diff --git a/evaluation/benchmarks/the_agent_company/browsing.py b/evaluation/benchmarks/the_agent_company/browsing.py
index e8747c2ded..3abb871e78 100644
--- a/evaluation/benchmarks/the_agent_company/browsing.py
+++ b/evaluation/benchmarks/the_agent_company/browsing.py
@@ -7,7 +7,7 @@ import os
 import re
 from dataclasses import dataclass
 from enum import Enum, auto
-from typing import Dict, List, Optional, Union
+from typing import Dict, List, Union
 
 from openhands.core.logger import openhands_logger as logger
 from openhands.events.action import BrowseInteractiveAction
@@ -133,7 +133,7 @@ def parse_content_to_elements(content: str) -> Dict[str, str]:
     return elements
 
 
-def find_matching_anchor(content: str, selector: str) -> Optional[str]:
+def find_matching_anchor(content: str, selector: str) -> str | None:
     """Find the anchor ID that matches the given selector description"""
     elements = parse_content_to_elements(content)
 
diff --git a/microagents/knowledge/docker.md b/microagents/knowledge/docker.md
index 057d75c0d4..80dad5272d 100644
--- a/microagents/knowledge/docker.md
+++ b/microagents/knowledge/docker.md
@@ -53,4 +53,3 @@ To verify Docker is working correctly, run the hello-world container:
 ```bash
 sudo docker run hello-world
 ```
-
diff --git a/openhands/core/message_format.md b/openhands/core/message_format.md
index caa9cf1b84..a0eaea5971 100644
--- a/openhands/core/message_format.md
+++ b/openhands/core/message_format.md
@@ -7,6 +7,7 @@ OpenHands uses its own `Message` class (`openhands/core/message.py`) which provi
 ## Class Structure
 
 Our `Message` class (`openhands/core/message.py`):
+
 ```python
 class Message(BaseModel):
     role: Literal['user', 'system', 'assistant', 'tool']
@@ -22,13 +23,14 @@ class Message(BaseModel):
 ```
 
 litellm's `Message` class (`litellm/types/utils.py`):
+
 ```python
 class Message(OpenAIObject):
-    content: Optional[str]
+    content: str | None
     role: Literal["assistant", "user", "system", "tool", "function"]
-    tool_calls: Optional[List[ChatCompletionMessageToolCall]]
-    function_call: Optional[FunctionCall]
-    audio: Optional[ChatCompletionAudioResponse] = None
+    tool_calls: List[ChatCompletionMessageToolCall] | None
+    function_call: FunctionCall | None
+    audio: ChatCompletionAudioResponse | None = None
 ```
 
 ## How It Works
@@ -36,6 +38,7 @@ class Message(OpenAIObject):
 1. **Message Creation**: Our `Message` class is a Pydantic model that supports rich content (text and images) through its `content` field.
 
 2. **Serialization**: The class uses Pydantic's `@model_serializer` to convert messages into dictionaries that litellm can understand. We have two serialization methods:
+
    ```python
    def _string_serializer(self) -> dict:
        # convert content to a single string
@@ -55,6 +58,7 @@ class Message(OpenAIObject):
    ```
 
    The appropriate serializer is chosen based on the message's capabilities:
+
    ```python
    @model_serializer
    def serialize_model(self) -> dict:
@@ -64,11 +68,13 @@ class Message(OpenAIObject):
    ```
 
 3. **Tool Call Handling**: Tool calls require special attention in serialization because:
+
    - They need to work with litellm's API calls (which accept both dicts and objects)
    - They need to be properly serialized for token counting
    - They need to maintain compatibility with different LLM providers' formats
 
 4. **litellm Integration**: When we pass our messages to `litellm.completion()`, litellm doesn't care about the message class type - it works with the dictionary representation. This works because:
+
    - litellm's transformation code (e.g., `litellm/llms/anthropic/chat/transformation.py`) processes messages based on their structure, not their type
    - our serialization produces dictionaries that match litellm's expected format
    - litellm handles rich content by looking at the message structure, supporting both simple string content and lists of content items
@@ -78,6 +84,7 @@ class Message(OpenAIObject):
 ### Token Counting
 
 To use litellm's token counter, we need to make sure that all message components (including tool calls) are properly serialized to dictionaries. This is because:
+
 - litellm's token counter expects dictionary structures
 - Tool calls need to be included in the token count
 - Different providers may count tokens differently for structured content
diff --git a/openhands/resolver/utils.py b/openhands/resolver/utils.py
index d12260a145..65129e12c0 100644
--- a/openhands/resolver/utils.py
+++ b/openhands/resolver/utils.py
@@ -4,7 +4,7 @@ import multiprocessing as mp
 import os
 import re
 from enum import Enum
-from typing import Callable, Optional
+from typing import Callable
 
 import pandas as pd
 import requests
@@ -22,7 +22,7 @@ class Platform(Enum):
     GITLAB = 2
 
 
-def identify_token(token: str, repo: Optional[str] = None) -> Platform:
+def identify_token(token: str, repo: str | None = None) -> Platform:
     """
     Identifies whether a token belongs to GitHub or GitLab.
 
diff --git a/openhands/runtime/impl/e2b/e2b_runtime.py b/openhands/runtime/impl/e2b/e2b_runtime.py
index 7c9c297f42..b54f833e36 100644
--- a/openhands/runtime/impl/e2b/e2b_runtime.py
+++ b/openhands/runtime/impl/e2b/e2b_runtime.py
@@ -1,4 +1,4 @@
-from typing import Callable, Optional
+from typing import Callable
 
 from openhands.core.config import AppConfig
 from openhands.events.action import (
@@ -27,7 +27,7 @@ class E2BRuntime(Runtime):
         sid: str = 'default',
         plugins: list[PluginRequirement] | None = None,
         sandbox: E2BSandbox | None = None,
-        status_callback: Optional[Callable] = None,
+        status_callback: Callable | None = None,
     ):
         super().__init__(
             config,
diff --git a/openhands/runtime/impl/local/local_runtime.py b/openhands/runtime/impl/local/local_runtime.py
index 547f2981d5..5a9acf9c22 100644
--- a/openhands/runtime/impl/local/local_runtime.py
+++ b/openhands/runtime/impl/local/local_runtime.py
@@ -7,7 +7,7 @@ import shutil
 import subprocess
 import tempfile
 import threading
-from typing import Callable, Optional
+from typing import Callable
 
 import requests
 import tenacity
@@ -155,7 +155,7 @@ class LocalRuntime(ActionExecutionClient):
 
         self.api_url = f'{self.config.sandbox.local_runtime_url}:{self._host_port}'
         self.status_callback = status_callback
-        self.server_process: Optional[subprocess.Popen[str]] = None
+        self.server_process: subprocess.Popen[str] | None = None
         self.action_semaphore = threading.Semaphore(1)  # Ensure one action at a time
 
         # Update env vars
diff --git a/openhands/runtime/impl/remote/remote_runtime.py b/openhands/runtime/impl/remote/remote_runtime.py
index 03882a06bf..6e32e889e6 100644
--- a/openhands/runtime/impl/remote/remote_runtime.py
+++ b/openhands/runtime/impl/remote/remote_runtime.py
@@ -1,5 +1,5 @@
 import os
-from typing import Callable, Optional
+from typing import Callable
 from urllib.parse import urlparse
 
 import requests
@@ -42,7 +42,7 @@ class RemoteRuntime(ActionExecutionClient):
         sid: str = 'default',
         plugins: list[PluginRequirement] | None = None,
         env_vars: dict[str, str] | None = None,
-        status_callback: Optional[Callable] = None,
+        status_callback: Callable | None = None,
         attach_to_existing: bool = False,
         headless_mode: bool = True,
         github_user_id: str | None = None,
diff --git a/openhands/server/data_models/feedback.py b/openhands/server/data_models/feedback.py
index 59f32008b5..eb89492de1 100644
--- a/openhands/server/data_models/feedback.py
+++ b/openhands/server/data_models/feedback.py
@@ -1,5 +1,5 @@
 import json
-from typing import Any, Literal, Optional
+from typing import Any, Literal
 
 import requests
 from pydantic import BaseModel
@@ -15,7 +15,7 @@ class FeedbackDataModel(BaseModel):
         'positive', 'negative'
     ]  # TODO: remove this, its here for backward compatibility
     permissions: Literal['public', 'private']
-    trajectory: Optional[list[dict[str, Any]]]
+    trajectory: list[dict[str, Any]] | None
 
 
 FEEDBACK_URL = 'https://share-od-trajectory-3u9bw9tx.uc.gateway.dev/share_od_trajectory'
diff --git a/openhands/server/session/agent_session.py b/openhands/server/session/agent_session.py
index 71fba3230d..8f382f7dc5 100644
--- a/openhands/server/session/agent_session.py
+++ b/openhands/server/session/agent_session.py
@@ -1,6 +1,6 @@
 import asyncio
 import time
-from typing import Callable, Optional
+from typing import Callable
 
 from pydantic import SecretStr
 
@@ -52,7 +52,7 @@ class AgentSession:
         sid: str,
         file_store: FileStore,
         monitoring_listener: MonitoringListener,
-        status_callback: Optional[Callable] = None,
+        status_callback: Callable | None = None,
         github_user_id: str | None = None,
     ):
         """Initializes a new instance of the Session class
diff --git a/openhands/storage/google_cloud.py b/openhands/storage/google_cloud.py
index 24466e81ef..b71e89ae61 100644
--- a/openhands/storage/google_cloud.py
+++ b/openhands/storage/google_cloud.py
@@ -1,5 +1,5 @@
 import os
-from typing import List, Optional
+from typing import List
 
 from google.api_core.exceptions import NotFound
 from google.cloud import storage
@@ -8,7 +8,7 @@ from openhands.storage.files import FileStore
 
 
 class GoogleCloudFileStore(FileStore):
-    def __init__(self, bucket_name: Optional[str] = None) -> None:
+    def __init__(self, bucket_name: str | None = None) -> None:
         """
         Create a new FileStore. If GOOGLE_APPLICATION_CREDENTIALS is defined in the
         environment it will be used for authentication. Otherwise access will be
diff --git a/tests/unit/test_storage.py b/tests/unit/test_storage.py
index 37b52f0a92..48c921a8e8 100644
--- a/tests/unit/test_storage.py
+++ b/tests/unit/test_storage.py
@@ -5,7 +5,7 @@ import shutil
 from abc import ABC
 from dataclasses import dataclass, field
 from io import BytesIO, StringIO
-from typing import Dict, List, Optional
+from typing import Dict, List
 from unittest import TestCase
 from unittest.mock import patch
 
@@ -145,10 +145,10 @@ class _MockGoogleCloudClient:
 class _MockGoogleCloudBucket:
     blobs_by_path: Dict[str, _MockGoogleCloudBlob] = field(default_factory=dict)
 
-    def blob(self, path: Optional[str] = None) -> _MockGoogleCloudBlob:
+    def blob(self, path: str | None = None) -> _MockGoogleCloudBlob:
         return self.blobs_by_path.get(path) or _MockGoogleCloudBlob(self, path)
 
-    def list_blobs(self, prefix: Optional[str] = None) -> List[_MockGoogleCloudBlob]:
+    def list_blobs(self, prefix: str | None = None) -> List[_MockGoogleCloudBlob]:
         blobs = list(self.blobs_by_path.values())
         if prefix and prefix != '/':
             blobs = [blob for blob in blobs if blob.name.startswith(prefix)]
@@ -159,7 +159,7 @@ class _MockGoogleCloudBucket:
 class _MockGoogleCloudBlob:
     bucket: _MockGoogleCloudBucket
     name: str
-    content: Optional[str | bytes] = None
+    content: str | bytes | None = None
 
     def open(self, op: str):
         if op == 'r':