diff --git a/.vscode/settings.json b/.vscode/settings.json
index 1346c37..9f23adb 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -22,7 +22,7 @@
     "prettier.singleQuote": true,
     "prettier.tabWidth": 4,
     // Extensions - Pylance
-    "python.analysis.typeCheckingMode": "basic",
+    "python.analysis.typeCheckingMode": "strict",
     "python.analysis.exclude": ["api/migrations/[0-9]*.py"],
     // Extensions - Python:black
     "python.formatting.blackArgs": ["--line-length=120"],
diff --git a/mdrsclient/api/file.py b/mdrsclient/api/file.py
index 26b8254..6ce3e97 100644
--- a/mdrsclient/api/file.py
+++ b/mdrsclient/api/file.py
@@ -1,4 +1,4 @@
-from typing import Final
+from typing import Any, Final
 
 from pydantic import TypeAdapter
 from pydantic.dataclasses import dataclass
@@ -29,7 +29,7 @@ class FileApi(BaseApi):
         # print(self.__class__.__name__ + "::" + sys._getframe().f_code.co_name)
         url = self.ENTRYPOINT
         token_check(self.connection)
-        data = {"folder_id": folder_id}
+        data: dict[str, str | int] = {"folder_id": folder_id}
         try:
             with open(path, mode="rb") as fp:
                 response = self.connection.post(url, data=data, files={"file": fp})
@@ -52,7 +52,7 @@ class FileApi(BaseApi):
                 raise UnexpectedException(f"Could not open `{path}` file.")
         else:
             # update metadata
-            data = {"name": file.name, "description": file.description}
+            data: dict[str, str | int] = {"name": file.name, "description": file.description}
             response = self.connection.put(url, data=data)
         self._raise_response_error(response)
         return True
@@ -68,13 +68,13 @@ class FileApi(BaseApi):
     def move(self, file: File, folder_id: str) -> bool:
         # print(self.__class__.__name__ + "::" + sys._getframe().f_code.co_name)
         url = self.ENTRYPOINT + file.id + "/move/"
-        data = {"folder": folder_id, "name": file.name}
+        data: dict[str, str | int] = {"folder": folder_id, "name": file.name}
         token_check(self.connection)
         response = self.connection.post(url, data=data)
         self._raise_response_error(response)
         return True
 
-    def metadata(self, file: File) -> dict:
+    def metadata(self, file: File) -> dict[str, Any]:
         # print(self.__class__.__name__ + "::" + sys._getframe().f_code.co_name)
         url = self.ENTRYPOINT + file.id + "/metadata/"
         token_check(self.connection)
diff --git a/mdrsclient/api/folder.py b/mdrsclient/api/folder.py
index 85215a9..fa407b9 100644
--- a/mdrsclient/api/folder.py
+++ b/mdrsclient/api/folder.py
@@ -1,4 +1,4 @@
-from typing import Final
+from typing import Any, Final
 
 import requests
 from pydantic import TypeAdapter
@@ -21,7 +21,7 @@ class FolderApi(BaseApi):
     def list(self, laboratory_id: int, path: str) -> list[FolderSimple]:
         # print(self.__class__.__name__ + "::" + sys._getframe().f_code.co_name)
         url = self.ENTRYPOINT
-        params = {"path": path, "laboratory_id": laboratory_id}
+        params: dict[str, str | int] = {"path": path, "laboratory_id": laboratory_id}
         token_check(self.connection)
         response = self.connection.get(url, params=params)
         self._raise_response_error(response)
@@ -42,7 +42,7 @@ class FolderApi(BaseApi):
     def create(self, name: str, parent_id: str) -> str:
         # print(self.__class__.__name__ + "::" + sys._getframe().f_code.co_name)
         url = self.ENTRYPOINT
-        data = {"name": name, "parent_id": parent_id, "description": "", "template_id": -1}
+        data: dict[str, str | int] = {"name": name, "parent_id": parent_id, "description": "", "template_id": -1}
         token_check(self.connection)
         response = self.connection.post(url, data=data)
         self._raise_response_error(response)
@@ -52,7 +52,7 @@ class FolderApi(BaseApi):
     def update(self, folder: FolderSimple) -> bool:
         # print(self.__class__.__name__ + "::" + sys._getframe().f_code.co_name)
         url = self.ENTRYPOINT + folder.id + "/"
-        data = {
+        data: dict[str, str | int] = {
             "name": folder.name,
             "description": folder.description,
         }
@@ -64,7 +64,7 @@ class FolderApi(BaseApi):
     def destroy(self, id: str, recursive: bool) -> bool:
         # print(self.__class__.__name__ + "::" + sys._getframe().f_code.co_name)
         url = self.ENTRYPOINT + id + "/"
-        params = {"recursive": recursive}
+        params: dict[str, str | int] = {"recursive": str(recursive)}
         token_check(self.connection)
         response = self.connection.delete(url, params=params)
         self._raise_response_error(response)
@@ -73,7 +73,7 @@ class FolderApi(BaseApi):
     def auth(self, id: str, password: str) -> bool:
         # print(self.__class__.__name__ + "::" + sys._getframe().f_code.co_name)
         url = self.ENTRYPOINT + id + "/auth/"
-        data = {"password": password}
+        data: dict[str, str | int] = {"password": password}
         token_check(self.connection)
         response = self.connection.post(url, data=data)
         if response.status_code == requests.codes.unauthorized:
@@ -84,7 +84,7 @@ class FolderApi(BaseApi):
     def acl(self, id: str, access_level: int, recursive: bool, password: str | None) -> bool:
         # print(self.__class__.__name__ + "::" + sys._getframe().f_code.co_name)
         url = self.ENTRYPOINT + id + "/acl/"
-        data: dict[str, int | str] = {"access_level": access_level}
+        data: dict[str, str | int] = {"access_level": access_level}
         if password is not None:
             data.update({"password": password})
         if recursive is True:
@@ -97,13 +97,13 @@ class FolderApi(BaseApi):
     def move(self, folder: FolderSimple, folder_id: str) -> bool:
         # print(self.__class__.__name__ + "::" + sys._getframe().f_code.co_name)
         url = self.ENTRYPOINT + folder.id + "/move/"
-        data = {"parent": folder_id}
+        data: dict[str, str | int] = {"parent": folder_id}
         token_check(self.connection)
         response = self.connection.post(url, data=data)
         self._raise_response_error(response)
         return True
 
-    def metadata(self, id: str) -> dict:
+    def metadata(self, id: str) -> dict[str, Any]:
         # print(self.__class__.__name__ + "::" + sys._getframe().f_code.co_name)
         url = self.ENTRYPOINT + id + "/metadata/"
         token_check(self.connection)
diff --git a/mdrsclient/api/user.py b/mdrsclient/api/user.py
index d07224a..fa17ed2 100644
--- a/mdrsclient/api/user.py
+++ b/mdrsclient/api/user.py
@@ -22,7 +22,7 @@ class UserApi(BaseApi):
     def auth(self, username: str, password: str) -> tuple[User, Token]:
         # print(self.__class__.__name__ + "::" + sys._getframe().f_code.co_name)
         url = self.ENTRYPOINT + "auth/"
-        data = {"username": username, "password": password}
+        data: dict[str, str | int] = {"username": username, "password": password}
         response = self.connection.post(url, data=data)
         if response.status_code == requests.codes.unauthorized:
             raise UnauthorizedException("Invalid username or password.")
@@ -37,7 +37,7 @@ class UserApi(BaseApi):
     def refresh(self, token: Token) -> Token:
         # print(self.__class__.__name__ + "::" + sys._getframe().f_code.co_name)
         url = self.ENTRYPOINT + "refresh/"
-        data = {"refresh": token.refresh}
+        data: dict[str, str | int] = {"refresh": token.refresh}
         response = self.connection.post(url, data=data)
         if response.status_code == requests.codes.unauthorized:
             raise UnauthorizedException("Token is invalid or expired.")
diff --git a/mdrsclient/commands/base.py b/mdrsclient/commands/base.py
index 74f5278..1f93ce3 100644
--- a/mdrsclient/commands/base.py
+++ b/mdrsclient/commands/base.py
@@ -1,6 +1,6 @@
 import re
 from abc import ABC, abstractmethod
-from argparse import _SubParsersAction
+from typing import Any
 from unicodedata import normalize
 
 from mdrsclient.api import FolderApi, LaboratoryApi
@@ -18,16 +18,18 @@ from mdrsclient.models import Folder, Laboratory
 class BaseCommand(ABC):
     @classmethod
     @abstractmethod
-    def register(cls, parsers: _SubParsersAction) -> None:
+    def register(cls, parsers: Any) -> None:
         raise UnexpectedException("Not implemented.")
 
-    def _create_connection(self, remote: str) -> MDRSConnection:
+    @classmethod
+    def _create_connection(cls, remote: str) -> MDRSConnection:
         config = ConfigFile(remote)
         if config.url is None:
             raise MissingConfigurationException(f"Remote host `{remote}` is not found.")
         return MDRSConnection(config.remote, config.url)
 
-    def _find_laboratory(self, connection: MDRSConnection, name: str) -> Laboratory:
+    @classmethod
+    def _find_laboratory(cls, connection: MDRSConnection, name: str) -> Laboratory:
         if connection.laboratories.empty() or connection.token is not None and connection.token.is_expired:
             laboratory_api = LaboratoryApi(connection)
             connection.laboratories = laboratory_api.list()
@@ -36,8 +38,9 @@ class BaseCommand(ABC):
             raise IllegalArgumentException(f"Laboratory `{name}` not found.")
         return laboratory
 
+    @classmethod
     def _find_folder(
-        self, connection: MDRSConnection, laboratory: Laboratory, path: str, password: str | None = None
+        cls, connection: MDRSConnection, laboratory: Laboratory, path: str, password: str | None = None
     ) -> Folder:
         folder_api = FolderApi(connection)
         folders = folder_api.list(laboratory.id, normalize("NFC", path))
@@ -49,14 +52,16 @@ class BaseCommand(ABC):
             folder_api.auth(folders[0].id, password)
         return folder_api.retrieve(folders[0].id)
 
-    def _parse_remote_host(self, path: str) -> str:
+    @classmethod
+    def _parse_remote_host(cls, path: str) -> str:
         path_array = path.split(":")
         remote_host = path_array[0]
         if len(path_array) == 2 and path_array[1] != "" or len(path_array) > 2:
             raise IllegalArgumentException("Invalid remote host")
         return remote_host
 
-    def _parse_remote_host_with_path(self, path: str) -> tuple[str, str, str]:
+    @classmethod
+    def _parse_remote_host_with_path(cls, path: str) -> tuple[str, str, str]:
         path = re.sub(r"//+|/\./+|/\.$", "/", path)
         if re.search(r"/\.\./|/\.\.$", path) is not None:
             raise IllegalArgumentException("Path traversal found.")
diff --git a/mdrsclient/commands/chacl.py b/mdrsclient/commands/chacl.py
index 6d9c99f..825f9c0 100644
--- a/mdrsclient/commands/chacl.py
+++ b/mdrsclient/commands/chacl.py
@@ -1,4 +1,5 @@
-from argparse import Namespace, _SubParsersAction
+from argparse import Namespace
+from typing import Any
 
 from mdrsclient.api import FolderApi
 from mdrsclient.commands.base import BaseCommand
@@ -8,25 +9,32 @@ from mdrsclient.models import FolderAccessLevel
 
 class ChaclCommand(BaseCommand):
     @classmethod
-    def register(cls, parsers: _SubParsersAction) -> None:
-        command = cls()
+    def register(cls, parsers: Any) -> None:
         chacl_parser = parsers.add_parser("chacl", help="change the folder access level")
         chacl_parser.add_argument("access_level", help="access level (private, cbs_open, pw_open)")
         chacl_parser.add_argument("-r", "--recursive", help="change access levels recursively", action="store_true")
         chacl_parser.add_argument("-p", "--password", help="password to set when access level is `pw_open`")
         chacl_parser.add_argument("remote_path", help="remote folder path (remote:/lab/path/)")
-        chacl_parser.set_defaults(func=command.chacl)
+        chacl_parser.set_defaults(func=cls.func)
 
-    def chacl(self, args: Namespace) -> None:
-        (remote, laboratory_name, r_path) = self._parse_remote_host_with_path(args.remote_path)
-        r_path = r_path.rstrip("/")
-        access_level = FolderAccessLevel.key2id(args.access_level)
+    @classmethod
+    def func(cls, args: Namespace) -> None:
+        remote_path = str(args.remote_path)
+        access_level = FolderAccessLevel.key2id(str(args.access_level))
         if access_level is None:
             raise IllegalArgumentException(
                 "Invalid `access_level` parameter. must be `private`, `cbs_open` or `pw_open`."
             )
-        connection = self._create_connection(remote)
-        laboratory = self._find_laboratory(connection, laboratory_name)
-        folder = self._find_folder(connection, laboratory, r_path)
+        password = str(args.password) if args.password else None
+        is_recursive = bool(args.recursive)
+        cls.chacl(remote_path, access_level, is_recursive, password)
+
+    @classmethod
+    def chacl(cls, remote_path: str, access_level: int, is_recursive: bool, password: str | None) -> None:
+        (remote, laboratory_name, r_path) = cls._parse_remote_host_with_path(remote_path)
+        r_path = r_path.rstrip("/")
+        connection = cls._create_connection(remote)
+        laboratory = cls._find_laboratory(connection, laboratory_name)
+        folder = cls._find_folder(connection, laboratory, r_path)
         folder_api = FolderApi(connection)
-        folder_api.acl(folder.id, access_level, args.recursive, args.password)
+        folder_api.acl(folder.id, access_level, is_recursive, password)
diff --git a/mdrsclient/commands/config.py b/mdrsclient/commands/config.py
index 50f148e..e97fd5e 100644
--- a/mdrsclient/commands/config.py
+++ b/mdrsclient/commands/config.py
@@ -1,4 +1,5 @@
-from argparse import Namespace, _SubParsersAction
+from argparse import Namespace
+from typing import Any, Callable
 
 from mdrsclient.commands.base import BaseCommand
 from mdrsclient.config import ConfigFile
@@ -7,58 +8,84 @@ from mdrsclient.exceptions import IllegalArgumentException
 
 class ConfigCommand(BaseCommand):
     @classmethod
-    def register(cls, parsers: _SubParsersAction) -> None:
-        command = cls()
+    def register(cls, parsers: Any) -> None:
         # config
         config_parser = parsers.add_parser("config", help="configure remote hosts")
-        config_parser.set_defaults(func=lambda x: config_parser.print_help())
+        func_help: Callable[[Namespace], None] = lambda _: config_parser.print_help()
+        config_parser.set_defaults(func=func_help)
         config_parsers = config_parser.add_subparsers(title="config subcommands")
         # config create
         create_parser = config_parsers.add_parser("create", help="create a new remote host")
         create_parser.add_argument("remote", help="label of remote host")
         create_parser.add_argument("url", help="API entrypoint url of remote host")
-        create_parser.set_defaults(func=command.create)
+        create_parser.set_defaults(func=cls.func_create)
         # config update
         update_parser = config_parsers.add_parser("update", help="update a new remote host")
         update_parser.add_argument("remote", help="label of remote host")
         update_parser.add_argument("url", help="API entrypoint url of remote host")
-        update_parser.set_defaults(func=command.update)
+        update_parser.set_defaults(func=cls.func_update)
         # config list
         list_parser = config_parsers.add_parser("list", help="list all the remote hosts")
         list_parser.add_argument("-l", "--long", help="show the api url", action="store_true")
-        list_parser.set_defaults(func=command.list)
+        list_parser.set_defaults(func=cls.func_list)
         # config delete
         delete_parser = config_parsers.add_parser("delete", help="delete an existing remote host")
         delete_parser.add_argument("remote", help="label of remote host")
-        delete_parser.set_defaults(func=command.delete)
+        delete_parser.set_defaults(func=cls.func_delete)
 
-    def create(self, args: Namespace) -> None:
-        remote = self._parse_remote_host(args.remote)
-        config = ConfigFile(remote=remote)
+    @classmethod
+    def func_create(cls, args: Namespace) -> None:
+        remote = str(args.remote)
+        url = str(args.url)
+        cls.create(remote, url)
+
+    @classmethod
+    def func_update(cls, args: Namespace) -> None:
+        remote = str(args.remote)
+        url = str(args.url)
+        cls.update(remote, url)
+
+    @classmethod
+    def func_list(cls, args: Namespace) -> None:
+        is_long = bool(args.long)
+        cls.list(is_long)
+
+    @classmethod
+    def func_delete(cls, args: Namespace) -> None:
+        remote = str(args.remote)
+        cls.delete(remote)
+
+    @classmethod
+    def create(cls, remote: str, url: str) -> None:
+        remote = cls._parse_remote_host(remote)
+        config = ConfigFile(remote)
         if config.url is not None:
             raise IllegalArgumentException(f"Remote host `{remote}` is already exists.")
         else:
-            config.url = args.url
+            config.url = url
 
-    def update(self, args: Namespace) -> None:
-        remote = self._parse_remote_host(args.remote)
-        config = ConfigFile(remote=remote)
+    @classmethod
+    def update(cls, remote: str, url: str) -> None:
+        remote = cls._parse_remote_host(remote)
+        config = ConfigFile(remote)
         if config.url is None:
             raise IllegalArgumentException(f"Remote host `{remote}` is not exists.")
         else:
-            config.url = args.url
+            config.url = url
 
-    def list(self, args: Namespace) -> None:
+    @classmethod
+    def list(cls, is_long: bool) -> None:
         config = ConfigFile("")
         for remote, url in config.list():
             line = f"{remote}:"
-            if args.long:
+            if is_long:
                 line += f"\t{url}"
             print(line)
 
-    def delete(self, args: Namespace) -> None:
-        remote = self._parse_remote_host(args.remote)
-        config = ConfigFile(remote=remote)
+    @classmethod
+    def delete(cls, remote: str) -> None:
+        remote = cls._parse_remote_host(remote)
+        config = ConfigFile(remote)
         if config.url is None:
             raise IllegalArgumentException(f"Remote host `{remote}` is not exists.")
         else:
diff --git a/mdrsclient/commands/download.py b/mdrsclient/commands/download.py
index f800b2a..35276cd 100644
--- a/mdrsclient/commands/download.py
+++ b/mdrsclient/commands/download.py
@@ -1,6 +1,7 @@
 import os
-from argparse import Namespace, _SubParsersAction
+from argparse import Namespace
 from concurrent.futures import ThreadPoolExecutor
+from typing import Any
 
 from pydantic.dataclasses import dataclass
 
@@ -20,8 +21,7 @@ class DownloadFileInfo:
 
 class DownloadCommand(BaseCommand):
     @classmethod
-    def register(cls, parsers: _SubParsersAction) -> None:
-        command = cls()
+    def register(cls, parsers: Any) -> None:
         download_parser = parsers.add_parser("download", help="download the file or folder")
         download_parser.add_argument(
             "-r", "--recursive", help="download folders and their contents recursive", action="store_true"
@@ -29,19 +29,28 @@ class DownloadCommand(BaseCommand):
         download_parser.add_argument("-p", "--password", help="password to use when open locked folder")
         download_parser.add_argument("remote_path", help="remote file path (remote:/lab/path/file)")
         download_parser.add_argument("local_path", help="local folder path (/foo/bar/)")
-        download_parser.set_defaults(func=command.download)
+        download_parser.set_defaults(func=cls.func)
 
-    def download(self, args: Namespace) -> None:
-        (remote, laboratory_name, r_path) = self._parse_remote_host_with_path(args.remote_path)
+    @classmethod
+    def func(cls, args: Namespace) -> None:
+        remote_path = str(args.remote_path)
+        local_path = str(args.local_path)
+        is_recursive = bool(args.recursive)
+        password = str(args.password) if args.password else None
+        cls.download(remote_path, local_path, is_recursive, password)
+
+    @classmethod
+    def download(cls, remote_path: str, local_path: str, is_recursive: bool, password: str | None) -> None:
+        (remote, laboratory_name, r_path) = cls._parse_remote_host_with_path(remote_path)
         r_path = r_path.rstrip("/")
         r_dirname = os.path.dirname(r_path)
         r_basename = os.path.basename(r_path)
-        connection = self._create_connection(remote)
-        l_dirname = os.path.realpath(args.local_path)
+        connection = cls._create_connection(remote)
+        l_dirname = os.path.realpath(local_path)
         if not os.path.isdir(l_dirname):
-            raise IllegalArgumentException(f"Local directory `{args.local_path}` not found.")
-        laboratory = self._find_laboratory(connection, laboratory_name)
-        r_parent_folder = self._find_folder(connection, laboratory, r_dirname, args.password)
+            raise IllegalArgumentException(f"Local directory `{local_path}` not found.")
+        laboratory = cls._find_laboratory(connection, laboratory_name)
+        r_parent_folder = cls._find_folder(connection, laboratory, r_dirname, password)
         file = r_parent_folder.find_file(r_basename)
         download_files: list[DownloadFileInfo] = []
         if file is not None:
@@ -51,14 +60,15 @@ class DownloadCommand(BaseCommand):
             folder = r_parent_folder.find_sub_folder(r_basename)
             if folder is None:
                 raise IllegalArgumentException(f"File or folder `{r_path}` not found.")
-            if not args.recursive:
+            if not is_recursive:
                 raise IllegalArgumentException(f"Cannot download `{r_path}`: Is a folder.")
             folder_api = FolderApi(connection)
-            self.__multiple_download_pickup_recursive_files(folder_api, download_files, folder.id, l_dirname)
-        self.__multiple_download(connection, download_files)
+            cls.__multiple_download_pickup_recursive_files(folder_api, download_files, folder.id, l_dirname)
+        cls.__multiple_download(connection, download_files)
 
+    @classmethod
     def __multiple_download_pickup_recursive_files(
-        self, folder_api: FolderApi, infolist: list[DownloadFileInfo], folder_id: str, basedir: str
+        cls, folder_api: FolderApi, infolist: list[DownloadFileInfo], folder_id: str, basedir: str
     ) -> None:
         folder = folder_api.retrieve(folder_id)
         dirname = os.path.join(basedir, folder.name)
@@ -69,13 +79,15 @@ class DownloadCommand(BaseCommand):
             path = os.path.join(dirname, file.name)
             infolist.append(DownloadFileInfo(file, path))
         for sub_folder in folder.sub_folders:
-            self.__multiple_download_pickup_recursive_files(folder_api, infolist, sub_folder.id, dirname)
+            cls.__multiple_download_pickup_recursive_files(folder_api, infolist, sub_folder.id, dirname)
 
-    def __multiple_download(self, connection: MDRSConnection, infolist: list[DownloadFileInfo]) -> None:
+    @classmethod
+    def __multiple_download(cls, connection: MDRSConnection, infolist: list[DownloadFileInfo]) -> None:
         file_api = FileApi(connection)
         with ThreadPoolExecutor(max_workers=CONCURRENT) as pool:
-            pool.map(lambda x: self.__multiple_download_worker(file_api, x), infolist)
+            pool.map(lambda x: cls.__multiple_download_worker(file_api, x), infolist)
 
-    def __multiple_download_worker(self, file_api: FileApi, info: DownloadFileInfo) -> None:
+    @classmethod
+    def __multiple_download_worker(cls, file_api: FileApi, info: DownloadFileInfo) -> None:
         file_api.download(info.file, info.path)
         print(info.path)
diff --git a/mdrsclient/commands/file_metadata.py b/mdrsclient/commands/file_metadata.py
index 2bc7120..c279b9a 100644
--- a/mdrsclient/commands/file_metadata.py
+++ b/mdrsclient/commands/file_metadata.py
@@ -1,6 +1,7 @@
 import json
 import os
-from argparse import Namespace, _SubParsersAction
+from argparse import Namespace
+from typing import Any
 
 from mdrsclient.api import FileApi
 from mdrsclient.commands.base import BaseCommand
@@ -9,21 +10,27 @@ from mdrsclient.exceptions import IllegalArgumentException
 
 class FileMetadataCommand(BaseCommand):
     @classmethod
-    def register(cls, parsers: _SubParsersAction) -> None:
-        command = cls()
+    def register(cls, parsers: Any) -> None:
         file_metadata_parser = parsers.add_parser("file-metadata", help="get the file metadata")
         file_metadata_parser.add_argument("-p", "--password", help="password to use when open locked folder")
         file_metadata_parser.add_argument("remote_path", help="remote file path (remote:/lab/path/file)")
-        file_metadata_parser.set_defaults(func=command.file_metadata)
+        file_metadata_parser.set_defaults(func=cls.func)
 
-    def file_metadata(self, args: Namespace) -> None:
-        (remote, laboratory_name, r_path) = self._parse_remote_host_with_path(args.remote_path)
+    @classmethod
+    def func(cls, args: Namespace) -> None:
+        remote_path = str(args.remote_path)
+        password = str(args.password) if args.password else None
+        cls.file_metadata(remote_path, password)
+
+    @classmethod
+    def file_metadata(cls, remote_path: str, password: str | None) -> None:
+        (remote, laboratory_name, r_path) = cls._parse_remote_host_with_path(remote_path)
         r_path = r_path.rstrip("/")
         r_dirname = os.path.dirname(r_path)
         r_basename = os.path.basename(r_path)
-        connection = self._create_connection(remote)
-        laboratory = self._find_laboratory(connection, laboratory_name)
-        folder = self._find_folder(connection, laboratory, r_dirname, args.password)
+        connection = cls._create_connection(remote)
+        laboratory = cls._find_laboratory(connection, laboratory_name)
+        folder = cls._find_folder(connection, laboratory, r_dirname, password)
         file = folder.find_file(r_basename)
         if file is None:
             raise IllegalArgumentException(f"File `{r_basename}` not found.")
diff --git a/mdrsclient/commands/labs.py b/mdrsclient/commands/labs.py
index 87a0b9d..7bbbf03 100644
--- a/mdrsclient/commands/labs.py
+++ b/mdrsclient/commands/labs.py
@@ -1,4 +1,5 @@
-from argparse import Namespace, _SubParsersAction
+from argparse import Namespace
+from typing import Any
 
 from mdrsclient.api import LaboratoryApi
 from mdrsclient.commands.base import BaseCommand
@@ -6,15 +7,20 @@ from mdrsclient.commands.base import BaseCommand
 
 class LabsCommand(BaseCommand):
     @classmethod
-    def register(cls, parsers: _SubParsersAction) -> None:
-        command = cls()
+    def register(cls, parsers: Any) -> None:
         labs_parser = parsers.add_parser("labs", help="list all laboratories")
         labs_parser.add_argument("remote", help="label of remote host")
-        labs_parser.set_defaults(func=command.labs)
+        labs_parser.set_defaults(func=cls.func)
 
-    def labs(self, args: Namespace) -> None:
-        remote = self._parse_remote_host(args.remote)
-        connection = self._create_connection(remote)
+    @classmethod
+    def func(cls, args: Namespace) -> None:
+        remote = str(args.remote)
+        cls.labs(remote)
+
+    @classmethod
+    def labs(cls, remote: str) -> None:
+        remote = cls._parse_remote_host(remote)
+        connection = cls._create_connection(remote)
         laboratory_api = LaboratoryApi(connection)
         laboratories = laboratory_api.list()
         connection.laboratories = laboratories
diff --git a/mdrsclient/commands/login.py b/mdrsclient/commands/login.py
index 3e5a832..c399f02 100644
--- a/mdrsclient/commands/login.py
+++ b/mdrsclient/commands/login.py
@@ -1,5 +1,6 @@
 import getpass
-from argparse import Namespace, _SubParsersAction
+from argparse import Namespace
+from typing import Any
 
 from mdrsclient.api import UserApi
 from mdrsclient.commands.base import BaseCommand
@@ -10,20 +11,25 @@ from mdrsclient.exceptions import MissingConfigurationException
 
 class LoginCommand(BaseCommand):
     @classmethod
-    def register(cls, parsers: _SubParsersAction) -> None:
-        command = cls()
+    def register(cls, parsers: Any) -> None:
         login_parser = parsers.add_parser("login", help="login to remote host")
         login_parser.add_argument("remote", help="label of remote host")
-        login_parser.set_defaults(func=command.login)
+        login_parser.set_defaults(func=cls.func)
 
-    def login(self, args: Namespace) -> None:
-        remote = self._parse_remote_host(args.remote)
+    @classmethod
+    def func(cls, args: Namespace) -> None:
+        remote = str(args.remote)
+        username = input("Username: ").strip()
+        password = getpass.getpass("Password: ").strip()
+        cls.login(remote, username, password)
+
+    @classmethod
+    def login(cls, remote: str, username: str, password: str) -> None:
+        remote = cls._parse_remote_host(remote)
         config = ConfigFile(remote)
         if config.url is None:
             raise MissingConfigurationException(f"Remote host `{remote}` is not found.")
         connection = MDRSConnection(config.remote, config.url)
-        username = input("Username: ").strip()
-        password = getpass.getpass("Password: ").strip()
         user_api = UserApi(connection)
         (user, token) = user_api.auth(username, password)
         print("Login Successful")
diff --git a/mdrsclient/commands/logout.py b/mdrsclient/commands/logout.py
index 4bc9a7a..84e3585 100644
--- a/mdrsclient/commands/logout.py
+++ b/mdrsclient/commands/logout.py
@@ -1,4 +1,5 @@
-from argparse import Namespace, _SubParsersAction
+from argparse import Namespace
+from typing import Any
 
 from mdrsclient.commands.base import BaseCommand
 from mdrsclient.config import ConfigFile
@@ -8,14 +9,19 @@ from mdrsclient.exceptions import MissingConfigurationException
 
 class LogoutCommand(BaseCommand):
     @classmethod
-    def register(cls, parsers: _SubParsersAction) -> None:
-        command = cls()
+    def register(cls, parsers: Any) -> None:
         logout_parser = parsers.add_parser("logout", help="logout from remote host")
         logout_parser.add_argument("remote", help="label of remote host")
-        logout_parser.set_defaults(func=command.logout)
+        logout_parser.set_defaults(func=cls.func)
 
-    def logout(self, args: Namespace) -> None:
-        remote = self._parse_remote_host(args.remote)
+    @classmethod
+    def func(cls, args: Namespace) -> None:
+        remote = str(args.remote)
+        cls.logout(remote)
+
+    @classmethod
+    def logout(cls, remote: str) -> None:
+        remote = cls._parse_remote_host(remote)
         config = ConfigFile(remote)
         if config.url is None:
             raise MissingConfigurationException(f"Remote host `{remote}` is not found.")
diff --git a/mdrsclient/commands/ls.py b/mdrsclient/commands/ls.py
index e653f4a..87e3b07 100644
--- a/mdrsclient/commands/ls.py
+++ b/mdrsclient/commands/ls.py
@@ -1,5 +1,6 @@
 import json
-from argparse import Namespace, _SubParsersAction
+from argparse import Namespace
+from typing import Any
 
 from pydantic.dataclasses import dataclass
 
@@ -28,8 +29,7 @@ class LsCommandContext:
 
 class LsCommand(BaseCommand):
     @classmethod
-    def register(cls, parsers: _SubParsersAction) -> None:
-        command = cls()
+    def register(cls, parsers: Any) -> None:
         ls_parser = parsers.add_parser("ls", help="list the folder contents")
         ls_parser.add_argument("-p", "--password", help="password to use when open locked folder")
         ls_parser.add_argument("-J", "--json", help="turn on json output", action="store_true")
@@ -41,35 +41,43 @@ class LsCommand(BaseCommand):
         )
         ls_parser.add_argument("-r", "--recursive", help="list the folder contents recursive", action="store_true")
         ls_parser.add_argument("remote_path", help="remote folder path (remote:/lab/path/)")
-        ls_parser.set_defaults(func=command.ls)
+        ls_parser.set_defaults(func=cls.func)
 
-    def ls(self, args: Namespace) -> None:
-        (remote, laboratory_name, r_path) = self._parse_remote_host_with_path(args.remote_path)
-        connection = self._create_connection(remote)
-        laboratory = self._find_laboratory(connection, laboratory_name)
-        password = str(args.password)
+    @classmethod
+    def func(cls, args: Namespace) -> None:
+        remote_path = str(args.remote_path)
+        password = str(args.password) if args.password else None
         is_json = bool(args.json)
         is_recursive = bool(args.recursive)
         is_quick = bool(args.quick) if not is_recursive else True
-        self.context = LsCommandContext(
+        cls.ls(remote_path, password, is_json, is_recursive, is_quick)
+
+    @classmethod
+    def ls(cls, remote_path: str, password: str | None, is_json: bool, is_recursive: bool, is_quick: bool) -> None:
+        (remote, laboratory_name, r_path) = cls._parse_remote_host_with_path(remote_path)
+        connection = cls._create_connection(remote)
+        laboratory = cls._find_laboratory(connection, laboratory_name)
+        context = LsCommandContext(
             f"{remote}:/{laboratory_name}",
             connection,
             laboratory,
-            password,
+            password if password is not None else "",
             is_json,
             is_quick,
             is_recursive,
         )
-        folder = self._find_folder(connection, laboratory, r_path, password)
-        if self.context.is_json:
-            self._ls_json(folder)
+        folder = cls._find_folder(connection, laboratory, r_path, password)
+        if context.is_json:
+            cls._ls_json(context, folder)
         else:
-            self._ls_plain(folder)
+            cls._ls_plain(context, folder)
 
-    def _ls_json(self, folder: Folder) -> None:
-        print(json.dumps(self._folder2dict(folder), ensure_ascii=False))
+    @classmethod
+    def _ls_json(cls, context: LsCommandContext, folder: Folder) -> None:
+        print(json.dumps(cls._folder2dict(context, folder), ensure_ascii=False))
 
-    def _ls_plain(self, folder: Folder) -> None:
+    @classmethod
+    def _ls_plain(cls, context: LsCommandContext, folder: Folder) -> None:
         label = {
             "type": "Type",
             "acl": "Access",
@@ -80,9 +88,9 @@ class LsCommand(BaseCommand):
         }
         length: dict[str, int] = {}
         for key in label.keys():
-            length[key] = len(label[key]) if not self.context.is_quick else 0
+            length[key] = len(label[key]) if not context.is_quick else 0
         for sub_folder in folder.sub_folders:
-            sub_laboratory = self.context.connection.laboratories.find_by_id(sub_folder.lab_id)
+            sub_laboratory = context.connection.laboratories.find_by_id(sub_folder.lab_id)
             sub_laboratory_name = sub_laboratory.name if sub_laboratory is not None else "(invalid)"
             length["acl"] = max(length["acl"], len(sub_folder.access_level_name))
             length["laboratory"] = max(length["laboratory"], len(sub_laboratory_name))
@@ -94,23 +102,23 @@ class LsCommand(BaseCommand):
             length["date"] = max(length["date"], len(file.updated_at_name))
             length["name"] = max(length["name"], len(file.name))
         length["acl"] = max(length["acl"], len(folder.access_level_name))
-        length["laboratory"] = max(length["laboratory"], len(self.context.laboratory.name))
+        length["laboratory"] = max(length["laboratory"], len(context.laboratory.name))
         header = (
             f"{label['type']:{length['type']}}\t{label['acl']:{length['acl']}}\t"
             f"{label['laboratory']:{length['laboratory']}}\t{label['size']:{length['size']}}\t"
             f"{label['date']:{length['date']}}\t{label['name']:{length['name']}}"
         )
 
-        if self.context.is_recursive:
-            print(f"{self.context.prefix}{folder.path}:")
+        if context.is_recursive:
+            print(f"{context.prefix}{folder.path}:")
             print(f"total {sum(f.size for f in folder.files)}")
 
-        if not self.context.is_quick:
+        if not context.is_quick:
             print(header)
             print("-" * len(header.expandtabs()))
 
         for sub_folder in sorted(folder.sub_folders, key=lambda x: x.name):
-            sub_laboratory_name = self._laboratory_name(sub_folder.lab_id)
+            sub_laboratory_name = cls._laboratory_name(context, sub_folder.lab_id)
             print(
                 f"{'[d]':{length['type']}}\t{sub_folder.access_level_name:{length['acl']}}\t"
                 f"{sub_laboratory_name:{length['laboratory']}}\t{sub_folder.lock_name:{length['size']}}\t"
@@ -119,56 +127,59 @@ class LsCommand(BaseCommand):
         for file in sorted(folder.files, key=lambda x: x.name):
             print(
                 f"{'[f]':{length['type']}}\t{folder.access_level_name:{length['acl']}}\t"
-                f"{self.context.laboratory.name:{length['laboratory']}}\t{file.size:{length['size']}}\t"
+                f"{context.laboratory.name:{length['laboratory']}}\t{file.size:{length['size']}}\t"
                 f"{file.updated_at_name:{length['date']}}\t{file.name:{length['name']}}"
             )
 
-        if self.context.is_recursive:
+        if context.is_recursive:
             print("")
             for sub_folder in sorted(folder.sub_folders, key=lambda x: x.name):
-                folder_api = FolderApi(self.context.connection)
+                folder_api = FolderApi(context.connection)
                 try:
                     if sub_folder.lock:
-                        folder_api.auth(sub_folder.id, self.context.password)
+                        folder_api.auth(sub_folder.id, context.password)
                     folder = folder_api.retrieve(sub_folder.id)
-                    self._ls_plain(folder)
+                    cls._ls_plain(context, folder)
                 except UnauthorizedException:
                     pass
 
-    def _folder2dict(self, folder: Folder | FolderSimple) -> dict:
-        data = {
+    @classmethod
+    def _folder2dict(cls, context: LsCommandContext, folder: Folder | FolderSimple) -> dict[str, Any]:
+        data: dict[str, Any] = {
             "id": folder.id,
             "pid": folder.pid,
             "name": folder.name,
             "access_level": folder.access_level_name,
             "lock": folder.lock,
-            "laboratory": self._laboratory_name(folder.lab_id),
+            "laboratory": cls._laboratory_name(context, folder.lab_id),
             "description": folder.description,
             "created_at": folder.created_at,
             "updated_at": folder.updated_at,
         }
         if isinstance(folder, Folder):
-            folder_api = FolderApi(self.context.connection)
+            folder_api = FolderApi(context.connection)
             data["metadata"] = folder_api.metadata(folder.id)
-            if self.context.is_recursive:
-                data["sub_folders"] = []
+            if context.is_recursive:
+                sub_folders: list[dict[str, Any]] = []
                 for sub_folder in sorted(folder.sub_folders, key=lambda x: x.name):
                     try:
                         if sub_folder.lock:
-                            folder_api.auth(sub_folder.id, self.context.password)
+                            folder_api.auth(sub_folder.id, context.password)
                         folder2 = folder_api.retrieve(sub_folder.id)
-                        data["sub_folders"].append(self._folder2dict(folder2))
+                        sub_folders.append(cls._folder2dict(context, folder2))
                     except UnauthorizedException:
                         pass
+                data["sub_folders"] = sub_folders
             else:
                 data["sub_folders"] = list(
-                    map(lambda x: self._folder2dict(x), sorted(folder.sub_folders, key=lambda x: x.name))
+                    map(lambda x: cls._folder2dict(context, x), sorted(folder.sub_folders, key=lambda x: x.name))
                 )
-            data["files"] = list(map(lambda x: self._file2dict(x), sorted(folder.files, key=lambda x: x.name)))
+            data["files"] = list(map(lambda x: cls._file2dict(context, x), sorted(folder.files, key=lambda x: x.name)))
         return data
 
-    def _file2dict(self, file: File) -> dict:
-        data = {
+    @classmethod
+    def _file2dict(cls, context: LsCommandContext, file: File) -> dict[str, Any]:
+        data: dict[str, Any] = {
             "id": file.id,
             "name": file.name,
             "type": file.type,
@@ -176,12 +187,13 @@ class LsCommand(BaseCommand):
             # "thumbnail": file.thumbnail,
             "description": file.description,
             "metadata": file.metadata,
-            "download_url": f"{self.context.connection.url}/v2/{file.download_url}",
+            "download_url": f"{context.connection.url}/v2/{file.download_url}",
             "created_at": file.created_at,
             "updated_at": file.updated_at,
         }
         return data
 
-    def _laboratory_name(self, laboratory_id: int) -> str:
-        laboratory = self.context.connection.laboratories.find_by_id(laboratory_id)
+    @classmethod
+    def _laboratory_name(cls, context: LsCommandContext, laboratory_id: int) -> str:
+        laboratory = context.connection.laboratories.find_by_id(laboratory_id)
         return laboratory.name if laboratory is not None else "(invalid)"
diff --git a/mdrsclient/commands/metadata.py b/mdrsclient/commands/metadata.py
index b141844..46c9c19 100644
--- a/mdrsclient/commands/metadata.py
+++ b/mdrsclient/commands/metadata.py
@@ -1,5 +1,6 @@
 import json
-from argparse import Namespace, _SubParsersAction
+from argparse import Namespace
+from typing import Any
 
 from mdrsclient.api import FolderApi
 from mdrsclient.commands.base import BaseCommand
@@ -7,18 +8,24 @@ from mdrsclient.commands.base import BaseCommand
 
 class MetadataCommand(BaseCommand):
     @classmethod
-    def register(cls, parsers: _SubParsersAction) -> None:
-        command = cls()
+    def register(cls, parsers: Any) -> None:
         metadata_parser = parsers.add_parser("metadata", help="get a folder metadata")
         metadata_parser.add_argument("-p", "--password", help="password to use when open locked folder")
         metadata_parser.add_argument("remote_path", help="remote folder path (remote:/lab/path/)")
-        metadata_parser.set_defaults(func=command.metadata)
+        metadata_parser.set_defaults(func=cls.func)
 
-    def metadata(self, args: Namespace) -> None:
-        (remote, laboratory_name, r_path) = self._parse_remote_host_with_path(args.remote_path)
-        connection = self._create_connection(remote)
-        laboratory = self._find_laboratory(connection, laboratory_name)
-        folder = self._find_folder(connection, laboratory, r_path, args.password)
+    @classmethod
+    def func(cls, args: Namespace) -> None:
+        remote_path = str(args.remote_path)
+        password = str(args.password) if args.password else None
+        cls.metadata(remote_path, password)
+
+    @classmethod
+    def metadata(cls, remote_path: str, password: str | None) -> None:
+        (remote, laboratory_name, r_path) = cls._parse_remote_host_with_path(remote_path)
+        connection = cls._create_connection(remote)
+        laboratory = cls._find_laboratory(connection, laboratory_name)
+        folder = cls._find_folder(connection, laboratory, r_path, password)
         folder_api = FolderApi(connection)
         metadata = folder_api.metadata(folder.id)
         print(json.dumps(metadata, ensure_ascii=False))
diff --git a/mdrsclient/commands/mkdir.py b/mdrsclient/commands/mkdir.py
index 6bca9d6..a5f6e84 100644
--- a/mdrsclient/commands/mkdir.py
+++ b/mdrsclient/commands/mkdir.py
@@ -1,5 +1,6 @@
 import os
-from argparse import Namespace, _SubParsersAction
+from argparse import Namespace
+from typing import Any
 from unicodedata import normalize
 
 from mdrsclient.api import FolderApi
@@ -9,20 +10,25 @@ from mdrsclient.exceptions import IllegalArgumentException
 
 class MkdirCommand(BaseCommand):
     @classmethod
-    def register(cls, parsers: _SubParsersAction) -> None:
-        command = cls()
+    def register(cls, parsers: Any) -> None:
         mkdir_parser = parsers.add_parser("mkdir", help="create a new folder")
         mkdir_parser.add_argument("remote_path", help="remote folder path (remote:/lab/path/)")
-        mkdir_parser.set_defaults(func=command.mkdir)
+        mkdir_parser.set_defaults(func=cls.func)
 
-    def mkdir(self, args: Namespace) -> None:
-        (remote, laboratory_name, r_path) = self._parse_remote_host_with_path(args.remote_path)
+    @classmethod
+    def func(cls, args: Namespace) -> None:
+        remote_path = str(args.remote_path)
+        cls.mkdir(remote_path)
+
+    @classmethod
+    def mkdir(cls, remote_path: str) -> None:
+        (remote, laboratory_name, r_path) = cls._parse_remote_host_with_path(remote_path)
         r_path = r_path.rstrip("/")
         r_dirname = os.path.dirname(r_path)
         r_basename = os.path.basename(r_path)
-        connection = self._create_connection(remote)
-        laboratory = self._find_laboratory(connection, laboratory_name)
-        parent_folder = self._find_folder(connection, laboratory, r_dirname)
+        connection = cls._create_connection(remote)
+        laboratory = cls._find_laboratory(connection, laboratory_name)
+        parent_folder = cls._find_folder(connection, laboratory, r_dirname)
         if parent_folder.find_sub_folder(r_basename) is not None or parent_folder.find_file(r_basename) is not None:
             raise IllegalArgumentException(f"Cannot create folder `{r_path}`: File exists.")
         folder_api = FolderApi(connection)
diff --git a/mdrsclient/commands/mv.py b/mdrsclient/commands/mv.py
index ff89604..a7305a4 100644
--- a/mdrsclient/commands/mv.py
+++ b/mdrsclient/commands/mv.py
@@ -1,6 +1,7 @@
 import dataclasses
 import os
-from argparse import Namespace, _SubParsersAction
+from argparse import Namespace
+from typing import Any
 from unicodedata import normalize
 
 from pydantic import TypeAdapter
@@ -13,16 +14,22 @@ from mdrsclient.models import File, FolderSimple
 
 class MvCommand(BaseCommand):
     @classmethod
-    def register(cls, parsers: _SubParsersAction) -> None:
-        command = cls()
+    def register(cls, parsers: Any) -> None:
         mv_parser = parsers.add_parser("mv", help="move or rename the file or folder")
         mv_parser.add_argument("src_path", help="source remote path (remote:/lab/path/src)")
         mv_parser.add_argument("dest_path", help="destination remote path (remote:/lab/path/dest)")
-        mv_parser.set_defaults(func=command.mv)
+        mv_parser.set_defaults(func=cls.func)
 
-    def mv(self, args: Namespace) -> None:
-        (s_remote, s_laboratory_name, s_path) = self._parse_remote_host_with_path(args.src_path)
-        (d_remote, d_laboratory_name, d_path) = self._parse_remote_host_with_path(args.dest_path)
+    @classmethod
+    def func(cls, args: Namespace) -> None:
+        src_path = str(args.src_path)
+        dest_path = str(args.dest_path)
+        cls.mv(src_path, dest_path)
+
+    @classmethod
+    def mv(cls, src_path: str, dest_path: str) -> None:
+        (s_remote, s_laboratory_name, s_path) = cls._parse_remote_host_with_path(src_path)
+        (d_remote, d_laboratory_name, d_path) = cls._parse_remote_host_with_path(dest_path)
         if s_remote != d_remote:
             raise IllegalArgumentException("Remote host mismatched.")
         if s_laboratory_name != d_laboratory_name:
@@ -36,10 +43,10 @@ class MvCommand(BaseCommand):
         else:
             d_dirname = os.path.dirname(d_path)
             d_basename = os.path.basename(d_path)
-        connection = self._create_connection(s_remote)
-        laboratory = self._find_laboratory(connection, s_laboratory_name)
-        s_parent_folder = self._find_folder(connection, laboratory, s_dirname)
-        d_parent_folder = self._find_folder(connection, laboratory, d_dirname)
+        connection = cls._create_connection(s_remote)
+        laboratory = cls._find_laboratory(connection, s_laboratory_name)
+        s_parent_folder = cls._find_folder(connection, laboratory, s_dirname)
+        d_parent_folder = cls._find_folder(connection, laboratory, d_dirname)
         s_file = s_parent_folder.find_file(s_basename)
         if s_file is not None:
             # source is file
diff --git a/mdrsclient/commands/rm.py b/mdrsclient/commands/rm.py
index 99b2b70..9c6397f 100644
--- a/mdrsclient/commands/rm.py
+++ b/mdrsclient/commands/rm.py
@@ -1,5 +1,6 @@
 import os
-from argparse import Namespace, _SubParsersAction
+from argparse import Namespace
+from typing import Any
 
 from mdrsclient.api import FileApi, FolderApi
 from mdrsclient.commands.base import BaseCommand
@@ -8,23 +9,29 @@ from mdrsclient.exceptions import IllegalArgumentException
 
 class RmCommand(BaseCommand):
     @classmethod
-    def register(cls, parsers: _SubParsersAction) -> None:
-        command = cls()
+    def register(cls, parsers: Any) -> None:
         rm_parser = parsers.add_parser("rm", help="remove the file or folder")
         rm_parser.add_argument(
             "-r", "--recursive", help="remove folders and their contents recursive", action="store_true"
         )
         rm_parser.add_argument("remote_path", help="remote file path (remote:/lab/path/file)")
-        rm_parser.set_defaults(func=command.rm)
+        rm_parser.set_defaults(func=cls.func)
 
-    def rm(self, args: Namespace) -> None:
-        (remote, laboratory_name, r_path) = self._parse_remote_host_with_path(args.remote_path)
+    @classmethod
+    def func(cls, args: Namespace) -> None:
+        remote_path = str(args.remote_path)
+        is_recursive = bool(args.recursive)
+        cls.rm(remote_path, is_recursive)
+
+    @classmethod
+    def rm(cls, remote_path: str, is_recursive: bool) -> None:
+        (remote, laboratory_name, r_path) = cls._parse_remote_host_with_path(remote_path)
         r_path = r_path.rstrip("/")
         r_dirname = os.path.dirname(r_path)
         r_basename = os.path.basename(r_path)
-        connection = self._create_connection(remote)
-        laboratory = self._find_laboratory(connection, laboratory_name)
-        parent_folder = self._find_folder(connection, laboratory, r_dirname)
+        connection = cls._create_connection(remote)
+        laboratory = cls._find_laboratory(connection, laboratory_name)
+        parent_folder = cls._find_folder(connection, laboratory, r_dirname)
         file = parent_folder.find_file(r_basename)
         if file is not None:
             file_api = FileApi(connection)
@@ -33,7 +40,7 @@ class RmCommand(BaseCommand):
             folder = parent_folder.find_sub_folder(r_basename)
             if folder is None:
                 raise IllegalArgumentException(f"Cannot remove `{r_path}`: No such file or folder.")
-            if not args.recursive:
+            if not is_recursive:
                 raise IllegalArgumentException(f"Cannot remove `{r_path}`: Is a folder.")
             folder_api = FolderApi(connection)
             folder_api.destroy(folder.id, True)
diff --git a/mdrsclient/commands/upload.py b/mdrsclient/commands/upload.py
index b71fdf1..0ff81aa 100644
--- a/mdrsclient/commands/upload.py
+++ b/mdrsclient/commands/upload.py
@@ -1,6 +1,7 @@
 import os
-from argparse import Namespace, _SubParsersAction
+from argparse import Namespace
 from concurrent.futures import ThreadPoolExecutor
+from typing import Any
 
 from pydantic.dataclasses import dataclass
 
@@ -20,28 +21,35 @@ class UploadFileInfo:
 
 class UploadCommand(BaseCommand):
     @classmethod
-    def register(cls, parsers: _SubParsersAction) -> None:
-        command = cls()
+    def register(cls, parsers: Any) -> None:
         upload_parser = parsers.add_parser("upload", help="upload the file or directory")
         upload_parser.add_argument(
             "-r", "--recursive", help="upload directories and their contents recursive", action="store_true"
         )
         upload_parser.add_argument("local_path", help="local file path (/foo/bar/data.txt)")
         upload_parser.add_argument("remote_path", help="remote folder path (remote:/lab/path/)")
-        upload_parser.set_defaults(func=command.upload)
+        upload_parser.set_defaults(func=cls.func)
 
-    def upload(self, args: Namespace) -> None:
-        (remote, laboratory_name, r_path) = self._parse_remote_host_with_path(args.remote_path)
-        l_path = os.path.realpath(args.local_path)
+    @classmethod
+    def func(cls, args: Namespace) -> None:
+        local_path = str(args.local_path)
+        remote_path = str(args.remote_path)
+        is_recursive = bool(args.recursive)
+        cls.upload(local_path, remote_path, is_recursive)
+
+    @classmethod
+    def upload(cls, local_path: str, remote_path: str, is_recursive: bool) -> None:
+        (remote, laboratory_name, r_path) = cls._parse_remote_host_with_path(remote_path)
+        l_path = os.path.realpath(local_path)
         if not os.path.exists(l_path):
-            raise IllegalArgumentException(f"File or directory `{args.local_path}` not found.")
-        connection = self._create_connection(remote)
-        laboratory = self._find_laboratory(connection, laboratory_name)
-        folder = self._find_folder(connection, laboratory, r_path)
+            raise IllegalArgumentException(f"File or directory `{local_path}` not found.")
+        connection = cls._create_connection(remote)
+        laboratory = cls._find_laboratory(connection, laboratory_name)
+        folder = cls._find_folder(connection, laboratory, r_path)
         infos: list[UploadFileInfo] = []
         if os.path.isdir(l_path):
-            if not args.recursive:
-                raise IllegalArgumentException(f"Cannot upload `{args.local_path}`: Is a directory.")
+            if not is_recursive:
+                raise IllegalArgumentException(f"Cannot upload `{local_path}`: Is a directory.")
             folder_api = FolderApi(connection)
             folder_map: dict[str, Folder] = {}
             folder_map[r_path] = folder
@@ -53,7 +61,7 @@ class UploadCommand(BaseCommand):
                 # prepare destination parent path
                 d_parent_dirname = os.path.dirname(d_dirname)
                 if folder_map.get(d_parent_dirname) is None:
-                    folder_map[d_parent_dirname] = self._find_folder(connection, laboratory, d_parent_dirname)
+                    folder_map[d_parent_dirname] = cls._find_folder(connection, laboratory, d_parent_dirname)
                 # prepare destination path
                 if folder_map.get(d_dirname) is None:
                     d_folder = folder_map[d_parent_dirname].find_sub_folder(d_basename)
@@ -70,14 +78,16 @@ class UploadCommand(BaseCommand):
                     infos.append(UploadFileInfo(folder_map[d_dirname], os.path.join(dirpath, filename)))
         else:
             infos.append(UploadFileInfo(folder, l_path))
-        self.__multiple_upload(connection, infos)
+        cls.__multiple_upload(connection, infos)
 
-    def __multiple_upload(self, connection: MDRSConnection, infos: list[UploadFileInfo]) -> None:
+    @classmethod
+    def __multiple_upload(cls, connection: MDRSConnection, infos: list[UploadFileInfo]) -> None:
         file_api = FileApi(connection)
         with ThreadPoolExecutor(max_workers=CONCURRENT) as pool:
-            pool.map(lambda x: self.__multiple_upload_worker(file_api, x), infos)
+            pool.map(lambda x: cls.__multiple_upload_worker(file_api, x), infos)
 
-    def __multiple_upload_worker(self, file_api: FileApi, info: UploadFileInfo) -> None:
+    @classmethod
+    def __multiple_upload_worker(cls, file_api: FileApi, info: UploadFileInfo) -> None:
         basename = os.path.basename(info.path)
         file = info.folder.find_file(basename)
         try:
diff --git a/mdrsclient/commands/whoami.py b/mdrsclient/commands/whoami.py
index 5d53c75..60a2712 100644
--- a/mdrsclient/commands/whoami.py
+++ b/mdrsclient/commands/whoami.py
@@ -1,5 +1,5 @@
-from argparse import Namespace, _SubParsersAction
-from typing import Final
+from argparse import Namespace
+from typing import Any, Final
 
 from mdrsclient.commands.base import BaseCommand
 from mdrsclient.config import ConfigFile
@@ -11,19 +11,24 @@ class WhoamiCommand(BaseCommand):
     ANONYMOUS_USERNAME: Final[str] = "(Anonymous)"
 
     @classmethod
-    def register(cls, parsers: _SubParsersAction) -> None:
-        command = cls()
+    def register(cls, parsers: Any) -> None:
         whoami_parser = parsers.add_parser("whoami", help="show current user name")
         whoami_parser.add_argument("remote", help="label of remote host")
-        whoami_parser.set_defaults(func=command.whoami)
+        whoami_parser.set_defaults(func=cls.func)
 
-    def whoami(self, args: Namespace) -> None:
-        remote = self._parse_remote_host(args.remote)
+    @classmethod
+    def func(cls, args: Namespace) -> None:
+        remote = str(args.remote)
+        cls.whoami(remote)
+
+    @classmethod
+    def whoami(cls, remote: str) -> None:
+        remote = cls._parse_remote_host(remote)
         config = ConfigFile(remote)
         if config.url is None:
             raise MissingConfigurationException(f"Remote host `{remote}` is not found.")
         connection = MDRSConnection(config.remote, config.url)
         if connection.token is not None and connection.token.is_expired:
             connection.logout()
-        username = connection.user.username if connection.user is not None else self.ANONYMOUS_USERNAME
+        username = connection.user.username if connection.user is not None else cls.ANONYMOUS_USERNAME
         print(username)
diff --git a/mdrsclient/config.py b/mdrsclient/config.py
index 5aa5abe..3768511 100644
--- a/mdrsclient/config.py
+++ b/mdrsclient/config.py
@@ -2,7 +2,7 @@ import configparser
 import os
 from typing import Final
 
-import validators
+import validators  # type: ignore
 
 from mdrsclient.exceptions import IllegalArgumentException
 from mdrsclient.settings import CONFIG_DIRNAME
diff --git a/mdrsclient/connection.py b/mdrsclient/connection.py
index 79ece4d..4a125ae 100644
--- a/mdrsclient/connection.py
+++ b/mdrsclient/connection.py
@@ -1,5 +1,7 @@
 import platform
 import threading
+from io import BufferedReader
+from typing import TypedDict, Unpack
 
 from requests import Response, Session
 
@@ -9,6 +11,27 @@ from mdrsclient.exceptions import MissingConfigurationException
 from mdrsclient.models import Laboratories, Token, User
 
 
+class _KwArgsMDRSConnectionGet(TypedDict, total=False):
+    params: dict[str, str | int]
+    stream: bool
+
+
+class _KwArgsMDRSConnectionPost(TypedDict, total=False):
+    params: dict[str, str | int]
+    data: dict[str, str | int]
+    files: dict[str, BufferedReader]
+
+
+class _KwArgsMDRSConnectionPut(TypedDict, total=False):
+    params: dict[str, str | int]
+    data: dict[str, str | int]
+    files: dict[str, BufferedReader]
+
+
+class _KwArgsMDRSConnectionDelete(TypedDict, total=False):
+    params: dict[str, str | int]
+
+
 class MDRSConnection:
     url: str
     session: Session
@@ -23,20 +46,17 @@ class MDRSConnection:
         self.__cache = CacheFile(remote)
         self.__prepare_headers()
 
-    def get(self, url, *args, **kwargs) -> Response:
-        return self.session.get(self.__build_url(url), *args, **kwargs)
+    def get(self, url: str, **kwargs: Unpack[_KwArgsMDRSConnectionGet]) -> Response:
+        return self.session.get(self.__build_url(url), **kwargs)
 
-    def post(self, url, *args, **kwargs) -> Response:
-        return self.session.post(self.__build_url(url), *args, **kwargs)
+    def post(self, url: str, **kwargs: Unpack[_KwArgsMDRSConnectionPost]) -> Response:
+        return self.session.post(self.__build_url(url), **kwargs)
 
-    def put(self, url, *args, **kwargs) -> Response:
-        return self.session.put(self.__build_url(url), *args, **kwargs)
+    def put(self, url: str, **kwargs: Unpack[_KwArgsMDRSConnectionPut]) -> Response:
+        return self.session.put(self.__build_url(url), **kwargs)
 
-    def delete(self, url, *args, **kwargs) -> Response:
-        return self.session.delete(self.__build_url(url), *args, **kwargs)
-
-    def patch(self, url, *args, **kwargs) -> Response:
-        return self.session.patch(self.__build_url(url), *args, **kwargs)
+    def delete(self, url: str, **kwargs: Unpack[_KwArgsMDRSConnectionDelete]) -> Response:
+        return self.session.delete(self.__build_url(url), **kwargs)
 
     def logout(self) -> None:
         del self.__cache.user
@@ -68,12 +88,10 @@ class MDRSConnection:
     def laboratories(self, laboratories: Laboratories) -> None:
         self.__cache.laboratories = laboratories
 
-    def __build_url(self, *args: str) -> str:
+    def __build_url(self, path: str) -> str:
         if self.url == "":
             raise MissingConfigurationException("remote host is not configured")
-        parts = [self.url]
-        parts.extend(args)
-        return "/".join(parts)
+        return f"{self.url}/{path}"
 
     def __prepare_headers(self) -> None:
         self.session.headers.update(
diff --git a/mdrsclient/models/file.py b/mdrsclient/models/file.py
index 739feaf..b015d11 100644
--- a/mdrsclient/models/file.py
+++ b/mdrsclient/models/file.py
@@ -1,3 +1,5 @@
+from typing import Any
+
 from pydantic.dataclasses import dataclass
 
 from mdrsclient.models.utils import iso8601_to_user_friendly
@@ -11,7 +13,7 @@ class File:
     size: int
     thumbnail: str | None
     description: str
-    metadata: dict
+    metadata: dict[str, Any]
     download_url: str
     created_at: str
     updated_at: str
diff --git a/mdrsclient/models/folder.py b/mdrsclient/models/folder.py
index 409680a..4d59c94 100644
--- a/mdrsclient/models/folder.py
+++ b/mdrsclient/models/folder.py
@@ -1,4 +1,4 @@
-from typing import Final, NamedTuple
+from typing import Any, Final, NamedTuple
 from unicodedata import normalize
 
 from pydantic.dataclasses import dataclass
@@ -66,7 +66,7 @@ class FolderSimple:
 
 @dataclass(frozen=True)
 class Folder(FolderSimple):
-    metadata: list[dict]
+    metadata: list[dict[str, Any]]
     sub_folders: list[FolderSimple]
     files: list[File]
     path: str
diff --git a/mdrsclient/models/user.py b/mdrsclient/models/user.py
index eff7753..ea9ab52 100644
--- a/mdrsclient/models/user.py
+++ b/mdrsclient/models/user.py
@@ -38,7 +38,7 @@ class Token:
         return (now + 10) > access_decoded.exp and (now - 10) < refresh_decoded.exp
 
     def __decode(self, token: str) -> DecodedJWT:
-        data = jwt.decode(token, options={"verify_signature": False})
+        data = jwt.decode(token, options={"verify_signature": False})  # type: ignore
         return TypeAdapter(DecodedJWT).validate_python(data)