diff --git a/ngc_ext_common.hpp b/ngc_ext_common.hpp
index 629eb79..962eded 100644
--- a/ngc_ext_common.hpp
+++ b/ngc_ext_common.hpp
@@ -72,13 +72,13 @@ enum _PacketType : uint8_t {
 	// - ]
 	FT1_DATA_ACK,
 
-	// sender has gotten every data fragment acked, so we signal finish
-	// - 1 byte (temporary_file_tf_id)
-	FT1_DATA_FIN,
+	//// sender has gotten every data fragment acked, so we signal finish
+	//// - 1 byte (temporary_file_tf_id)
+	//FT1_DATA_FIN,
 
-	// and we ack that, we need this, so file_id is not reused earlier
-	// - 1 byte (temporary_file_tf_id)
-	FT1_DATA_FIN_ACK,
+	//// and we ack that, we need this, so file_id is not reused earlier
+	//// - 1 byte (temporary_file_tf_id)
+	//FT1_DATA_FIN_ACK,
 };
 
 struct _GroupKey {
diff --git a/ngc_hs1.cpp b/ngc_hs1.cpp
index 0b4d2ca..7bf660d 100644
--- a/ngc_hs1.cpp
+++ b/ngc_hs1.cpp
@@ -71,14 +71,14 @@ void _handle_HS1_RESPONSE_LAST_IDS(
 	size_t length
 );
 
-void _handle_HS1_ft_request_message(
+void _handle_HS1_ft_recv_request(
 	Tox *tox, NGC_EXT_CTX* ngc_ext_ctx,
 	uint32_t group_number,
 	uint32_t peer_number,
 	const uint8_t* file_id, size_t file_id_size
 );
 
-bool _handle_HS1_ft_init_message(
+bool _handle_HS1_ft_recv_init(
 	Tox *tox, NGC_EXT_CTX* ngc_ext_ctx,
 	uint32_t group_number,
 	uint32_t peer_number,
@@ -87,6 +87,15 @@ bool _handle_HS1_ft_init_message(
 	const size_t file_size
 );
 
+void _handle_HS1_ft_recv_data(
+	Tox *tox, NGC_EXT_CTX* ngc_ext_ctx,
+	uint32_t group_number,
+	uint32_t peer_number,
+	uint8_t transfer_id,
+	size_t data_offset,
+	const uint8_t* data, size_t data_size
+);
+
 bool NGC_HS1_init(NGC_EXT_CTX* ngc_ext_ctx, const struct NGC_HS1_options* options) {
 	ngc_ext_ctx->ngc_hs1_ctx = new NGC_HS1;
 	ngc_ext_ctx->ngc_hs1_ctx->options = *options;
@@ -94,8 +103,10 @@ bool NGC_HS1_init(NGC_EXT_CTX* ngc_ext_ctx, const struct NGC_HS1_options* option
 	ngc_ext_ctx->callbacks[HS1_REQUEST_LAST_IDS] = _handle_HS1_REQUEST_LAST_IDS;
 	ngc_ext_ctx->callbacks[HS1_RESPONSE_LAST_IDS] = _handle_HS1_RESPONSE_LAST_IDS;
 
-	NGC_FT1_register_callback_recv_request(ngc_ext_ctx, NGC_FT1_file_kind::NGC_HS1_MESSAGE_BY_ID, _handle_HS1_ft_request_message);
-	NGC_FT1_register_callback_recv_init(ngc_ext_ctx, NGC_FT1_file_kind::NGC_HS1_MESSAGE_BY_ID, _handle_HS1_ft_init_message);
+	NGC_FT1_register_callback_recv_request(ngc_ext_ctx, NGC_FT1_file_kind::NGC_HS1_MESSAGE_BY_ID, _handle_HS1_ft_recv_request);
+	NGC_FT1_register_callback_recv_init(ngc_ext_ctx, NGC_FT1_file_kind::NGC_HS1_MESSAGE_BY_ID, _handle_HS1_ft_recv_init);
+	NGC_FT1_register_callback_recv_data(ngc_ext_ctx, NGC_FT1_file_kind::NGC_HS1_MESSAGE_BY_ID, _handle_HS1_ft_recv_data);
+	//NGC_FT1_register_callback_send_data(ngc_ext_ctx, NGC_FT1_file_kind::NGC_HS1_MESSAGE_BY_ID, _handle_HS1_ft_init_message);
 
 	return true;
 }
@@ -350,7 +361,7 @@ void NGC_HS1_record_message(
 	ngc_hs1_ctx->history[g_id].peers[p_id].append(message_id, type, std::string{message, message+length});
 }
 
-void _handle_HS1_ft_request_message(
+void _handle_HS1_ft_recv_request(
 	Tox *tox, NGC_EXT_CTX* ngc_ext_ctx,
 	uint32_t group_number,
 	uint32_t peer_number,
@@ -411,7 +422,7 @@ void _handle_HS1_ft_request_message(
 	);
 }
 
-bool _handle_HS1_ft_init_message(
+bool _handle_HS1_ft_recv_init(
 	Tox *tox, NGC_EXT_CTX* ngc_ext_ctx,
 	uint32_t group_number,
 	uint32_t peer_number,
@@ -460,12 +471,48 @@ bool _handle_HS1_ft_init_message(
 		return false; // deny
 	}
 
+	// TODO: if allready acked but got init again, they did not get the ack
+
 	// TODO: more?
 	pending.at(msg_id).time_since_ft_activity = 0.f;
+	//pending.at(msg_id).transfer_acked;
+	group.transfers
 
 	return true; // accept
 }
 
+void _handle_HS1_ft_recv_data(
+	Tox *tox, NGC_EXT_CTX* ngc_ext_ctx,
+	uint32_t group_number,
+	uint32_t peer_number,
+	uint8_t transfer_id,
+	size_t data_offset,
+	const uint8_t* data, size_t data_size
+) {
+	// get group id
+	_GroupKey g_id{};
+	{ // TODO: error
+		tox_group_get_chat_id(tox, group_number, g_id.data.data(), nullptr);
+	}
+
+	auto& group = ngc_ext_ctx->ngc_hs1_ctx->history[g_id];
+
+	//auto& pending = group.peers[peer_key].pending;
+	// get based on transfer_id
+	if (!group.transfers.count(std::make_pair(peer_number, transfer_id))) {
+		if (data_offset != 0) {
+			fprintf(stderr, "!! got stray tf data from %d tid:%d\n", peer_number, transfer_id);
+			return;
+		}
+
+		// new transfer?
+		fprintf(stderr, "!! got transfer from %d tid:%d\n", peer_number, transfer_id);
+	}
+
+	// add data to tmp buffer
+	// TODO: data done?
+}
+
 #define _HS1_HAVE(x, error) if ((length - curser) < (x)) { error; }
 
 void _handle_HS1_REQUEST_LAST_IDS(
diff --git a/ngc_hs1.hpp b/ngc_hs1.hpp
index 948cccb..a4b304f 100644
--- a/ngc_hs1.hpp
+++ b/ngc_hs1.hpp
@@ -51,6 +51,17 @@ struct NGC_HS1 {
 
 	struct Group {
 		std::map<_PeerKey, Peer> peers;
+
+		struct FileTransfers {
+			//uint32_t peer_number; // the peer we requested the message from
+			float time_since_ft_activity {0.f};
+			_PeerKey msg_peer;
+			uint32_t msg_id;
+			std::vector<uint8_t> recv_buffer; // message gets dumped into here
+		};
+		// key: peer_number + transfer_id
+		std::map<std::pair<uint32_t, uint8_t>, FileTransfers> transfers;
+
 	};
 
 	std::map<_GroupKey, Group> history;