diff --git a/include/ircd/m/sync.h b/include/ircd/m/sync.h
index 0456ab4d4..f3520c181 100644
--- a/include/ircd/m/sync.h
+++ b/include/ircd/m/sync.h
@@ -42,7 +42,7 @@ namespace ircd::m::sync
 struct ircd::m::sync::item
 :instance_multimap<std::string, item, std::less<>>
 {
-	using handle = std::function<void (data &)>;
+	using handle = std::function<bool (data &)>;
 
 	std::string conf_name[2];
 	conf::item<bool> enable;
@@ -54,9 +54,9 @@ struct ircd::m::sync::item
 	string_view name() const;
 	string_view member_name() const;
 
-	void poll(data &, const m::event &);
-	void linear(data &);
-	void polylog(data &);
+	bool poll(data &, const m::event &);
+	bool linear(data &);
+	bool polylog(data &);
 
 	item(std::string name,
 	     handle polylog    = {},
@@ -90,8 +90,6 @@ struct ircd::m::sync::data
 
 	/// The json::stack master object
 	json::stack out;
-	bool committed {false};
-	bool commit();
 
 	// apropos contextual
 	const m::event *event {nullptr};
diff --git a/ircd/m.cc b/ircd/m.cc
index bd77ced08..1829f720d 100644
--- a/ircd/m.cc
+++ b/ircd/m.cc
@@ -531,13 +531,12 @@ ircd::m::sync::loghead(const data &data)
 
 	return fmt::sprintf
 	{
-		headbuf, "%s %s %lu:%lu %s commit:%b chunk:%zu %s in %s",
+		headbuf, "%s %s %lu:%lu %s chunk:%zu %s in %s",
 		remstr,
 		string_view{data.user.user_id},
 		data.range.first,
 		data.range.second,
 		ircd::pretty(iecbuf[0], iec(flush_bytes + size(data.out.completed()))),
-		data.committed,
 		flush_count,
 		ircd::pretty(iecbuf[1], iec(flush_bytes)),
 		tmstr
@@ -609,14 +608,6 @@ noexcept
 {
 }
 
-bool
-ircd::m::sync::data::commit()
-{
-	const auto ret{committed};
-	committed = true;
-	return ret;
-}
-
 //
 // item
 //
@@ -680,12 +671,12 @@ noexcept
 	};
 }
 
-void
+bool
 ircd::m::sync::item::polylog(data &data)
 try
 {
 	if(!enable)
-		return;
+		return false;
 
 	#ifdef RB_DEBUG
 	sync::stats stats
@@ -699,7 +690,10 @@ try
 		stats.timer = {};
 	#endif
 
-	_polylog(data);
+	const bool ret
+	{
+		_polylog(data)
+	};
 
 	#ifdef RB_DEBUG
 	if(data.stats && (stats_info || stats_debug))
@@ -708,13 +702,16 @@ try
 		thread_local char tmbuf[32];
 		log::debug
 		{
-			log, "polylog %s '%s' %s",
+			log, "polylog %s commit:%b '%s' %s",
 			loghead(data),
+			ret,
 			name(),
 			ircd::pretty(tmbuf, stats.timer.at<microseconds>(), true)
 		};
 	}
 	#endif
+
+	return ret;
 }
 catch(const std::bad_function_call &e)
 {
@@ -725,6 +722,8 @@ catch(const std::bad_function_call &e)
 		name(),
 		e.what()
 	};
+
+	return false;
 }
 catch(const m::error &e)
 {
@@ -736,6 +735,8 @@ catch(const m::error &e)
 		e.what(),
 		e.content
 	};
+
+	return false;
 }
 catch(const std::exception &e)
 {
@@ -750,11 +751,11 @@ catch(const std::exception &e)
 	throw;
 }
 
-void
+bool
 ircd::m::sync::item::linear(data &data)
 try
 {
-	_linear(data);
+	return _linear(data);
 }
 catch(const std::bad_function_call &e)
 {
@@ -766,9 +767,11 @@ catch(const std::bad_function_call &e)
 		name(),
 		e.what()
 	};
+
+	return false;
 }
 
-void
+bool
 ircd::m::sync::item::poll(data &data,
                           const m::event &event)
 try
@@ -778,7 +781,7 @@ try
 		data.event, &event
 	};
 
-	_linear(data);
+	return _linear(data);
 }
 catch(const std::bad_function_call &e)
 {
@@ -790,6 +793,8 @@ catch(const std::bad_function_call &e)
 		name(),
 		e.what()
 	};
+
+	return false;
 }
 
 ircd::string_view
diff --git a/modules/client/sync.cc b/modules/client/sync.cc
index acdb54431..808ab5e69 100644
--- a/modules/client/sync.cc
+++ b/modules/client/sync.cc
@@ -160,7 +160,17 @@ ircd::m::sync::handle_get(client &client,
 void
 ircd::m::sync::empty_response(data &data)
 {
-	data.commit();
+	// Empty objects added to output otherwise Riot b0rks.
+	json::stack::object
+	{
+		data.out, "rooms"
+	};
+
+	json::stack::object
+	{
+		data.out, "presence"
+	};
+
 	json::stack::member
 	{
 		data.out, "next_batch", json::value
@@ -168,10 +178,6 @@ ircd::m::sync::empty_response(data &data)
 			lex_cast(data.range.second), json::STRING
 		}
 	};
-
-	// Empty objects added to output otherwise Riot b0rks.
-	json::stack::object{data.out, "rooms"};
-	json::stack::object{data.out, "presence"};
 }
 
 ircd::const_buffer
@@ -179,12 +185,6 @@ ircd::m::sync::flush(data &data,
                      resource::response::chunked &response,
                      const const_buffer &buffer)
 {
-	if(!data.committed)
-		return const_buffer
-		{
-			buffer::data(buffer), 0UL
-		};
-
 	const size_t wrote
 	{
 		response.write(buffer)
@@ -210,32 +210,53 @@ bool
 ircd::m::sync::polylog::handle(data &data)
 try
 {
-	m::sync::for_each(string_view{}, [&data]
+	json::stack::checkpoint checkpoint
+	{
+		data.out
+	};
+
+	bool ret{false};
+	m::sync::for_each(string_view{}, [&data, &ret]
 	(item &item)
 	{
-		json::stack::member member
+		json::stack::checkpoint checkpoint
+		{
+			data.out
+		};
+
+		json::stack::object object
 		{
 			data.out, item.member_name()
 		};
 
-		item.polylog(data);
+		if(item.polylog(data))
+			ret = true;
+		else
+			checkpoint.rollback();
+
 		return true;
 	});
 
-	json::stack::member
-	{
-		data.out, "next_batch", json::value
+	if(ret)
+		json::stack::member
 		{
-			lex_cast(data.range.second), json::STRING
-		}
-	};
+			data.out, "next_batch", json::value
+			{
+				lex_cast(data.range.second), json::STRING
+			}
+		};
+
+	if(!ret)
+		checkpoint.rollback();
 
 	if(stats_info) log::info
 	{
-		log, "polylog %s complete", loghead(data)
+		log, "polylog %s commit:%b complete",
+		loghead(data),
+		ret
 	};
 
-	return data.committed;
+	return ret;
 }
 catch(const std::exception &e)
 {
@@ -257,7 +278,8 @@ bool
 ircd::m::sync::linear::handle(data &data)
 try
 {
-	m::events::for_each(data.range, [&data]
+	bool ret{false};
+	m::events::for_each(data.range, [&data, &ret]
 	(const m::event::idx &event_idx, const m::event &event)
 	{
 		const scope_restore<decltype(data.event)> theirs
@@ -265,7 +287,7 @@ try
 			data.event, &event
 		};
 
-		m::sync::for_each(string_view{}, [&data]
+		m::sync::for_each(string_view{}, [&data, &ret]
 		(item &item)
 		{
 			json::stack::member member
@@ -273,7 +295,7 @@ try
 				data.out, item.member_name()
 			};
 
-			item.linear(data);
+			ret |= item.linear(data);
 			return true;
 		});
 
@@ -293,7 +315,7 @@ try
 		log, "linear %s complete", loghead(data)
 	};
 
-	return data.committed;
+	return ret;
 }
 catch(const std::exception &e)
 {
diff --git a/modules/client/sync/account_data.cc b/modules/client/sync/account_data.cc
index 88b9445bb..ca4414b04 100644
--- a/modules/client/sync/account_data.cc
+++ b/modules/client/sync/account_data.cc
@@ -17,8 +17,8 @@ IRCD_MODULE
 namespace ircd::m::sync
 {
 	static bool account_data_(data &, const m::event &, const m::event::idx &);
-	static void account_data_polylog(data &);
-	static void account_data_linear(data &);
+	static bool account_data_polylog(data &);
+	static bool account_data_linear(data &);
 
 	extern item account_data;
 }
@@ -31,20 +31,15 @@ ircd::m::sync::account_data
 	account_data_linear
 };
 
-void
+bool
 ircd::m::sync::account_data_linear(data &data)
 {
-
+	return false;
 }
 
-void
+bool
 ircd::m::sync::account_data_polylog(data &data)
 {
-	json::stack::object object
-	{
-		data.out
-	};
-
 	json::stack::array array
 	{
 		data.out, "events"
@@ -60,12 +55,14 @@ ircd::m::sync::account_data_polylog(data &data)
 		data.user_room, &fopts
 	};
 
-	state.for_each("ircd.account_data", [&data, &array]
+	bool ret{false};
+	state.for_each("ircd.account_data", [&data, &array, &ret]
 	(const m::event &event)
 	{
-		if(account_data_(data, event, index(event)))
-			data.commit();
+		ret |= account_data_(data, event, index(event));
 	});
+
+	return ret;
 }
 
 bool
@@ -82,8 +79,6 @@ ircd::m::sync::account_data_(data &data,
 	if(json::get<"room_id"_>(event) != data.user_room.room_id)
 		return false;
 
-	data.commit();
-
 	// Each account_data event is an object in the events array
 	json::stack::object object
 	{
diff --git a/modules/client/sync/device_lists.cc b/modules/client/sync/device_lists.cc
index 1bd344e9b..10678210f 100644
--- a/modules/client/sync/device_lists.cc
+++ b/modules/client/sync/device_lists.cc
@@ -16,8 +16,8 @@ IRCD_MODULE
 
 namespace ircd::m::sync
 {
-	static void device_lists_polylog(data &);
-	static void device_lists_linear(data &);
+	static bool device_lists_polylog(data &);
+	static bool device_lists_linear(data &);
 
 	extern item device_lists;
 }
@@ -30,20 +30,15 @@ ircd::m::sync::device_lists
 	device_lists_linear
 };
 
-void
+bool
 ircd::m::sync::device_lists_linear(data &data)
 {
-
+	return false;
 }
 
-void
+bool
 ircd::m::sync::device_lists_polylog(data &data)
 {
-	json::stack::object object
-	{
-		data.out
-	};
-
 	json::stack::array
 	{
 		data.out, "changed"
@@ -53,4 +48,6 @@ ircd::m::sync::device_lists_polylog(data &data)
 	{
 		data.out, "left"
 	};
+
+	return false;
 }
diff --git a/modules/client/sync/device_one_time_keys_count.cc b/modules/client/sync/device_one_time_keys_count.cc
index f492bfea3..10251fa43 100644
--- a/modules/client/sync/device_one_time_keys_count.cc
+++ b/modules/client/sync/device_one_time_keys_count.cc
@@ -16,8 +16,8 @@ IRCD_MODULE
 
 namespace ircd::m::sync
 {
-	static void device_one_time_keys_count_polylog(data &);
-	static void device_one_time_keys_count_linear(data &);
+	static bool device_one_time_keys_count_polylog(data &);
+	static bool device_one_time_keys_count_linear(data &);
 
 	extern item device_one_time_keys_count;
 }
@@ -30,18 +30,14 @@ ircd::m::sync::device_one_time_keys_count
 	device_one_time_keys_count_linear
 };
 
-void
+bool
 ircd::m::sync::device_one_time_keys_count_linear(data &data)
 {
-
+	return false;
 }
 
-void
+bool
 ircd::m::sync::device_one_time_keys_count_polylog(data &data)
 {
-	json::stack::object object
-	{
-		data.out
-	};
-
+	return false;
 }
diff --git a/modules/client/sync/presence.cc b/modules/client/sync/presence.cc
index b5691f37b..4f37606fa 100644
--- a/modules/client/sync/presence.cc
+++ b/modules/client/sync/presence.cc
@@ -16,11 +16,11 @@ IRCD_MODULE
 
 namespace ircd::m::sync
 {
-	static void presence_polylog_events(data &);
-	static void presence_polylog(data &);
+	static bool presence_polylog_events(data &);
+	static bool presence_polylog(data &);
 
-	static void presence_linear_events(data &);
-	static void presence_linear(data &);
+	static bool presence_linear_events(data &);
+	static bool presence_linear(data &);
 
 	extern item presence;
 }
@@ -33,11 +33,9 @@ ircd::m::sync::presence
 	presence_linear,
 };
 
-void
+bool
 ircd::m::sync::presence_linear(data &data)
 {
-	return;
-
 	assert(data.event);
 	const m::event &event
 	{
@@ -45,10 +43,10 @@ ircd::m::sync::presence_linear(data &data)
 	};
 
 	if(json::get<"type"_>(event) != "ircd.presence")
-		return;
+		return false;
 
 	if(json::get<"sender"_>(event) != m::me.user_id)
-		return;
+		return false;
 
 	// sender
 	json::stack::member
@@ -68,21 +66,16 @@ ircd::m::sync::presence_linear(data &data)
 		data.out, "content", at<"content"_>(event)
 	};
 
-	return;
+	return true;
 }
 
-void
+bool
 ircd::m::sync::presence_polylog(data &data)
 {
-	json::stack::object object
-	{
-		data.out
-	};
-
-	presence_polylog_events(data);
+	return presence_polylog_events(data);
 }
 
-void
+bool
 ircd::m::sync::presence_polylog_events(data &data)
 {
 	json::stack::array array
@@ -90,16 +83,17 @@ ircd::m::sync::presence_polylog_events(data &data)
 		data.out, "events"
 	};
 
+	bool ret{false};
 	ctx::mutex mutex;
-	const auto append_event{[&data, &array, &mutex]
+	const auto append_event{[&data, &array, &mutex, &ret]
 	(const json::object &event)
 	{
 		// Lock the json::stack for the append operations. This mutex will only be
 		// contended during a json::stack flush to the client; not during database
 		// queries leading to this.
 		const std::lock_guard<decltype(mutex)> l{mutex};
+		ret = true;
 
-		data.commit();
 		json::stack::object object
 		{
 			array
@@ -158,4 +152,6 @@ ircd::m::sync::presence_polylog_events(data &data)
 		q[pos] = strlcpy(buf->at(pos), user.user_id);
 		parallel();
 	});
+
+	return ret;
 }
diff --git a/modules/client/sync/rooms.cc b/modules/client/sync/rooms.cc
index b09ef3e2c..185c5164b 100644
--- a/modules/client/sync/rooms.cc
+++ b/modules/client/sync/rooms.cc
@@ -16,12 +16,12 @@ IRCD_MODULE
 
 namespace ircd::m::sync
 {
-	static void _rooms_polylog_room(data &, const m::room &);
-	static void _rooms_polylog(data &, const string_view &membership);
-	static void rooms_polylog(data &);
+	static bool _rooms_polylog_room(data &, const m::room &);
+	static bool _rooms_polylog(data &, const string_view &membership);
+	static bool rooms_polylog(data &);
 
-	static void _rooms_linear(data &, const string_view &membership);
-	static void rooms_linear(data &);
+	static bool _rooms_linear(data &, const string_view &membership);
+	static bool rooms_linear(data &);
 
 	extern item rooms;
 }
@@ -34,17 +34,33 @@ ircd::m::sync::rooms
 	rooms_linear
 };
 
-void
+bool
 ircd::m::sync::rooms_linear(data &data)
 {
-	json::stack::object object{data.out};
-	_rooms_linear(data, "invite");
-	_rooms_linear(data, "join");
-	_rooms_linear(data, "leave");
-	_rooms_linear(data, "ban");
+	assert(data.event);
+	const auto &event{*data.event};
+	if(!json::get<"room_id"_>(event))
+		return false;
+
+	const m::room room
+	{
+		json::get<"room_id"_>(event)
+	};
+
+	const scope_restore<decltype(data.room)> theirs
+	{
+		data.room, &room
+	};
+
+	bool ret{false};
+	ret |= _rooms_linear(data, "invite");
+	ret |= _rooms_linear(data, "join");
+	ret |= _rooms_linear(data, "leave");
+	ret |= _rooms_linear(data, "ban");
+	return ret;
 }
 
-void
+bool
 ircd::m::sync::_rooms_linear(data &data,
                              const string_view &membership)
 {
@@ -53,30 +69,34 @@ ircd::m::sync::_rooms_linear(data &data,
 		data.membership, membership
 	};
 
-	m::sync::for_each("rooms", [&](item &item)
+	bool ret{false};
+	m::sync::for_each("rooms", [&data, &ret]
+	(item &item)
 	{
-		json::stack::member member
+		json::stack::object object
 		{
 			data.out, item.member_name()
 		};
 
-		item.linear(data);
+		ret |= item.linear(data);
 		return true;
 	});
+
+	return ret;
 }
 
-void
+bool
 ircd::m::sync::rooms_polylog(data &data)
 {
-	json::stack::object object{data.out};
-	_rooms_polylog(data, "invite");
-	_rooms_polylog(data, "join");
-	_rooms_polylog(data, "leave");
-	_rooms_polylog(data, "ban");
-	return;
+	bool ret{false};
+	ret |= _rooms_polylog(data, "invite");
+	ret |= _rooms_polylog(data, "join");
+	ret |= _rooms_polylog(data, "leave");
+	ret |= _rooms_polylog(data, "ban");
+	return ret;
 }
 
-void
+bool
 ircd::m::sync::_rooms_polylog(data &data,
                               const string_view &membership)
 {
@@ -85,12 +105,18 @@ ircd::m::sync::_rooms_polylog(data &data,
 		data.membership, membership
 	};
 
+	json::stack::checkpoint checkpoint
+	{
+		data.out
+	};
+
 	json::stack::object object
 	{
 		data.out, membership
 	};
 
-	data.user_rooms.for_each(membership, [&data]
+	bool ret{false};
+	data.user_rooms.for_each(membership, [&data, &ret]
 	(const m::room &room, const string_view &membership_)
 	{
 		#if defined(RB_DEBUG) && 0
@@ -105,7 +131,7 @@ ircd::m::sync::_rooms_polylog(data &data,
 			stats.timer = timer{};
 		#endif
 
-		_rooms_polylog_room(data, room);
+		ret |= _rooms_polylog_room(data, room);
 
 		#if defined(RB_DEBUG) && 0
 		thread_local char tmbuf[32];
@@ -118,9 +144,14 @@ ircd::m::sync::_rooms_polylog(data &data,
 		};
 		#endif
 	});
+
+	if(!ret)
+		checkpoint.rollback();
+
+	return ret;
 }
 
-void
+bool
 ircd::m::sync::_rooms_polylog_room(data &data,
                                    const m::room &room)
 {
@@ -129,6 +160,11 @@ ircd::m::sync::_rooms_polylog_room(data &data,
 		data.room, &room
 	};
 
+	json::stack::checkpoint checkpoint
+	{
+		data.out
+	};
+
 	json::stack::object object
 	{
 		data.out, room.room_id
@@ -144,15 +180,30 @@ ircd::m::sync::_rooms_polylog_room(data &data,
 		data.room_head, room_head
 	};
 
-	m::sync::for_each("rooms", [&data]
+	bool ret{false};
+	m::sync::for_each("rooms", [&data, &ret]
 	(item &item)
 	{
+		json::stack::checkpoint checkpoint
+		{
+			data.out
+		};
+
 		json::stack::object object
 		{
 			data.out, item.member_name()
 		};
 
-		item.polylog(data);
+		if(item.polylog(data))
+			ret = true;
+		else
+			checkpoint.rollback();
+
 		return true;
 	});
+
+	if(!ret)
+		checkpoint.rollback();
+
+	return ret;
 }
diff --git a/modules/client/sync/rooms/account_data.cc b/modules/client/sync/rooms/account_data.cc
index bdbe80242..06ae6d7e3 100644
--- a/modules/client/sync/rooms/account_data.cc
+++ b/modules/client/sync/rooms/account_data.cc
@@ -16,9 +16,9 @@ IRCD_MODULE
 
 namespace ircd::m::sync
 {
-	static void room_account_data_polylog_events_event(data &, const m::event &);
-	static void room_account_data_polylog_events(data &);
-	static void room_account_data_polylog(data &);
+	static bool room_account_data_polylog_events_event(data &, const m::event &);
+	static bool room_account_data_polylog_events(data &);
+	static bool room_account_data_polylog(data &);
 
 	extern item room_account_data;
 }
@@ -30,13 +30,13 @@ ircd::m::sync::room_account_data
 	room_account_data_polylog
 };
 
-void
+bool
 ircd::m::sync::room_account_data_polylog(data &data)
 {
-	room_account_data_polylog_events(data);
+	return room_account_data_polylog_events(data);
 }
 
-void
+bool
 ircd::m::sync::room_account_data_polylog_events(data &data)
 {
 	json::stack::array array
@@ -61,19 +61,21 @@ ircd::m::sync::room_account_data_polylog_events(data &data)
 		data.user_room, &fopts
 	};
 
-	state.for_each(type, [&data]
+	bool ret{false};
+	state.for_each(type, [&data, &ret]
 	(const m::event &event)
 	{
 		if(apropos(data, event))
-			room_account_data_polylog_events_event(data, event);
+			ret |= room_account_data_polylog_events_event(data, event);
 	});
+
+	return ret;
 }
 
-void
+bool
 ircd::m::sync::room_account_data_polylog_events_event(data &data,
                                                       const m::event &event)
 {
-	data.commit();
 	json::stack::object object
 	{
 		data.out
@@ -88,4 +90,6 @@ ircd::m::sync::room_account_data_polylog_events_event(data &data,
 	{
 		object, "content", at<"content"_>(event)
 	};
+
+	return true;
 }
diff --git a/modules/client/sync/rooms/ephemeral.cc b/modules/client/sync/rooms/ephemeral.cc
index 7cb8d3abc..bc060a713 100644
--- a/modules/client/sync/rooms/ephemeral.cc
+++ b/modules/client/sync/rooms/ephemeral.cc
@@ -16,9 +16,9 @@ IRCD_MODULE
 
 namespace ircd::m::sync
 {
-	static void rooms_ephemeral_events_polylog(data &);
-	static void rooms_ephemeral_polylog(data &);
-	static void rooms_ephemeral_linear(data &);
+	static bool rooms_ephemeral_events_polylog(data &);
+	static bool rooms_ephemeral_polylog(data &);
+	static bool rooms_ephemeral_linear(data &);
 	extern item rooms_ephemeral;
 }
 
@@ -30,19 +30,19 @@ ircd::m::sync::rooms_ephemeral
 	rooms_ephemeral_linear
 };
 
-void
+bool
 ircd::m::sync::rooms_ephemeral_linear(data &data)
 {
-
+	return false;
 }
 
-void
+bool
 ircd::m::sync::rooms_ephemeral_polylog(data &data)
 {
-	rooms_ephemeral_events_polylog(data);
+	return rooms_ephemeral_events_polylog(data);
 }
 
-void
+bool
 ircd::m::sync::rooms_ephemeral_events_polylog(data &data)
 {
 	json::stack::array array
@@ -50,10 +50,22 @@ ircd::m::sync::rooms_ephemeral_events_polylog(data &data)
 		data.out, "events"
 	};
 
-	m::sync::for_each("rooms.ephemeral", [&]
+	bool ret{false};
+	m::sync::for_each("rooms.ephemeral", [&data, &ret]
 	(item &item)
 	{
-		item.polylog(data);
+		json::stack::checkpoint checkpoint
+		{
+			data.out
+		};
+
+		if(item.polylog(data))
+			ret = true;
+		else
+			checkpoint.rollback();
+
 		return true;
 	});
+
+	return ret;
 }
diff --git a/modules/client/sync/rooms/ephemeral/receipt.cc b/modules/client/sync/rooms/ephemeral/receipt.cc
index 10d2ecb51..1bb5dfd7f 100644
--- a/modules/client/sync/rooms/ephemeral/receipt.cc
+++ b/modules/client/sync/rooms/ephemeral/receipt.cc
@@ -16,9 +16,9 @@ IRCD_MODULE
 
 namespace ircd::m::sync
 {
-	static void _handle_message_receipt(data &, const m::event &);
-	static void _handle_message(data &, const m::event::idx &);
-	static void room_ephemeral_m_receipt_m_read_polylog(data &);
+	static bool _handle_message_receipt(data &, const m::event &);
+	static bool _handle_message(data &, const m::event::idx &);
+	static bool room_ephemeral_m_receipt_m_read_polylog(data &);
 	extern item room_ephemeral_m_receipt_m_read;
 }
 
@@ -29,7 +29,7 @@ ircd::m::sync::room_ephemeral_m_receipt_m_read
 	room_ephemeral_m_receipt_m_read_polylog
 };
 
-void
+bool
 ircd::m::sync::room_ephemeral_m_receipt_m_read_polylog(data &data)
 {
 	const m::room &room{*data.room};
@@ -54,17 +54,24 @@ ircd::m::sync::room_ephemeral_m_receipt_m_read_polylog(data &data)
 	if(i > 0 && !it && idx)
 		it.seek(idx);
 
+	bool ret{false};
 	if(i > 0 && idx)
 		for(; it && i > -1; ++it, --i)
-			_handle_message(data, it.event_idx());
+			ret |= _handle_message(data, it.event_idx());
+
+	return ret;
 }
 
-void
+bool
 ircd::m::sync::_handle_message(data &data,
                                const event::idx &idx)
 {
+	bool ret{false};
+	if(!apropos(data, idx))
+		return ret;
+
 	const event::refs refs{idx};
-	refs.for_each(dbs::ref::M_RECEIPT__M_READ, [&data]
+	refs.for_each(dbs::ref::M_RECEIPT__M_READ, [&data, &ret]
 	(const event::idx &idx, const auto &type)
 	{
 		assert(type == dbs::ref::M_RECEIPT__M_READ);
@@ -79,17 +86,18 @@ ircd::m::sync::_handle_message(data &data,
 		};
 
 		if(event.valid)
-			_handle_message_receipt(data, event);
+			ret |= _handle_message_receipt(data, event);
 
 		return true;
 	});
+
+	return ret;
 }
 
-void
+bool
 ircd::m::sync::_handle_message_receipt(data &data,
                                        const m::event &event)
 {
-	data.commit();
 	const json::object content
 	{
 		at<"content"_>(event)
@@ -131,4 +139,6 @@ ircd::m::sync::_handle_message_receipt(data &data,
 	{
 		sender_, "ts", json::value(content.at("ts"))
 	};
+
+	return true;
 }
diff --git a/modules/client/sync/rooms/state.cc b/modules/client/sync/rooms/state.cc
index a5ae611e4..25dc651ee 100644
--- a/modules/client/sync/rooms/state.cc
+++ b/modules/client/sync/rooms/state.cc
@@ -10,11 +10,11 @@
 
 namespace ircd::m::sync
 {
-	static void room_state_polylog_events(data &);
-	static void room_state_polylog(data &);
+	static bool room_state_polylog_events(data &);
+	static bool room_state_polylog(data &);
 
-	static void room_state_linear_events(data &);
-	static void room_state_linear(data &);
+	static bool room_state_linear_events(data &);
+	static bool room_state_linear(data &);
 
 	extern const event::keys::include _default_keys;
 	extern event::fetch::opts _default_fopts;
@@ -59,7 +59,7 @@ ircd::m::sync::_default_fopts
 	_default_keys
 };
 
-void
+bool
 ircd::m::sync::room_state_linear(data &data)
 {
 	assert(data.event);
@@ -67,22 +67,25 @@ ircd::m::sync::room_state_linear(data &data)
 	assert(json::get<"room_id"_>(*data.event));
 
 	if(!json::get<"state_key"_>(*data.event))
-		return;
+		return false;
 
 	if(!data.room->membership(data.user, data.membership))
-		return;
+		return false;
 
 	//data.array->append(*data.event);
+	return false;
 }
 
-void
+bool
 ircd::m::sync::room_state_polylog(data &data)
 {
-	if(apropos(data, data.room_head))
-		room_state_polylog_events(data);
+	if(!apropos(data, data.room_head))
+		return false;
+
+	return room_state_polylog_events(data);
 }
 
-void
+bool
 ircd::m::sync::room_state_polylog_events(data &data)
 {
 	const m::room &room{*data.room};
@@ -92,8 +95,9 @@ ircd::m::sync::room_state_polylog_events(data &data)
 		data.out, "events"
 	};
 
+	bool ret{false};
 	ctx::mutex mutex;
-	const event::closure_idx each_idx{[&data, &array, &mutex]
+	const event::closure_idx each_idx{[&data, &array, &mutex, &ret]
 	(const m::event::idx event_idx)
 	{
 		const event::fetch event
@@ -106,8 +110,8 @@ ircd::m::sync::room_state_polylog_events(data &data)
 			return;
 
 		const std::lock_guard<decltype(mutex)> lock{mutex};
-		data.commit();
 		array.append(event);
+		ret = true;
 	}};
 
 	//TODO: conf
@@ -123,4 +127,6 @@ ircd::m::sync::room_state_polylog_events(data &data)
 		if(apropos(data, event_idx))
 			parallel(event_idx);
 	});
+
+	return ret;
 }
diff --git a/modules/client/sync/rooms/timeline.cc b/modules/client/sync/rooms/timeline.cc
index c1ae66438..1dd2c38df 100644
--- a/modules/client/sync/rooms/timeline.cc
+++ b/modules/client/sync/rooms/timeline.cc
@@ -16,11 +16,11 @@ IRCD_MODULE
 
 namespace ircd::m::sync
 {
-	static event::id::buf _room_timeline_polylog_events(data &, const m::room &, bool &);
-	static void room_timeline_polylog(data &);
+	static event::id::buf _room_timeline_polylog_events(data &, const m::room &, bool &, bool &);
+	static bool room_timeline_polylog(data &);
 
 	static event::id::buf _room_timeline_linear_events(data &, const m::room &, bool &);
-	static void room_timeline_linear(data &);
+	static bool room_timeline_linear(data &);
 
 	extern const event::keys::include default_keys;
 	extern item room_timeline;
@@ -49,11 +49,9 @@ ircd::m::sync::default_keys
 	"type",
 };
 
-void
+bool
 ircd::m::sync::room_timeline_linear(data &data)
 {
-	return;
-
 	json::stack::object object
 	{
 		data.out
@@ -80,7 +78,7 @@ ircd::m::sync::room_timeline_linear(data &data)
 		object, "limited", json::value{limited}
 	};
 
-	return;
+	return false;
 }
 
 ircd::m::event::id::buf
@@ -96,18 +94,18 @@ ircd::m::sync::_room_timeline_linear_events(data &data,
 	return {};
 }
 
-void
+bool
 ircd::m::sync::room_timeline_polylog(data &data)
 {
 	if(!apropos(data, data.room_head))
-		return;
+		return false;
 
 	// events
 	assert(data.room);
-	bool limited{false};
+	bool limited{false}, ret{false};
 	m::event::id::buf prev
 	{
-		_room_timeline_polylog_events(data, *data.room, limited)
+		_room_timeline_polylog_events(data, *data.room, limited, ret)
 	};
 
 	// prev_batch
@@ -121,12 +119,15 @@ ircd::m::sync::room_timeline_polylog(data &data)
 	{
 		data.out, "limited", json::value{limited}
 	};
+
+	return ret;
 }
 
 ircd::m::event::id::buf
 ircd::m::sync::_room_timeline_polylog_events(data &data,
                                              const m::room &room,
-                                             bool &limited)
+                                             bool &limited,
+                                             bool &ret)
 {
 	static const event::fetch::opts fopts
 	{
@@ -159,23 +160,12 @@ ircd::m::sync::_room_timeline_polylog_events(data &data,
 	}
 
 	limited = i >= 10;
-	if(i > 0)
-		data.commit();
-
 	if(i > 0 && !it)
 		it.seek(event_id);
 
-	if(i > 0 && it)
-	{
-		data.commit();
-		//const m::event &event{*it};
-		//data.state_at = at<"depth"_>(event);
-	}
-
 	if(i > 0)
 		for(; it && i > -1; ++it, --i)
 		{
-			data.commit();
 			json::stack::object object
 			{
 				array
@@ -183,6 +173,7 @@ ircd::m::sync::_room_timeline_polylog_events(data &data,
 
 			const m::event &event(*it);
 			object.append(event);
+			ret = true;
 
 			json::stack::object unsigned_
 			{
diff --git a/modules/client/sync/rooms/unread_notifications.cc b/modules/client/sync/rooms/unread_notifications.cc
index e80f583c2..b45c9b22a 100644
--- a/modules/client/sync/rooms/unread_notifications.cc
+++ b/modules/client/sync/rooms/unread_notifications.cc
@@ -18,8 +18,8 @@ namespace ircd::m::sync
 {
 	static long _notification_count(const room &, const event::idx &a, const event::idx &b);
 	static long _highlight_count(const room &, const user &u, const event::idx &a, const event::idx &b);
-	static void room_unread_notifications_polylog(data &);
-	static void room_unread_notifications_linear(data &);
+	static bool room_unread_notifications_polylog(data &);
+	static bool room_unread_notifications_linear(data &);
 	extern item room_unread_notifications;
 }
 
@@ -31,25 +31,28 @@ ircd::m::sync::room_unread_notifications
 	room_unread_notifications_linear
 };
 
-void
+bool
 ircd::m::sync::room_unread_notifications_linear(data &data)
 {
-
+	return false;
 }
 
-void
+bool
 ircd::m::sync::room_unread_notifications_polylog(data &data)
 {
 	const auto &room{*data.room};
 	m::event::id::buf last_read;
 	if(!m::receipt::read(last_read, room.room_id, data.user))
-		return;
+		return false;
 
 	const auto start_idx
 	{
 		index(last_read)
 	};
 
+	if(!apropos(data, start_idx))
+		return false;
+
 	// highlight_count
 	json::stack::member
 	{
@@ -68,7 +71,7 @@ ircd::m::sync::room_unread_notifications_polylog(data &data)
 		}
 	};
 
-	data.commit();
+	return true;
 }
 
 long
diff --git a/modules/client/sync/to_device.cc b/modules/client/sync/to_device.cc
index 315e2c0ce..edfe79aca 100644
--- a/modules/client/sync/to_device.cc
+++ b/modules/client/sync/to_device.cc
@@ -16,8 +16,8 @@ IRCD_MODULE
 
 namespace ircd::m::sync
 {
-	static void to_device_polylog(data &);
-	static void to_device_linear(data &);
+	static bool to_device_polylog(data &);
+	static bool to_device_linear(data &);
 
 	extern item to_device;
 }
@@ -30,20 +30,15 @@ ircd::m::sync::to_device
 	to_device_linear
 };
 
-void
+bool
 ircd::m::sync::to_device_linear(data &data)
 {
-
+	return false;
 }
 
-void
+bool
 ircd::m::sync::to_device_polylog(data &data)
 {
-	json::stack::object object
-	{
-		data.out
-	};
-
 	json::stack::array array
 	{
 		data.out, "events"
@@ -59,6 +54,7 @@ ircd::m::sync::to_device_polylog(data &data)
 		user_room
 	};
 
+	bool ret{false};
 	for(; it; ++it)
 	{
 		const auto &event_idx(it.event_idx());
@@ -75,10 +71,9 @@ ircd::m::sync::to_device_polylog(data &data)
 		if(!relevant)
 			continue;
 
-		m::get(std::nothrow, event_idx, "content", [&data, &array]
+		m::get(std::nothrow, event_idx, "content", [&data, &array, &ret]
 		(const json::object &content)
 		{
-			data.commit();
 			json::stack::object event
 			{
 				array
@@ -109,6 +104,10 @@ ircd::m::sync::to_device_polylog(data &data)
 				{
 					content_, property, value
 				};
+
+			ret = true;
 		});
 	}
+
+	return ret;
 }