diff --git a/CMakeLists.txt b/CMakeLists.txt
index 60c0fe6..ddf7192 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -65,5 +65,6 @@ target_link_libraries(solanaceae_sha1_ngcft1 PUBLIC
 	sha1::sha1
 	solanaceae_tox_contacts
 	solanaceae_message3
+	solanaceae_object_store
 )
 
diff --git a/solanaceae/ngc_ft1_sha1/sha1_ngcft1.cpp b/solanaceae/ngc_ft1_sha1/sha1_ngcft1.cpp
index 5e7b070..6adad5c 100644
--- a/solanaceae/ngc_ft1_sha1/sha1_ngcft1.cpp
+++ b/solanaceae/ngc_ft1_sha1/sha1_ngcft1.cpp
@@ -26,11 +26,11 @@
 
 namespace Message::Components {
 
-	using Content = ContentHandle;
+	using Content = ObjectHandle;
 
 } // Message::Components
 
-// TODO: rename to content components
+// TODO: rename to object components
 namespace Components {
 
 	struct Messages {
@@ -112,7 +112,7 @@ static size_t chunkSize(const FT1InfoSHA1& sha1_info, size_t chunk_index) {
 	}
 }
 
-void SHA1_NGCFT1::queueUpRequestChunk(uint32_t group_number, uint32_t peer_number, ContentHandle content, const SHA1Digest& hash) {
+void SHA1_NGCFT1::queueUpRequestChunk(uint32_t group_number, uint32_t peer_number, ObjectHandle content, const SHA1Digest& hash) {
 	for (auto& [i_g, i_p, i_m, i_h, i_t] : _queue_requested_chunk) {
 		// if already in queue
 		if (i_g == group_number && i_p == peer_number && i_h == hash) {
@@ -156,7 +156,7 @@ uint64_t SHA1_NGCFT1::combineIds(const uint32_t group_number, const uint32_t pee
 	return (uint64_t(group_number) << 32) | peer_number;
 }
 
-void SHA1_NGCFT1::updateMessages(ContentHandle ce) {
+void SHA1_NGCFT1::updateMessages(ObjectHandle ce) {
 	assert(ce.all_of<Components::Messages>());
 
 	for (auto msg : ce.get<Components::Messages>().messages) {
@@ -185,7 +185,7 @@ void SHA1_NGCFT1::updateMessages(ContentHandle ce) {
 	}
 }
 
-std::optional<std::pair<uint32_t, uint32_t>> SHA1_NGCFT1::selectPeerForRequest(ContentHandle ce) {
+std::optional<std::pair<uint32_t, uint32_t>> SHA1_NGCFT1::selectPeerForRequest(ObjectHandle ce) {
 	// get a list of peers we can request this file from
 	// TODO: randomly request from non SuspectedParticipants
 	std::vector<std::pair<uint32_t, uint32_t>> tox_peers;
@@ -248,11 +248,13 @@ std::optional<std::pair<uint32_t, uint32_t>> SHA1_NGCFT1::selectPeerForRequest(C
 }
 
 SHA1_NGCFT1::SHA1_NGCFT1(
+	ObjectStore2& os,
 	Contact3Registry& cr,
 	RegistryMessageModel& rmm,
 	NGCFT1& nft,
 	ToxContactModel2& tcm
 ) :
+	_os(os),
 	_cr(cr),
 	_rmm(rmm),
 	_nft(nft),
@@ -350,8 +352,8 @@ void SHA1_NGCFT1::iterate(float delta) {
 		}
 
 		{ // requested info timers
-			std::vector<Content> timed_out;
-			_contentr.view<Components::ReRequestInfoTimer>().each([delta, &timed_out](Content e, Components::ReRequestInfoTimer& rrit) {
+			std::vector<Object> timed_out;
+			_os.registry().view<Components::ReRequestInfoTimer>().each([delta, &timed_out](Object e, Components::ReRequestInfoTimer& rrit) {
 				rrit.timer += delta;
 
 				// 15sec, TODO: config
@@ -361,12 +363,13 @@ void SHA1_NGCFT1::iterate(float delta) {
 			});
 			for (const auto e : timed_out) {
 				// TODO: avoid dups
-				_queue_content_want_info.push_back({_contentr, e});
-				_contentr.remove<Components::ReRequestInfoTimer>(e);
+				_queue_content_want_info.push_back(_os.objectHandle(e));
+				_os.registry().remove<Components::ReRequestInfoTimer>(e);
+				// TODO: throw update?
 			}
 		}
 		{ // requested chunk timers
-			_contentr.view<Components::FT1ChunkSHA1Requested>().each([delta](Components::FT1ChunkSHA1Requested& ftchunk_requested) {
+			_os.registry().view<Components::FT1ChunkSHA1Requested>().each([delta](Components::FT1ChunkSHA1Requested& ftchunk_requested) {
 				for (auto it = ftchunk_requested.chunks.begin(); it != ftchunk_requested.chunks.end();) {
 					it->second += delta;
 
@@ -1087,12 +1090,13 @@ bool SHA1_NGCFT1::onEvent(const Events::NGCFT1_recv_message& e) {
 
 	// check if content exists
 	const auto sha1_info_hash = std::vector<uint8_t>{e.file_id, e.file_id+e.file_id_size};
-	ContentHandle ce;
+	ObjectHandle ce;
 	if (_info_to_content.count(sha1_info_hash)) {
 		ce = _info_to_content.at(sha1_info_hash);
 		std::cout << "SHA1_NGCFT1: new message has existing content\n";
 	} else {
-		ce = {_contentr, _contentr.create()};
+		// TODO: backend
+		ce = {_os.registry(), _os.registry().create()};
 		_info_to_content[sha1_info_hash] = ce;
 		std::cout << "SHA1_NGCFT1: new message has new content\n";
 
@@ -1249,7 +1253,7 @@ bool SHA1_NGCFT1::sendFilePath(const Contact3 c, std::string_view file_name, std
 				std::cout << "SHA1_NGCFT1 sha1_info_hash: " << bin2hex(sha1_info_hash) << "\n";
 
 				// check if content exists
-				ContentHandle ce;
+				ObjectHandle ce;
 				if (self->_info_to_content.count(sha1_info_hash)) {
 					ce = self->_info_to_content.at(sha1_info_hash);
 
@@ -1318,7 +1322,8 @@ bool SHA1_NGCFT1::sendFilePath(const Contact3 c, std::string_view file_name, std
 						it = self->_queue_content_want_chunk.erase(it);
 					}
 				} else {
-					ce = {self->_contentr, self->_contentr.create()};
+					// TODO: backend
+					ce = {self->_os.registry(), self->_os.registry().create()};
 					self->_info_to_content[sha1_info_hash] = ce;
 
 					ce.emplace<Components::FT1InfoSHA1>(sha1_info);
diff --git a/solanaceae/ngc_ft1_sha1/sha1_ngcft1.hpp b/solanaceae/ngc_ft1_sha1/sha1_ngcft1.hpp
index 0e725bb..87f058c 100644
--- a/solanaceae/ngc_ft1_sha1/sha1_ngcft1.hpp
+++ b/solanaceae/ngc_ft1_sha1/sha1_ngcft1.hpp
@@ -2,6 +2,7 @@
 
 // solanaceae port of sha1 fts for NGCFT1
 
+#include <solanaceae/object_store/object_store.hpp>
 #include <solanaceae/contact/contact_model3.hpp>
 #include <solanaceae/message3/registry_message_model.hpp>
 #include <solanaceae/tox_contacts/tox_contact_model2.hpp>
@@ -20,11 +21,9 @@
 #include <mutex>
 #include <list>
 
-enum class Content : uint32_t {};
-using ContentRegistry = entt::basic_registry<Content>;
-using ContentHandle = entt::basic_handle<ContentRegistry>;
-
 class SHA1_NGCFT1 : public RegistryMessageModelEventI, public NGCFT1EventI {
+	ObjectStore2& _os;
+	// TODO: backend abstraction
 	Contact3Registry& _cr;
 	RegistryMessageModel& _rmm;
 	NGCFT1& _nft;
@@ -32,21 +31,18 @@ class SHA1_NGCFT1 : public RegistryMessageModelEventI, public NGCFT1EventI {
 
 	std::minstd_rand _rng {1337*11};
 
-	// registry per group?
-	ContentRegistry _contentr;
-
 	// limit this to each group?
-	entt::dense_map<SHA1Digest, ContentHandle> _info_to_content;
+	entt::dense_map<SHA1Digest, ObjectHandle> _info_to_content;
 
 	// sha1 chunk index
 	// TODO: optimize lookup
 	// TODO: multiple contents. hashes might be unique, but data is not
-	entt::dense_map<SHA1Digest, ContentHandle> _chunks;
+	entt::dense_map<SHA1Digest, ObjectHandle> _chunks;
 
 	// group_number, peer_number, content, chunk_hash, timer
-	std::deque<std::tuple<uint32_t, uint32_t, ContentHandle, SHA1Digest, float>> _queue_requested_chunk;
+	std::deque<std::tuple<uint32_t, uint32_t, ObjectHandle, SHA1Digest, float>> _queue_requested_chunk;
 	//void queueUpRequestInfo(uint32_t group_number, uint32_t peer_number, const SHA1Digest& hash);
-	void queueUpRequestChunk(uint32_t group_number, uint32_t peer_number, ContentHandle content, const SHA1Digest& hash);
+	void queueUpRequestChunk(uint32_t group_number, uint32_t peer_number, ObjectHandle content, const SHA1Digest& hash);
 
 	struct SendingTransfer {
 		struct Info {
@@ -56,7 +52,7 @@ class SHA1_NGCFT1 : public RegistryMessageModelEventI, public NGCFT1EventI {
 		};
 
 		struct Chunk {
-			ContentHandle content;
+			ObjectHandle content;
 			size_t chunk_index; // <.< remove offset_into_file
 			//uint64_t offset_into_file;
 			// or data?
@@ -72,14 +68,14 @@ class SHA1_NGCFT1 : public RegistryMessageModelEventI, public NGCFT1EventI {
 
 	struct ReceivingTransfer {
 		struct Info {
-			ContentHandle content;
+			ObjectHandle content;
 			// copy of info data
 			// too large?
 			std::vector<uint8_t> info_data;
 		};
 
 		struct Chunk {
-			ContentHandle content;
+			ObjectHandle content;
 			std::vector<size_t> chunk_indices;
 			// or data?
 			// if memmapped, this would be just a pointer
@@ -93,8 +89,8 @@ class SHA1_NGCFT1 : public RegistryMessageModelEventI, public NGCFT1EventI {
 	entt::dense_map<uint64_t, entt::dense_map<uint8_t, ReceivingTransfer>> _receiving_transfers;
 
 	// makes request rotate around open content
-	std::deque<ContentHandle> _queue_content_want_info;
-	std::deque<ContentHandle> _queue_content_want_chunk;
+	std::deque<ObjectHandle> _queue_content_want_info;
+	std::deque<ObjectHandle> _queue_content_want_chunk;
 
 	std::atomic_bool _info_builder_dirty {false};
 	std::mutex _info_builder_queue_mutex;
@@ -108,9 +104,9 @@ class SHA1_NGCFT1 : public RegistryMessageModelEventI, public NGCFT1EventI {
 
 	static uint64_t combineIds(const uint32_t group_number, const uint32_t peer_number);
 
-	void updateMessages(ContentHandle ce);
+	void updateMessages(ObjectHandle ce);
 
-	std::optional<std::pair<uint32_t, uint32_t>> selectPeerForRequest(ContentHandle ce);
+	std::optional<std::pair<uint32_t, uint32_t>> selectPeerForRequest(ObjectHandle ce);
 
 	public: // TODO: config
 		bool _udp_only {false};
@@ -122,6 +118,7 @@ class SHA1_NGCFT1 : public RegistryMessageModelEventI, public NGCFT1EventI {
 
 	public:
 		SHA1_NGCFT1(
+			ObjectStore2& os,
 			Contact3Registry& cr,
 			RegistryMessageModel& rmm,
 			NGCFT1& nft,