diff --git a/polybot/bot.py b/polybot/bot.py
index aa59150..7d43b52 100644
--- a/polybot/bot.py
+++ b/polybot/bot.py
@@ -1,15 +1,16 @@
+import argparse
 import configparser
-import pickle
 import logging
-import argparse
+import pickle
 import signal
 import sys
-from typing import List, Union, Optional, Any
-from .service import Service, PostError, ALL_SERVICES
+from typing import Any, Optional, Union
+
 from .image import Image
+from .service import ALL_SERVICES, PostError, Service
 
 
-class Bot(object):
+class Bot:
     path = ""
 
     def __init__(self, name: str) -> None:
@@ -41,7 +42,7 @@ def __init__(self, name: str) -> None:
         self.log = logging.getLogger(__name__)
 
         self.name = name
-        self.services: List[Service] = []
+        self.services: list[Service] = []
         self.state: Any = {}
 
     def run(self) -> None:
@@ -51,9 +52,10 @@ def run(self) -> None:
 
         profile = ""
         if len(self.args.profile):
-            profile = "-%s" % self.args.profile
-        self.config_path = "%s%s%s.conf" % (self.path, self.name, profile)
-        self.state_path = "%s%s%s.state" % (self.path, self.name, profile)
+            profile = "-" + self.args.profile
+        prefix = f"{self.path}{self.name}{profile}"
+        self.config_path = prefix + ".conf"
+        self.state_path = prefix + ".state"
         self.read_config()
 
         if self.args.setup:
@@ -101,21 +103,20 @@ def setup(self) -> None:
         print("=" * 80)
         for Svc in ALL_SERVICES:
             if Svc.name not in self.config:
-                result = input("Configure %s (y/n)? " % Svc.name)
+                result = input(f"Configure {Svc.name} (y/n)? ")
                 if result[0] == "y":
                     if Svc(self.config, False).setup():
-                        print("Configuring %s succeeded, writing config" % Svc.name)
+                        print(f"Configuring {Svc.name} succeeded, writing config")
                         self.write_config()
                     else:
-                        print("Configuring %s failed." % Svc.name)
+                        print(f"Configuring {Svc.name} failed.")
                 else:
                     print("OK, skipping.")
             else:
-                print("Service %s is already configured" % Svc.name)
+                print(f"Service {Svc.name} is already configured")
             print("-" * 80)
         print(
-            "Setup complete. To reconfigure, remove the service details from %s"
-            % self.config_path
+            f"Setup complete. To reconfigure, remove the service details from {self.config_path}"
         )
 
     def main(self) -> None:
@@ -125,10 +126,11 @@ def load_state(self) -> None:
         try:
             with open(self.state_path, "rb") as f:
                 self.state = pickle.load(f)
-        except IOError:
+        except OSError:
             self.log.info("No state file found")
 
     def save_state(self) -> None:
+        """Save the bot's state to disk."""
         if len(self.state) != 0:
             self.log.info("Saving state...")
             with open(self.state_path, "wb") as f:
@@ -136,9 +138,9 @@ def save_state(self) -> None:
 
     def post(
         self,
-        status: Union[str, List[str]],
+        status: Union[str, list[str]],
         wrap: bool = False,
-        images: List[Image] = [],
+        images: list[Image] = [],
         in_reply_to_id=None,
         lat: Optional[float] = None,
         lon: Optional[float] = None,
@@ -163,7 +165,7 @@ def post(
             if not len(status):
                 raise ValueError("Cannot supply an empty list")
 
-        if not isinstance(images, List) or not all(
+        if not isinstance(images, list) or not all(
             isinstance(i, Image) for i in images
         ):
             raise ValueError("The images argument must be a list of Image objects")
diff --git a/polybot/image.py b/polybot/image.py
index 3b8b57b..540a203 100644
--- a/polybot/image.py
+++ b/polybot/image.py
@@ -1,8 +1,9 @@
-from typing import BinaryIO, Optional
+import logging
 from io import BytesIO
 from pathlib import Path
+from typing import BinaryIO, Optional
+
 from PIL import Image as PILImage
-import logging
 
 log = logging.getLogger(__name__)
 
@@ -45,8 +46,8 @@ def __init__(
     def resize_to_target(
         self, target_bytes: int, target_pixels: Optional[int] = None
     ) -> "Image":
-        """Resize the image to a target maximum size in bytes and (optionally) pixels. Returns a new Image object.
-        This is required for Bluesky's silly image size limit.
+        """Resize the image to a target maximum size in bytes and (optionally) pixels.
+        Returns a new Image object.
         """
 
         original_bytes = len(self.data)
@@ -63,9 +64,10 @@ def resize_to_target(
             target_pixels = original_pixels
 
         while new_bytes > target_bytes or new_pixels > target_pixels:
-            new_pixels = int(original_pixels * (target_bytes * margin / original_bytes))
-            if target_pixels is not None:
-                new_pixels = min(new_pixels, target_pixels)
+            new_pixels = min(
+                int(original_pixels * (target_bytes * margin / original_bytes)),
+                target_pixels,
+            )
 
             ratio = (new_pixels / original_pixels) ** 0.5
             new_size = (int(img.width * ratio), int(img.height * ratio))
diff --git a/polybot/service.py b/polybot/service.py
index 40eed9a..385b6c3 100644
--- a/polybot/service.py
+++ b/polybot/service.py
@@ -1,14 +1,15 @@
-from io import BytesIO
 import logging
-import textwrap
 import mimetypes
+import textwrap
+from importlib.metadata import PackageNotFoundError, version
+from io import BytesIO
 from time import time
-from typing import List, Union, Optional, Type
+from typing import Optional, Union
+
+import httpx
 from atproto import Client, models  # type: ignore
 from atproto_client.exceptions import RequestException  # type: ignore
 from mastodon import Mastodon as MastodonClient  # type: ignore
-from importlib.metadata import PackageNotFoundError, version
-import httpx
 
 from .image import Image
 
@@ -24,7 +25,7 @@ class PostError(Exception):
     pass
 
 
-class Service(object):
+class Service:
     name = None  # type: str
     ellipsis_length = 1
     max_length = None  # type: int
@@ -47,7 +48,7 @@ def auth(self) -> None:
     def setup(self) -> bool:
         raise NotImplementedError()
 
-    def longest_allowed(self, status: list, images: List[Image]) -> str:
+    def longest_allowed(self, status: list, images: list[Image]) -> str:
         max_len = self.max_length_image if images else self.max_length
         picked = status[0]
         for s in sorted(status, key=len):
@@ -57,9 +58,9 @@ def longest_allowed(self, status: list, images: List[Image]) -> str:
 
     def post(
         self,
-        status: Union[str, List[str]],
+        status: Union[str, list[str]],
         wrap=False,
-        images: List[Image] = [],
+        images: list[Image] = [],
         lat: Optional[float] = None,
         lon: Optional[float] = None,
         in_reply_to_id=None,
@@ -78,7 +79,7 @@ def post(
     def do_post(
         self,
         status: str,
-        images: List[Image] = [],
+        images: list[Image] = [],
         lat: Optional[float] = None,
         lon: Optional[float] = None,
         in_reply_to_id=None,
@@ -88,7 +89,7 @@ def do_post(
     def do_wrapped(
         self,
         status,
-        images: List[Image] = [],
+        images: list[Image] = [],
         lat=None,
         lon=None,
         in_reply_to_id=None,
@@ -101,9 +102,9 @@ def do_wrapped(
         first = True
         for line in wrapped:
             if first and len(wrapped) > 1:
-                line = "%s\u2026" % line
+                line = line + "\u2026"
             if not first:
-                line = "\u2026%s" % line
+                line = "\u2026" + line
 
             if images and first:
                 out = self.do_post(line, images, lat, lon, in_reply_to_id)
@@ -184,7 +185,7 @@ def setup(self):
     def do_post(
         self,
         status,
-        images: List[Image] = [],
+        images: list[Image] = [],
         lat=None,
         lon=None,
         in_reply_to_id=None,
@@ -397,7 +398,7 @@ def setup(self):
     def do_post(
         self,
         status,
-        images: List[Image] = [],
+        images: list[Image] = [],
         lat=None,
         lon=None,
         in_reply_to_id=None,
@@ -476,7 +477,7 @@ def setup(self):
     def do_post(
         self,
         status,
-        images: List[Image] = [],
+        images: list[Image] = [],
         lat=None,
         lon=None,
         in_reply_to_id=None,
@@ -511,4 +512,4 @@ def do_post(
             raise PostError(e)
 
 
-ALL_SERVICES: List[Type[Service]] = [Twitter, Mastodon, Bluesky]
+ALL_SERVICES: list[type[Service]] = [Twitter, Mastodon, Bluesky]
diff --git a/pyproject.toml b/pyproject.toml
index d67289d..d33bb86 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -27,3 +27,14 @@ dev = ["mypy>=1.13.0", "ruff>=0.8.1", "pytest>=8.3.4"]
 
 [tool.pytest.ini_options]
 pythonpath = ["."]
+
+[tool.ruff]
+line-length = 110
+
+[tool.ruff.lint]
+select = ["E", "F", "UP", "I"]
+
+[tool.ruff.format]
+quote-style = "single"
+indent-style = "tab"
+docstring-code-format = true
diff --git a/tests/test_image.py b/tests/test_image.py
index 298a056..bb72a83 100644
--- a/tests/test_image.py
+++ b/tests/test_image.py
@@ -1,8 +1,10 @@
-from polybot.image import Image
 from io import BytesIO
-from PIL import Image as PILImage
 from pathlib import Path
 
+from PIL import Image as PILImage
+
+from polybot.image import Image
+
 
 def count_pixels(image):
     img = PILImage.open(BytesIO(image.data))
diff --git a/tests/test_mastodon.py b/tests/test_mastodon.py
index 2ec2b2a..2d81474 100644
--- a/tests/test_mastodon.py
+++ b/tests/test_mastodon.py
@@ -1,4 +1,5 @@
 import configparser
+
 from polybot.service import Mastodon
 
 
diff --git a/uv.lock b/uv.lock
index d966c88..5d9cc47 100644
--- a/uv.lock
+++ b/uv.lock
@@ -557,7 +557,7 @@ wheels = [
 
 [[package]]
 name = "polybot"
-version = "0.9.4"
+version = "0.9.5"
 source = { virtual = "." }
 dependencies = [
     { name = "atproto" },