diff --git a/nextcloud_mcp_server/app.py b/nextcloud_mcp_server/app.py
index 00481f4..21939a4 100644
--- a/nextcloud_mcp_server/app.py
+++ b/nextcloud_mcp_server/app.py
@@ -5,6 +5,7 @@ from contextlib import AsyncExitStack, asynccontextmanager
 from dataclasses import dataclass
 
 import click
+import httpx
 import uvicorn
 from mcp.server.auth.settings import AuthSettings
 from mcp.server.fastmcp import Context, FastMCP
@@ -14,7 +15,7 @@ from starlette.routing import Mount
 
 from nextcloud_mcp_server.auth import NextcloudTokenVerifier, load_or_register_client
 from nextcloud_mcp_server.client import NextcloudClient
-from nextcloud_mcp_server.config import setup_logging, LOGGING_CONFIG
+from nextcloud_mcp_server.config import LOGGING_CONFIG, setup_logging
 from nextcloud_mcp_server.context import get_client as get_nextcloud_client
 from nextcloud_mcp_server.server import (
     configure_calendar_tools,
@@ -176,8 +177,6 @@ async def app_lifespan_oauth(server: FastMCP) -> AsyncIterator[OAuthAppContext]:
 
     try:
         # Fetch OIDC discovery
-        import httpx
-
         async with httpx.AsyncClient() as client:
             response = await client.get(discovery_url)
             response.raise_for_status()
@@ -266,8 +265,6 @@ async def setup_oauth_config():
     logger.info(f"Performing OIDC discovery: {discovery_url}")
 
     # Fetch OIDC discovery
-    import httpx
-
     async with httpx.AsyncClient() as client:
         response = await client.get(discovery_url)
         response.raise_for_status()
diff --git a/nextcloud_mcp_server/client/__init__.py b/nextcloud_mcp_server/client/__init__.py
index ae37e79..094a85f 100644
--- a/nextcloud_mcp_server/client/__init__.py
+++ b/nextcloud_mcp_server/client/__init__.py
@@ -21,8 +21,8 @@ from .groups import GroupsClient
 from .notes import NotesClient
 from .sharing import SharingClient
 from .tables import TablesClient
-from .webdav import WebDAVClient
 from .users import UsersClient
+from .webdav import WebDAVClient
 
 logger = logging.getLogger(__name__)
 
diff --git a/nextcloud_mcp_server/client/calendar.py b/nextcloud_mcp_server/client/calendar.py
index 98830d3..22112e1 100644
--- a/nextcloud_mcp_server/client/calendar.py
+++ b/nextcloud_mcp_server/client/calendar.py
@@ -7,9 +7,8 @@ import xml.etree.ElementTree as ET
 from typing import Any, Dict, List, Optional, Tuple
 
 from httpx import HTTPStatusError
-from icalendar import Alarm, Calendar
+from icalendar import Alarm, Calendar, vRecur
 from icalendar import Event as ICalEvent
-from icalendar import vRecur
 
 from .base import BaseNextcloudClient
 
diff --git a/nextcloud_mcp_server/client/users.py b/nextcloud_mcp_server/client/users.py
index 210fea7..b85af69 100644
--- a/nextcloud_mcp_server/client/users.py
+++ b/nextcloud_mcp_server/client/users.py
@@ -1,4 +1,5 @@
-from typing import List, Optional, Dict
+from typing import Dict, List, Optional
+
 from nextcloud_mcp_server.client.base import BaseNextcloudClient
 from nextcloud_mcp_server.models.users import UserDetails
 
diff --git a/nextcloud_mcp_server/models/users.py b/nextcloud_mcp_server/models/users.py
index 784254f..770e490 100644
--- a/nextcloud_mcp_server/models/users.py
+++ b/nextcloud_mcp_server/models/users.py
@@ -1,4 +1,5 @@
 from typing import Any, Dict, List, Optional, Union
+
 from pydantic import BaseModel, ConfigDict, Field
 
 
diff --git a/nextcloud_mcp_server/server/sharing.py b/nextcloud_mcp_server/server/sharing.py
index d1a07a4..2c31e9e 100644
--- a/nextcloud_mcp_server/server/sharing.py
+++ b/nextcloud_mcp_server/server/sharing.py
@@ -2,9 +2,10 @@
 
 import json
 
-from nextcloud_mcp_server.context import get_client
 from mcp.server.fastmcp import Context, FastMCP
 
+from nextcloud_mcp_server.context import get_client
+
 
 def configure_sharing_tools(mcp: FastMCP):
     """Configure sharing-related MCP tools.
diff --git a/pyproject.toml b/pyproject.toml
index bdd36e3..2ce516a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -40,6 +40,9 @@ version_provider = "uv"
 update_changelog_on_bump = true
 major_version_zero = true
 
+[tool.ruff.lint]
+extend-select = ["I"]
+
 [build-system]
 requires = ["poetry-core>=2.0.0,<3.0.0"]
 build-backend = "poetry.core.masonry.api"
diff --git a/tests/load/oauth_workloads.py b/tests/load/oauth_workloads.py
index 8f54a4e..bbd4b32 100644
--- a/tests/load/oauth_workloads.py
+++ b/tests/load/oauth_workloads.py
@@ -13,7 +13,7 @@ import time
 import uuid
 from abc import ABC, abstractmethod
 from dataclasses import dataclass, field
-from typing import Any, Callable, Awaitable
+from typing import Any, Awaitable, Callable
 
 from tests.load.oauth_pool import UserSessionWrapper
 
diff --git a/tests/server/test_mcp_oauth.py b/tests/server/test_mcp_oauth.py
index ad3b09b..308b3dd 100644
--- a/tests/server/test_mcp_oauth.py
+++ b/tests/server/test_mcp_oauth.py
@@ -1,5 +1,6 @@
 import json
 import logging
+
 import pytest
 
 logger = logging.getLogger(__name__)
diff --git a/tests/server/test_users_api.py b/tests/server/test_users_api.py
index 172aa15..f81c4f8 100644
--- a/tests/server/test_users_api.py
+++ b/tests/server/test_users_api.py
@@ -1,4 +1,5 @@
 import pytest
+
 from nextcloud_mcp_server.client import NextcloudClient