diff --git a/apps/emqx/src/emqx_gen_mod.erl b/apps/emqx/src/emqx_gen_mod.erl
deleted file mode 100644
index 0ebf6b59a..000000000
--- a/apps/emqx/src/emqx_gen_mod.erl
+++ /dev/null
@@ -1,23 +0,0 @@
-%%--------------------------------------------------------------------
-%% Copyright (c) 2017-2021 EMQ Technologies Co., Ltd. All Rights Reserved.
-%%
-%% Licensed under the Apache License, Version 2.0 (the "License");
-%% you may not use this file except in compliance with the License.
-%% You may obtain a copy of the License at
-%%
-%%     http://www.apache.org/licenses/LICENSE-2.0
-%%
-%% Unless required by applicable law or agreed to in writing, software
-%% distributed under the License is distributed on an "AS IS" BASIS,
-%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-%% See the License for the specific language governing permissions and
-%% limitations under the License.
-%%--------------------------------------------------------------------
-
--module(emqx_gen_mod).
-
--callback(load(Opts :: any()) -> ok | {error, term()}).
-
--callback(unload(State :: term()) -> term()).
-
--callback(description() -> any()).
diff --git a/apps/emqx_modules/etc/emqx_modules.conf b/apps/emqx_modules/etc/emqx_modules.conf
index c90515b74..9049ca6c7 100644
--- a/apps/emqx_modules/etc/emqx_modules.conf
+++ b/apps/emqx_modules/etc/emqx_modules.conf
@@ -1,37 +1,32 @@
-# empty
-emqx_modules: {
-    modules:[
+delayed: {
+    enable: true
+    max_delayed_messages: 0
+}
+
+recon: {
+    enable: true
+}
+
+telemetry: {
+    enable: true
+}
+
+presence: {
+    enable: true
+}
+
+topic_metrics:{
+    topics: ["topic/#"]
+}
+
+rewrite:{
+    rules: [
         {
-            type: delayed
-            enable: false
-        },
-        {
-            type: presence
-            enable: true
-            qos: 1
-        },
-        {
-            type: recon
-            enable: true
-        },
-        {
-            type: rewrite
-            enable: false
-            rules:[{
-                action: publish
-                source_topic: "x/#"
-                re: "^x/y/(.+)$"
-                dest_topic: "z/y/$1"
-            }]
-        },
-        {
-            type: topic_metrics
-            enable: false
-            topics: ["topic/#"]
-        },
-        {
-            type: telemetry
-            enable: false
+            action: publish
+            source_topic: "x/#"
+            re: "^x/y/(.+)$"
+            dest_topic: "z/y/$1"
         }
     ]
 }
+
diff --git a/apps/emqx_modules/src/emqx_mod_delayed.erl b/apps/emqx_modules/src/emqx_delayed.erl
similarity index 87%
rename from apps/emqx_modules/src/emqx_mod_delayed.erl
rename to apps/emqx_modules/src/emqx_delayed.erl
index 925952078..e63453b54 100644
--- a/apps/emqx_modules/src/emqx_mod_delayed.erl
+++ b/apps/emqx_modules/src/emqx_delayed.erl
@@ -14,10 +14,9 @@
 %% limitations under the License.
 %%--------------------------------------------------------------------
 
--module(emqx_mod_delayed).
+-module(emqx_delayed).
 
 -behaviour(gen_server).
--behaviour(emqx_gen_mod).
 
 -include_lib("emqx/include/emqx.hrl").
 -include_lib("emqx/include/logger.hrl").
@@ -30,12 +29,6 @@
 -boot_mnesia({mnesia, [boot]}).
 -copy_mnesia({mnesia, [copy]}).
 
-%% emqx_gen_mod callbacks
--export([ load/1
-        , unload/1
-        , description/0
-        ]).
-
 -export([ start_link/0
         , on_message_publish/1
         ]).
@@ -49,10 +42,13 @@
         , code_change/3
         ]).
 
--record(delayed_message,
-        { key
-        , msg
-        }).
+%% gen_server callbacks
+-export([ get_status/0
+        , enable/0
+        , disable/0
+        ]).
+
+-record(delayed_message, {key, msg}).
 
 -define(TAB, ?MODULE).
 -define(SERVER, ?MODULE).
@@ -63,7 +59,6 @@
 %%--------------------------------------------------------------------
 %% Mnesia bootstrap
 %%--------------------------------------------------------------------
-
 mnesia(boot) ->
     ok = ekka_mnesia:create_table(?TAB, [
                 {type, ordered_set},
@@ -75,25 +70,8 @@ mnesia(copy) ->
     ok = ekka_mnesia:copy_table(?TAB, disc_copies).
 
 %%--------------------------------------------------------------------
-%% Load/Unload
-%%--------------------------------------------------------------------
-
--spec(load(list()) -> ok).
-load(_Env) ->
-    emqx_mod_sup:start_child(?MODULE, worker),
-    emqx:hook('message.publish', {?MODULE, on_message_publish, []}).
-
--spec(unload(list()) -> ok).
-unload(_Env) ->
-    emqx:unhook('message.publish', {?MODULE, on_message_publish}),
-    emqx_mod_sup:stop_child(?MODULE).
-
-description() ->
-    "EMQ X Delayed Publish Module".
-%%--------------------------------------------------------------------
 %% Hooks
 %%--------------------------------------------------------------------
-
 on_message_publish(Msg = #message{
                             id = Id,
                             topic = <<"$delayed/", Topic/binary>>,
@@ -124,25 +102,48 @@ on_message_publish(Msg) ->
 
 -spec(start_link() -> emqx_types:startlink_ret()).
 start_link() ->
-    gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
+    Opts = emqx_config:get([delayed], #{}),
+    gen_server:start_link({local, ?SERVER}, ?MODULE, [Opts], []).
 
 -spec(store(#delayed_message{}) -> ok).
 store(DelayedMsg) ->
     gen_server:call(?SERVER, {store, DelayedMsg}, infinity).
 
+get_status() ->
+    gen_server:call(?SERVER, get_status).
+
+enable() ->
+    gen_server:call(?SERVER, enable).
+
+disable() ->
+    gen_server:call(?SERVER, disable).
+
 %%--------------------------------------------------------------------
 %% gen_server callback
 %%--------------------------------------------------------------------
 
-init([]) ->
+init([_Opts]) ->
     {ok, ensure_stats_event(
-           ensure_publish_timer(#{timer => undefined, publish_at => 0}))}.
+           ensure_publish_timer(#{timer => undefined,
+                                  publish_at => 0,
+                                  enabled => false}))}.
 
 handle_call({store, DelayedMsg = #delayed_message{key = Key}}, _From, State) ->
     ok = ekka_mnesia:dirty_write(?TAB, DelayedMsg),
     emqx_metrics:inc('messages.delayed'),
     {reply, ok, ensure_publish_timer(Key, State)};
 
+handle_call(enable, _From, State) ->
+    emqx_hooks:put('message.publish', {?MODULE, on_message_publish, []}),
+    {reply, ok, State};
+
+handle_call(disable, _From, State) ->
+    emqx_hooks:del('message.publish', {?MODULE, on_message_publish}),
+    {reply, ok, State};
+
+handle_call(get_status, _From, State = #{enabled := Enabled}) ->
+    {reply, Enabled, State};
+
 handle_call(Req, _From, State) ->
     ?LOG(error, "Unexpected call: ~p", [Req]),
     {reply, ignored, State}.
diff --git a/apps/emqx_modules/src/emqx_mod_api_topic_metrics.erl b/apps/emqx_modules/src/emqx_mod_api_topic_metrics.erl
deleted file mode 100644
index 2f8fbd017..000000000
--- a/apps/emqx_modules/src/emqx_mod_api_topic_metrics.erl
+++ /dev/null
@@ -1,207 +0,0 @@
-%%--------------------------------------------------------------------
-%% Copyright (c) 2020-2021 EMQ Technologies Co., Ltd. All Rights Reserved.
-%%
-%% Licensed under the Apache License, Version 2.0 (the "License");
-%% you may not use this file except in compliance with the License.
-%% You may obtain a copy of the License at
-%%
-%%     http://www.apache.org/licenses/LICENSE-2.0
-%%
-%% Unless required by applicable law or agreed to in writing, software
-%% distributed under the License is distributed on an "AS IS" BASIS,
-%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-%% See the License for the specific language governing permissions and
-%% limitations under the License.
-%%--------------------------------------------------------------------
-
--module(emqx_mod_api_topic_metrics).
-
--rest_api(#{name   => list_all_topic_metrics,
-            method => 'GET',
-            path   => "/topic-metrics",
-            func   => list,
-            descr  => "A list of all topic metrics of all nodes in the cluster"}).
-
--rest_api(#{name   => list_topic_metrics,
-            method => 'GET',
-            path   => "/topic-metrics/:bin:topic",
-            func   => list,
-            descr  => "A list of specfied topic metrics of all nodes in the cluster"}).
-
--rest_api(#{name   => register_topic_metrics,
-            method => 'POST',
-            path   => "/topic-metrics",
-            func   => register,
-            descr  => "Register topic metrics"}).
-
--rest_api(#{name   => unregister_all_topic_metrics,
-            method => 'DELETE',
-            path   => "/topic-metrics",
-            func   => unregister,
-            descr  => "Unregister all topic metrics"}).
-
--rest_api(#{name   => unregister_topic_metrics,
-            method => 'DELETE',
-            path   => "/topic-metrics/:bin:topic",
-            func   => unregister,
-            descr  => "Unregister topic metrics"}).
-
--export([ list/2
-        , register/2
-        , unregister/2
-        ]).
-
--export([ get_topic_metrics/2
-        , register_topic_metrics/2
-        , unregister_topic_metrics/2
-        , unregister_all_topic_metrics/1
-        ]).
-
-list(#{topic := Topic0}, _Params) ->
-    execute_when_enabled(fun() ->
-        Topic = emqx_mgmt_util:urldecode(Topic0),
-        case safe_validate(Topic) of
-            true ->
-                case get_topic_metrics(Topic) of
-                    {error, Reason} -> return({error, Reason});
-                    Metrics         -> return({ok, maps:from_list(Metrics)})
-                end;
-            false ->
-                return({error, invalid_topic_name})
-        end
-    end);
-
-list(_Bindings, _Params) ->
-    execute_when_enabled(fun() ->
-        case get_all_topic_metrics() of
-            {error, Reason} -> return({error, Reason});
-            Metrics         -> return({ok, Metrics})
-        end
-    end).
-
-register(_Bindings, Params) ->
-    execute_when_enabled(fun() ->
-        case proplists:get_value(<<"topic">>, Params) of
-            undefined ->
-                return({error, missing_required_params});
-            Topic ->
-                case safe_validate(Topic) of
-                    true ->
-                        register_topic_metrics(Topic),
-                        return(ok);
-                    false ->
-                        return({error, invalid_topic_name})
-                end
-        end
-    end).
-
-unregister(Bindings, _Params) when map_size(Bindings) =:= 0 ->
-    execute_when_enabled(fun() ->
-        unregister_all_topic_metrics(),
-        return(ok)
-    end);
-
-unregister(#{topic := Topic0}, _Params) ->
-    execute_when_enabled(fun() ->
-        Topic = emqx_mgmt_util:urldecode(Topic0),
-        case safe_validate(Topic) of
-            true ->
-                unregister_topic_metrics(Topic),
-                return(ok);
-            false ->
-                return({error, invalid_topic_name})
-        end
-    end).
-
-execute_when_enabled(Fun) ->
-    case emqx_modules:find_module(topic_metrics) of
-        true ->
-            Fun();
-        false ->
-            return({error, module_not_loaded})
-    end.
-
-safe_validate(Topic) ->
-    try emqx_topic:validate(name, Topic) of
-        true -> true
-    catch
-        error:_Error ->
-            false
-    end.
-
-get_all_topic_metrics() ->
-    lists:foldl(fun(Topic, Acc) ->
-                    case get_topic_metrics(Topic) of
-                        {error, _Reason} ->
-                            Acc;
-                        Metrics ->
-                            [#{topic => Topic, metrics => Metrics} | Acc]
-                    end
-                end, [], emqx_mod_topic_metrics:all_registered_topics()).
-
-get_topic_metrics(Topic) ->
-    lists:foldl(fun(Node, Acc) ->
-                    case get_topic_metrics(Node, Topic) of
-                        {error, _Reason} ->
-                            Acc;
-                        Metrics ->
-                            case Acc of
-                                [] -> Metrics;
-                                _ ->
-                                    lists:foldl(fun({K, V}, Acc0) ->
-                                                    [{K, V + proplists:get_value(K, Metrics, 0)} | Acc0]
-                                                end, [], Acc)
-                            end
-                    end
-                end, [], ekka_mnesia:running_nodes()).
-
-get_topic_metrics(Node, Topic) when Node =:= node() ->
-    emqx_mod_topic_metrics:metrics(Topic);
-get_topic_metrics(Node, Topic) ->
-    rpc_call(Node, get_topic_metrics, [Node, Topic]).
-
-register_topic_metrics(Topic) ->
-    Results = [register_topic_metrics(Node, Topic) || Node <- ekka_mnesia:running_nodes()],
-    case lists:any(fun(Item) -> Item =:= ok end, Results) of
-        true  -> ok;
-        false -> lists:last(Results)
-    end.
-
-register_topic_metrics(Node, Topic) when Node =:= node() ->
-    emqx_mod_topic_metrics:register(Topic);
-register_topic_metrics(Node, Topic) ->
-    rpc_call(Node, register_topic_metrics, [Node, Topic]).
-
-unregister_topic_metrics(Topic) ->
-    Results = [unregister_topic_metrics(Node, Topic) || Node <- ekka_mnesia:running_nodes()],
-    case lists:any(fun(Item) -> Item =:= ok end, Results) of
-        true  -> ok;
-        false -> lists:last(Results)
-    end.
-
-unregister_topic_metrics(Node, Topic) when Node =:= node() ->
-    emqx_mod_topic_metrics:unregister(Topic);
-unregister_topic_metrics(Node, Topic) ->
-    rpc_call(Node, unregister_topic_metrics, [Node, Topic]).
-
-unregister_all_topic_metrics() ->
-    Results = [unregister_all_topic_metrics(Node) || Node <- ekka_mnesia:running_nodes()],
-    case lists:any(fun(Item) -> Item =:= ok end, Results) of
-        true  -> ok;
-        false -> lists:last(Results)
-    end.
-
-unregister_all_topic_metrics(Node) when Node =:= node() ->
-    emqx_mod_topic_metrics:unregister_all();
-unregister_all_topic_metrics(Node) ->
-    rpc_call(Node, unregister_topic_metrics, [Node]).
-
-rpc_call(Node, Fun, Args) ->
-    case rpc:call(Node, ?MODULE, Fun, Args) of
-        {badrpc, Reason} -> {error, Reason};
-        Res -> Res
-    end.
-
-return(_) ->
-%%    TODO: V5 API
-    ok.
diff --git a/apps/emqx_modules/src/emqx_mod_sup.erl b/apps/emqx_modules/src/emqx_mod_sup.erl
deleted file mode 100644
index 6cb2cf722..000000000
--- a/apps/emqx_modules/src/emqx_mod_sup.erl
+++ /dev/null
@@ -1,79 +0,0 @@
-%%--------------------------------------------------------------------
-%% Copyright (c) 2020-2021 EMQ Technologies Co., Ltd. All Rights Reserved.
-%%
-%% Licensed under the Apache License, Version 2.0 (the "License");
-%% you may not use this file except in compliance with the License.
-%% You may obtain a copy of the License at
-%%
-%%     http://www.apache.org/licenses/LICENSE-2.0
-%%
-%% Unless required by applicable law or agreed to in writing, software
-%% distributed under the License is distributed on an "AS IS" BASIS,
-%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-%% See the License for the specific language governing permissions and
-%% limitations under the License.
-%%--------------------------------------------------------------------
-
--module(emqx_mod_sup).
-
--behaviour(supervisor).
-
--include_lib("emqx/include/types.hrl").
-
--export([ start_link/0
-        , start_child/1
-        , start_child/2
-        , stop_child/1
-        ]).
-
--export([init/1]).
-
-%% Helper macro for declaring children of supervisor
--define(CHILD(Mod, Type), #{id => Mod,
-                            start => {Mod, start_link, []},
-                            restart => permanent,
-                            shutdown => 5000,
-                            type => Type,
-                            modules => [Mod]}).
-
-start_link() ->
-    supervisor:start_link({local, ?MODULE}, ?MODULE, []).
-
--spec start_child(supervisor:child_spec()) -> ok.
-start_child(ChildSpec) when is_map(ChildSpec) ->
-    assert_started(supervisor:start_child(?MODULE, ChildSpec)).
-
--spec start_child(atom(), atom()) -> ok.
-start_child(Mod, Type) when is_atom(Mod) andalso is_atom(Type) ->
-    assert_started(supervisor:start_child(?MODULE, ?CHILD(Mod, Type))).
-
--spec(stop_child(any()) -> ok | {error, term()}).
-stop_child(ChildId) ->
-    case supervisor:terminate_child(?MODULE, ChildId) of
-        ok -> supervisor:delete_child(?MODULE, ChildId);
-        Error -> Error
-    end.
-
-%%--------------------------------------------------------------------
-%% Supervisor callbacks
-%%--------------------------------------------------------------------
-
-init([]) ->
-    Env = [],
-    {ok, {{one_for_one, 10, 3600},
-          [#{id       => telemetry,
-             start    => {emqx_mod_telemetry, start_link, [Env]},
-             restart  => permanent,
-             shutdown => 5000,
-             type     => worker,
-             modules  => [emqx_mod_telemetry]}]}}.
-
-%%--------------------------------------------------------------------
-%% Internal functions
-%%--------------------------------------------------------------------
-
-assert_started({ok, _Pid}) -> ok;
-assert_started({ok, _Pid, _Info}) -> ok;
-assert_started({error, {already_tarted, _Pid}}) -> ok;
-assert_started({error, Reason}) -> erlang:error(Reason).
-
diff --git a/apps/emqx_modules/src/emqx_modules.app.src b/apps/emqx_modules/src/emqx_modules.app.src
index 5d251abc9..155f581c0 100644
--- a/apps/emqx_modules/src/emqx_modules.app.src
+++ b/apps/emqx_modules/src/emqx_modules.app.src
@@ -1,9 +1,9 @@
 {application, emqx_modules,
- [{description, "EMQ X Module Management"},
+ [{description, "EMQ X Modules"},
   {vsn, "5.0.0"},
   {modules, []},
   {applications, [kernel,stdlib]},
   {mod, {emqx_modules_app, []}},
-  {registered, [emqx_mod_sup]},
+  {registered, [emqx_modules_sup]},
   {env, []}
  ]}.
diff --git a/apps/emqx_modules/src/emqx_modules.erl b/apps/emqx_modules/src/emqx_modules.erl
deleted file mode 100644
index e27f3afc2..000000000
--- a/apps/emqx_modules/src/emqx_modules.erl
+++ /dev/null
@@ -1,154 +0,0 @@
-%%--------------------------------------------------------------------
-%% Copyright (c) 2020-2021 EMQ Technologies Co., Ltd. All Rights Reserved.
-%%
-%% Licensed under the Apache License, Version 2.0 (the "License");
-%% you may not use this file except in compliance with the License.
-%% You may obtain a copy of the License at
-%%
-%%     http://www.apache.org/licenses/LICENSE-2.0
-%%
-%% Unless required by applicable law or agreed to in writing, software
-%% distributed under the License is distributed on an "AS IS" BASIS,
-%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-%% See the License for the specific language governing permissions and
-%% limitations under the License.
-%%--------------------------------------------------------------------
-
--module(emqx_modules).
-
--include_lib("emqx/include/logger.hrl").
-
--logger_header("[Modules]").
-
--export([ list/0
-        , load/0
-        , load/2
-        , unload/0
-        , unload/1
-        , reload/1
-        , find_module/1
-        ]).
-
--export([cli/1]).
-
-%% @doc List all available plugins
--spec(list() -> [{atom(), boolean()}]).
-list() ->
-    persistent_term:get(?MODULE, []).
-
-%% @doc Load all the extended modules.
--spec(load() -> ok).
-load() ->
-    Modules = emqx_config:get([emqx_modules, modules], []),
-    lists:foreach(fun(#{type := Module, enable := Enable} = Config) ->
-        case Enable of
-            true ->
-                load(name(Module), maps:without([type, enable], Config));
-            false ->
-                ok
-        end
-    end, Modules).
-
-load(Module, Env) ->
-    ModuleName = name(Module),
-    case find_module(ModuleName) of
-        false ->
-            load_mod(ModuleName, Env);
-        true ->
-            ?LOG(notice, "Module ~s is already started", [ModuleName]),
-            {error, already_started}
-    end.
-
-%% @doc Unload all the extended modules.
--spec(unload() -> ok).
-unload() ->
-    Modules = emqx_config:get([emqx_modules, modules], []),
-    lists:foreach(fun(#{type := Module, enable := Enable}) ->
-        case Enable of
-            true ->
-                unload_mod(name(Module));
-            false ->
-                ok
-        end
-    end, Modules).
-
-unload(ModuleName) ->
-    case find_module(ModuleName) of
-        false ->
-            ?LOG(alert, "Module ~s not found, cannot load it", [ModuleName]),
-            {error, not_started};
-        true ->
-            unload_mod(ModuleName)
-    end.
-
--spec(reload(module()) -> ok | ignore | {error, any()}).
-reload(_) ->
-    ignore.
-
-find_module(ModuleName) ->
-    lists:member(ModuleName, persistent_term:get(?MODULE, [])).
-
-load_mod(ModuleName, Env) ->
-    case ModuleName:load(Env) of
-        ok ->
-            Modules = persistent_term:get(?MODULE, []),
-            persistent_term:put(?MODULE, [ModuleName| Modules]),
-            ?LOG(info, "Load ~s module successfully.", [ModuleName]);
-        {error, Error} ->
-            ?LOG(error, "Load module ~s failed, cannot load for ~0p", [ModuleName, Error]),
-            {error, Error}
-    end.
-
-unload_mod(ModuleName) ->
-    case ModuleName:unload(#{}) of
-        ok ->
-            Modules = persistent_term:get(?MODULE, []),
-            persistent_term:put(?MODULE, Modules -- [ModuleName]),
-            ?LOG(info, "Unload ~s module successfully.", [ModuleName]);
-        {error, Error} ->
-            ?LOG(error, "Unload module ~s failed, cannot unload for ~0p", [ModuleName, Error])
-    end.
-
-%%--------------------------------------------------------------------
-%% @doc Modules Command
-cli(["list"]) ->
-    lists:foreach(fun(Name) ->
-                    emqx_ctl:print("Module(~s, description=~s)~n",
-                        [Name, Name:description()])
-                  end, emqx_modules:list());
-
-cli(["load", Name]) ->
-    case emqx_modules:load(list_to_atom(Name), #{}) of
-        ok ->
-            emqx_ctl:print("Module ~s loaded successfully.~n", [Name]);
-        {error, Reason}   ->
-            emqx_ctl:print("Load module ~s error: ~p.~n", [Name, Reason])
-    end;
-
-cli(["unload", Name]) ->
-    case emqx_modules:unload(list_to_atom(Name)) of
-        ok ->
-            emqx_ctl:print("Module ~s unloaded successfully.~n", [Name]);
-        {error, Reason} ->
-            emqx_ctl:print("Unload module ~s error: ~p.~n", [Name, Reason])
-    end;
-
-cli(["reload", Name]) ->
-    emqx_ctl:print("Module: ~p does not need to be reloaded.~n", [Name]);
-
-cli(_) ->
-    emqx_ctl:usage([{"modules list",            "Show loaded modules"},
-                    {"modules load <Module>",   "Load module"},
-                    {"modules unload <Module>", "Unload module"},
-                    {"modules reload <Module>", "Reload module"}
-                   ]).
-
-name(Name) when is_binary(Name) ->
-    name(binary_to_atom(Name, utf8));
-name(delayed) -> emqx_mod_delayed;
-name(presence) -> emqx_mod_presence;
-name(recon) -> emqx_mod_recon;
-name(rewrite) -> emqx_mod_rewrite;
-name(topic_metrics) -> emqx_mod_topic_metrics;
-name(telemetry) -> emqx_mod_telemetry;
-name(Name) -> Name.
diff --git a/apps/emqx_modules/src/emqx_modules_api.erl b/apps/emqx_modules/src/emqx_modules_api.erl
deleted file mode 100644
index 99a3b89f9..000000000
--- a/apps/emqx_modules/src/emqx_modules_api.erl
+++ /dev/null
@@ -1,171 +0,0 @@
-%%--------------------------------------------------------------------
-%% Copyright (c) 2020-2021 EMQ Technologies Co., Ltd. All Rights Reserved.
-%%
-%% Licensed under the Apache License, Version 2.0 (the "License");
-%% you may not use this file except in compliance with the License.
-%% You may obtain a copy of the License at
-%%
-%%     http://www.apache.org/licenses/LICENSE-2.0
-%%
-%% Unless required by applicable law or agreed to in writing, software
-%% distributed under the License is distributed on an "AS IS" BASIS,
-%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-%% See the License for the specific language governing permissions and
-%% limitations under the License.
-%%--------------------------------------------------------------------
-
--module(emqx_modules_api).
-
--rest_api(#{name   => list_all_modules,
-            method => 'GET',
-            path   => "/modules/",
-            func   => list,
-            descr  => "List all modules in the cluster"}).
-
--rest_api(#{name   => list_node_modules,
-            method => 'GET',
-            path   => "/nodes/:atom:node/modules/",
-            func   => list,
-            descr  => "List all modules on a node"}).
-
--rest_api(#{name   => load_node_module,
-            method => 'PUT',
-            path   => "/nodes/:atom:node/modules/:atom:module/load",
-            func   => load,
-            descr  => "Load a module"}).
-
--rest_api(#{name   => unload_node_module,
-            method => 'PUT',
-            path   => "/nodes/:atom:node/modules/:atom:module/unload",
-            func   => unload,
-            descr  => "Unload a module"}).
-
--rest_api(#{name   => reload_node_module,
-            method => 'PUT',
-            path   => "/nodes/:atom:node/modules/:atom:module/reload",
-            func   => reload,
-            descr  => "Reload a module"}).
-
--rest_api(#{name   => load_module,
-            method => 'PUT',
-            path   => "/modules/:atom:module/load",
-            func   => load,
-            descr  => "load a module in the cluster"}).
-
--rest_api(#{name   => unload_module,
-            method => 'PUT',
-            path   => "/modules/:atom:module/unload",
-            func   => unload,
-            descr  => "Unload a module in the cluster"}).
-
--rest_api(#{name   => reload_module,
-            method => 'PUT',
-            path   => "/modules/:atom:module/reload",
-            func   => reload,
-            descr  => "Reload a module in the cluster"}).
-
--export([ list/2
-        , list_modules/1
-        , load/2
-        , unload/2
-        , reload/2
-        ]).
-
--export([ do_load_module/3
-        , do_unload_module/2
-        ]).
-
-list(#{node := Node}, _Params) ->
-    return({ok, [format(Module) || Module <- list_modules(Node)]});
-
-list(_Bindings, _Params) ->
-    return({ok, [format(Node, Modules) || {Node, Modules} <- list_modules()]}).
-
-load(#{node := Node, module := Module}, Params) ->
-    return(do_load_module(Node, Module, Params));
-
-load(#{module := Module}, Params) ->
-    Results = [do_load_module(Node, Module, Params) || Node <- ekka_mnesia:running_nodes()],
-    case lists:filter(fun(Item) -> Item =/= ok end, Results) of
-        [] ->
-            return(ok);
-        Errors ->
-            return(lists:last(Errors))
-    end.
-
-unload(#{node := Node, module := Module}, _Params) ->
-    return(do_unload_module(Node, Module));
-
-unload(#{module := Module}, _Params) ->
-    Results = [do_unload_module(Node, Module) || Node <- ekka_mnesia:running_nodes()],
-    case lists:filter(fun(Item) -> Item =/= ok end, Results) of
-        [] ->
-            return(ok);
-        Errors ->
-            return(lists:last(Errors))
-    end.
-
-reload(#{node := Node, module := Module}, _Params) ->
-    case reload_module(Node, Module) of
-        ignore -> return(ok);
-        Result -> return(Result)
-    end;
-
-reload(#{module := Module}, _Params) ->
-    Results = [reload_module(Node, Module) || Node <- ekka_mnesia:running_nodes()],
-    case lists:filter(fun(Item) -> Item =/= ok end, Results) of
-        [] ->
-            return(ok);
-        Errors ->
-            return(lists:last(Errors))
-    end.
-
-%%------------------------------------------------------------------------------
-%% Internal Functions
-%%------------------------------------------------------------------------------
-
-format(Node, Modules) ->
-    #{node => Node, modules => [format(Module) || Module <- Modules]}.
-
-format(Name) ->
-    #{name => name(Name),
-      description => iolist_to_binary(Name:description())}.
-
-list_modules() ->
-    [{Node, list_modules(Node)} || Node <- ekka_mnesia:running_nodes()].
-
-list_modules(Node) when Node =:= node() ->
-    emqx_modules:list();
-list_modules(Node) ->
-    rpc_call(Node, list_modules, [Node]).
-
-do_load_module(Node, Module, Env) when Node =:= node() ->
-    emqx_modules:load(Module, Env);
-do_load_module(Node, Module, Env) ->
-    rpc_call(Node, do_load_module, [Node, Module, Env]).
-
-do_unload_module(Node, Module) when Node =:= node() ->
-    emqx_modules:unload(Module);
-do_unload_module(Node, Module) ->
-    rpc_call(Node, do_unload_module, [Node, Module]).
-
-reload_module(Node, Module) when Node =:= node() ->
-    emqx_modules:reload(Module);
-reload_module(Node, Module) ->
-    rpc_call(Node, reload_module, [Node, Module]).
-
-rpc_call(Node, Fun, Args) ->
-    case rpc:call(Node, ?MODULE, Fun, Args) of
-        {badrpc, Reason} -> {error, Reason};
-        Res -> Res
-    end.
-
-name(emqx_mod_delayed) -> delayed;
-name(emqx_mod_presence) -> presence;
-name(emqx_mod_recon) -> recon;
-name(emqx_mod_rewrite) -> rewrite;
-name(emqx_mod_topic_metrics) -> topic_metrics.
-
-return(_) ->
-%%    TODO: V5 API
-    ok.
diff --git a/apps/emqx_modules/src/emqx_modules_app.erl b/apps/emqx_modules/src/emqx_modules_app.erl
index 33f18459e..2b0ee482d 100644
--- a/apps/emqx_modules/src/emqx_modules_app.erl
+++ b/apps/emqx_modules/src/emqx_modules_app.erl
@@ -23,11 +23,26 @@
 -export([stop/1]).
 
 start(_Type, _Args) ->
-    {ok, Pid} = emqx_mod_sup:start_link(),
-    ok = emqx_modules:load(),
-    emqx_ctl:register_command(modules, {emqx_modules, cli}, []),
-    {ok, Pid}.
+    {ok, Sup} = emqx_modules_sup:start_link(),
+    maybe_enable_modules(),
+    {ok, Sup}.
 
 stop(_State) ->
-    emqx_ctl:unregister_command(modules),
-    emqx_modules:unload().
+    maybe_disable_modules(),
+    ok.
+
+maybe_enable_modules() ->
+    emqx_config:get([delayed, enable], true) andalso emqx_delayed:enable(),
+    emqx_config:get([presence, enable], true) andalso emqx_presence:enable(),
+    emqx_config:get([telemetry, enable], true) andalso emqx_telemetry:enable(),
+    emqx_config:get([recon, enable], true) andalso emqx_recon:enable(),
+    emqx_rewrite:enable(),
+    emqx_topic_metrics:enable().
+
+maybe_disable_modules() ->
+    emqx_config:get([delayed, enable], true) andalso emqx_delayed:disable(),
+    emqx_config:get([presence, enable], true) andalso emqx_presence:disable(),
+    emqx_config:get([telemetry, enable], true) andalso emqx_telemetry:disable(),
+    emqx_config:get([recon, enable], true) andalso emqx_recon:disable(),
+    emqx_rewrite:disable(),
+    emqx_topic_metrics:disable().
diff --git a/apps/emqx_modules/src/emqx_modules_schema.erl b/apps/emqx_modules/src/emqx_modules_schema.erl
index 55050987e..e7b8742e4 100644
--- a/apps/emqx_modules/src/emqx_modules_schema.erl
+++ b/apps/emqx_modules/src/emqx_modules_schema.erl
@@ -23,40 +23,31 @@
 -export([ structs/0
         , fields/1]).
 
-structs() -> ["emqx_modules"].
+structs() ->
+    ["delayed",
+     "recon",
+     "telemetry",
+     "presence",
+     "rewrite",
+     "topic_metrics"].
 
-fields("emqx_modules") ->
-    [{modules, hoconsc:array(hoconsc:union([ hoconsc:ref(?MODULE, "common")
-                                           , hoconsc:ref(?MODULE, "presence")
-                                           , hoconsc:ref(?MODULE, "rewrite")
-                                           , hoconsc:ref(?MODULE, "topic_metrics")
-                                           , hoconsc:ref(?MODULE, "telemetry")
-                                           ]))}];
-fields("common") ->
-    [ {type, hoconsc:enum([delayed, recon])}
-    , {enable, emqx_schema:t(boolean(), undefined, false)}
+fields(Name) when Name =:= "recon";
+                  Name =:= "telemetry";
+                  Name =:= "presence" ->
+    [ {enable, emqx_schema:t(boolean(), undefined, false)}
     ];
 
-fields("presence") ->
-    [ {type, hoconsc:enum([presence])}
-    , {enable, emqx_schema:t(boolean(), undefined, false)}
-    , {qos, emqx_schema:t(integer(), undefined, 1)}
+fields("delayed") ->
+    [ {enable, emqx_schema:t(boolean(), undefined, false)}
+    , {max_delayed_messages, emqx_schema:t(integer())}
     ];
+
 fields("rewrite") ->
-    [ {type, hoconsc:enum([rewrite])}
-    , {enable, emqx_schema:t(boolean(), undefined, false)}
-    , {rules, hoconsc:array(hoconsc:ref(?MODULE, "rules"))}
+    [ {rules, hoconsc:array(hoconsc:ref(?MODULE, "rules"))}
     ];
 
 fields("topic_metrics") ->
-    [ {type, hoconsc:enum([topic_metrics])}
-    , {enable, emqx_schema:t(boolean(), undefined, false)}
-    , {topics, hoconsc:array(binary())}
-    ];
-
-fields("telemetry") ->
-    [ {type, hoconsc:enum([telemetry])}
-    , {enable, emqx_schema:t(boolean(), undefined, false)}
+    [ {topics, hoconsc:array(binary())}
     ];
 
 fields("rules") ->
diff --git a/apps/emqx_modules/src/emqx_modules_sup.erl b/apps/emqx_modules/src/emqx_modules_sup.erl
new file mode 100644
index 000000000..570082896
--- /dev/null
+++ b/apps/emqx_modules/src/emqx_modules_sup.erl
@@ -0,0 +1,43 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2020-2021 EMQ Technologies Co., Ltd. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%--------------------------------------------------------------------
+
+-module(emqx_modules_sup).
+
+-behaviour(supervisor).
+
+-export([start_link/0]).
+
+-export([init/1]).
+
+%% Helper macro for declaring children of supervisor
+-define(CHILD(Mod), #{id => Mod,
+                      start => {Mod, start_link, []},
+                      restart => permanent,
+                      shutdown => 5000,
+                      type => worker,
+                      modules => [Mod]}).
+
+start_link() ->
+    supervisor:start_link({local, ?MODULE}, ?MODULE, []).
+
+%%--------------------------------------------------------------------
+%% Supervisor callbacks
+%%--------------------------------------------------------------------
+init([]) ->
+    {ok, {{one_for_one, 10, 3600},
+          [?CHILD(emqx_telemetry),
+           ?CHILD(emqx_topic_metrics),
+           ?CHILD(emqx_delayed)]}}.
diff --git a/apps/emqx_modules/src/emqx_mod_presence.erl b/apps/emqx_modules/src/emqx_presence.erl
similarity index 86%
rename from apps/emqx_modules/src/emqx_mod_presence.erl
rename to apps/emqx_modules/src/emqx_presence.erl
index 729316663..c85d951e1 100644
--- a/apps/emqx_modules/src/emqx_mod_presence.erl
+++ b/apps/emqx_modules/src/emqx_presence.erl
@@ -14,55 +14,49 @@
 %% limitations under the License.
 %%--------------------------------------------------------------------
 
--module(emqx_mod_presence).
-
--behaviour(emqx_gen_mod).
+-module(emqx_presence).
 
 -include_lib("emqx/include/emqx.hrl").
 -include_lib("emqx/include/logger.hrl").
 
 -logger_header("[Presence]").
 
-%% emqx_gen_mod callbacks
--export([ load/1
-        , unload/1
-        , description/0
+-export([ enable/0
+        , disable/0
         ]).
 
--export([ on_client_connected/3
-        , on_client_disconnected/4
+-export([ on_client_connected/2
+        , on_client_disconnected/3
         ]).
 
 -ifdef(TEST).
 -export([reason/1]).
 -endif.
 
-load(Env) ->
-    emqx_hooks:put('client.connected',    {?MODULE, on_client_connected, [Env]}),
-    emqx_hooks:put('client.disconnected', {?MODULE, on_client_disconnected, [Env]}).
+enable() ->
+    emqx_hooks:put('client.connected',    {?MODULE, on_client_connected, []}),
+    emqx_hooks:put('client.disconnected', {?MODULE, on_client_disconnected, []}).
 
-unload(_Env) ->
+disable() ->
     emqx_hooks:del('client.connected',    {?MODULE, on_client_connected}),
     emqx_hooks:del('client.disconnected', {?MODULE, on_client_disconnected}).
 
-description() ->
-    "EMQ X Presence Module".
 %%--------------------------------------------------------------------
 %% Callbacks
 %%--------------------------------------------------------------------
 
-on_client_connected(ClientInfo = #{clientid := ClientId}, ConnInfo, Env) ->
+on_client_connected(ClientInfo = #{clientid := ClientId}, ConnInfo) ->
     Presence = connected_presence(ClientInfo, ConnInfo),
     case emqx_json:safe_encode(Presence) of
         {ok, Payload} ->
             emqx_broker:safe_publish(
-              make_msg(qos(Env), topic(connected, ClientId), Payload));
+              make_msg(topic(connected, ClientId), Payload));
         {error, _Reason} ->
             ?LOG(error, "Failed to encode 'connected' presence: ~p", [Presence])
     end.
 
 on_client_disconnected(_ClientInfo = #{clientid := ClientId, username := Username},
-                       Reason, _ConnInfo = #{disconnected_at := DisconnectedAt}, Env) ->
+                       Reason, _ConnInfo = #{disconnected_at := DisconnectedAt}) ->
     Presence = #{clientid => ClientId,
                  username => Username,
                  reason => reason(Reason),
@@ -72,7 +66,7 @@ on_client_disconnected(_ClientInfo = #{clientid := ClientId, username := Usernam
     case emqx_json:safe_encode(Presence) of
         {ok, Payload} ->
             emqx_broker:safe_publish(
-              make_msg(qos(Env), topic(disconnected, ClientId), Payload));
+              make_msg(topic(disconnected, ClientId), Payload));
         {error, _Reason} ->
             ?LOG(error, "Failed to encode 'disconnected' presence: ~p", [Presence])
     end.
@@ -107,18 +101,16 @@ connected_presence(#{peerhost := PeerHost,
       ts => erlang:system_time(millisecond)
      }.
 
-make_msg(QoS, Topic, Payload) ->
+make_msg(Topic, Payload) ->
     emqx_message:set_flag(
       sys, emqx_message:make(
-             ?MODULE, QoS, Topic, iolist_to_binary(Payload))).
+             ?MODULE, 0, Topic, iolist_to_binary(Payload))).
 
 topic(connected, ClientId) ->
     emqx_topic:systop(iolist_to_binary(["clients/", ClientId, "/connected"]));
 topic(disconnected, ClientId) ->
     emqx_topic:systop(iolist_to_binary(["clients/", ClientId, "/disconnected"])).
 
-qos(Env) -> maps:get(qos, Env, 0).
-
 -compile({inline, [reason/1]}).
 reason(Reason) when is_atom(Reason) -> Reason;
 reason({shutdown, Reason}) when is_atom(Reason) -> Reason;
diff --git a/apps/emqx_modules/src/emqx_mod_recon.erl b/apps/emqx_modules/src/emqx_recon.erl
similarity index 89%
rename from apps/emqx_modules/src/emqx_mod_recon.erl
rename to apps/emqx_modules/src/emqx_recon.erl
index 38d046b10..b16d1b051 100644
--- a/apps/emqx_modules/src/emqx_mod_recon.erl
+++ b/apps/emqx_modules/src/emqx_recon.erl
@@ -14,37 +14,24 @@
 %% limitations under the License.
 %%--------------------------------------------------------------------
 
--module(emqx_mod_recon).
+-module(emqx_recon).
 
--behaviour(emqx_gen_mod).
-
-%% emqx_gen_mod callbacks
--export([ load/1
-        , unload/1
-        , description/0
+-export([ enable/0
+        , disable/0
         ]).
 
 -export([cmd/1]).
 
 
 %%--------------------------------------------------------------------
-%% Load/Unload
+%% enable/disable
 %%--------------------------------------------------------------------
-
--spec(load(list()) -> ok).
-load(_Env) ->
-    load().
-
--spec(unload(list()) -> ok).
-unload(_Env) ->
-    unload().
-
-description() ->
-    "EMQ X Recon Module".
-
-load() ->
+enable() ->
     emqx_ctl:register_command(recon, {?MODULE, cmd}, []).
 
+disable() ->
+    emqx_ctl:unregister_command(recon).
+
 cmd(["memory"]) ->
     Print = fun(Key, Keyword) ->
               emqx_ctl:print("~-20s: ~w~n", [concat(Key, Keyword), recon_alloc:memory(Key, Keyword)])
@@ -76,9 +63,6 @@ cmd(_) ->
                     {"recon remote_load Mod",  "recon:remote_load(Mod)"},
                     {"recon proc_count Attr N","recon:proc_count(Attr, N)"}]).
 
-unload() ->
-    emqx_ctl:unregister_command(recon).
-
 concat(Key, Keyword) ->
     lists:concat([atom_to_list(Key), "/", atom_to_list(Keyword)]).
 
diff --git a/apps/emqx_modules/src/emqx_mod_rewrite.erl b/apps/emqx_modules/src/emqx_rewrite.erl
similarity index 85%
rename from apps/emqx_modules/src/emqx_mod_rewrite.erl
rename to apps/emqx_modules/src/emqx_rewrite.erl
index e1ee6e1b6..20e51ae16 100644
--- a/apps/emqx_modules/src/emqx_mod_rewrite.erl
+++ b/apps/emqx_modules/src/emqx_rewrite.erl
@@ -14,9 +14,7 @@
 %% limitations under the License.
 %%--------------------------------------------------------------------
 
--module(emqx_mod_rewrite).
-
--behaviour(emqx_gen_mod).
+-module(emqx_rewrite).
 
 -include_lib("emqx/include/emqx.hrl").
 -include_lib("emqx/include/emqx_mqtt.hrl").
@@ -33,21 +31,29 @@
         , rewrite_publish/2
         ]).
 
-%% emqx_gen_mod callbacks
--export([ load/1
-        , unload/1
-        , description/0
+-export([ enable/0
+        , disable/0
         ]).
 
 %%--------------------------------------------------------------------
 %% Load/Unload
 %%--------------------------------------------------------------------
 
-load(Env) ->
-    {PubRules, SubRules} = compile(maps:get(rules, Env, [])),
-    emqx_hooks:put('client.subscribe',   {?MODULE, rewrite_subscribe, [SubRules]}),
-    emqx_hooks:put('client.unsubscribe', {?MODULE, rewrite_unsubscribe, [SubRules]}),
-    emqx_hooks:put('message.publish',    {?MODULE, rewrite_publish, [PubRules]}).
+enable() ->
+    Rules = emqx_config:get([rewrite, rules], []),
+    case Rules =:= [] of
+        true -> ok;
+        false ->
+            {PubRules, SubRules} = compile(Rules),
+            emqx_hooks:put('client.subscribe',   {?MODULE, rewrite_subscribe, [SubRules]}),
+            emqx_hooks:put('client.unsubscribe', {?MODULE, rewrite_unsubscribe, [SubRules]}),
+            emqx_hooks:put('message.publish',    {?MODULE, rewrite_publish, [PubRules]})
+    end.
+
+disable() ->
+    emqx_hooks:del('client.subscribe',   {?MODULE, rewrite_subscribe}),
+    emqx_hooks:del('client.unsubscribe', {?MODULE, rewrite_unsubscribe}),
+    emqx_hooks:del('message.publish',    {?MODULE, rewrite_publish}).
 
 rewrite_subscribe(_ClientInfo, _Properties, TopicFilters, Rules) ->
     {ok, [{match_and_rewrite(Topic, Rules), Opts} || {Topic, Opts} <- TopicFilters]}.
@@ -58,13 +64,6 @@ rewrite_unsubscribe(_ClientInfo, _Properties, TopicFilters, Rules) ->
 rewrite_publish(Message = #message{topic = Topic}, Rules) ->
     {ok, Message#message{topic = match_and_rewrite(Topic, Rules)}}.
 
-unload(_) ->
-    emqx_hooks:del('client.subscribe',   {?MODULE, rewrite_subscribe}),
-    emqx_hooks:del('client.unsubscribe', {?MODULE, rewrite_unsubscribe}),
-    emqx_hooks:del('message.publish',    {?MODULE, rewrite_publish}).
-
-description() ->
-    "EMQ X Topic Rewrite Module".
 %%--------------------------------------------------------------------
 %% Internal functions
 %%--------------------------------------------------------------------
diff --git a/apps/emqx_modules/src/emqx_mod_telemetry.erl b/apps/emqx_modules/src/emqx_telemetry.erl
similarity index 97%
rename from apps/emqx_modules/src/emqx_mod_telemetry.erl
rename to apps/emqx_modules/src/emqx_telemetry.erl
index 21082285d..50fc6a243 100644
--- a/apps/emqx_modules/src/emqx_mod_telemetry.erl
+++ b/apps/emqx_modules/src/emqx_telemetry.erl
@@ -14,12 +14,10 @@
 %% limitations under the License.
 %%--------------------------------------------------------------------
 
--module(emqx_mod_telemetry).
+-module(emqx_telemetry).
 
 -behaviour(gen_server).
 
--behaviour(emqx_gen_mod).
-
 -include_lib("emqx/include/emqx.hrl").
 -include_lib("emqx/include/logger.hrl").
 
@@ -34,7 +32,7 @@
 -boot_mnesia({mnesia, [boot]}).
 -copy_mnesia({mnesia, [copy]}).
 
--export([ start_link/1
+-export([ start_link/0
         , stop/0
         ]).
 
@@ -48,10 +46,8 @@
         , code_change/3
         ]).
 
-%% emqx_gen_mod callbacks
--export([ load/1
-        , unload/1
-        , description/0
+-export([ enable/0
+        , disable/0
         ]).
 
 -export([ get_status/0
@@ -111,16 +107,17 @@ mnesia(copy) ->
 %% API
 %%--------------------------------------------------------------------
 
-start_link(Opts) ->
+start_link() ->
+    Opts = emqx_config:get([telemetry], #{}),
     gen_server:start_link({local, ?MODULE}, ?MODULE, [Opts], []).
 
 stop() ->
     gen_server:stop(?MODULE).
 
-load(_Env) ->
+enable() ->
     gen_server:call(?MODULE, enable).
 
-unload(_Env) ->
+disable() ->
     gen_server:call(?MODULE, disable).
 
 get_status() ->
@@ -132,9 +129,6 @@ get_uuid() ->
 get_telemetry() ->
     gen_server:call(?MODULE, get_telemetry).
 
-description() ->
-    "".
-
 %%--------------------------------------------------------------------
 %% gen_server callbacks
 %%--------------------------------------------------------------------
@@ -300,7 +294,8 @@ active_plugins() ->
                     end, [], emqx_plugins:list()).
 
 active_modules() ->
-    emqx_modules:list().
+    [].
+    % emqx_modules:list().
 
 num_clients() ->
     emqx_stats:getstat('connections.max').
diff --git a/apps/emqx_modules/src/emqx_mod_telemetry_api.erl b/apps/emqx_modules/src/emqx_telemetry_api.erl
similarity index 95%
rename from apps/emqx_modules/src/emqx_mod_telemetry_api.erl
rename to apps/emqx_modules/src/emqx_telemetry_api.erl
index ab0d040f7..af5f40b02 100644
--- a/apps/emqx_modules/src/emqx_mod_telemetry_api.erl
+++ b/apps/emqx_modules/src/emqx_telemetry_api.erl
@@ -14,7 +14,7 @@
 %% limitations under the License.
 %%--------------------------------------------------------------------
 
--module(emqx_mod_telemetry_api).
+-module(emqx_telemetry_api).
 
 -behavior(minirest_api).
 
@@ -149,7 +149,7 @@ status(put, Request) ->
     {ok, Body, _} = cowboy_req:read_body(Request),
     Params = emqx_json:decode(Body, [return_maps]),
     Enable = maps:get(<<"enable">>, Params),
-    case Enable =:= emqx_mod_telemetry:get_status() of
+    case Enable =:= emqx_telemetry:get_status() of
         true ->
             Reason = case Enable of
                 true -> <<"Telemetry status is already enabled">>;
@@ -168,7 +168,7 @@ data(get, _Request) ->
 %%--------------------------------------------------------------------
 % cli(["enable", Enable0]) ->
 %     Enable = list_to_atom(Enable0),
-%     case Enable =:= emqx_mod_telemetry:is_enabled() of
+%     case Enable =:= emqx_telemetry:is_enabled() of
 %         true ->
 %             case Enable of
 %                 true -> emqx_ctl:print("Telemetry status is already enabled~n");
@@ -215,18 +215,18 @@ enable_telemetry(Enable) ->
 enable_telemetry(Node, Enable) when Node =:= node() ->
     case Enable of
         true ->
-            emqx_mod_telemetry:load(#{});
+            emqx_telemetry:enable();
         false ->
-            emqx_mod_telemetry:unload(#{})
+            emqx_telemetry:disable()
     end;
 enable_telemetry(Node, Enable) ->
     rpc_call(Node, ?MODULE, enable_telemetry, [Node, Enable]).
 
 get_telemetry_status() ->
-    #{enabled => emqx_mod_telemetry:get_status()}.
+    #{enabled => emqx_telemetry:get_status()}.
 
 get_telemetry_data() ->
-    {ok, TelemetryData} = emqx_mod_telemetry:get_telemetry(),
+    {ok, TelemetryData} = emqx_telemetry:get_telemetry(),
     TelemetryData.
 
 rpc_call(Node, Module, Fun, Args) ->
diff --git a/apps/emqx_modules/src/emqx_mod_topic_metrics.erl b/apps/emqx_modules/src/emqx_topic_metrics.erl
similarity index 94%
rename from apps/emqx_modules/src/emqx_mod_topic_metrics.erl
rename to apps/emqx_modules/src/emqx_topic_metrics.erl
index 0196b9b2a..7297878fe 100644
--- a/apps/emqx_modules/src/emqx_mod_topic_metrics.erl
+++ b/apps/emqx_modules/src/emqx_topic_metrics.erl
@@ -14,10 +14,9 @@
 %% limitations under the License.
 %%--------------------------------------------------------------------
 
--module(emqx_mod_topic_metrics).
+-module(emqx_topic_metrics).
 
 -behaviour(gen_server).
--behaviour(emqx_gen_mod).
 
 -include_lib("emqx/include/emqx.hrl").
 -include_lib("emqx/include/logger.hrl").
@@ -25,11 +24,6 @@
 
 -logger_header("[TOPIC_METRICS]").
 
--export([ load/1
-        , unload/1
-        , description/0
-        ]).
-
 -export([ on_message_publish/1
         , on_message_delivered/2
         , on_message_dropped/3
@@ -40,11 +34,11 @@
         , stop/0
         ]).
 
--export([ inc/2
-        , inc/3
-        , val/2
-        , rate/2
-        , metrics/1
+-export([ enable/0
+        , disable/0
+        ]).
+
+-export([ metrics/1
         , register/1
         , unregister/1
         , unregister_all/0
@@ -52,9 +46,6 @@
         , all_registered_topics/0
         ]).
 
-%% stats.
--export([ rates/2 ]).
-
 %% gen_server callbacks
 -export([ init/1
         , handle_call/3
@@ -63,7 +54,10 @@
         , terminate/2
         ]).
 
--define(CRefID(Topic), {?MODULE, Topic}).
+-ifdef(TEST).
+-compile(export_all).
+-compile(nowarn_export_all).
+-endif.
 
 -define(MAX_TOPICS, 512).
 -define(TAB, ?MODULE).
@@ -99,21 +93,15 @@
 %%------------------------------------------------------------------------------
 %% APIs
 %%------------------------------------------------------------------------------
-
-load(_Env) ->
-    emqx_mod_sup:start_child(?MODULE, worker),
+enable() ->
     emqx_hooks:put('message.publish',   {?MODULE, on_message_publish, []}),
     emqx_hooks:put('message.dropped',   {?MODULE, on_message_dropped, []}),
     emqx_hooks:put('message.delivered', {?MODULE, on_message_delivered, []}).
 
-unload(_Env) ->
+disable() ->
     emqx_hooks:del('message.publish',   {?MODULE, on_message_publish}),
     emqx_hooks:del('message.dropped',   {?MODULE, on_message_dropped}),
-    emqx_hooks:del('message.delivered', {?MODULE, on_message_delivered}),
-    emqx_mod_sup:stop_child(?MODULE).
-
-description() ->
-    "EMQ X Topic Metrics Module".
+    emqx_hooks:del('message.delivered', {?MODULE, on_message_delivered}).
 
 on_message_publish(#message{topic = Topic, qos = QoS}) ->
     case is_registered(Topic) of
@@ -150,55 +138,12 @@ on_message_dropped(#message{topic = Topic}, _, _) ->
     end.
 
 start_link() ->
-    gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
+    Opts = emqx_config:get([topic_metrics], #{}),
+    gen_server:start_link({local, ?MODULE}, ?MODULE, [Opts], []).
 
 stop() ->
     gen_server:stop(?MODULE).
 
-try_inc(Topic, Metric) ->
-    _ = inc(Topic, Metric),
-    ok.
-
-inc(Topic, Metric) ->
-    inc(Topic, Metric, 1).
-
-inc(Topic, Metric, Val) ->
-    case get_counters(Topic) of
-        {error, topic_not_found} ->
-            {error, topic_not_found};
-        CRef ->
-            case metric_idx(Metric) of
-                {error, invalid_metric} ->
-                    {error, invalid_metric};
-                Idx ->
-                    counters:add(CRef, Idx, Val)
-            end
-    end.
-
-val(Topic, Metric) ->
-    case ets:lookup(?TAB, Topic) of
-        [] ->
-            {error, topic_not_found};
-        [{Topic, CRef}] ->
-            case metric_idx(Metric) of
-                {error, invalid_metric} ->
-                    {error, invalid_metric};
-                Idx ->
-                    counters:get(CRef, Idx)
-            end
-    end.
-
-rate(Topic, Metric) ->
-    case rates(Topic, Metric) of
-        #{short := Last} ->
-            Last;
-        {error, Reason} ->
-            {error, Reason}
-    end.
-
-rates(Topic, Metric) ->
-    gen_server:call(?MODULE, {get_rates, Topic, Metric}).
-
 metrics(Topic) ->
     case ets:lookup(?TAB, Topic) of
         [] ->
@@ -229,7 +174,7 @@ all_registered_topics() ->
 %% gen_server callbacks
 %%--------------------------------------------------------------------
 
-init([]) ->
+init([_Opts]) ->
     erlang:process_flag(trap_exit, true),
     ok = emqx_tables:new(?TAB, [{read_concurrency, true}]),
     erlang:send_after(timer:seconds(?TICKING_INTERVAL), self(), ticking),
@@ -279,7 +224,7 @@ handle_call({get_rates, Topic, Metric}, _From, State = #state{speeds = Speeds})
                 undefined ->
                     {reply, {error, invalid_metric}, State};
                 #speed{last = Short, last_medium = Medium, last_long = Long}  ->
-                    {reply, #{ short => Short, medium => Medium, long => Long }, State}
+                    {reply, #{short => Short, medium => Medium, long => Long }, State}
             end
     end.
 
@@ -309,6 +254,47 @@ terminate(_Reason, _State) ->
 %% Internal Functions
 %%------------------------------------------------------------------------------
 
+try_inc(Topic, Metric) ->
+    _ = inc(Topic, Metric),
+    ok.
+
+inc(Topic, Metric) ->
+    inc(Topic, Metric, 1).
+
+inc(Topic, Metric, Val) ->
+    case get_counters(Topic) of
+        {error, topic_not_found} ->
+            {error, topic_not_found};
+        CRef ->
+            case metric_idx(Metric) of
+                {error, invalid_metric} ->
+                    {error, invalid_metric};
+                Idx ->
+                    counters:add(CRef, Idx, Val)
+            end
+    end.
+
+val(Topic, Metric) ->
+    case ets:lookup(?TAB, Topic) of
+        [] ->
+            {error, topic_not_found};
+        [{Topic, CRef}] ->
+            case metric_idx(Metric) of
+                {error, invalid_metric} ->
+                    {error, invalid_metric};
+                Idx ->
+                    counters:get(CRef, Idx)
+            end
+    end.
+
+rate(Topic, Metric) ->
+    case gen_server:call(?MODULE, {get_rates, Topic, Metric}) of
+        #{short := Last} ->
+            Last;
+        {error, Reason} ->
+            {error, Reason}
+    end.
+
 metric_idx('messages.in') ->       01;
 metric_idx('messages.out') ->      02;
 metric_idx('messages.qos0.in') ->  03;
diff --git a/apps/emqx_modules/src/emqx_topic_metrics_api.erl b/apps/emqx_modules/src/emqx_topic_metrics_api.erl
new file mode 100644
index 000000000..1a2365703
--- /dev/null
+++ b/apps/emqx_modules/src/emqx_topic_metrics_api.erl
@@ -0,0 +1,207 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2020-2021 EMQ Technologies Co., Ltd. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%--------------------------------------------------------------------
+
+-module(emqx_topic_metrics_api).
+
+% -rest_api(#{name   => list_all_topic_metrics,
+%             method => 'GET',
+%             path   => "/topic-metrics",
+%             func   => list,
+%             descr  => "A list of all topic metrics of all nodes in the cluster"}).
+
+% -rest_api(#{name   => list_topic_metrics,
+%             method => 'GET',
+%             path   => "/topic-metrics/:bin:topic",
+%             func   => list,
+%             descr  => "A list of specfied topic metrics of all nodes in the cluster"}).
+
+% -rest_api(#{name   => register_topic_metrics,
+%             method => 'POST',
+%             path   => "/topic-metrics",
+%             func   => register,
+%             descr  => "Register topic metrics"}).
+
+% -rest_api(#{name   => unregister_all_topic_metrics,
+%             method => 'DELETE',
+%             path   => "/topic-metrics",
+%             func   => unregister,
+%             descr  => "Unregister all topic metrics"}).
+
+% -rest_api(#{name   => unregister_topic_metrics,
+%             method => 'DELETE',
+%             path   => "/topic-metrics/:bin:topic",
+%             func   => unregister,
+%             descr  => "Unregister topic metrics"}).
+
+% -export([ list/2
+%         , register/2
+%         , unregister/2
+%         ]).
+
+% -export([ get_topic_metrics/2
+%         , register_topic_metrics/2
+%         , unregister_topic_metrics/2
+%         , unregister_all_topic_metrics/1
+%         ]).
+
+% list(#{topic := Topic0}, _Params) ->
+%     execute_when_enabled(fun() ->
+%         Topic = emqx_mgmt_util:urldecode(Topic0),
+%         case safe_validate(Topic) of
+%             true ->
+%                 case get_topic_metrics(Topic) of
+%                     {error, Reason} -> return({error, Reason});
+%                     Metrics         -> return({ok, maps:from_list(Metrics)})
+%                 end;
+%             false ->
+%                 return({error, invalid_topic_name})
+%         end
+%     end);
+
+% list(_Bindings, _Params) ->
+%     execute_when_enabled(fun() ->
+%         case get_all_topic_metrics() of
+%             {error, Reason} -> return({error, Reason});
+%             Metrics         -> return({ok, Metrics})
+%         end
+%     end).
+
+% register(_Bindings, Params) ->
+%     execute_when_enabled(fun() ->
+%         case proplists:get_value(<<"topic">>, Params) of
+%             undefined ->
+%                 return({error, missing_required_params});
+%             Topic ->
+%                 case safe_validate(Topic) of
+%                     true ->
+%                         register_topic_metrics(Topic),
+%                         return(ok);
+%                     false ->
+%                         return({error, invalid_topic_name})
+%                 end
+%         end
+%     end).
+
+% unregister(Bindings, _Params) when map_size(Bindings) =:= 0 ->
+%     execute_when_enabled(fun() ->
+%         unregister_all_topic_metrics(),
+%         return(ok)
+%     end);
+
+% unregister(#{topic := Topic0}, _Params) ->
+%     execute_when_enabled(fun() ->
+%         Topic = emqx_mgmt_util:urldecode(Topic0),
+%         case safe_validate(Topic) of
+%             true ->
+%                 unregister_topic_metrics(Topic),
+%                 return(ok);
+%             false ->
+%                 return({error, invalid_topic_name})
+%         end
+%     end).
+
+% execute_when_enabled(Fun) ->
+%     case emqx_modules:find_module(topic_metrics) of
+%         true ->
+%             Fun();
+%         false ->
+%             return({error, module_not_loaded})
+%     end.
+
+% safe_validate(Topic) ->
+%     try emqx_topic:validate(name, Topic) of
+%         true -> true
+%     catch
+%         error:_Error ->
+%             false
+%     end.
+
+% get_all_topic_metrics() ->
+%     lists:foldl(fun(Topic, Acc) ->
+%                     case get_topic_metrics(Topic) of
+%                         {error, _Reason} ->
+%                             Acc;
+%                         Metrics ->
+%                             [#{topic => Topic, metrics => Metrics} | Acc]
+%                     end
+%                 end, [], emqx_mod_topic_metrics:all_registered_topics()).
+
+% get_topic_metrics(Topic) ->
+%     lists:foldl(fun(Node, Acc) ->
+%                     case get_topic_metrics(Node, Topic) of
+%                         {error, _Reason} ->
+%                             Acc;
+%                         Metrics ->
+%                             case Acc of
+%                                 [] -> Metrics;
+%                                 _ ->
+%                                     lists:foldl(fun({K, V}, Acc0) ->
+%                                                     [{K, V + proplists:get_value(K, Metrics, 0)} | Acc0]
+%                                                 end, [], Acc)
+%                             end
+%                     end
+%                 end, [], ekka_mnesia:running_nodes()).
+
+% get_topic_metrics(Node, Topic) when Node =:= node() ->
+%     emqx_mod_topic_metrics:metrics(Topic);
+% get_topic_metrics(Node, Topic) ->
+%     rpc_call(Node, get_topic_metrics, [Node, Topic]).
+
+% register_topic_metrics(Topic) ->
+%     Results = [register_topic_metrics(Node, Topic) || Node <- ekka_mnesia:running_nodes()],
+%     case lists:any(fun(Item) -> Item =:= ok end, Results) of
+%         true  -> ok;
+%         false -> lists:last(Results)
+%     end.
+
+% register_topic_metrics(Node, Topic) when Node =:= node() ->
+%     emqx_mod_topic_metrics:register(Topic);
+% register_topic_metrics(Node, Topic) ->
+%     rpc_call(Node, register_topic_metrics, [Node, Topic]).
+
+% unregister_topic_metrics(Topic) ->
+%     Results = [unregister_topic_metrics(Node, Topic) || Node <- ekka_mnesia:running_nodes()],
+%     case lists:any(fun(Item) -> Item =:= ok end, Results) of
+%         true  -> ok;
+%         false -> lists:last(Results)
+%     end.
+
+% unregister_topic_metrics(Node, Topic) when Node =:= node() ->
+%     emqx_mod_topic_metrics:unregister(Topic);
+% unregister_topic_metrics(Node, Topic) ->
+%     rpc_call(Node, unregister_topic_metrics, [Node, Topic]).
+
+% unregister_all_topic_metrics() ->
+%     Results = [unregister_all_topic_metrics(Node) || Node <- ekka_mnesia:running_nodes()],
+%     case lists:any(fun(Item) -> Item =:= ok end, Results) of
+%         true  -> ok;
+%         false -> lists:last(Results)
+%     end.
+
+% unregister_all_topic_metrics(Node) when Node =:= node() ->
+%     emqx_mod_topic_metrics:unregister_all();
+% unregister_all_topic_metrics(Node) ->
+%     rpc_call(Node, unregister_topic_metrics, [Node]).
+
+% rpc_call(Node, Fun, Args) ->
+%     case rpc:call(Node, ?MODULE, Fun, Args) of
+%         {badrpc, Reason} -> {error, Reason};
+%         Res -> Res
+%     end.
+
+% return(_) ->
+% %%    TODO: V5 API
+%     ok.
diff --git a/apps/emqx_modules/test/emqx_mod_delayed_SUITE.erl b/apps/emqx_modules/test/emqx_delayed_SUITE.erl
similarity index 77%
rename from apps/emqx_modules/test/emqx_mod_delayed_SUITE.erl
rename to apps/emqx_modules/test/emqx_delayed_SUITE.erl
index 2cd1107f6..c79903f42 100644
--- a/apps/emqx_modules/test/emqx_mod_delayed_SUITE.erl
+++ b/apps/emqx_modules/test/emqx_delayed_SUITE.erl
@@ -14,9 +14,9 @@
 %% limitations under the License.
 %%--------------------------------------------------------------------
 
--module(emqx_mod_delayed_SUITE).
+-module(emqx_delayed_SUITE).
 
--import(emqx_mod_delayed, [on_message_publish/1]).
+-import(emqx_delayed, [on_message_publish/1]).
 
 -compile(export_all).
 -compile(nowarn_export_all).
@@ -35,6 +35,8 @@ all() ->
     emqx_ct:all(?MODULE).
 
 init_per_suite(Config) ->
+    ekka_mnesia:start(),
+    ok = emqx_delayed:mnesia(boot),
     emqx_ct_helpers:start_apps([emqx_modules]),
     Config.
 
@@ -46,26 +48,28 @@ end_per_suite(_) ->
 %%--------------------------------------------------------------------
 
 t_load_case(_) ->
-    UnHooks = emqx_hooks:lookup('message.publish'),
-    ?assertEqual([], UnHooks),
-    ok = emqx_mod_delayed:load([]),
     Hooks = emqx_hooks:lookup('message.publish'),
-    ?assertEqual(1, length(Hooks)),
+    MFA = {emqx_delayed,on_message_publish,[]},
+    ?assertEqual(false, lists:keyfind(MFA, 2, Hooks)),
+    ok = emqx_delayed:enable(),
+    Hooks1 = emqx_hooks:lookup('message.publish'),
+    ct:pal("----~p~n", [Hooks1]),
+    ?assertNotEqual(false, lists:keyfind(MFA, 2, Hooks1)),
     ok.
 
 t_delayed_message(_) ->
-    ok = emqx_mod_delayed:load([]),
+    ok = emqx_delayed:enable(),
     DelayedMsg = emqx_message:make(?MODULE, 1, <<"$delayed/1/publish">>, <<"delayed_m">>),
     ?assertEqual({stop, DelayedMsg#message{topic = <<"publish">>, headers = #{allow_publish => false}}}, on_message_publish(DelayedMsg)),
 
     Msg = emqx_message:make(?MODULE, 1, <<"no_delayed_msg">>, <<"no_delayed">>),
     ?assertEqual({ok, Msg}, on_message_publish(Msg)),
 
-    [Key] = mnesia:dirty_all_keys(emqx_mod_delayed),
-    [#delayed_message{msg = #message{payload = Payload}}] = mnesia:dirty_read({emqx_mod_delayed, Key}),
+    [Key] = mnesia:dirty_all_keys(emqx_delayed),
+    [#delayed_message{msg = #message{payload = Payload}}] = mnesia:dirty_read({emqx_delayed, Key}),
     ?assertEqual(<<"delayed_m">>, Payload),
     timer:sleep(5000),
 
-    EmptyKey = mnesia:dirty_all_keys(emqx_mod_delayed),
+    EmptyKey = mnesia:dirty_all_keys(emqx_delayed),
     ?assertEqual([], EmptyKey),
-    ok = emqx_mod_delayed:unload([]).
+    ok = emqx_delayed:disable().
diff --git a/apps/emqx_modules/test/emqx_mod_topic_metrics_SUITE.erl b/apps/emqx_modules/test/emqx_mod_topic_metrics_SUITE.erl
deleted file mode 100644
index d41150e4a..000000000
--- a/apps/emqx_modules/test/emqx_mod_topic_metrics_SUITE.erl
+++ /dev/null
@@ -1,95 +0,0 @@
-%%--------------------------------------------------------------------
-%% Copyright (c) 2020-2021 EMQ Technologies Co., Ltd. All Rights Reserved.
-%%
-%% Licensed under the Apache License, Version 2.0 (the "License");
-%% you may not use this file except in compliance with the License.
-%% You may obtain a copy of the License at
-%%
-%%     http://www.apache.org/licenses/LICENSE-2.0
-%%
-%% Unless required by applicable law or agreed to in writing, software
-%% distributed under the License is distributed on an "AS IS" BASIS,
-%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-%% See the License for the specific language governing permissions and
-%% limitations under the License.
-%%--------------------------------------------------------------------
-
--module(emqx_mod_topic_metrics_SUITE).
-
--compile(export_all).
--compile(nowarn_export_all).
-
--include_lib("eunit/include/eunit.hrl").
-
-all() -> emqx_ct:all(?MODULE).
-
-init_per_suite(Config) ->
-    emqx_ct_helpers:boot_modules(all),
-    emqx_ct_helpers:start_apps([emqx_modules]),
-    Config.
-
-end_per_suite(_Config) ->
-    emqx_ct_helpers:stop_apps([emqx_modules]).
-
-t_nonexistent_topic_metrics(_) ->
-    emqx_mod_topic_metrics:load([]),
-    ?assertEqual({error, topic_not_found}, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
-    ?assertEqual({error, topic_not_found}, emqx_mod_topic_metrics:inc(<<"a/b/c">>, 'messages.in')),
-    ?assertEqual({error, topic_not_found}, emqx_mod_topic_metrics:rate(<<"a/b/c">>, 'messages.in')),
-    ?assertEqual({error, topic_not_found}, emqx_mod_topic_metrics:rates(<<"a/b/c">>, 'messages.in')),
-    emqx_mod_topic_metrics:register(<<"a/b/c">>),
-    ?assertEqual(0, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
-    ?assertEqual({error, invalid_metric}, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'invalid.metrics')),
-    ?assertEqual({error, invalid_metric}, emqx_mod_topic_metrics:inc(<<"a/b/c">>, 'invalid.metrics')),
-    ?assertEqual({error, invalid_metric}, emqx_mod_topic_metrics:rate(<<"a/b/c">>, 'invalid.metrics')),
-    ?assertEqual({error, invalid_metric}, emqx_mod_topic_metrics:rates(<<"a/b/c">>, 'invalid.metrics')),
-    emqx_mod_topic_metrics:unregister(<<"a/b/c">>),
-    emqx_mod_topic_metrics:unload([]).
-
-t_topic_metrics(_) ->
-    emqx_mod_topic_metrics:load([]),
-
-    ?assertEqual(false, emqx_mod_topic_metrics:is_registered(<<"a/b/c">>)),
-    ?assertEqual([], emqx_mod_topic_metrics:all_registered_topics()),
-    emqx_mod_topic_metrics:register(<<"a/b/c">>),
-    ?assertEqual(true, emqx_mod_topic_metrics:is_registered(<<"a/b/c">>)),
-    ?assertEqual([<<"a/b/c">>], emqx_mod_topic_metrics:all_registered_topics()),
-
-    ?assertEqual(0, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
-    ?assertEqual(ok, emqx_mod_topic_metrics:inc(<<"a/b/c">>, 'messages.in')),
-    ?assertEqual(1, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
-    ?assert(emqx_mod_topic_metrics:rate(<<"a/b/c">>, 'messages.in') =:= 0),
-    ?assert(emqx_mod_topic_metrics:rates(<<"a/b/c">>, 'messages.in') =:= #{long => 0,medium => 0,short => 0}),
-    emqx_mod_topic_metrics:unregister(<<"a/b/c">>),
-    emqx_mod_topic_metrics:unload([]).
-
-t_hook(_) ->
-    emqx_mod_topic_metrics:load([]),
-    emqx_mod_topic_metrics:register(<<"a/b/c">>),
-
-    ?assertEqual(0, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
-    ?assertEqual(0, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'messages.qos0.in')),
-    ?assertEqual(0, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'messages.out')),
-    ?assertEqual(0, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'messages.qos0.out')),
-    ?assertEqual(0, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'messages.dropped')),
-
-    {ok, C} = emqtt:start_link([{host, "localhost"},
-                                {clientid, "myclient"},
-                                {username, "myuser"}]),
-    {ok, _} = emqtt:connect(C),
-    emqtt:publish(C, <<"a/b/c">>, <<"Hello world">>, 0),
-    ct:sleep(100),
-    ?assertEqual(1, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
-    ?assertEqual(1, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'messages.qos0.in')),
-    ?assertEqual(1, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'messages.dropped')),
-
-    emqtt:subscribe(C, <<"a/b/c">>),
-    emqtt:publish(C, <<"a/b/c">>, <<"Hello world">>, 0),
-    ct:sleep(100),
-    ?assertEqual(2, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
-    ?assertEqual(2, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'messages.qos0.in')),
-    ?assertEqual(1, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'messages.out')),
-    ?assertEqual(1, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'messages.qos0.out')),
-    ?assertEqual(1, emqx_mod_topic_metrics:val(<<"a/b/c">>, 'messages.dropped')),
-    emqx_mod_topic_metrics:unregister(<<"a/b/c">>),
-    emqx_mod_topic_metrics:unload([]).
diff --git a/apps/emqx_modules/test/emqx_modules_SUITE.erl b/apps/emqx_modules/test/emqx_modules_SUITE.erl
deleted file mode 100644
index 0ee097258..000000000
--- a/apps/emqx_modules/test/emqx_modules_SUITE.erl
+++ /dev/null
@@ -1,203 +0,0 @@
-%%--------------------------------------------------------------------
-%% Copyright (c) 2020-2021 EMQ Technologies Co., Ltd. All Rights Reserved.
-%%
-%% Licensed under the Apache License, Version 2.0 (the "License");
-%% you may not use this file except in compliance with the License.
-%% You may obtain a copy of the License at
-%%
-%%     http://www.apache.org/licenses/LICENSE-2.0
-%%
-%% Unless required by applicable law or agreed to in writing, software
-%% distributed under the License is distributed on an "AS IS" BASIS,
-%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-%% See the License for the specific language governing permissions and
-%% limitations under the License.
-%%--------------------------------------------------------------------
-
--module(emqx_modules_SUITE).
-
--compile(export_all).
--compile(nowarn_export_all).
-
--include_lib("eunit/include/eunit.hrl").
-
--define(CONTENT_TYPE, "application/x-www-form-urlencoded").
-
--define(HOST, "http://127.0.0.1:8081/").
-
--define(API_VERSION, "v4").
-
--define(BASE_PATH, "api").
-
-all() -> emqx_ct:all(?MODULE).
-
-init_per_suite(Config) ->
-    emqx_ct_helpers:start_apps([emqx_management, emqx_modules], fun set_special_configs/1),
-    emqx_ct_http:create_default_app(),
-    Config.
-
-set_special_configs(emqx_management) ->
-    emqx_config:put([emqx_management], #{listeners => [#{protocol => http, port => 8081}],
-        applications =>[#{id => "admin", secret => "public"}]}),
-    ok;
-set_special_configs(_) ->
-    ok.
-
-end_per_suite(_Config) ->
-    emqx_ct_http:delete_default_app(),
-    emqx_ct_helpers:stop_apps([emqx_modules, emqx_management]).
-
-t_load(_) ->
-    ?assertEqual(ok, emqx_modules:unload()),
-    ?assertEqual(ok, emqx_modules:load()),
-    ?assertEqual({error, not_started}, emqx_modules:unload(rewrite)),
-    ?assertEqual(ignore, emqx_modules:reload(rewrite)).
-
-t_list(_) ->
-    emqx_modules:load(presence, #{qos => 1}),
-    ?assertMatch([_ | _ ], emqx_modules:list()),
-    emqx_modules:unload(presence).
-
-%% TODO: V5 API
-%%t_modules_api(_) ->
-%%    emqx_modules:load(presence, #{qos => 1}),
-%%    timer:sleep(50),
-%%    {ok, Modules1} = request_api(get, api_path(["modules"]), auth_header_()),
-%%    [Modules11] = filter(get(<<"data">>, Modules1), <<"node">>, atom_to_binary(node(), utf8)),
-%%    [Module1] = filter(maps:get(<<"modules">>, Modules11), <<"name">>, <<"presence">>),
-%%    ?assertEqual(<<"presence">>, maps:get(<<"name">>, Module1)),
-%%    {ok, _} = request_api(put,
-%%                          api_path(["modules",
-%%                                    atom_to_list(presence),
-%%                                    "unload"]),
-%%                          auth_header_()),
-%%    {ok, Error1} = request_api(put,
-%%                               api_path(["modules",
-%%                                         atom_to_list(presence),
-%%                                         "unload"]),
-%%                               auth_header_()),
-%%    ?assertEqual(<<"not_started">>, get(<<"message">>, Error1)),
-%%    {ok, Modules2} = request_api(get,
-%%                                 api_path(["nodes", atom_to_list(node()), "modules"]),
-%%                                 auth_header_()),
-%%    [Module2] = filter(get(<<"data">>, Modules2), <<"name">>, <<"presence">>),
-%%    ?assertEqual(<<"presence">>, maps:get(<<"name">>, Module2)),
-%%
-%%    {ok, _} = request_api(put,
-%%                          api_path(["nodes",
-%%                                    atom_to_list(node()),
-%%                                    "modules",
-%%                                    atom_to_list(presence),
-%%                                    "load"]),
-%%                          auth_header_()),
-%%    {ok, Modules3} = request_api(get,
-%%                                 api_path(["nodes", atom_to_list(node()), "modules"]),
-%%                                 auth_header_()),
-%%    [Module3] = filter(get(<<"data">>, Modules3), <<"name">>, <<"presence">>),
-%%    ?assertEqual(<<"presence">>, maps:get(<<"name">>, Module3)),
-%%
-%%    {ok, _} = request_api(put,
-%%                          api_path(["nodes",
-%%                                    atom_to_list(node()),
-%%                                    "modules",
-%%                                    atom_to_list(presence),
-%%                                    "unload"]),
-%%                          auth_header_()),
-%%    {ok, Error2} = request_api(put,
-%%                               api_path(["nodes",
-%%                                         atom_to_list(node()),
-%%                                         "modules",
-%%                                         atom_to_list(presence),
-%%                                         "unload"]),
-%%                               auth_header_()),
-%%    ?assertEqual(<<"not_started">>, get(<<"message">>, Error2)),
-%%    emqx_modules:unload(presence).
-
-
-t_modules_cmd(_) ->
-    mock_print(),
-    meck:new(emqx_modules, [non_strict, passthrough]),
-    meck:expect(emqx_modules, load, fun(_) -> ok end),
-    meck:expect(emqx_modules, unload, fun(_) -> ok end),
-    meck:expect(emqx_modules, reload, fun(_) -> ok end),
-    ?assertEqual(emqx_modules:cli(["list"]), ok),
-    ?assertEqual(emqx_modules:cli(["load", "delayed"]),
-                 "Module delayed loaded successfully.\n"),
-    ?assertEqual(emqx_modules:cli(["unload", "delayed"]),
-                 "Module delayed unloaded successfully.\n"),
-    unmock_print().
-
-%% For: https://github.com/emqx/emqx/issues/4511
-t_join_cluster(_) ->
-    %% Started by emqx application
-    {error, {already_started, emqx_modules}} = application:start(emqx_modules),
-    %% After clustered
-    emqx:shutdown(),
-    emqx:reboot(),
-    {error,{already_started,emqx_modules}} = application:start(emqx_modules),
-    %% After emqx reboot, we should not interfere with other tests
-    _ = end_per_suite([]),
-    _ = init_per_suite([]),
-    ok.
-
-mock_print() ->
-    catch meck:unload(emqx_ctl),
-    meck:new(emqx_ctl, [non_strict, passthrough]),
-    meck:expect(emqx_ctl, print, fun(Arg) -> emqx_ctl:format(Arg) end),
-    meck:expect(emqx_ctl, print, fun(Msg, Arg) -> emqx_ctl:format(Msg, Arg) end),
-    meck:expect(emqx_ctl, usage, fun(Usages) -> emqx_ctl:format_usage(Usages) end),
-    meck:expect(emqx_ctl, usage, fun(Cmd, Descr) -> emqx_ctl:format_usage(Cmd, Descr) end).
-
-unmock_print() ->
-    meck:unload(emqx_ctl).
-
-get(Key, ResponseBody) ->
-   maps:get(Key, jiffy:decode(list_to_binary(ResponseBody), [return_maps])).
-
-request_api(Method, Url, Auth) ->
-    request_api(Method, Url, [], Auth, []).
-
-request_api(Method, Url, QueryParams, Auth) ->
-    request_api(Method, Url, QueryParams, Auth, []).
-
-request_api(Method, Url, QueryParams, Auth, []) ->
-    NewUrl = case QueryParams of
-                 "" -> Url;
-                 _ -> Url ++ "?" ++ QueryParams
-             end,
-    do_request_api(Method, {NewUrl, [Auth]});
-request_api(Method, Url, QueryParams, Auth, Body) ->
-    NewUrl = case QueryParams of
-                 "" -> Url;
-                 _ -> Url ++ "?" ++ QueryParams
-             end,
-    do_request_api(Method, {NewUrl, [Auth], "application/json", emqx_json:encode(Body)}).
-
-do_request_api(Method, Request)->
-    ct:pal("Method: ~p, Request: ~p", [Method, Request]),
-    case httpc:request(Method, Request, [], []) of
-        {error, socket_closed_remotely} ->
-            {error, socket_closed_remotely};
-        {ok, {{"HTTP/1.1", Code, _}, _, Return} }
-            when Code =:= 200 orelse Code =:= 201 ->
-            {ok, Return};
-        {ok, {Reason, _, _}} ->
-            {error, Reason}
-    end.
-
-auth_header_() ->
-    AppId = <<"admin">>,
-    AppSecret = <<"public">>,
-    auth_header_(binary_to_list(AppId), binary_to_list(AppSecret)).
-
-auth_header_(User, Pass) ->
-    Encoded = base64:encode_to_string(lists:append([User,":",Pass])),
-    {"Authorization","Basic " ++ Encoded}.
-
-api_path(Parts)->
-    ?HOST ++ filename:join([?BASE_PATH, ?API_VERSION] ++ Parts).
-
-filter(List, Key, Value) ->
-    lists:filter(fun(Item) ->
-        maps:get(Key, Item) == Value
-    end, List).
diff --git a/apps/emqx_modules/test/emqx_mod_presence_SUITE.erl b/apps/emqx_modules/test/emqx_presence_SUITE.erl
similarity index 83%
rename from apps/emqx_modules/test/emqx_mod_presence_SUITE.erl
rename to apps/emqx_modules/test/emqx_presence_SUITE.erl
index e02fa6fdd..de6e7bccc 100644
--- a/apps/emqx_modules/test/emqx_mod_presence_SUITE.erl
+++ b/apps/emqx_modules/test/emqx_presence_SUITE.erl
@@ -14,7 +14,7 @@
 %% limitations under the License.
 %%--------------------------------------------------------------------
 
--module(emqx_mod_presence_SUITE).
+-module(emqx_presence_SUITE).
 
 -compile(export_all).
 -compile(nowarn_export_all).
@@ -27,16 +27,13 @@ all() -> emqx_ct:all(?MODULE).
 init_per_suite(Config) ->
     emqx_ct_helpers:boot_modules(all),
     emqx_ct_helpers:start_apps([emqx_modules]),
-    %% Ensure all the modules unloaded.
-    ok = emqx_modules:unload(),
     Config.
 
 end_per_suite(_Config) ->
     emqx_ct_helpers:stop_apps([emqx_modules]).
 
-%% Test case for emqx_mod_presence
 t_mod_presence(_) ->
-    ok = emqx_mod_presence:load(#{qos => ?QOS_1}),
+    ok = emqx_presence:enable(),
     {ok, C1} = emqtt:start_link([{clientid, <<"monsys">>}]),
     {ok, _} = emqtt:connect(C1),
     {ok, _Props, [?QOS_1]} = emqtt:subscribe(C1, <<"$SYS/brokers/+/clients/#">>, qos1),
@@ -49,16 +46,16 @@ t_mod_presence(_) ->
     ok = emqtt:disconnect(C2),
     ok = recv_and_check_presence(<<"clientid">>, <<"disconnected">>),
     ok = emqtt:disconnect(C1),
-    ok = emqx_mod_presence:unload([]).
+    ok = emqx_presence:disable().
 
 t_mod_presence_reason(_) ->
-    ?assertEqual(normal, emqx_mod_presence:reason(normal)),
-    ?assertEqual(discarded, emqx_mod_presence:reason({shutdown, discarded})),
-    ?assertEqual(tcp_error, emqx_mod_presence:reason({tcp_error, einval})),
-    ?assertEqual(internal_error, emqx_mod_presence:reason(<<"unknown error">>)).
+    ?assertEqual(normal, emqx_presence:reason(normal)),
+    ?assertEqual(discarded, emqx_presence:reason({shutdown, discarded})),
+    ?assertEqual(tcp_error, emqx_presence:reason({tcp_error, einval})),
+    ?assertEqual(internal_error, emqx_presence:reason(<<"unknown error">>)).
 
 recv_and_check_presence(ClientId, Presence) ->
-    {ok, #{qos := ?QOS_1, topic := Topic, payload := Payload}} = receive_publish(100),
+    {ok, #{qos := ?QOS_0, topic := Topic, payload := Payload}} = receive_publish(100),
     ?assertMatch([<<"$SYS">>, <<"brokers">>, _Node, <<"clients">>, ClientId, Presence],
                  binary:split(Topic, <<"/">>, [global])),
     case Presence of
diff --git a/apps/emqx_modules/test/emqx_mod_rewrite_SUITE.erl b/apps/emqx_modules/test/emqx_rewrite_SUITE.erl
similarity index 79%
rename from apps/emqx_modules/test/emqx_mod_rewrite_SUITE.erl
rename to apps/emqx_modules/test/emqx_rewrite_SUITE.erl
index 9b94cba8c..f7a681ffb 100644
--- a/apps/emqx_modules/test/emqx_mod_rewrite_SUITE.erl
+++ b/apps/emqx_modules/test/emqx_rewrite_SUITE.erl
@@ -14,7 +14,7 @@
 %% limitations under the License.
 %%--------------------------------------------------------------------
 
--module(emqx_mod_rewrite_SUITE).
+-module(emqx_rewrite_SUITE).
 
 -compile(export_all).
 -compile(nowarn_export_all).
@@ -38,8 +38,6 @@ all() -> emqx_ct:all(?MODULE).
 init_per_suite(Config) ->
     emqx_ct_helpers:boot_modules(all),
     emqx_ct_helpers:start_apps([emqx_modules]),
-    %% Ensure all the modules unloaded.
-    ok = emqx_modules:unload(),
     Config.
 
 end_per_suite(_Config) ->
@@ -47,7 +45,12 @@ end_per_suite(_Config) ->
 
 %% Test case for emqx_mod_write
 t_mod_rewrite(_Config) ->
-    ok = emqx_mod_rewrite:load(#{rules => ?RULES}),
+    %% important! let emqx_schema include the current app!
+    meck:new(emqx_schema, [non_strict, passthrough, no_history, no_link]),
+    meck:expect(emqx_schema, includes, fun() -> ["rewrite"] end ),
+    meck:expect(emqx_schema, extra_schema_fields, fun(FieldName) -> emqx_modules_schema:fields(FieldName) end),
+    ok = emqx_config:update([rewrite, rules], ?RULES),
+    ok = emqx_rewrite:enable(),
     {ok, C} = emqtt:start_link([{clientid, <<"rewrite_client">>}]),
     {ok, _} = emqtt:connect(C),
     PubOrigTopics = [<<"x/y/2">>, <<"x/1/2">>],
@@ -79,14 +82,15 @@ t_mod_rewrite(_Config) ->
     {ok, _, _} = emqtt:unsubscribe(C, PubDestTopics),
 
     ok = emqtt:disconnect(C),
-    ok = emqx_mod_rewrite:unload(?RULES).
+    ok = emqx_rewrite:disable(),
+    meck:unload(emqx_schema).
 
 t_rewrite_rule(_Config) ->
-    {PubRules, SubRules} = emqx_mod_rewrite:compile(?RULES),
-    ?assertEqual(<<"z/y/2">>, emqx_mod_rewrite:match_and_rewrite(<<"x/y/2">>, PubRules)),
-    ?assertEqual(<<"x/1/2">>, emqx_mod_rewrite:match_and_rewrite(<<"x/1/2">>, PubRules)),
-    ?assertEqual(<<"y/z/b">>, emqx_mod_rewrite:match_and_rewrite(<<"y/a/z/b">>, SubRules)),
-    ?assertEqual(<<"y/def">>, emqx_mod_rewrite:match_and_rewrite(<<"y/def">>, SubRules)).
+    {PubRules, SubRules} = emqx_rewrite:compile(?RULES),
+    ?assertEqual(<<"z/y/2">>, emqx_rewrite:match_and_rewrite(<<"x/y/2">>, PubRules)),
+    ?assertEqual(<<"x/1/2">>, emqx_rewrite:match_and_rewrite(<<"x/1/2">>, PubRules)),
+    ?assertEqual(<<"y/z/b">>, emqx_rewrite:match_and_rewrite(<<"y/a/z/b">>, SubRules)),
+    ?assertEqual(<<"y/def">>, emqx_rewrite:match_and_rewrite(<<"y/def">>, SubRules)).
 
 %%--------------------------------------------------------------------
 %% Internal functions
diff --git a/apps/emqx_modules/test/emqx_mod_telemetry_SUITE.erl b/apps/emqx_modules/test/emqx_telemetry_SUITE.erl
similarity index 51%
rename from apps/emqx_modules/test/emqx_mod_telemetry_SUITE.erl
rename to apps/emqx_modules/test/emqx_telemetry_SUITE.erl
index 1aaa2f3c7..7352c4de5 100644
--- a/apps/emqx_modules/test/emqx_mod_telemetry_SUITE.erl
+++ b/apps/emqx_modules/test/emqx_telemetry_SUITE.erl
@@ -14,7 +14,7 @@
 %% limitations under the License.
 %%--------------------------------------------------------------------
 
--module(emqx_mod_telemetry_SUITE).
+-module(emqx_telemetry_SUITE).
 
 -compile(export_all).
 -compile(nowarn_export_all).
@@ -29,8 +29,7 @@ all() -> emqx_ct:all(?MODULE).
 
 init_per_suite(Config) ->
     ok = ekka_mnesia:start(),
-    ok = emqx_mod_telemetry:mnesia(boot),
-    emqx_ct_helpers:boot_modules(all),
+    ok = emqx_telemetry:mnesia(boot),
     emqx_ct_helpers:start_apps([emqx_modules]),
     Config.
 
@@ -38,57 +37,57 @@ end_per_suite(_Config) ->
     emqx_ct_helpers:stop_apps([emqx_modules]).
 
 t_uuid(_) ->
-    UUID = emqx_mod_telemetry:generate_uuid(),
+    UUID = emqx_telemetry:generate_uuid(),
     Parts = binary:split(UUID, <<"-">>, [global, trim]),
     ?assertEqual(5, length(Parts)),
-    {ok, UUID2} = emqx_mod_telemetry:get_uuid(),
-    emqx_mod_telemetry:unload(#{}),
-    emqx_mod_telemetry:load(#{}),
-    {ok, UUID3} = emqx_mod_telemetry:get_uuid(),
+    {ok, UUID2} = emqx_telemetry:get_uuid(),
+    emqx_telemetry:disable(),
+    emqx_telemetry:enable(),
+    {ok, UUID3} = emqx_telemetry:get_uuid(),
     ?assertEqual(UUID2, UUID3).
 
 t_official_version(_) ->
-    true = emqx_mod_telemetry:official_version("0.0.0"),
-    true = emqx_mod_telemetry:official_version("1.1.1"),
-    true = emqx_mod_telemetry:official_version("10.10.10"),
-    false = emqx_mod_telemetry:official_version("0.0.0.0"),
-    false = emqx_mod_telemetry:official_version("1.1.a"),
-    true = emqx_mod_telemetry:official_version("0.0-alpha.1"),
-    true = emqx_mod_telemetry:official_version("1.1-alpha.1"),
-    true = emqx_mod_telemetry:official_version("10.10-alpha.10"),
-    false = emqx_mod_telemetry:official_version("1.1-alpha.0"),
-    true = emqx_mod_telemetry:official_version("1.1-beta.1"),
-    true = emqx_mod_telemetry:official_version("1.1-rc.1"),
-    false = emqx_mod_telemetry:official_version("1.1-alpha.a").
+    true = emqx_telemetry:official_version("0.0.0"),
+    true = emqx_telemetry:official_version("1.1.1"),
+    true = emqx_telemetry:official_version("10.10.10"),
+    false = emqx_telemetry:official_version("0.0.0.0"),
+    false = emqx_telemetry:official_version("1.1.a"),
+    true = emqx_telemetry:official_version("0.0-alpha.1"),
+    true = emqx_telemetry:official_version("1.1-alpha.1"),
+    true = emqx_telemetry:official_version("10.10-alpha.10"),
+    false = emqx_telemetry:official_version("1.1-alpha.0"),
+    true = emqx_telemetry:official_version("1.1-beta.1"),
+    true = emqx_telemetry:official_version("1.1-rc.1"),
+    false = emqx_telemetry:official_version("1.1-alpha.a").
 
 t_get_telemetry(_) ->
-    {ok, TelemetryData} = emqx_mod_telemetry:get_telemetry(),
+    {ok, TelemetryData} = emqx_telemetry:get_telemetry(),
     OTPVersion = bin(erlang:system_info(otp_release)),
     ?assertEqual(OTPVersion, get_value(otp_version, TelemetryData)),
-    {ok, UUID} = emqx_mod_telemetry:get_uuid(),
+    {ok, UUID} = emqx_telemetry:get_uuid(),
     ?assertEqual(UUID, get_value(uuid, TelemetryData)),
     ?assertEqual(0, get_value(num_clients, TelemetryData)).
 
 t_enable(_) ->
-    ok = meck:new(emqx_mod_telemetry, [non_strict, passthrough, no_history, no_link]),
-    ok = meck:expect(emqx_mod_telemetry, official_version, fun(_) -> true end),
-    ok = emqx_mod_telemetry:load(#{}),
-    ?assertEqual(true, emqx_mod_telemetry:get_status()),
-    ok = emqx_mod_telemetry:unload(#{}),
-    ?assertEqual(false, emqx_mod_telemetry:get_status()),
-    meck:unload([emqx_mod_telemetry]).
+    ok = meck:new(emqx_telemetry, [non_strict, passthrough, no_history, no_link]),
+    ok = meck:expect(emqx_telemetry, official_version, fun(_) -> true end),
+    ok = emqx_telemetry:enable(),
+    ?assertEqual(true, emqx_telemetry:get_status()),
+    ok = emqx_telemetry:disable(),
+    ?assertEqual(false, emqx_telemetry:get_status()),
+    meck:unload([emqx_telemetry]).
 
 t_send_after_enable(_) ->
-    ok = meck:new(emqx_mod_telemetry, [non_strict, passthrough, no_history, no_link]),
-    ok = meck:expect(emqx_mod_telemetry, official_version, fun(_) -> true end),
-    ok = emqx_mod_telemetry:unload(#{}),
+    ok = meck:new(emqx_telemetry, [non_strict, passthrough, no_history, no_link]),
+    ok = meck:expect(emqx_telemetry, official_version, fun(_) -> true end),
+    ok = emqx_telemetry:disable(),
     ok = snabbkaffe:start_trace(),
     try
-        ok = emqx_mod_telemetry:load(#{}),
+        ok = emqx_telemetry:enable(),
         ?assertMatch({ok, _}, ?block_until(#{?snk_kind := telemetry_data_reported}, 2000, 100))
     after
         ok = snabbkaffe:stop(),
-        meck:unload([emqx_mod_telemetry])
+        meck:unload([emqx_telemetry])
     end.
 
 bin(L) when is_list(L) ->
diff --git a/apps/emqx_modules/test/emqx_topic_metrics_SUITE.erl b/apps/emqx_modules/test/emqx_topic_metrics_SUITE.erl
new file mode 100644
index 000000000..5d1c5f84a
--- /dev/null
+++ b/apps/emqx_modules/test/emqx_topic_metrics_SUITE.erl
@@ -0,0 +1,95 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2020-2021 EMQ Technologies Co., Ltd. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%--------------------------------------------------------------------
+
+-module(emqx_topic_metrics_SUITE).
+
+-compile(export_all).
+-compile(nowarn_export_all).
+
+-include_lib("eunit/include/eunit.hrl").
+
+all() -> emqx_ct:all(?MODULE).
+
+init_per_suite(Config) ->
+    emqx_ct_helpers:boot_modules(all),
+    emqx_ct_helpers:start_apps([emqx_modules]),
+    Config.
+
+end_per_suite(_Config) ->
+    emqx_ct_helpers:stop_apps([emqx_modules]).
+
+t_nonexistent_topic_metrics(_) ->
+    emqx_topic_metrics:enable(),
+    ?assertEqual({error, topic_not_found}, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
+    ?assertEqual({error, topic_not_found}, emqx_topic_metrics:inc(<<"a/b/c">>, 'messages.in')),
+    ?assertEqual({error, topic_not_found}, emqx_topic_metrics:rate(<<"a/b/c">>, 'messages.in')),
+    % ?assertEqual({error, topic_not_found}, emqx_topic_metrics:rates(<<"a/b/c">>, 'messages.in')),
+    emqx_topic_metrics:register(<<"a/b/c">>),
+    ?assertEqual(0, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
+    ?assertEqual({error, invalid_metric}, emqx_topic_metrics:val(<<"a/b/c">>, 'invalid.metrics')),
+    ?assertEqual({error, invalid_metric}, emqx_topic_metrics:inc(<<"a/b/c">>, 'invalid.metrics')),
+    ?assertEqual({error, invalid_metric}, emqx_topic_metrics:rate(<<"a/b/c">>, 'invalid.metrics')),
+    % ?assertEqual({error, invalid_metric}, emqx_topic_metrics:rates(<<"a/b/c">>, 'invalid.metrics')),
+    emqx_topic_metrics:unregister(<<"a/b/c">>),
+    emqx_topic_metrics:disable().
+
+t_topic_metrics(_) ->
+    emqx_topic_metrics:enable(),
+
+    ?assertEqual(false, emqx_topic_metrics:is_registered(<<"a/b/c">>)),
+    ?assertEqual([], emqx_topic_metrics:all_registered_topics()),
+    emqx_topic_metrics:register(<<"a/b/c">>),
+    ?assertEqual(true, emqx_topic_metrics:is_registered(<<"a/b/c">>)),
+    ?assertEqual([<<"a/b/c">>], emqx_topic_metrics:all_registered_topics()),
+
+    ?assertEqual(0, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
+    ?assertEqual(ok, emqx_topic_metrics:inc(<<"a/b/c">>, 'messages.in')),
+    ?assertEqual(1, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
+    ?assert(emqx_topic_metrics:rate(<<"a/b/c">>, 'messages.in') =:= 0),
+    % ?assert(emqx_topic_metrics:rates(<<"a/b/c">>, 'messages.in') =:= #{long => 0,medium => 0,short => 0}),
+    emqx_topic_metrics:unregister(<<"a/b/c">>),
+    emqx_topic_metrics:disable().
+
+t_hook(_) ->
+    emqx_topic_metrics:enable(),
+    emqx_topic_metrics:register(<<"a/b/c">>),
+
+    ?assertEqual(0, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
+    ?assertEqual(0, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.qos0.in')),
+    ?assertEqual(0, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.out')),
+    ?assertEqual(0, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.qos0.out')),
+    ?assertEqual(0, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.dropped')),
+
+    {ok, C} = emqtt:start_link([{host, "localhost"},
+                                {clientid, "myclient"},
+                                {username, "myuser"}]),
+    {ok, _} = emqtt:connect(C),
+    emqtt:publish(C, <<"a/b/c">>, <<"Hello world">>, 0),
+    ct:sleep(100),
+    ?assertEqual(1, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
+    ?assertEqual(1, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.qos0.in')),
+    ?assertEqual(1, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.dropped')),
+
+    emqtt:subscribe(C, <<"a/b/c">>),
+    emqtt:publish(C, <<"a/b/c">>, <<"Hello world">>, 0),
+    ct:sleep(100),
+    ?assertEqual(2, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.in')),
+    ?assertEqual(2, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.qos0.in')),
+    ?assertEqual(1, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.out')),
+    ?assertEqual(1, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.qos0.out')),
+    ?assertEqual(1, emqx_topic_metrics:val(<<"a/b/c">>, 'messages.dropped')),
+    emqx_topic_metrics:unregister(<<"a/b/c">>),
+    emqx_topic_metrics:disable().
diff --git a/extension_schemas.config b/extension_schemas.config
index 2eb4f3d08..4880dfa86 100644
--- a/extension_schemas.config
+++ b/extension_schemas.config
@@ -8,10 +8,15 @@
 , {"emqx_authn", emqx_authn_schema}
 , {"authorization", emqx_authz_schema}
 , {"emqx_bridge_mqtt", emqx_bridge_mqtt_schema}
-, {"emqx_modules", emqx_modules_schema}
 , {"emqx_management", emqx_management_schema}
 , {"emqx_dashboard", emqx_dashboard_schema}
 , {"emqx_gateway", emqx_gateway_schema}
 , {"prometheus", emqx_prometheus_schema}
 , {"statsd", emqx_statsd_schema}
+, {"delayed", emqx_modules_schema}
+, {"recon", emqx_modules_schema}
+, {"telemetry", emqx_modules_schema}
+, {"presence", emqx_modules_schema}
+, {"rewrite", emqx_modules_schema}
+, {"topic_metrics", emqx_modules_schema}
 ].