diff --git a/.python-version b/.python-version
index 6324d40..763b626 100644
--- a/.python-version
+++ b/.python-version
@@ -1 +1 @@
-3.14
+3.12.12
diff --git a/src/code_trajectory/path_utils.py b/src/code_trajectory/path_utils.py
new file mode 100644
index 0000000..46f6015
--- /dev/null
+++ b/src/code_trajectory/path_utils.py
@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: MIT
+import os
+import pathlib
+from typing import Optional
+
+def to_posix_path(path: str) -> str:
+    """Converts a path to POSIX format (forward slashes).
+
+    This is useful for interacting with tools that expect POSIX paths,
+    such as Git, even when running on Windows.
+    """
+    return path.replace("\\", "/")
+
+def normalize_path(path: str) -> str:
+    """Returns the absolute, normalized path."""
+    return os.path.abspath(path)
+
+def is_subpath(path: str, parent: str) -> bool:
+    """Checks if path is a subpath of parent.
+
+    Handles platform-specific case sensitivity and normalization.
+    """
+    try:
+        # Resolve paths to handle symlinks and relative paths
+        # We use pathlib for robust comparison
+        p_path = pathlib.Path(path).resolve()
+        p_parent = pathlib.Path(parent).resolve()
+
+        # Check if p_path is relative to p_parent
+        p_path.relative_to(p_parent)
+        return True
+    except (ValueError, RuntimeError):
+        return False
+
+def get_relative_path(path: str, start: str) -> str:
+    """Returns a relative path from start to path.
+
+    Wraps os.path.relpath but ensures consistent behavior or error handling if needed.
+    """
+    return os.path.relpath(path, start)
+
+def is_git_directory(path: str) -> bool:
+    """Checks if the path is a .git directory or inside one."""
+    # Robust check for .git in path components
+    p = pathlib.Path(path)
+    return ".git" in p.parts
diff --git a/src/code_trajectory/recorder.py b/src/code_trajectory/recorder.py
index a32d683..0de5b87 100644
--- a/src/code_trajectory/recorder.py
+++ b/src/code_trajectory/recorder.py
@@ -5,13 +5,14 @@
 import logging
 import os
 from typing import Optional
+from . import path_utils
 
 logger = logging.getLogger(__name__)
 
 
 class Recorder:
     def __init__(self, repo_path: str):
-        self.project_root = os.path.abspath(repo_path)
+        self.project_root = path_utils.normalize_path(repo_path)
         self.shadow_repo_path = os.path.join(self.project_root, ".trajectory")
         self.current_intent: Optional[str] = None
         self.current_intent: Optional[str] = None
@@ -116,8 +117,10 @@ def get_history(self, filepath: str, max_count: int = 5):
         else:
             abs_path = filepath
 
+        abs_path = path_utils.normalize_path(abs_path)
+
         # Check if path is within project root
-        if not abs_path.startswith(self.project_root):
+        if not path_utils.is_subpath(abs_path, self.project_root):
             logger.error(
                 f"Path {filepath} is not within project root {self.project_root}"
             )
diff --git a/src/code_trajectory/server.py b/src/code_trajectory/server.py
index 4f73a02..4e3e750 100644
--- a/src/code_trajectory/server.py
+++ b/src/code_trajectory/server.py
@@ -6,6 +6,7 @@
 from .recorder import Recorder
 from .watcher import Watcher
 from .trajectory import Trajectory
+from . import path_utils
 
 # Configure logging
 logging.basicConfig(
@@ -47,7 +48,7 @@ def _check_configured() -> str | None:
 
 
 def _initialize_components(path: str) -> str:
-    target_path = os.path.abspath(path)
+    target_path = path_utils.normalize_path(path)
     if not os.path.exists(target_path):
         raise ValueError(f"Target path does not exist: {target_path}")
 
diff --git a/src/code_trajectory/trajectory.py b/src/code_trajectory/trajectory.py
index a6b0052..5643649 100644
--- a/src/code_trajectory/trajectory.py
+++ b/src/code_trajectory/trajectory.py
@@ -4,6 +4,7 @@
 import os
 
 from .recorder import Recorder
+from . import path_utils
 
 logger = logging.getLogger(__name__)
 
@@ -29,14 +30,18 @@ def get_file_trajectory(self, filepath: str, depth: int = 5) -> str:
         trajectory = [f"# Trajectory for {filepath}"]
 
         # Normalize filepath for tree access (must be relative to project root).
+        # We need a POSIX path for git tree traversal.
         if os.path.isabs(filepath):
             try:
-                rel_filepath = os.path.relpath(filepath, self.recorder.project_root)
+                rel_filepath = path_utils.get_relative_path(filepath, self.recorder.project_root)
             except ValueError:
                 rel_filepath = filepath  # Fallback
         else:
             rel_filepath = filepath
 
+        # Ensure it is posix style for git
+        rel_filepath = path_utils.to_posix_path(rel_filepath)
+
         # Track content hashes to detect reverts.
         # Map: content_hash -> (timestamp, message)
         seen_states = {}
diff --git a/src/code_trajectory/watcher.py b/src/code_trajectory/watcher.py
index 17560cf..868b4fd 100644
--- a/src/code_trajectory/watcher.py
+++ b/src/code_trajectory/watcher.py
@@ -4,6 +4,7 @@
 from watchdog.events import FileSystemEventHandler
 from threading import Timer
 from .recorder import Recorder
+from . import path_utils
 
 logger = logging.getLogger(__name__)
 
@@ -27,7 +28,7 @@ def on_modified(self, event):
 
         filepath = event.src_path
         # Ignore .git directory.
-        if ".git" in filepath:
+        if path_utils.is_git_directory(filepath):
             return
 
         # Check if ignored by git.