diff --git a/include/ircd/m/event/prev.h b/include/ircd/m/event/prev.h
index 86d164115..a3af2f7d5 100644
--- a/include/ircd/m/event/prev.h
+++ b/include/ircd/m/event/prev.h
@@ -75,7 +75,8 @@ ircd::m::event::prev::ids(event::id (&out)[N])
 const
 {
 	size_t i(0);
-	m::for_each(*this, [&i, &out](const event::id &event_id)
+	m::for_each(*this, [&i, &out]
+	(const event::id &event_id) noexcept
 	{
 		out[i++] = event_id;
 		return i < N;
diff --git a/ircd/ctx.cc b/ircd/ctx.cc
index fa177be0b..ecc579bb7 100644
--- a/ircd/ctx.cc
+++ b/ircd/ctx.cc
@@ -1360,7 +1360,7 @@ ircd::ctx::context::join()
 
 	assert(bool(c));
 	mark(prof::event::JOIN);
-	ctx::adjoindre.wait([this]
+	ctx::adjoindre.wait([this]() noexcept
 	{
 		return joined();
 	});
diff --git a/matrix/app.cc b/matrix/app.cc
index 4f58efa50..10f36c00f 100644
--- a/matrix/app.cc
+++ b/matrix/app.cc
@@ -278,7 +278,7 @@ void
 ircd::m::app::worker()
 try
 {
-	child.dock.wait([this]
+	child.dock.wait([this]() noexcept
 	{
 		return child.pid >= 0;
 	});
diff --git a/matrix/bridge.cc b/matrix/bridge.cc
index 86e288e40..79e95d02e 100644
--- a/matrix/bridge.cc
+++ b/matrix/bridge.cc
@@ -195,8 +195,9 @@ bool
 ircd::m::bridge::config::exists(const string_view &id)
 {
 	return get(std::nothrow, id, []
-	(const auto &, const auto &, const auto &)
+	(const auto &, const auto &, const auto &) noexcept
 	{
+		// no action
 	});
 }
 
diff --git a/matrix/event.cc b/matrix/event.cc
index a6fde39d6..70fb018e3 100644
--- a/matrix/event.cc
+++ b/matrix/event.cc
@@ -1076,7 +1076,7 @@ ircd::m::bad(const id::event &event_id)
 {
 	bool ret {false};
 	index(std::nothrow, event_id, [&ret]
-	(const event::idx &event_idx)
+	(const event::idx &event_idx) noexcept
 	{
 		ret = event_idx == 0;
 	});
diff --git a/matrix/event_prev.cc b/matrix/event_prev.cc
index 02d6ca726..3a918178e 100644
--- a/matrix/event_prev.cc
+++ b/matrix/event_prev.cc
@@ -66,7 +66,8 @@ size_t
 ircd::m::count(const event::prev &prev)
 {
 	size_t ret{0};
-	m::for_each(prev, [&ret](const event::id &event_id)
+	m::for_each(prev, [&ret]
+	(const event::id &event_id) noexcept
 	{
 		++ret;
 		return true;
diff --git a/matrix/event_refs.cc b/matrix/event_refs.cc
index d18f1437b..fd88e2169 100644
--- a/matrix/event_refs.cc
+++ b/matrix/event_refs.cc
@@ -75,7 +75,7 @@ ircd::m::event::refs::rebuild()
 		++i;
 	}
 
-	dock.wait([&i, &j]
+	dock.wait([&i, &j]() noexcept
 	{
 		return i == j;
 	});
@@ -133,7 +133,7 @@ const
 {
 	size_t ret(0);
 	for_each(type, [&ret]
-	(const event::idx &, const dbs::ref &)
+	(const event::idx &, const dbs::ref &) noexcept
 	{
 		++ret;
 		return true;
@@ -154,7 +154,7 @@ ircd::m::event::refs::has(const dbs::ref &type)
 const
 {
 	return !for_each(type, [&type]
-	(const event::idx &, const dbs::ref &ref)
+	(const event::idx &, const dbs::ref &ref) noexcept
 	{
 		assert(ref == type);
 		return false;
@@ -167,7 +167,7 @@ ircd::m::event::refs::has(const dbs::ref &type,
 const
 {
 	return !for_each(type, [&idx]
-	(const event::idx &ref, const dbs::ref &)
+	(const event::idx &ref, const dbs::ref &) noexcept
 	{
 		return ref != idx; // true to continue, false to break
 	});
diff --git a/matrix/events.cc b/matrix/events.cc
index 4554b1876..6ae006324 100644
--- a/matrix/events.cc
+++ b/matrix/events.cc
@@ -556,7 +556,7 @@ ircd::m::events::type::has(const string_view &type)
 {
 	bool ret{false};
 	for_each(type, [&ret, &type]
-	(const string_view &type_)
+	(const string_view &type_) noexcept
 	{
 		ret = type == type_;
 		return false; // uncond break out of loop after first result
@@ -570,7 +570,7 @@ ircd::m::events::type::has_prefix(const string_view &type)
 {
 	bool ret{false};
 	for_each(type, [&ret, &type]
-	(const string_view &type_)
+	(const string_view &type_) noexcept
 	{
 		ret = startswith(type_, type);
 		return false; // uncond break out of loop after first result
diff --git a/matrix/init_backfill.cc b/matrix/init_backfill.cc
index d40ff15a3..fb4434501 100644
--- a/matrix/init_backfill.cc
+++ b/matrix/init_backfill.cc
@@ -129,7 +129,7 @@ ircd::m::init::backfill::worker_context;
 decltype(ircd::m::init::backfill::handle_quit)
 ircd::m::init::backfill::handle_quit
 {
-	run::level::QUIT, []
+	run::level::QUIT, []() noexcept
 	{
 		term();
 	}
diff --git a/matrix/keys.cc b/matrix/keys.cc
index ffa28d137..e69552632 100644
--- a/matrix/keys.cc
+++ b/matrix/keys.cc
@@ -288,7 +288,7 @@ size_t
 ircd::m::keys::fetch(const queries &queries)
 {
 	size_t ret(0);
-	get(queries, [&ret](const auto &)
+	get(queries, [&ret](const auto &) noexcept
 	{
 		++ret;
 		return true;
diff --git a/matrix/push.cc b/matrix/push.cc
index e69f8c0bf..6ed1c3d41 100644
--- a/matrix/push.cc
+++ b/matrix/push.cc
@@ -392,7 +392,7 @@ try
 	};
 
 	power.for_each("notifications", [&required_level, &key]
-	(const auto &name, const auto &level)
+	(const auto &name, const auto &level) noexcept
 	{
 		if(name == key)
 		{
diff --git a/matrix/room.cc b/matrix/room.cc
index 838c9db5b..86f4f3452 100644
--- a/matrix/room.cc
+++ b/matrix/room.cc
@@ -489,7 +489,11 @@ ircd::m::exists(const id::room_alias &room_alias,
 	if(!remote_query)
 		return false;
 
-	return room::aliases::cache::get(std::nothrow, room_alias, [](const room::id &room_id) {});
+	return room::aliases::cache::get(std::nothrow, room_alias, []
+	(const room::id &) noexcept
+	{
+		// no action
+	});
 }
 
 int64_t
@@ -1407,7 +1411,7 @@ const
 
 		if(!match)
 			column(byte_view<string_view>(event_idx), std::nothrow, [&match, &type]
-			(const string_view &value)
+			(const string_view &value) noexcept
 			{
 				match = value == type;
 			});
diff --git a/matrix/room_aliases.cc b/matrix/room_aliases.cc
index bf185dcc9..813ec91bd 100644
--- a/matrix/room_aliases.cc
+++ b/matrix/room_aliases.cc
@@ -44,7 +44,8 @@ ircd::m::room::aliases::count(const string_view &server)
 const
 {
 	size_t ret(0);
-	for_each(server, [&ret](const auto &a)
+	for_each(server, [&ret]
+	(const auto &a) noexcept
 	{
 		++ret;
 		return true;
@@ -58,7 +59,7 @@ ircd::m::room::aliases::has(const alias &alias)
 const
 {
 	return !for_each(alias.host(), [&alias]
-	(const id::room_alias &a)
+	(const id::room_alias &a) noexcept
 	{
 		assert(a.host() == alias.host());
 		return a == alias? false : true; // false to break on found
diff --git a/matrix/room_auth.cc b/matrix/room_auth.cc
index 59606471b..f05e8d3a0 100644
--- a/matrix/room_auth.cc
+++ b/matrix/room_auth.cc
@@ -660,28 +660,28 @@ ircd::m::room::auth::hookdata::hookdata(const m::event &event,
 }
 ,auth_create
 {
-	find([](const auto &event)
+	find([](const auto &event) noexcept
 	{
 		return json::get<"type"_>(event) == "m.room.create";
 	})
 }
 ,auth_power
 {
-	find([](const auto &event)
+	find([](const auto &event) noexcept
 	{
 		return json::get<"type"_>(event) == "m.room.power_levels";
 	})
 }
 ,auth_join_rules
 {
-	find([](const auto &event)
+	find([](const auto &event) noexcept
 	{
 		return json::get<"type"_>(event) == "m.room.join_rules";
 	})
 }
 ,auth_member_target
 {
-	find([&event](const auto &auth_event)
+	find([&event](const auto &auth_event) noexcept
 	{
 		return json::get<"type"_>(auth_event) == "m.room.member" &&
 		       json::get<"state_key"_>(auth_event) == json::get<"state_key"_>(event);
@@ -689,7 +689,7 @@ ircd::m::room::auth::hookdata::hookdata(const m::event &event,
 }
 ,auth_member_sender
 {
-	find([&event](const auto &auth_event)
+	find([&event](const auto &auth_event) noexcept
 	{
 		return json::get<"type"_>(auth_event) == "m.room.member" &&
 		       json::get<"state_key"_>(auth_event) == json::get<"sender"_>(event);
@@ -725,7 +725,8 @@ ircd::m::room::auth::refs::count(const string_view &type)
 const
 {
 	size_t ret(0);
-	for_each(type, [&ret](const auto &)
+	for_each(type, [&ret]
+	(const auto &) noexcept
 	{
 		++ret;
 		return true;
@@ -738,7 +739,8 @@ bool
 ircd::m::room::auth::refs::has(const event::idx &idx)
 const
 {
-	return !for_each([&idx](const event::idx &ref)
+	return !for_each([&idx]
+	(const event::idx &ref) noexcept
 	{
 		return ref != idx; // true to continue, false to break
 	});
@@ -749,7 +751,8 @@ ircd::m::room::auth::refs::has(const string_view &type)
 const
 {
 	bool ret{false};
-	for_each(type, [&ret](const auto &)
+	for_each(type, [&ret]
+	(const auto &) noexcept
 	{
 		ret = true;
 		return false;
@@ -782,7 +785,7 @@ const
 		bool match;
 		const auto matcher
 		{
-			[&type, &match](const string_view &type_)
+			[&type, &match](const string_view &type_) noexcept
 			{
 				match = type == type_;
 			}
@@ -814,7 +817,8 @@ ircd::m::room::auth::chain::depth()
 const
 {
 	size_t ret(0);
-	for_each([&ret](const auto &)
+	for_each([&ret]
+	(const auto &) noexcept
 	{
 		++ret;
 		return true;
@@ -832,7 +836,7 @@ const
 	(const auto &idx)
 	{
 		m::get(std::nothrow, idx, "type", [&type, &ret]
-		(const auto &value)
+		(const auto &value) noexcept
 		{
 			ret = value == type;
 		});
diff --git a/matrix/room_events.cc b/matrix/room_events.cc
index a888226f7..5e8be093a 100644
--- a/matrix/room_events.cc
+++ b/matrix/room_events.cc
@@ -56,7 +56,7 @@ ircd::m::twain(const room &room)
 	};
 
 	s.rfor_each([&ret]
-	(const auto &range, const auto &event_idx)
+	(const auto &range, const auto &event_idx) noexcept
 	{
 		ret.first = range.first - 1;
 		return false;
@@ -79,7 +79,7 @@ ircd::m::sounding(const room &room)
 	};
 
 	s.rfor_each([&ret]
-	(const auto &range, const auto &event_idx)
+	(const auto &range, const auto &event_idx) noexcept
 	{
 		ret.first = range.second;
 		ret.second = event_idx;
@@ -103,7 +103,7 @@ ircd::m::hazard(const room &room)
 	};
 
 	s.for_each([&ret]
-	(const auto &range, const auto &event_idx)
+	(const auto &range, const auto &event_idx) noexcept
 	{
 		ret.first = range.first;
 		return false;
@@ -438,7 +438,7 @@ const
 {
 	size_t ret{0};
 	for_each([&ret]
-	(const auto &event_id, const auto &depth, const auto &event_idx)
+	(const auto &event_id, const auto &depth, const auto &event_idx) noexcept
 	{
 		++ret;
 		return true;
@@ -662,7 +662,7 @@ const
 {
 	size_t ret{0};
 	for_each([&ret]
-	(const auto &event_id, const auto &depth, const auto &event_idx)
+	(const auto &event_id, const auto &depth, const auto &event_idx) noexcept
 	{
 		++ret;
 		return true;
@@ -677,7 +677,7 @@ const
 {
 	const std::function<bool (const string_view &)> in_room
 	{
-		[this](const string_view &room_id)
+		[this](const string_view &room_id) noexcept
 		{
 			return room_id == this->room.room_id;
 		}
diff --git a/matrix/room_head.cc b/matrix/room_head.cc
index ee00567de..9033d7370 100644
--- a/matrix/room_head.cc
+++ b/matrix/room_head.cc
@@ -225,7 +225,7 @@ const
 {
 	size_t ret(0);
 	for_each([&ret]
-	(const event::idx &event_idx, const event::id &event_id)
+	(const event::idx &event_idx, const event::id &event_id) noexcept
 	{
 		++ret;
 		return true;
@@ -240,7 +240,7 @@ const
 {
 	bool ret{false};
 	for_each([&ret, &event_id]
-	(const event::idx &event_idx, const event::id &event_id_)
+	(const event::idx &event_idx, const event::id &event_id_) noexcept
 	{
 		ret = event_id_ == event_id;
 		return !ret; // for_each protocol: false to break
diff --git a/matrix/room_members.cc b/matrix/room_members.cc
index 66bd8fd7a..78dfe63de 100644
--- a/matrix/room_members.cc
+++ b/matrix/room_members.cc
@@ -28,7 +28,7 @@ ircd::m::room::members::empty(const string_view &membership,
 const
 {
 	return for_each(membership, host, closure{[]
-	(const user::id &user_id)
+	(const user::id &user_id) noexcept
 	{
 		return false;
 	}});
@@ -55,7 +55,7 @@ const
 {
 	size_t ret{0};
 	for_each(membership, host, closure{[&ret]
-	(const user::id &user_id)
+	(const user::id &user_id) noexcept
 	{
 		++ret;
 		return true;
diff --git a/matrix/room_origins.cc b/matrix/room_origins.cc
index 481e01ea3..848e0d3d9 100644
--- a/matrix/room_origins.cc
+++ b/matrix/room_origins.cc
@@ -90,7 +90,7 @@ ircd::m::room::origins::empty()
 const
 {
 	return for_each(closure_bool{[]
-	(const string_view &)
+	(const string_view &) noexcept
 	{
 		// return false to break and return false.
 		return false;
@@ -102,7 +102,8 @@ ircd::m::room::origins::count()
 const
 {
 	size_t ret{0};
-	for_each([&ret](const string_view &)
+	for_each([&ret]
+	(const string_view &) noexcept
 	{
 		++ret;
 	});
@@ -150,7 +151,7 @@ const
 {
 	ushort ret{2};
 	for_each(closure_bool{[&ret, &origin]
-	(const string_view &origin_) -> bool
+	(const string_view &origin_) noexcept -> bool
 	{
 		if(origin == origin_)
 			ret = 1;
diff --git a/matrix/room_power.cc b/matrix/room_power.cc
index fba0ba391..c4cc1fcce 100644
--- a/matrix/room_power.cc
+++ b/matrix/room_power.cc
@@ -551,7 +551,7 @@ const
 {
 	size_t ret{0};
 	for_each([&ret]
-	(const string_view &, const int64_t &)
+	(const string_view &, const int64_t &) noexcept
 	{
 		++ret;
 		return true;
@@ -581,7 +581,7 @@ const
 {
 	size_t ret{0};
 	for_each(prop, [&ret]
-	(const string_view &, const int64_t &)
+	(const string_view &, const int64_t &) noexcept
 	{
 		++ret;
 		return true;
diff --git a/matrix/room_server_acl.cc b/matrix/room_server_acl.cc
index d9790dd2d..dc87e8aed 100644
--- a/matrix/room_server_acl.cc
+++ b/matrix/room_server_acl.cc
@@ -173,7 +173,7 @@ const
 	};
 
 	return !for_each(prop, [&server]
-	(const string_view &expression)
+	(const string_view &expression) noexcept
 	{
 		const globular_imatch match
 		{
@@ -191,7 +191,7 @@ ircd::m::room::server_acl::has(const string_view &prop,
 const
 {
 	return !for_each(prop, [&expr]
-	(const string_view &_expr)
+	(const string_view &_expr) noexcept
 	{
 		// false to break on match
 		return _expr == expr? false : true;
@@ -240,7 +240,7 @@ const
 {
 	size_t ret(0);
 	for_each(prop, [&ret]
-	(const string_view &)
+	(const string_view &) noexcept
 	{
 		++ret;
 		return true;
diff --git a/matrix/room_state.cc b/matrix/room_state.cc
index ccc3876bd..f4a139948 100644
--- a/matrix/room_state.cc
+++ b/matrix/room_state.cc
@@ -85,7 +85,7 @@ const
 {
 	event::idx ret;
 	get(type, state_key, event::closure_idx{[&ret]
-	(const event::idx &event_idx)
+	(const event::idx &event_idx) noexcept
 	{
 		ret = event_idx;
 	}});
@@ -101,7 +101,7 @@ const
 {
 	event::idx ret{0};
 	get(std::nothrow, type, state_key, event::closure_idx{[&ret]
-	(const event::idx &event_idx)
+	(const event::idx &event_idx) noexcept
 	{
 		ret = event_idx;
 	}});
@@ -295,7 +295,7 @@ const
 	}
 
 	return !for_each(type, []
-	(const string_view &, const string_view &, const event::idx &)
+	(const string_view &, const string_view &, const event::idx &) noexcept
 	{
 		return false;
 	});
@@ -366,7 +366,7 @@ const
 
 	size_t ret(0);
 	for_each(type, [&ret]
-	(const string_view &, const string_view &, const event::idx &)
+	(const string_view &, const string_view &, const event::idx &) noexcept
 	{
 		++ret;
 		return true;
@@ -755,7 +755,7 @@ ircd::m::room::state::is(const event::idx &event_idx)
 {
 	bool ret{false};
 	m::get(event_idx, "state_key", [&ret]
-	(const string_view &state_key)
+	(const string_view &state_key) noexcept
 	{
 		ret = true;
 	});
@@ -769,7 +769,7 @@ ircd::m::room::state::is(std::nothrow_t,
 {
 	bool ret{false};
 	m::get(std::nothrow, event_idx, "state_key", [&ret]
-	(const string_view &state_key)
+	(const string_view &state_key) noexcept
 	{
 		ret = true;
 	});
@@ -797,7 +797,8 @@ ircd::m::room::state::purge_replaced(const room::id &room_id)
 	for(; it; ++it)
 	{
 		const m::event::idx &event_idx(it.event_idx());
-		if(!m::get(std::nothrow, event_idx, "state_key", [](const auto &) {}))
+		static const auto no_action{[](const auto &) noexcept {}};
+		if(!m::get(std::nothrow, event_idx, "state_key", no_action))
 			continue;
 
 		if(!m::event::refs(event_idx).count(m::dbs::ref::NEXT_STATE))
@@ -846,7 +847,7 @@ ircd::m::room::state::prev(const event::idx &event_idx)
 {
 	event::idx ret{0};
 	prev(event_idx, [&ret]
-	(const event::idx &event_idx)
+	(const event::idx &event_idx) noexcept
 	{
 		if(event_idx > ret)
 			ret = event_idx;
@@ -862,7 +863,7 @@ ircd::m::room::state::next(const event::idx &event_idx)
 {
 	event::idx ret{0};
 	next(event_idx, [&ret]
-	(const event::idx &event_idx)
+	(const event::idx &event_idx) noexcept
 	{
 		if(event_idx > ret)
 			ret = event_idx;
diff --git a/matrix/room_state_history.cc b/matrix/room_state_history.cc
index 02832948b..605366244 100644
--- a/matrix/room_state_history.cc
+++ b/matrix/room_state_history.cc
@@ -102,7 +102,7 @@ const
 	event::idx ret{0};
 	assert(type && defined(state_key));
 	for_each(type, state_key, [&ret]
-	(const auto &, const auto &, const auto &, const auto &event_idx)
+	(const auto &, const auto &, const auto &, const auto &event_idx) noexcept
 	{
 		ret = event_idx;
 		return false;
@@ -124,7 +124,7 @@ ircd::m::room::state::history::has(const string_view &type,
 const
 {
 	return !for_each(type, state_key, []
-	(const auto &type, const auto &state_key, const auto &depth, const auto &event_idx)
+	(const auto &, const auto &, const auto &, const auto &) noexcept
 	{
 		return false;
 	});
@@ -144,7 +144,7 @@ const
 {
 	size_t ret(0);
 	for_each(type, state_key, [&ret]
-	(const auto &type, const auto &state_key, const auto &depth, const auto &event_idx)
+	(const auto &, const auto &, const auto &, const auto &) noexcept
 	{
 		++ret;
 		return true;
diff --git a/matrix/room_state_space.cc b/matrix/room_state_space.cc
index 338ebc35f..8dbb509a9 100644
--- a/matrix/room_state_space.cc
+++ b/matrix/room_state_space.cc
@@ -73,7 +73,7 @@ ircd::m::room::state::space::has(const string_view &type,
 const
 {
 	return !for_each(type, state_key, depth, []
-	(const auto &type, const auto &state_key, const auto &depth, const auto &event_idx)
+	(const auto &, const auto &, const auto &, const auto &) noexcept
 	{
 		return false;
 	});
@@ -109,7 +109,7 @@ const
 {
 	size_t ret(0);
 	for_each(type, state_key, depth, [&ret]
-	(const auto &type, const auto &state_key, const auto &depth, const auto &event_idx)
+	(const auto &, const auto &, const auto &, const auto &) noexcept
 	{
 		++ret;
 		return true;
diff --git a/matrix/room_type.cc b/matrix/room_type.cc
index b1298716d..987a2fc13 100644
--- a/matrix/room_type.cc
+++ b/matrix/room_type.cc
@@ -34,7 +34,7 @@ ircd::m::room::type::empty()
 const
 {
 	return for_each([]
-	(const auto &type, const auto &depth, const auto &event_idx)
+	(const auto &type, const auto &depth, const auto &event_idx) noexcept
 	{
 		return false;
 	});
@@ -46,7 +46,7 @@ const
 {
 	size_t ret(0);
 	for_each([&ret]
-	(const auto &type, const auto &depth, const auto &event_idx)
+	(const auto &type, const auto &depth, const auto &event_idx) noexcept
 	{
 		++ret;
 		return true;
diff --git a/matrix/rooms.cc b/matrix/rooms.cc
index f5de7fcdb..44b34cc0f 100644
--- a/matrix/rooms.cc
+++ b/matrix/rooms.cc
@@ -64,7 +64,7 @@ bool
 ircd::m::rooms::has(const opts &opts)
 {
 	return !for_each(opts, []
-	(const m::room::id &)
+	(const m::room::id &) noexcept
 	{
 		// false to break; for_each() returns false
 		return false;
@@ -76,7 +76,7 @@ ircd::m::rooms::count(const opts &opts)
 {
 	size_t ret{0};
 	for_each(opts, [&ret]
-	(const m::room::id &)
+	(const m::room::id &) noexcept
 	{
 		++ret;
 		return true;
@@ -216,7 +216,7 @@ ircd::m::rooms::for_each(const opts &opts,
 	{
 		++prefetch;
 		prefetched += m::prefetch(event_idx, "room_id");
-		dock.wait([&]
+		dock.wait([&]() noexcept
 		{
 			return fetch + opts.prefetch > prefetch;
 		});
diff --git a/matrix/sync.cc b/matrix/sync.cc
index 069650f26..cd6b7d24f 100644
--- a/matrix/sync.cc
+++ b/matrix/sync.cc
@@ -461,7 +461,7 @@ const
 {
 	size_t ret(0);
 	sync::for_each(this->name(), [&ret]
-	(auto &item)
+	(auto &item) noexcept
 	{
 		++ret;
 		return true;
diff --git a/matrix/txn.cc b/matrix/txn.cc
index 2644b9e73..1451569ec 100644
--- a/matrix/txn.cc
+++ b/matrix/txn.cc
@@ -89,7 +89,7 @@ ircd::m::txn::create(const closure &closure,
 	{
 		iov, !empty(pdu),
 		{
-			"pdus", [&pdu]() -> json::value
+			"pdus", [&pdu]() noexcept -> json::value
 			{
 				return { data(pdu), size(pdu) };
 			}
@@ -100,7 +100,7 @@ ircd::m::txn::create(const closure &closure,
 	{
 		iov, !empty(edu),
 		{
-			"edus", [&edu]() -> json::value
+			"edus", [&edu]() noexcept -> json::value
 			{
 				return { data(edu), size(edu) };
 			}
@@ -111,7 +111,7 @@ ircd::m::txn::create(const closure &closure,
 	{
 		iov, !empty(pdu_failure),
 		{
-			"pdu_failures", [&pdu_failure]() -> json::value
+			"pdu_failures", [&pdu_failure]() noexcept -> json::value
 			{
 				return { data(pdu_failure), size(pdu_failure) };
 			}
diff --git a/matrix/user_devices.cc b/matrix/user_devices.cc
index ccefb733e..359b31d34 100644
--- a/matrix/user_devices.cc
+++ b/matrix/user_devices.cc
@@ -237,7 +237,7 @@ const
 	const bool got
 	{
 		get(std::nothrow, id, prop, [&val, &dup]
-		(const auto &event_idx, const json::string &existing)
+		(const auto &event_idx, const json::string &existing) noexcept
 		{
 			dup = val == existing;
 		})
@@ -293,7 +293,7 @@ const
 {
 	bool ret{false};
 	get(std::nothrow, id, prop, [&ret]
-	(const auto &event_idx, const string_view &value)
+	(const auto &event_idx, const string_view &value) noexcept
 	{
 		ret = !empty(value);
 	});
diff --git a/matrix/user_events.cc b/matrix/user_events.cc
index 29adabb9c..475f86bce 100644
--- a/matrix/user_events.cc
+++ b/matrix/user_events.cc
@@ -13,7 +13,7 @@ ircd::m::user::events::count()
 const
 {
 	size_t ret{0};
-	for_each([&ret](const event::idx &)
+	for_each([&ret](const event::idx &) noexcept
 	{
 		++ret;
 		return true;
diff --git a/matrix/user_ignores.cc b/matrix/user_ignores.cc
index 055601b92..42f0da201 100644
--- a/matrix/user_ignores.cc
+++ b/matrix/user_ignores.cc
@@ -33,7 +33,7 @@ ircd::m::user::ignores::has(const m::user::id &other)
 const
 {
 	return !for_each([&other]
-	(const m::user::id &user_id, const json::object &)
+	(const m::user::id &user_id, const json::object &) noexcept
 	{
 		return user_id != other;
 	});
diff --git a/matrix/user_mitsein.cc b/matrix/user_mitsein.cc
index b068aa275..b614afbb5 100644
--- a/matrix/user_mitsein.cc
+++ b/matrix/user_mitsein.cc
@@ -15,7 +15,7 @@ const
 {
 	// Return true if broken out of loop.
 	return !for_each(other, membership, []
-	(const m::room &, const string_view &)
+	(const m::room &, const string_view &) noexcept
 	{
 		// Break out of loop at first shared room
 		return false;
@@ -27,7 +27,8 @@ ircd::m::user::mitsein::count(const string_view &membership)
 const
 {
 	size_t ret{0};
-	for_each(membership, [&ret](const m::user &)
+	for_each(membership, [&ret]
+	(const m::user &) noexcept
 	{
 		++ret;
 		return true;
@@ -42,7 +43,8 @@ ircd::m::user::mitsein::count(const m::user &user,
 const
 {
 	size_t ret{0};
-	for_each(user, membership, [&ret](const m::room &, const string_view &)
+	for_each(user, membership, [&ret]
+	(const m::room &, const string_view &) noexcept
 	{
 		++ret;
 		return true;
diff --git a/matrix/user_notifications.cc b/matrix/user_notifications.cc
index f4af8b00c..926777c5f 100644
--- a/matrix/user_notifications.cc
+++ b/matrix/user_notifications.cc
@@ -58,7 +58,7 @@ ircd::m::user::notifications::empty(const opts &opts)
 const
 {
 	return !for_each(opts, closure_meta{[&]
-	(const auto &, const auto &)
+	(const auto &, const auto &) noexcept
 	{
 		return false;
 	}});
@@ -70,7 +70,7 @@ const
 {
 	size_t ret(0);
 	for_each(opts, closure_meta{[&ret]
-	(const auto &, const auto &)
+	(const auto &, const auto &) noexcept
 	{
 		++ret;
 		return true;
diff --git a/matrix/user_profile.cc b/matrix/user_profile.cc
index 4f44d7477..ef4dcc37d 100644
--- a/matrix/user_profile.cc
+++ b/matrix/user_profile.cc
@@ -152,7 +152,7 @@ ircd::m::user::profile::fetch(const m::user &user,
 	{
 		bool exists{false};
 		profile.get(std::nothrow, member.first, [&exists, &member]
-		(const string_view &key, const string_view &val)
+		(const string_view &key, const string_view &val) noexcept
 		{
 			exists = member.second == val;
 		});
diff --git a/matrix/user_pushers.cc b/matrix/user_pushers.cc
index 267b6fb32..039efa985 100644
--- a/matrix/user_pushers.cc
+++ b/matrix/user_pushers.cc
@@ -125,7 +125,8 @@ ircd::m::user::pushers::has(const string_view &key)
 const
 {
 	return !for_each([&key] // for_each() returns true if no match
-	(const event::idx &pusher_idx, const string_view &pushkey, const push::pusher &pusher)
+	(const event::idx &, const string_view &pushkey, const push::pusher &)
+	noexcept
 	{
 		return key != pushkey;
 	});
@@ -136,7 +137,8 @@ ircd::m::user::pushers::any(const string_view &kind)
 const
 {
 	return !for_each([&kind] // for_each() returns true if no match
-	(const event::idx &pusher_idx, const string_view &pushkey, const push::pusher &pusher)
+	(const event::idx &, const string_view &, const push::pusher &pusher)
+	noexcept
 	{
 		if(!kind)
 			return false;
@@ -154,7 +156,8 @@ const
 {
 	size_t ret{0};
 	for_each([&ret, &kind]
-	(const event::idx &pusher_idx, const string_view &pushkey, const push::pusher &pusher)
+	(const event::idx &, const string_view &, const push::pusher &pusher)
+	noexcept
 	{
 		ret += !kind || json::get<"kind"_>(pusher) == kind;
 		return true;
diff --git a/matrix/user_rooms.cc b/matrix/user_rooms.cc
index 2ddcf1788..0cf666ad0 100644
--- a/matrix/user_rooms.cc
+++ b/matrix/user_rooms.cc
@@ -14,7 +14,7 @@ const
 {
 	size_t ret{0};
 	for_each([&ret]
-	(const m::room &, const string_view &membership)
+	(const m::room &, const string_view &membership) noexcept
 	{
 		++ret;
 	});
@@ -28,7 +28,7 @@ const
 {
 	size_t ret{0};
 	for_each(membership, [&ret]
-	(const m::room &, const string_view &membership)
+	(const m::room &, const string_view &membership) noexcept
 	{
 		++ret;
 	});
diff --git a/matrix/users.cc b/matrix/users.cc
index 039b140f4..d0f77c8e3 100644
--- a/matrix/users.cc
+++ b/matrix/users.cc
@@ -21,7 +21,7 @@ bool
 ircd::m::users::exists(const opts &opts)
 {
 	return !for_each(opts, []
-	(const auto &)
+	(const auto &) noexcept
 	{
 		// return false to break and have for_each() returns false
 		return false;
@@ -32,7 +32,8 @@ size_t
 ircd::m::users::count(const opts &opts)
 {
 	size_t ret(0);
-	for_each(opts, [&ret](const auto &)
+	for_each(opts, [&ret]
+	(const auto &) noexcept
 	{
 		++ret;
 		return true;
diff --git a/matrix/users_servers.cc b/matrix/users_servers.cc
index a4fd12a9e..d7fc974ea 100644
--- a/matrix/users_servers.cc
+++ b/matrix/users_servers.cc
@@ -15,7 +15,7 @@ const
 {
 	// Return true if broken out of loop.
 	return !for_each(membership, []
-	(const auto &server)
+	(const auto &server) noexcept
 	{
 		// Break out of loop at first shared room
 		return false;
@@ -28,7 +28,7 @@ const
 {
 	size_t ret{0};
 	for_each(membership, [&ret]
-	(const auto &server)
+	(const auto &server) noexcept
 	{
 		++ret;
 		return true;