diff --git a/maubot/cli/commands/build.py b/maubot/cli/commands/build.py
index 0f3201c..823cb2e 100644
--- a/maubot/cli/commands/build.py
+++ b/maubot/cli/commands/build.py
@@ -118,6 +118,8 @@ def upload_plugin(output: Union[str, IO]) -> None:
               default=False)
 def build(path: str, output: str, upload: bool) -> None:
     meta = read_meta(path)
+    if not meta:
+        return
     if output or not upload:
         output = read_output_path(output, meta)
         if not output:
diff --git a/maubot/client.py b/maubot/client.py
index 5b91d8c..1ec6d4f 100644
--- a/maubot/client.py
+++ b/maubot/client.py
@@ -55,7 +55,7 @@ class Client:
                                          token=self.access_token, client_session=self.http_client,
                                          log=self.log, loop=self.loop, store=self.db_instance)
         if self.autojoin:
-            self.client.add_event_handler(self._handle_invite, EventType.ROOM_MEMBER)
+            self.client.add_event_handler(EventType.ROOM_MEMBER, self._handle_invite)
 
     async def start(self, try_n: Optional[int] = 0) -> None:
         try:
@@ -260,9 +260,9 @@ class Client:
         if value == self.db_instance.autojoin:
             return
         if value:
-            self.client.add_event_handler(self._handle_invite, EventType.ROOM_MEMBER)
+            self.client.add_event_handler(EventType.ROOM_MEMBER, self._handle_invite)
         else:
-            self.client.remove_event_handler(self._handle_invite, EventType.ROOM_MEMBER)
+            self.client.remove_event_handler(EventType.ROOM_MEMBER, self._handle_invite)
         self.db_instance.autojoin = value
 
     @property
diff --git a/maubot/config.py b/maubot/config.py
index ab3e080..b36a5c5 100644
--- a/maubot/config.py
+++ b/maubot/config.py
@@ -29,7 +29,8 @@ class Config(BaseFileConfig):
         return "".join(random.choice(string.ascii_lowercase + string.digits) for _ in range(64))
 
     def do_update(self, helper: ConfigUpdateHelper) -> None:
-        base, copy, _ = helper
+        base = helper.base
+        copy = helper.copy
         copy("database")
         copy("plugin_directories.upload")
         copy("plugin_directories.load")
diff --git a/maubot/handlers/command.py b/maubot/handlers/command.py
index c2e8199..5e1b894 100644
--- a/maubot/handlers/command.py
+++ b/maubot/handlers/command.py
@@ -13,89 +13,196 @@
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
-from typing import Union, Callable, Sequence, Pattern, Awaitable, NewType, Optional, Any
+from typing import Union, Callable, Sequence, Pattern, Awaitable, NewType, Optional, Any, List, Dict
 import functools
 import re
 
-from mautrix.client import EventHandler
-from mautrix.types import MessageType
+from mautrix.types import MessageType, EventType
 
 from ..matrix import MaubotMessageEvent
-from .event import EventHandlerDecorator
+from . import event
 
-PrefixType = Union[str, Callable[[], str]]
-CommandDecorator = Callable[[PrefixType, str], EventHandlerDecorator]
+PrefixType = Optional[Union[str, Callable[[], str]]]
+CommandHandlerFunc = NewType("CommandHandlerFunc",
+                             Callable[[MaubotMessageEvent, Any], Awaitable[Any]])
+CommandHandlerDecorator = NewType("CommandHandlerDecorator",
+                                  Callable[[Union['CommandHandler', CommandHandlerFunc]],
+                                           'CommandHandler'])
+PassiveCommandHandlerDecorator = NewType("PassiveCommandHandlerDecorator",
+                                         Callable[[CommandHandlerFunc], CommandHandlerFunc])
 
 
-def _get_subcommand_decorator(parent: EventHandler) -> CommandDecorator:
-    def subcommand(name: PrefixType, help: str = None) -> EventHandlerDecorator:
-        cmd_decorator = new(name=f"{parent.__mb_name__} {name}", help=help)
+class CommandHandler:
+    def __init__(self, func: CommandHandlerFunc) -> None:
+        self.__mb_func__: CommandHandlerFunc = func
+        self.__mb_subcommands__: Dict[str, CommandHandler] = {}
+        self.__mb_arguments__: List[Argument] = []
+        self.__mb_help__: str = None
+        self.__mb_name__: str = None
+        self.__mb_prefix__: str = None
+        self.__mb_require_subcommand__: bool = True
+        self.__mb_event_handler__: bool = True
+        self.__mb_event_type__: EventType = EventType.ROOM_MESSAGE
+        self.__class_instance: Any = None
 
-        def decorator(func: EventHandler) -> EventHandler:
-            func = cmd_decorator(func)
-            parent.__mb_subcommands__.append(func)
+    async def __call__(self, evt: MaubotMessageEvent, *,
+                       _existing_args: Dict[str, Any] = None) -> Any:
+        body = evt.content.body
+        if evt.sender == evt.client.mxid or not body.startswith(self.__mb_prefix__):
+            return
+        call_args: Dict[str, Any] = {**_existing_args} if _existing_args else {}
+        remaining_val = body[len(self.__mb_prefix__) + 1:]
+        # TODO update remaining_val somehow
+        for arg in self.__mb_arguments__:
+            try:
+                call_args[arg.name] = arg.match(remaining_val)
+                if arg.required and not call_args[arg.name]:
+                    raise ValueError("Argument required")
+            except ArgumentSyntaxError as e:
+                await evt.reply(e.message + (f"\n{self.__mb_usage__}" if e.show_usage else ""))
+                return
+            except ValueError as e:
+                await evt.reply(self.__mb_usage__)
+                return
+
+        if len(self.__mb_subcommands__) > 0:
+            split = remaining_val.split(" ") if len(remaining_val) > 0 else []
+            try:
+                subcommand = self.__mb_subcommands__[split[0]]
+                return await subcommand(evt, _existing_args=call_args)
+            except (KeyError, IndexError):
+                if self.__mb_require_subcommand__:
+                    await evt.reply(self.__mb_full_help__)
+                    return
+        return (await self.__mb_func__(self.__class_instance, evt, **call_args)
+                if self.__class_instance
+                else await self.__mb_func__(evt, **call_args))
+
+    def __get__(self, instance, instancetype):
+        self.__class_instance = instance
+        return self
+
+    @property
+    def __mb_full_help__(self) -> str:
+        basic = self.__mb_usage__
+        usage = f"{basic} <subcommand> [...]\n\n"
+        usage += "\n".join(f"* {cmd.__mb_name__} {cmd.__mb_usage_args__} - {cmd.__mb_help__}"
+                           for cmd in self.__mb_subcommands__.values())
+        return usage
+
+    @property
+    def __mb_usage_args__(self) -> str:
+        return " ".join(f"<{arg.label}>" if arg.required else f"[{arg.label}]"
+                        for arg in self.__mb_arguments__)
+
+    @property
+    def __mb_usage__(self) -> str:
+        return f"**Usage:** {self.__mb_prefix__} {self.__mb_usage_args__}"
+
+    def subcommand(self, name: PrefixType = None, help: str = None
+                   ) -> CommandHandlerDecorator:
+        def decorator(func: Union[CommandHandler, CommandHandlerFunc]) -> CommandHandler:
+            if not isinstance(func, CommandHandler):
+                func = CommandHandler(func)
+            func.__mb_name__ = name or func.__name__
+            func.__mb_prefix__ = f"{self.__mb_prefix__} {func.__mb_name__}"
+            func.__mb_help__ = help
+            func.__mb_event_handler__ = False
+            self.__mb_subcommands__[func.__mb_name__] = func
             return func
 
         return decorator
 
-    return subcommand
+
+class ArgumentSyntaxError(ValueError):
+    def __init__(self, message: str, show_usage: bool = True) -> None:
+        super().__init__(message)
+        self.message = message
+        self.show_usage = show_usage
 
 
-def new(name: Union[str, Callable[[], str]], help: str = None) -> EventHandlerDecorator:
-    def decorator(func: EventHandler) -> EventHandler:
-        func.__mb_subcommands__ = []
+class Argument:
+    def __init__(self, name: str, label: str = None, *, required: bool = False,
+                 matches: Optional[str] = None, parser: Optional[Callable[[str], Any]] = None,
+                 pass_raw: bool = False) -> None:
+        self.name = name
+        self.required = required
+        self.label = label or name
+
+        if not parser:
+            if matches:
+                regex = re.compile(matches)
+
+                def parser(val: str) -> Optional[Sequence[str]]:
+                    match = regex.match(val)
+                    return match.groups() if match else None
+            else:
+                def parser(val: str) -> str:
+                    return val
+
+        if not pass_raw:
+            o_parser = parser
+
+            def parser(val: str) -> Any:
+                val = val.strip().split(" ")
+                return o_parser(val[0])
+
+        self.parser = parser
+
+    def match(self, val: str) -> Any:
+        return self.parser(val)
+
+    def __call__(self, func: Union[CommandHandler, CommandHandlerFunc]) -> CommandHandler:
+        if not isinstance(func, CommandHandler):
+            func = CommandHandler(func)
+        func.__mb_arguments__.append(self)
+        return func
+
+
+def new(name: PrefixType, *, help: str = None, event_type: EventType = EventType.ROOM_MESSAGE,
+        require_subcommand: bool = True) -> CommandHandlerDecorator:
+    def decorator(func: Union[CommandHandler, CommandHandlerFunc]) -> CommandHandler:
+        if not isinstance(func, CommandHandler):
+            func = CommandHandler(func)
         func.__mb_help__ = help
         func.__mb_name__ = name or func.__name__
-        func.subcommand = _get_subcommand_decorator(func)
+        func.__mb_require_subcommand__ = require_subcommand
+        func.__mb_prefix__ = f"!{func.__mb_name__}"
+        func.__mb_event_type__ = event_type
         return func
 
     return decorator
 
 
-PassiveCommandHandler = Callable[[MaubotMessageEvent, ...], Awaitable[None]]
-PassiveCommandHandlerDecorator = NewType("PassiveCommandHandlerDecorator",
-                                         Callable[[PassiveCommandHandler], PassiveCommandHandler])
+def argument(name: str, label: str = None, *, required: bool = True, matches: Optional[str] = None,
+             parser: Optional[Callable[[str], Any]] = None) -> CommandHandlerDecorator:
+    return Argument(name, label, required=required, matches=matches, parser=parser)
 
 
 def passive(regex: Union[str, Pattern], msgtypes: Sequence[MessageType] = (MessageType.TEXT,),
-            field: Callable[[MaubotMessageEvent], str] = lambda event: event.content.body
-            ) -> PassiveCommandHandlerDecorator:
+            field: Callable[[MaubotMessageEvent], str] = lambda event: event.content.body,
+            event_type: EventType = EventType.ROOM_MESSAGE) -> PassiveCommandHandlerDecorator:
     if not isinstance(regex, Pattern):
         regex = re.compile(regex)
 
-    def decorator(func: PassiveCommandHandler) -> PassiveCommandHandler:
+    def decorator(func: CommandHandlerFunc) -> CommandHandlerFunc:
+        @event.on(event_type)
         @functools.wraps(func)
-        async def replacement(event: MaubotMessageEvent) -> None:
-            if event.sender == event.client.mxid:
+        async def replacement(self, evt: MaubotMessageEvent) -> None:
+            if isinstance(self, MaubotMessageEvent):
+                evt = self
+                self = None
+            if evt.sender == evt.client.mxid:
                 return
-            elif msgtypes and event.content.msgtype not in msgtypes:
+            elif msgtypes and evt.content.msgtype not in msgtypes:
                 return
-            match = regex.match(field(event))
+            match = regex.match(field(evt))
             if match:
-                await func(event, *list(match.groups()))
+                if self:
+                    await func(self, evt, *list(match.groups()))
+                else:
+                    await func(evt, *list(match.groups()))
 
         return replacement
 
     return decorator
-
-
-class _Argument:
-    def __init__(self, name: str, required: bool, matches: Optional[str],
-                 parser: Optional[Callable[[str], Any]]) -> None:
-        pass
-
-
-def argument(name: str, *, required: bool = True, matches: Optional[str] = None,
-             parser: Optional[Callable[[str], Any]] = None) -> EventHandlerDecorator:
-    def decorator(func: EventHandler) -> EventHandler:
-        if not hasattr(func, "__mb_arguments__"):
-            func.__mb_arguments__ = []
-        func.__mb_arguments__.append(_Argument(name, required, matches, parser))
-        return func
-
-    return decorator
-
-
-def vararg(func: EventHandler) -> EventHandler:
-    func.__mb_vararg__ = True
-    return func
diff --git a/maubot/handlers/event.py b/maubot/handlers/event.py
index 7bec17e..d6bde8e 100644
--- a/maubot/handlers/event.py
+++ b/maubot/handlers/event.py
@@ -13,11 +13,9 @@
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
-from typing import Callable, Union, NewType, Any, Tuple, Optional
-import functools
-import re
+from typing import Callable, Union, NewType
 
-from mautrix.types import EventType, Event, EventContent, MessageEvent, MessageEventContent
+from mautrix.types import EventType
 from mautrix.client import EventHandler
 
 EventHandlerDecorator = NewType("EventHandlerDecorator", Callable[[EventHandler], EventHandler])
@@ -25,93 +23,12 @@ EventHandlerDecorator = NewType("EventHandlerDecorator", Callable[[EventHandler]
 
 def on(var: Union[EventType, EventHandler]) -> Union[EventHandlerDecorator, EventHandler]:
     def decorator(func: EventHandler) -> EventHandler:
-        @functools.wraps(func)
-        async def wrapper(event: Event) -> None:
-            pass
-
-        wrapper.__mb_event_handler__ = True
+        func.__mb_event_handler__ = True
         if isinstance(var, EventType):
-            wrapper.__mb_event_type__ = var
+            func.__mb_event_type__ = var
         else:
-            wrapper.__mb_event_type__ = EventType.ALL
+            func.__mb_event_type__ = EventType.ALL
 
-        return wrapper
-
-    return decorator if isinstance(var, EventType) else decorator(var)
-
-
-class Field:
-    body: Callable[[MessageEventContent], str] = lambda content: content.body
-    msgtype: Callable[[MessageEventContent], str] = lambda content: content.msgtype
-
-
-def _parse_key(key: str) -> Tuple[str, Optional[str]]:
-    if '.' not in key:
-        return key, None
-    key, next_key = key.split('.', 1)
-    if len(key) > 0 and key[0] == "[":
-        end_index = next_key.index("]")
-        key = key[1:] + "." + next_key[:end_index]
-        next_key = next_key[end_index + 2:] if len(next_key) > end_index + 1 else None
-    return key, next_key
-
-
-def _recursive_get(data: EventContent, key: str) -> Any:
-    key, next_key = _parse_key(key)
-    if next_key is not None:
-        next_data = data.get(key, None)
-        if next_data is None:
-            return None
-        return _recursive_get(next_data, next_key)
-    return data.get(key, None)
-
-
-def _find_content_field(content: EventContent, field: str) -> Any:
-    val = _recursive_get(content, field)
-    if not val and hasattr(content, "unrecognized_"):
-        val = _recursive_get(content.unrecognized_, field)
-    return val
-
-
-def handle_own_events(func: EventHandler) -> EventHandler:
-    func.__mb_handle_own_events__ = True
-
-
-def filter_content(field: Union[str, Callable[[EventContent], Any]], substr: str = None,
-                   pattern: str = None, exact: bool = False):
-    if substr and pattern:
-        raise ValueError("You can only provide one of substr or pattern.")
-    elif not substr and not pattern:
-        raise ValueError("You must provide either substr or pattern.")
-
-    if not callable(field):
-        field = functools.partial(_find_content_field, field=field)
-
-    if substr:
-        def func(evt: MessageEvent) -> bool:
-            val = field(evt.content)
-            if val is None:
-                return False
-            elif substr in val:
-                return True
-    else:
-        pattern = re.compile(pattern)
-
-        def func(evt: MessageEvent) -> bool:
-            val = field(evt.content)
-            if val is None:
-                return False
-            elif pattern.match(val):
-                return True
-
-    return filter(func)
-
-
-def filter(func: Callable[[MessageEvent], bool]) -> EventHandlerDecorator:
-    def decorator(func: EventHandler) -> EventHandler:
-        if not hasattr(func, "__mb_event_filters__"):
-            func.__mb_event_filters__ = []
-        func.__mb_event_filters__.append(func)
         return func
 
-    return decorator
+    return decorator if isinstance(var, EventType) else decorator(var)
diff --git a/maubot/plugin_base.py b/maubot/plugin_base.py
index 2835b66..c720cc5 100644
--- a/maubot/plugin_base.py
+++ b/maubot/plugin_base.py
@@ -51,7 +51,7 @@ class Plugin(ABC):
     async def start(self) -> None:
         for key in dir(self):
             val = getattr(self, key)
-            if hasattr(val, "__mb_event_handler__"):
+            if hasattr(val, "__mb_event_handler__") and val.__mb_event_handler__:
                 self._handlers_at_startup.append((val, val.__mb_event_type__))
                 self.client.add_event_handler(val.__mb_event_type__, val)