diff --git a/include/ircd/m/sync.h b/include/ircd/m/sync.h
index 1d090aae3..f1002ed66 100644
--- a/include/ircd/m/sync.h
+++ b/include/ircd/m/sync.h
@@ -22,7 +22,6 @@ namespace ircd::m::sync
 	struct stats;
 	struct data;
 	struct item;
-	struct response;
 	using item_closure = std::function<void (item &)>;
 	using item_closure_bool = std::function<bool (item &)>;
 
@@ -42,7 +41,7 @@ namespace ircd::m::sync
 struct ircd::m::sync::item
 :instance_multimap<std::string, item, std::less<>>
 {
-	using handle = std::function<bool (data &)>;
+	using handle = std::function<void (data &)>;
 
 	handle _polylog;
 	handle _linear;
@@ -51,9 +50,9 @@ struct ircd::m::sync::item
 	string_view name() const;
 	string_view member_name() const;
 
-	bool poll(data &, const m::event &);
-	bool linear(data &);
-	bool polylog(data &);
+	void poll(data &, const m::event &);
+	void linear(data &);
+	void polylog(data &);
 
 	item(std::string name,
 	     handle polylog    = {},
@@ -66,27 +65,28 @@ struct ircd::m::sync::item
 
 struct ircd::m::sync::data
 {
-	sync::stats &stats;
-	ircd::client &client;
+	/// Range to synchronize. Starting index is inclusive, ending index is
+	/// exclusive. Generally the starting index is a since token, and ending
+	/// index is one beyond the vm::current_sequence and used for next_batch.
+	m::events::range range;
 
-	// Range related
-	const uint64_t &since;
-	const uint64_t current;
+	/// Statistics tracking. If null, stats won't be accumulated for the sync.
+	sync::stats *stats {nullptr};
+
+	/// The client. This may be null if sync is being called internally.
+	ircd::client *client {nullptr};
 
 	// User related
 	const m::user user;
 	const m::user::room user_room;
 	const m::room::state user_state;
 	const m::user::rooms user_rooms;
-
-	// Filter to use
 	const std::string filter_buf;
 	const m::filter filter;
 
-	// response state
-	const std::unique_ptr<response> resp;
+	/// The json::stack master object
 	json::stack out;
-	bool committed() const;
+	bool committed {false};
 	bool commit();
 
 	// apropos contextual
@@ -94,11 +94,14 @@ struct ircd::m::sync::data
 	const m::room *room {nullptr};
 	string_view membership;
 
-	data(sync::stats &stats,
-	     ircd::client &client,
-	     const m::user &user,
-	     const std::pair<event::idx, event::idx> &range,
-	     const string_view &filter_id);
+	data(const m::user &user,
+	     const m::events::range &range,
+	     const mutable_buffer &,
+	     json::stack::flush_callback,
+	     const size_t &flush_hiwat = 64_KiB,
+	     ircd::client *const &client = nullptr,
+	     sync::stats *const &stats = nullptr,
+	     const string_view &filter_id = {});
 
 	data(data &&) = delete;
 	data(const data &) = delete;
diff --git a/ircd/m/m.cc b/ircd/m/m.cc
index b711b8fc9..8c38311f2 100644
--- a/ircd/m/m.cc
+++ b/ircd/m/m.cc
@@ -485,132 +485,83 @@ bool
 ircd::m::sync::apropos(const data &d,
                        const event::idx &event_idx)
 {
-	return d.since <= event_idx && d.current >= event_idx;
+	return event_idx >= d.range.first &&
+	       event_idx < d.range.second;
 }
 
 ircd::string_view
 ircd::m::sync::loghead(const data &data)
 {
 	thread_local char headbuf[256], rembuf[128], iecbuf[2][64], tmbuf[32];
+
+	const auto remstr
+	{
+		data.client?
+			string(rembuf, ircd::remote(*data.client)):
+			string_view{}
+	};
+
+	const auto flush_bytes
+	{
+		data.stats?
+			data.stats->flush_bytes:
+			0U
+	};
+
+	const auto flush_count
+	{
+		data.stats?
+			data.stats->flush_count:
+			0U
+	};
+
+	const auto tmstr
+	{
+		data.stats?
+			ircd::pretty(tmbuf, data.stats->timer.at<milliseconds>(), true):
+			string_view{}
+	};
+
 	return fmt::sprintf
 	{
 		headbuf, "%s %s %lu:%lu %s chunk:%zu %s in %s",
-		string(rembuf, ircd::remote(data.client)),
+		remstr,
 		string_view{data.user.user_id},
-		data.since,
-		data.current,
-		ircd::pretty(iecbuf[0], iec(data.stats.flush_bytes + size(data.out.completed()))),
-		data.stats.flush_count,
-		ircd::pretty(iecbuf[1], iec(data.stats.flush_bytes)),
-		ircd::pretty(tmbuf, data.stats.timer.at<milliseconds>(), true),
+		data.range.first,
+		data.range.second,
+		ircd::pretty(iecbuf[0], iec(flush_bytes + size(data.out.completed()))),
+		flush_count,
+		ircd::pretty(iecbuf[1], iec(flush_bytes)),
+		tmstr
 	};
 }
 
-//
-// response
-//
-
-struct ircd::m::sync::response
-{
-	static conf::item<size_t> flush_hiwat;
-
-	sync::stats &stats;
-	ircd::client &client;
-	unique_buffer<mutable_buffer> buf;
-	std::unique_ptr<resource::response::chunked> resp;
-	bool committed;
-
-	const_buffer flush(const const_buffer &buf);
-	void commit();
-
-	response(sync::stats &stats, ircd::client &client);
-	~response() noexcept;
-};
-
-decltype(ircd::m::sync::response::flush_hiwat)
-ircd::m::sync::response::flush_hiwat
-{
-    { "name",     "ircd.m.sync.flush.hiwat"  },
-    { "default",  long(32_KiB)               },
-};
-
-//
-// response::response
-//
-
-ircd::m::sync::response::response(sync::stats &stats,
-                                  ircd::client &client)
-:stats
-{
-	stats
-}
-,client
-{
-	client
-}
-,buf
-{
-	std::max(size_t(96_KiB), size_t(flush_hiwat))
-}
-,committed
-{
-	false
-}
-{
-}
-
-ircd::m::sync::response::~response()
-noexcept
-{
-}
-
-ircd::const_buffer
-ircd::m::sync::response::flush(const const_buffer &buf)
-{
-	if(!committed)
-		return buf;
-
-	if(!resp)
-		commit();
-
-	stats.flush_bytes += resp->write(buf);
-	stats.flush_count++;
-	return buf;
-}
-
-void
-ircd::m::sync::response::commit()
-{
-	static const string_view content_type
-	{
-		"application/json; charset=utf-8"
-	};
-
-	assert(!resp);
-	resp = std::make_unique<resource::response::chunked>
-	(
-		client, http::OK, content_type
-	);
-}
-
 //
 // data
 //
 
-ircd::m::sync::data::data(sync::stats &stats,
-                          ircd::client &client,
-                          const m::user &user,
-                          const std::pair<event::idx, event::idx> &range,
-                          const string_view &filter_id)
-:stats{stats}
-,client{client}
-,since
+ircd::m::sync::data::data
+(
+	const m::user &user,
+	const m::events::range &range,
+	const mutable_buffer &buf,
+	json::stack::flush_callback flusher,
+	const size_t &flush_hiwat,
+	ircd::client *const &client,
+	sync::stats *const &stats,
+	const string_view &filter_id
+)
+:range
 {
-	range.first
+	range
 }
-,current
+,stats
 {
-	range.second
+	stats
+}
+,client
+{
+	client
 }
 ,user
 {
@@ -638,13 +589,9 @@ ircd::m::sync::data::data(sync::stats &stats,
 {
 	json::object{filter_buf}
 }
-,resp
-{
-	std::make_unique<response>(stats, client)
-}
 ,out
 {
-	resp->buf, std::bind(&response::flush, resp.get(), ph::_1), size_t(resp->flush_hiwat)
+	buf, std::move(flusher), flush_hiwat
 }
 {
 }
@@ -657,20 +604,11 @@ noexcept
 bool
 ircd::m::sync::data::commit()
 {
-	assert(resp);
-	const auto ret{resp->committed};
-	resp->committed = true;
+	const auto ret{committed};
+	committed = true;
 	return ret;
 }
 
-bool
-ircd::m::sync::data::committed()
-const
-{
-	assert(resp);
-	return resp->committed;
-}
-
 //
 // item
 //
@@ -719,33 +657,38 @@ noexcept
 	};
 }
 
-bool
+void
 ircd::m::sync::item::polylog(data &data)
 try
 {
 	#ifdef RB_DEBUG
-	sync::stats stats{data.stats};
-	stats.timer = {};
+	sync::stats stats
+	{
+		data.stats?
+			*data.stats:
+			sync::stats{}
+	};
+
+	if(data.stats)
+		stats.timer = {};
 	#endif
 
-	const bool ret
-	{
-		_polylog(data)
-	};
+	_polylog(data);
 
 	#ifdef RB_DEBUG
-	//data.out.flush();
-	thread_local char tmbuf[32];
-	log::debug
+	if(data.stats)
 	{
-		log, "polylog %s '%s' %s",
-		loghead(data),
-		name(),
-		ircd::pretty(tmbuf, stats.timer.at<microseconds>(), true)
-	};
+		//data.out.flush();
+		thread_local char tmbuf[32];
+		log::debug
+		{
+			log, "polylog %s '%s' %s",
+			loghead(data),
+			name(),
+			ircd::pretty(tmbuf, stats.timer.at<microseconds>(), true)
+		};
+	}
 	#endif
-
-	return ret;
 }
 catch(const std::bad_function_call &e)
 {
@@ -756,8 +699,6 @@ catch(const std::bad_function_call &e)
 		name(),
 		e.what()
 	};
-
-	return false;
 }
 catch(const std::exception &e)
 {
@@ -772,33 +713,25 @@ catch(const std::exception &e)
 	throw;
 }
 
-bool
+void
 ircd::m::sync::item::linear(data &data)
 try
 {
-	const auto ret
-	{
-		_linear(data)
-	};
-
-	return ret;
+	_linear(data);
 }
 catch(const std::bad_function_call &e)
 {
 	thread_local char rembuf[128];
 	log::dwarning
 	{
-		log, "linear %s %s '%s' missing handler :%s",
-		string(rembuf, ircd::remote(data.client)),
-		string_view{data.user.user_id},
+		log, "linear %s '%s' missing handler :%s",
+		loghead(data),
 		name(),
 		e.what()
 	};
-
-	return false;
 }
 
-bool
+void
 ircd::m::sync::item::poll(data &data,
                           const m::event &event)
 try
@@ -808,26 +741,18 @@ try
 		data.event, &event
 	};
 
-	const auto ret
-	{
-		_linear(data)
-	};
-
-	return ret;
+	_linear(data);
 }
 catch(const std::bad_function_call &e)
 {
 	thread_local char rembuf[128];
 	log::dwarning
 	{
-		log, "poll %s %s '%s' missing handler :%s",
-		string(rembuf, ircd::remote(data.client)),
-		string_view{data.user.user_id},
+		log, "poll %s '%s' missing handler :%s",
+		loghead(data),
 		name(),
 		e.what()
 	};
-
-	return false;
 }
 
 ircd::string_view
diff --git a/modules/client/sync.cc b/modules/client/sync.cc
index 3849ea9e5..e96408711 100644
--- a/modules/client/sync.cc
+++ b/modules/client/sync.cc
@@ -56,6 +56,27 @@ ircd::m::sync::args::timeout_default
 	{ "default",  10 * 1000L                          },
 };
 
+decltype(ircd::m::sync::flush_hiwat)
+ircd::m::sync::flush_hiwat
+{
+	{ "name",     "ircd.client.sync.flush.hiwat" },
+	{ "default",  long(48_KiB)                   },
+};
+
+decltype(ircd::m::sync::buffer_size)
+ircd::m::sync::buffer_size
+{
+	{ "name",     "ircd.client.sync.buffer_size" },
+	{ "default",  long(128_KiB)                  },
+};
+
+decltype(ircd::m::sync::linear::delta_max)
+ircd::m::sync::linear::delta_max
+{
+	{ "name",     "ircd.client.sync.linear.delta.max" },
+	{ "default",  1024                                },
+};
+
 //
 // GET sync
 //
@@ -73,23 +94,57 @@ ircd::m::sync::method_get
 ircd::resource::response
 ircd::m::sync::handle_get(client &client,
                           const resource::request &request)
-try
 {
+	// Parse the request options
 	const args args
 	{
 		request
 	};
 
-	const std::pair<event::idx, event::idx> range
+	// The range to `/sync`. We involve events starting at the range.first
+	// index in this sync. We will not involve events with an index equal
+	// or greater than the range.second. In this case the range.second does not
+	// exist yet because it is one past the server's current_sequence counter.
+	const m::events::range range
 	{
 		args.since,                  // start at since token
-		m::vm::current_sequence      // stop at present
+		m::vm::current_sequence + 1  // stop before future
 	};
 
+	// When the range indexes are the same, the client is polling for the next
+	// event which doesn't exist yet. There is no reason for the since parameter
+	// to be greater than that.
+	if(range.first > range.second)
+		throw m::NOT_FOUND
+		{
+			"Since parameter is too far in the future..."
+		};
+
+	// Setup an output buffer to compose the response. This has to be at least
+	// the worst-case size of a matrix event (64_KiB) or bad things happen.
+	const unique_buffer<mutable_buffer> buffer
+	{
+		size_t(buffer_size)
+	};
+
+	// Setup a chunked encoded response.
+	resource::response::chunked response
+	{
+		client, http::OK
+	};
+
+	// Keep state for statistics of this sync here on the stack.
 	stats stats;
 	data data
 	{
-		stats, client, request.user_id, range, args.filter_id
+		request.user_id,
+		range,
+		buffer,
+		std::bind(&sync::flush, std::ref(data), std::ref(response), ph::_1),
+		size_t(flush_hiwat),
+		&client,
+		&stats,
+		args.filter_id
 	};
 
 	log::debug
@@ -97,56 +152,76 @@ try
 		log, "request %s", loghead(data)
 	};
 
-	if(data.since > data.current + 1)
-		throw m::NOT_FOUND
-		{
-			"Since parameter is too far in the future..."
-		};
-
-	const size_t linear_delta_max
+	json::stack::object object
 	{
-		linear::delta_max
+		data.out
 	};
 
 	const bool shortpolled
 	{
 		range.first > range.second?
 			false:
-		range.second - range.first <= linear_delta_max?
+		range.second - range.first <= size_t(linear::delta_max)?
 			polylog::handle(data):
 			polylog::handle(data)
 	};
 
 	// When shortpoll was successful, do nothing else.
 	if(shortpolled)
-		return {};
+		return response;
 
 	// When longpoll was successful, do nothing else.
 	if(longpoll::poll(data, args))
-		return {};
+		return response;
 
 	// A user-timeout occurred. According to the spec we return a
 	// 200 with empty fields rather than a 408.
-	const json::value next_batch
-	{
-		lex_cast(m::vm::current_sequence + 0), json::STRING
-	};
+	empty_response(data);
+	return response;
+}
 
-	return resource::response
+void
+ircd::m::sync::empty_response(data &data)
+{
+	data.commit();
+	json::stack::member
 	{
-		client, json::members
+		data.out, "next_batch", json::value
 		{
-			{ "next_batch",  next_batch      },
-			{ "rooms",       json::object{}  },
-			{ "presence",    json::object{}  },
+			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"};
 }
-catch(const bad_lex_cast &e)
+
+ircd::const_buffer
+ircd::m::sync::flush(data &data,
+                     resource::response::chunked &response,
+                     const const_buffer &buffer)
 {
-	throw m::BAD_REQUEST
+	if(!data.committed)
+		return const_buffer
+		{
+			buffer::data(buffer), 0UL
+		};
+
+	const size_t wrote
 	{
-		"Since parameter invalid :%s", e.what()
+		response.write(buffer)
+	};
+
+	if(data.stats)
+	{
+		data.stats->flush_bytes += wrote;
+		data.stats->flush_count++;
+	}
+
+	return const_buffer
+	{
+		buffer::data(buffer), wrote
 	};
 }
 
@@ -158,11 +233,6 @@ bool
 ircd::m::sync::polylog::handle(data &data)
 try
 {
-	json::stack::object object
-	{
-		data.out
-	};
-
 	m::sync::for_each(string_view{}, [&data]
 	(item &item)
 	{
@@ -175,24 +245,20 @@ try
 		return true;
 	});
 
-	const json::value next_batch
-	{
-		lex_cast(data.current + 1), json::STRING
-	};
-
 	json::stack::member
 	{
-		object, "next_batch", next_batch
+		data.out, "next_batch", json::value
+		{
+			lex_cast(data.range.second), json::STRING
+		}
 	};
 
 	log::info
 	{
-		log, "polylog %s (next_batch:%s)",
-		loghead(data),
-		string_view{next_batch}
+		log, "polylog %s complete", loghead(data)
 	};
 
-	return data.committed();
+	return data.committed;
 }
 catch(const std::exception &e)
 {
@@ -210,28 +276,11 @@ catch(const std::exception &e)
 // linear
 //
 
-decltype(ircd::m::sync::linear::delta_max)
-ircd::m::sync::linear::delta_max
-{
-	{ "name",     "ircd.client.sync.linear.delta.max" },
-	{ "default",  1024                                },
-};
-
 bool
 ircd::m::sync::linear::handle(data &data)
 try
 {
-	json::stack::object object
-	{
-		data.out
-	};
-
-	const m::events::range range
-	{
-		data.since, data.current + 1
-	};
-
-	m::events::for_each(range, [&data]
+	m::events::for_each(data.range, [&data]
 	(const m::event::idx &event_idx, const m::event &event)
 	{
 		const scope_restore<decltype(data.event)> theirs
@@ -254,24 +303,20 @@ try
 		return true;
 	});
 
-	const json::value next_batch
-	{
-		lex_cast(data.current + 1), json::STRING
-	};
-
 	json::stack::member
 	{
-		object, "next_batch", next_batch
+		data.out, "next_batch", json::value
+		{
+			lex_cast(data.range.second), json::STRING
+		}
 	};
 
 	log::debug
 	{
-		log, "linear %s (next_batch:%s)",
-		loghead(data),
-		string_view{next_batch}
+		log, "linear %s complete", loghead(data)
 	};
 
-	return data.committed();
+	return data.committed;
 }
 catch(const std::exception &e)
 {
diff --git a/modules/client/sync.h b/modules/client/sync.h
index 835b2d56f..9dd6c2bd5 100644
--- a/modules/client/sync.h
+++ b/modules/client/sync.h
@@ -19,8 +19,11 @@ namespace ircd::m::sync
 	extern resource resource;
 	extern resource::method method_get;
 
-	static long notification_count(const room &, const event::idx &a, const event::idx &b);
-	static long highlight_count(const room &, const user &, const event::idx &a, const event::idx &b);
+	extern conf::item<size_t> flush_hiwat;
+	extern conf::item<size_t> buffer_size;
+
+	static const_buffer flush(data &, resource::response::chunked &, const const_buffer &);
+	static void empty_response(data &);
 	static resource::response handle_get(client &, const resource::request &);
 }
 
@@ -77,14 +80,12 @@ namespace ircd::m::sync::polylog
 /// Argument parser for the client's /sync request
 struct ircd::m::sync::args
 {
+	args(const resource::request &request);
+
 	static conf::item<milliseconds> timeout_max;
 	static conf::item<milliseconds> timeout_min;
 	static conf::item<milliseconds> timeout_default;
 
-	args(const resource::request &request)
-	:request{request}
-	{}
-
 	const resource::request &request;
 
 	string_view filter_id
@@ -132,3 +133,20 @@ struct ircd::m::sync::args
 		request.query.get("set_presence", true)
 	};
 };
+
+inline
+ircd::m::sync::args::args(const resource::request &request)
+try
+:request
+{
+	request
+}
+{
+}
+catch(const bad_lex_cast &e)
+{
+	throw m::BAD_REQUEST
+	{
+		"Since parameter invalid :%s", e.what()
+	};
+}
diff --git a/modules/client/sync/account_data.cc b/modules/client/sync/account_data.cc
index e031186ff..b74ad69c8 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 bool account_data_polylog(data &);
-	static bool account_data_linear(data &);
+	static void account_data_polylog(data &);
+	static void account_data_linear(data &);
 
 	extern item account_data;
 }
@@ -31,13 +31,13 @@ ircd::m::sync::account_data
 	account_data_linear
 };
 
-bool
+void
 ircd::m::sync::account_data_linear(data &data)
 {
-	return true;
+
 }
 
-bool
+void
 ircd::m::sync::account_data_polylog(data &data)
 {
 	json::stack::object object
@@ -61,8 +61,6 @@ ircd::m::sync::account_data_polylog(data &data)
 		if(account_data_(data, event, index(event)))
 			data.commit();
 	});
-
-	return true;
 }
 
 bool
diff --git a/modules/client/sync/presence.cc b/modules/client/sync/presence.cc
index 37457ed75..87d9e0326 100644
--- a/modules/client/sync/presence.cc
+++ b/modules/client/sync/presence.cc
@@ -17,10 +17,10 @@ IRCD_MODULE
 namespace ircd::m::sync
 {
 	static void presence_polylog_events(data &);
-	static bool presence_polylog(data &);
+	static void presence_polylog(data &);
 
 	static void presence_linear_events(data &);
-	static bool presence_linear(data &);
+	static void presence_linear(data &);
 
 	extern item presence;
 }
@@ -33,10 +33,10 @@ ircd::m::sync::presence
 	presence_linear,
 };
 
-bool
+void
 ircd::m::sync::presence_linear(data &data)
 {
-	return true;
+	return;
 
 	assert(data.event);
 	const m::event &event
@@ -45,10 +45,10 @@ ircd::m::sync::presence_linear(data &data)
 	};
 
 	if(json::get<"type"_>(event) != "ircd.presence")
-		return true;
+		return;
 
 	if(json::get<"sender"_>(event) != m::me.user_id)
-		return true;
+		return;
 
 	// sender
 	json::stack::member
@@ -68,10 +68,10 @@ ircd::m::sync::presence_linear(data &data)
 		data.out, "content", at<"content"_>(event)
 	};
 
-	return true;
+	return;
 }
 
-bool
+void
 ircd::m::sync::presence_polylog(data &data)
 {
 	json::stack::object object
@@ -80,7 +80,6 @@ ircd::m::sync::presence_polylog(data &data)
 	};
 
 	presence_polylog_events(data);
-	return true;
 }
 
 void
@@ -126,9 +125,9 @@ ircd::m::sync::presence_polylog_events(data &data)
 	}};
 
 	//TODO: conf
-	static const size_t fibers(16);
+	static const size_t fibers(32);
 	std::array<string_view, fibers> q;
-	std::array<char[256], fibers> buf;
+	std::array<char[128], fibers> buf; //TODO: X
 	ctx::parallel<string_view> parallel
 	{
 		m::sync::pool, q, [&data, &closure](const auto &user_id)
@@ -136,7 +135,7 @@ ircd::m::sync::presence_polylog_events(data &data)
 			const m::user user{user_id};
 			const m::user::room user_room{user};
 			//TODO: can't check event_idx cuz only closed presence content
-			if(head_idx(std::nothrow, user_room) > data.since)
+			if(head_idx(std::nothrow, user_room) >= data.range.first)
 				m::presence::get(std::nothrow, user, closure);
 		}
 	};
diff --git a/modules/client/sync/rooms.cc b/modules/client/sync/rooms.cc
index f986fc1bc..75dcff177 100644
--- a/modules/client/sync/rooms.cc
+++ b/modules/client/sync/rooms.cc
@@ -18,10 +18,10 @@ namespace ircd::m::sync
 {
 	static void _rooms_polylog_room(data &, const m::room &);
 	static void _rooms_polylog(data &, const string_view &membership);
-	static bool rooms_polylog(data &);
+	static void rooms_polylog(data &);
 
 	static void _rooms_linear(data &, const string_view &membership);
-	static bool rooms_linear(data &);
+	static void rooms_linear(data &);
 
 	extern item rooms;
 }
@@ -34,7 +34,7 @@ ircd::m::sync::rooms
 	rooms_linear
 };
 
-bool
+void
 ircd::m::sync::rooms_linear(data &data)
 {
 	json::stack::object object{data.out};
@@ -42,7 +42,6 @@ ircd::m::sync::rooms_linear(data &data)
 	_rooms_linear(data, "join");
 	_rooms_linear(data, "leave");
 	_rooms_linear(data, "ban");
-	return true;
 }
 
 void
@@ -66,7 +65,7 @@ ircd::m::sync::_rooms_linear(data &data,
 	});
 }
 
-bool
+void
 ircd::m::sync::rooms_polylog(data &data)
 {
 	json::stack::object object{data.out};
@@ -74,7 +73,7 @@ ircd::m::sync::rooms_polylog(data &data)
 	_rooms_polylog(data, "join");
 	_rooms_polylog(data, "leave");
 	_rooms_polylog(data, "ban");
-	return true;
+	return;
 }
 
 void
@@ -100,13 +99,20 @@ ircd::m::sync::_rooms_polylog(data &data,
 		};
 
 		assert(head_idx); // room should exist
-		if(!head_idx || head_idx < data.since)
+		if(!head_idx || head_idx < data.range.first)
 			return;
 
 		// Generate individual stats for this room's sync
 		#ifdef RB_DEBUG
-		sync::stats stats{data.stats};
-		stats.timer = timer{};
+		sync::stats stats
+		{
+			data.stats?
+				*data.stats:
+				sync::stats{}
+		};
+
+		if(data.stats)
+			stats.timer = timer{};
 		#endif
 
 		_rooms_polylog_room(data, room);
@@ -118,7 +124,9 @@ ircd::m::sync::_rooms_polylog(data &data,
 			log, "polylog %s %s in %s",
 			loghead(data),
 			string_view{room.room_id},
-			ircd::pretty(tmbuf, stats.timer.at<milliseconds>(), true)
+			data.stats?
+				ircd::pretty(tmbuf, stats.timer.at<milliseconds>(), true):
+				string_view{"<no stats>"}
 		};
 		#endif
 	});
diff --git a/modules/client/sync/rooms/account_data.cc b/modules/client/sync/rooms/account_data.cc
index 0c5bfabde..61571d0ef 100644
--- a/modules/client/sync/rooms/account_data.cc
+++ b/modules/client/sync/rooms/account_data.cc
@@ -18,7 +18,7 @@ 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 bool room_account_data_polylog(data &);
+	static void room_account_data_polylog(data &);
 
 	extern item room_account_data;
 }
@@ -30,7 +30,7 @@ ircd::m::sync::room_account_data
 	room_account_data_polylog
 };
 
-bool
+void
 ircd::m::sync::room_account_data_polylog(data &data)
 {
 	json::stack::object object
@@ -39,7 +39,6 @@ ircd::m::sync::room_account_data_polylog(data &data)
 	};
 
 	room_account_data_polylog_events(data);
-	return true;
 }
 
 void
diff --git a/modules/client/sync/rooms/ephemeral.cc b/modules/client/sync/rooms/ephemeral.cc
index 0c6d9b7b9..054796682 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 bool rooms_ephemeral_events_polylog(data &);
-	static bool rooms_ephemeral_polylog(data &);
-	static bool rooms_ephemeral_linear(data &);
+	static void rooms_ephemeral_events_polylog(data &);
+	static void rooms_ephemeral_polylog(data &);
+	static void rooms_ephemeral_linear(data &);
 	extern item rooms_ephemeral;
 }
 
@@ -30,13 +30,13 @@ ircd::m::sync::rooms_ephemeral
 	rooms_ephemeral_linear
 };
 
-bool
+void
 ircd::m::sync::rooms_ephemeral_linear(data &data)
 {
-	return true;
+
 }
 
-bool
+void
 ircd::m::sync::rooms_ephemeral_polylog(data &data)
 {
 	json::stack::object object
@@ -45,10 +45,9 @@ ircd::m::sync::rooms_ephemeral_polylog(data &data)
 	};
 
 	rooms_ephemeral_events(data);
-	return true;
 }
 
-bool
+void
 ircd::m::sync::rooms_ephemeral_events_polylog(data &data)
 {
 	json::stack::array array
@@ -62,6 +61,4 @@ ircd::m::sync::rooms_ephemeral_events_polylog(data &data)
 		item.polylog(data);
 		return true;
 	});
-
-	return true;
 }
diff --git a/modules/client/sync/rooms/receipt.cc b/modules/client/sync/rooms/receipt.cc
index fbb20de44..19df2104b 100644
--- a/modules/client/sync/rooms/receipt.cc
+++ b/modules/client/sync/rooms/receipt.cc
@@ -19,7 +19,7 @@ namespace ircd::m::sync
 	static void _reformat_receipt(json::stack::object &, const m::event &);
 	static void _handle_receipt(data &, const m::event &);
 	static void _handle_user(data &, const m::user &);
-	static bool room_ephemeral_m_receipt_m_read_polylog(data &);
+	static void room_ephemeral_m_receipt_m_read_polylog(data &);
 	extern item room_ephemeral_m_receipt_m_read;
 }
 
@@ -30,7 +30,7 @@ ircd::m::sync::room_ephemeral_m_receipt_m_read
 	room_ephemeral_m_receipt_m_read_polylog
 };
 
-bool
+void
 ircd::m::sync::room_ephemeral_m_receipt_m_read_polylog(data &data)
 {
 	const m::room &room{*data.room};
@@ -44,8 +44,6 @@ ircd::m::sync::room_ephemeral_m_receipt_m_read_polylog(data &data)
 	{
 		_handle_user(data, user_id);
 	}});
-
-	return true;
 }
 
 void
@@ -62,7 +60,7 @@ ircd::m::sync::_handle_user(data &data,
 
 	m::user::room user_room{user};
 	user_room.fopts = &fopts;
-	if(head_idx(std::nothrow, user_room) < data.since)
+	if(head_idx(std::nothrow, user_room) < data.range.first)
 		return;
 
 	const m::room::id &room_id{*data.room};
diff --git a/modules/client/sync/rooms/state.cc b/modules/client/sync/rooms/state.cc
index 9de4f27f9..fe29be06c 100644
--- a/modules/client/sync/rooms/state.cc
+++ b/modules/client/sync/rooms/state.cc
@@ -16,11 +16,11 @@ IRCD_MODULE
 
 namespace ircd::m::sync
 {
-	static bool room_state_polylog_events(data &);
-	static bool room_state_polylog(data &);
+	static void room_state_polylog_events(data &);
+	static void room_state_polylog(data &);
 
-	static bool room_state_linear_events(data &);
-	static bool room_state_linear(data &);
+	static void room_state_linear_events(data &);
+	static void room_state_linear(data &);
 
 	extern const event::keys::include _default_keys;
 	extern item room_state;
@@ -48,7 +48,7 @@ ircd::m::sync::_default_keys
 	"type",
 };
 
-bool
+void
 ircd::m::sync::room_state_linear(data &data)
 {
 	assert(data.event);
@@ -56,16 +56,15 @@ ircd::m::sync::room_state_linear(data &data)
 	assert(json::get<"room_id"_>(*data.event));
 
 	if(!json::get<"state_key"_>(*data.event))
-		return false;
+		return;
 
 	if(!data.room->membership(data.user, data.membership))
-		return false;
+		return;
 
 	//data.array->append(*data.event);
-	return true;
 }
 
-bool
+void
 ircd::m::sync::room_state_polylog(data &data)
 {
 	json::stack::object object
@@ -73,10 +72,10 @@ ircd::m::sync::room_state_polylog(data &data)
 		data.out
 	};
 
-	return room_state_polylog_events(data);
+	room_state_polylog_events(data);
 }
 
-bool
+void
 ircd::m::sync::room_state_polylog_events(data &data)
 {
 	json::stack::array array
@@ -107,7 +106,7 @@ ircd::m::sync::room_state_polylog_events(data &data)
 	}};
 
 	//TODO: conf
-	std::array<event::idx, 8> md;
+	std::array<event::idx, 16> md;
 	ctx::parallel<event::idx> parallel
 	{
 		m::sync::pool, md, each_idx
@@ -121,6 +120,4 @@ ircd::m::sync::room_state_polylog_events(data &data)
 		if(apropos(data, event_idx))
 			parallel(event_idx);
 	});
-
-	return true;
 }
diff --git a/modules/client/sync/rooms/timeline.cc b/modules/client/sync/rooms/timeline.cc
index bff9be06c..c1d60ae3d 100644
--- a/modules/client/sync/rooms/timeline.cc
+++ b/modules/client/sync/rooms/timeline.cc
@@ -16,13 +16,11 @@ IRCD_MODULE
 
 namespace ircd::m::sync
 {
-	struct room_timeline;
-
 	static event::id::buf _room_timeline_polylog_events(data &, const m::room &, bool &);
-	static bool room_timeline_polylog(data &);
+	static void room_timeline_polylog(data &);
 
 	static event::id::buf _room_timeline_linear_events(data &, const m::room &, bool &);
-	static bool room_timeline_linear(data &);
+	static void room_timeline_linear(data &);
 
 	extern const event::keys::include default_keys;
 	extern item room_timeline;
@@ -51,10 +49,10 @@ ircd::m::sync::default_keys
 	"type",
 };
 
-bool
+void
 ircd::m::sync::room_timeline_linear(data &data)
 {
-	return true;
+	return;
 
 	json::stack::object object
 	{
@@ -82,7 +80,7 @@ ircd::m::sync::room_timeline_linear(data &data)
 		object, "limited", json::value{limited}
 	};
 
-	return true;
+	return;
 }
 
 ircd::m::event::id::buf
@@ -98,7 +96,7 @@ ircd::m::sync::_room_timeline_linear_events(data &data,
 	return {};
 }
 
-bool
+void
 ircd::m::sync::room_timeline_polylog(data &data)
 {
 	json::stack::object object
@@ -124,8 +122,6 @@ ircd::m::sync::room_timeline_polylog(data &data)
 	{
 		object, "limited", json::value{limited}
 	};
-
-	return true;
 }
 
 ircd::m::event::id::buf
@@ -159,10 +155,10 @@ ircd::m::sync::_room_timeline_polylog_events(data &data,
 	for(; it && i < 10; --it, ++i)
 	{
 		event_id = it.event_id();
-		if(it.event_idx() < data.since)
+		if(it.event_idx() < data.range.first)
 			break;
 
-		if(it.event_idx() > data.current)
+		if(it.event_idx() >= data.range.second)
 			break;
 	}
 
diff --git a/modules/client/sync/rooms/unread_notifications.cc b/modules/client/sync/rooms/unread_notifications.cc
index f1b4ca3d8..55ff981d6 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 bool room_unread_notifications_polylog(data &);
-	static bool room_unread_notifications_linear(data &);
+	static void room_unread_notifications_polylog(data &);
+	static void room_unread_notifications_linear(data &);
 	extern item room_unread_notifications;
 }
 
@@ -31,19 +31,19 @@ ircd::m::sync::room_unread_notifications
 	room_unread_notifications_linear
 };
 
-bool
+void
 ircd::m::sync::room_unread_notifications_linear(data &data)
 {
-	return true;
+
 }
 
-bool
+void
 ircd::m::sync::room_unread_notifications_polylog(data &data)
 {
 	auto &room{*data.room};
 	m::event::id::buf last_read;
 	if(!m::receipt::read(last_read, room.room_id, data.user))
-		return false;
+		return;
 
 	data.commit();
 	json::stack::object out
@@ -51,7 +51,7 @@ ircd::m::sync::room_unread_notifications_polylog(data &data)
 		data.out
 	};
 
-	const auto last_read_idx
+	const auto start_idx
 	{
 		index(last_read)
 	};
@@ -61,7 +61,7 @@ ircd::m::sync::room_unread_notifications_polylog(data &data)
 	{
 		out, "highlight_count", json::value
 		{
-			_highlight_count(room, data.user, last_read_idx, data.current)
+			_highlight_count(room, data.user, start_idx, data.range.second)
 		}
 	};
 
@@ -70,11 +70,9 @@ ircd::m::sync::room_unread_notifications_polylog(data &data)
 	{
 		out, "notification_count", json::value
 		{
-			_notification_count(room, last_read_idx, data.current)
+			_notification_count(room, start_idx, data.range.second)
 		}
 	};
-
-	return true;
 }
 
 long