy
+	// they only exist for the serializers (for now)
+	// TODO: version
+	MessageSerializerNJ msnj_src{cr, {}, {}};
+	MessageFragmentStore mfs_src(cr, rmm, os_src, fsb_src, msnj_src);
+	MessageSerializerNJ msnj_dst{cr, {}, {}};
+	MessageFragmentStore mfs_dst(cr, rmm, os_dst, fsb_dst, msnj_dst);
+
+	// add message fragment store too (adds meta?)
+
+	// hookup events
+	struct EventListener : public ObjectStoreEventI {
+		ObjectStore2& _os_src;
+		backend::FilesystemStorage& _fsb_src;
+
+		ObjectStore2& _os_dst;
+		backend::FilesystemStorage& _fsb_dst;
+
+		EventListener(
+			ObjectStore2& os_src,
+			backend::FilesystemStorage& fsb_src,
+			ObjectStore2& os_dst,
+			backend::FilesystemStorage& fsb_dst
+		) :
+			_os_src(os_src),
+			_fsb_src(fsb_src),
+			_os_dst(os_dst),
+			_fsb_dst(fsb_dst)
+		{
+			_os_src.subscribe(this, ObjectStore_Event::object_construct);
+			_os_src.subscribe(this, ObjectStore_Event::object_update);
+		}
+
+		protected: // os
+			bool onEvent(const ObjectStore::Events::ObjectConstruct& e) override {
+				assert(e.e.all_of<ObjComp::Ephemeral::MetaFileType>());
+				assert(e.e.all_of<ObjComp::ID>());
+
+				// !! we read the obj first, so we can discard empty objects
+				// technically we could just copy the file, but meh
+				// read src and write dst data
+				std::vector<uint8_t> tmp_buffer;
+				std::function<StorageBackendI::read_from_storage_put_data_cb> cb = [&tmp_buffer](const ByteSpan buffer) {
+					tmp_buffer.insert(tmp_buffer.end(), buffer.cbegin(), buffer.cend());
+				};
+				if (!_fsb_src.read(e.e, cb)) {
+					std::cerr << "failed to read obj '" << bin2hex(e.e.get<ObjComp::ID>().v) << "'\n";
+					return false;
+				}
+
+				if (tmp_buffer.empty()) {
+					std::cerr << "discarded empty obj '" << bin2hex(e.e.get<ObjComp::ID>().v) << "'\n";
+					return false;
+				}
+				{ // try getting lucky and see if its an empty json
+					const auto j = nlohmann::json::parse(tmp_buffer, nullptr, false);
+					if (j.is_array() && j.empty()) {
+						std::cerr << "discarded empty json array obj '" << bin2hex(e.e.get<ObjComp::ID>().v) << "'\n";
+						return false;
+					}
+				}
+
+				// WARNING: manual and hardcoded
+				// manually upconvert message json to msgpack (v1 to v2)
+				if (true && e.e.get<ObjComp::MessagesVersion>().v == 1) {
+					// TODO: error handling
+					const auto j = nlohmann::json::parse(tmp_buffer);
+
+					if (true) {
+						e.e.replace<ObjComp::MessagesVersion>(uint16_t(2));
+
+						// overwrite og
+						tmp_buffer = nlohmann::json::to_msgpack(j);
+					}
+				}
+
+				// we dont copy meta file type, it will be the same for all "new" objects
+				auto oh = _fsb_dst.newObject(ByteSpan{e.e.get<ObjComp::ID>().v});
+
+				if (!static_cast<bool>(oh)) {
+					// already exists
+					return false;
+				}
+
+				{ // sync meta
+					// some hardcoded ehpemeral (besides mft/id)
+					oh.emplace_or_replace<ObjComp::Ephemeral::MetaEncryptionType>(e.e.get_or_emplace<ObjComp::Ephemeral::MetaEncryptionType>());
+					oh.emplace_or_replace<ObjComp::Ephemeral::MetaCompressionType>(e.e.get_or_emplace<ObjComp::Ephemeral::MetaCompressionType>());
+
+					// serializable
+					for (const auto& [type, fn] : _os_src.registry().ctx().get<SerializerJsonCallbacks<Object>>()._serl) {
+						//if (!e.e.registry()->storage(type)->contains(e.e)) {
+							//continue;
+						//}
+
+						// this is hacky but we serialize and then deserialize the component
+						// raw copy might be better in the future
+						nlohmann::json tmp_j;
+						if (fn(e.e, tmp_j)) {
+							_os_dst.registry().ctx().get<SerializerJsonCallbacks<Object>>()._deserl.at(type)(oh, tmp_j);
+						}
+					}
+				}
+
+				static_cast<StorageBackendI&>(_fsb_dst).write(oh, ByteSpan{tmp_buffer});
+
+				//assert(std::filesystem::file_size(e.e.get<ObjComp::Ephemeral::FilePath>().path) == std::filesystem::file_size(oh.get<ObjComp::Ephemeral::FilePath>().path));
+
+				return false;
+			}
+
+			bool onEvent(const ObjectStore::Events::ObjectUpdate&) override {
+				std::cerr << "Update called\n";
+				assert(false);
+				return false;
+			}
+	} el {
+		os_src,
+		fsb_src,
+		os_dst,
+		fsb_dst,
+	};
+
+	// perform scan (which triggers events)
+	fsb_dst.scanAsync(); // fill with existing?
+	fsb_src.scanAsync(); // the scan
+
+	// done
+	return 0;
+}
+