diff --git a/examples/hooks/fix_file_permissions_example.py b/examples/hooks/fix_file_permissions_example.py
new file mode 100755
index 00000000..791def97
--- /dev/null
+++ b/examples/hooks/fix_file_permissions_example.py
@@ -0,0 +1,163 @@
+#!/usr/bin/env python3
+"""
+Claude Code Hook: Fix File Permissions After Write
+===================================================
+This hook runs as a PostToolUse hook for the Write and Edit tools.
+It fixes file permissions to respect the system's umask setting.
+
+This addresses the issue where Claude Code's Write tool creates files with
+restrictive 0600 permissions, ignoring the user's umask setting.
+
+Read more about hooks here: https://docs.anthropic.com/en/docs/claude-code/hooks
+
+Configuration example for ~/.claude/settings.json or .claude/settings.local.json:
+
+{
+  "hooks": {
+    "PostToolUse": [
+      {
+        "matcher": "Write|Edit",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "python3 /path/to/claude-code/examples/hooks/fix_file_permissions_example.py"
+          }
+        ]
+      }
+    ]
+  }
+}
+
+How it works:
+- After Write or Edit tool completes, this hook runs
+- Gets the file path from the tool input
+- Calculates the correct permissions based on the current umask
+- Applies the umask-respecting permissions to the file
+
+For example:
+- With umask 022: files become 0644 (rw-r--r--)
+- With umask 002: files become 0664 (rw-rw-r--)
+- With umask 077: files remain 0600 (rw-------)
+"""
+
+import json
+import os
+import stat
+import sys
+
+
+def get_umask() -> int:
+    """Get the current umask value.
+
+    We temporarily set umask to get the current value, then restore it.
+    This is the standard way to read umask in Python.
+    """
+    current_umask = os.umask(0)
+    os.umask(current_umask)
+    return current_umask
+
+
+def calculate_file_permissions(umask_value: int) -> int:
+    """Calculate file permissions based on umask.
+
+    Standard Unix behavior: new files start with 0666 base permissions,
+    then umask is applied to remove bits.
+
+    Args:
+        umask_value: The current umask value (e.g., 0o022)
+
+    Returns:
+        The file permissions after applying umask (e.g., 0o644)
+    """
+    base_permissions = 0o666  # rw-rw-rw-
+    return base_permissions & ~umask_value
+
+
+def fix_file_permissions(file_path: str) -> dict:
+    """Fix permissions for a file to respect umask.
+
+    Args:
+        file_path: Path to the file to fix
+
+    Returns:
+        Dict with status information
+    """
+    if not file_path:
+        return {"status": "skipped", "reason": "no file path provided"}
+
+    if not os.path.exists(file_path):
+        return {"status": "skipped", "reason": "file does not exist"}
+
+    if not os.path.isfile(file_path):
+        return {"status": "skipped", "reason": "path is not a file"}
+
+    try:
+        # Get current permissions
+        current_mode = stat.S_IMODE(os.stat(file_path).st_mode)
+
+        # Calculate expected permissions based on umask
+        umask_value = get_umask()
+        expected_mode = calculate_file_permissions(umask_value)
+
+        # Only change if current permissions are more restrictive than expected
+        # This handles the case where Write tool sets 0600 instead of umask-based perms
+        if current_mode == 0o600 and expected_mode != 0o600:
+            os.chmod(file_path, expected_mode)
+            return {
+                "status": "fixed",
+                "file": file_path,
+                "old_mode": oct(current_mode),
+                "new_mode": oct(expected_mode),
+                "umask": oct(umask_value),
+            }
+        else:
+            return {
+                "status": "unchanged",
+                "file": file_path,
+                "current_mode": oct(current_mode),
+                "expected_mode": oct(expected_mode),
+            }
+
+    except PermissionError as e:
+        return {"status": "error", "reason": f"permission denied: {e}"}
+    except OSError as e:
+        return {"status": "error", "reason": f"OS error: {e}"}
+
+
+def main():
+    """Main entry point for the PostToolUse hook."""
+    try:
+        input_data = json.load(sys.stdin)
+    except json.JSONDecodeError as e:
+        # Exit 0 - don't block on invalid input, just log to stderr
+        print(f"Warning: Invalid JSON input: {e}", file=sys.stderr)
+        sys.exit(0)
+
+    tool_name = input_data.get("tool_name", "")
+
+    # Only process Write and Edit tools
+    if tool_name not in ("Write", "Edit"):
+        sys.exit(0)
+
+    tool_input = input_data.get("tool_input", {})
+    file_path = tool_input.get("file_path", "")
+
+    if not file_path:
+        sys.exit(0)
+
+    result = fix_file_permissions(file_path)
+
+    # Output result as JSON for logging/debugging
+    # This will appear in the transcript when running with --debug
+    if result.get("status") == "fixed":
+        output = {
+            "systemMessage": f"Fixed file permissions for {file_path}: {result['old_mode']} -> {result['new_mode']} (umask: {result['umask']})"
+        }
+        print(json.dumps(output))
+
+    # Always exit 0 - this is a PostToolUse hook, we don't want to block
+    sys.exit(0)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/examples/hooks/test_fix_file_permissions.py b/examples/hooks/test_fix_file_permissions.py
new file mode 100755
index 00000000..bea13a71
--- /dev/null
+++ b/examples/hooks/test_fix_file_permissions.py
@@ -0,0 +1,278 @@
+#!/usr/bin/env python3
+"""
+Tests for the fix_file_permissions_example.py hook.
+
+Run these tests with:
+    python3 examples/hooks/test_fix_file_permissions.py
+
+Or with pytest:
+    pytest examples/hooks/test_fix_file_permissions.py -v
+"""
+
+import json
+import os
+import stat
+import subprocess
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+
+# Path to the hook script
+HOOK_SCRIPT = Path(__file__).parent / "fix_file_permissions_example.py"
+
+
+class TestFixFilePermissionsHook(unittest.TestCase):
+    """Test cases for the file permissions fix hook."""
+
+    def setUp(self):
+        """Set up test fixtures."""
+        self.temp_dir = tempfile.mkdtemp()
+        self.test_file = os.path.join(self.temp_dir, "test_file.txt")
+
+    def tearDown(self):
+        """Clean up test files."""
+        if os.path.exists(self.test_file):
+            os.remove(self.test_file)
+        if os.path.exists(self.temp_dir):
+            os.rmdir(self.temp_dir)
+
+    def run_hook(self, tool_name: str, file_path: str) -> subprocess.CompletedProcess:
+        """Run the hook script with given input."""
+        input_data = {
+            "tool_name": tool_name,
+            "tool_input": {"file_path": file_path},
+            "session_id": "test-session",
+            "cwd": os.getcwd(),
+        }
+
+        result = subprocess.run(
+            [sys.executable, str(HOOK_SCRIPT)],
+            input=json.dumps(input_data),
+            capture_output=True,
+            text=True,
+        )
+        return result
+
+    def create_file_with_permissions(self, path: str, mode: int) -> None:
+        """Create a test file with specific permissions."""
+        with open(path, "w") as f:
+            f.write("test content")
+        os.chmod(path, mode)
+
+    def get_file_permissions(self, path: str) -> int:
+        """Get the permission bits of a file."""
+        return stat.S_IMODE(os.stat(path).st_mode)
+
+    def test_fixes_restrictive_permissions_with_umask_022(self):
+        """Test that 0600 permissions are fixed to 0644 with umask 022."""
+        # Save and set umask
+        old_umask = os.umask(0o022)
+        try:
+            # Create file with restrictive permissions (simulating Write tool bug)
+            self.create_file_with_permissions(self.test_file, 0o600)
+            self.assertEqual(self.get_file_permissions(self.test_file), 0o600)
+
+            # Run the hook
+            result = self.run_hook("Write", self.test_file)
+            self.assertEqual(result.returncode, 0)
+
+            # Check permissions were fixed
+            expected_mode = 0o644  # 0666 & ~0022
+            self.assertEqual(
+                self.get_file_permissions(self.test_file),
+                expected_mode,
+                f"Expected {oct(expected_mode)}, got {oct(self.get_file_permissions(self.test_file))}",
+            )
+        finally:
+            os.umask(old_umask)
+
+    def test_fixes_restrictive_permissions_with_umask_002(self):
+        """Test that 0600 permissions are fixed to 0664 with umask 002."""
+        # Save and set umask
+        old_umask = os.umask(0o002)
+        try:
+            # Create file with restrictive permissions
+            self.create_file_with_permissions(self.test_file, 0o600)
+            self.assertEqual(self.get_file_permissions(self.test_file), 0o600)
+
+            # Run the hook
+            result = self.run_hook("Write", self.test_file)
+            self.assertEqual(result.returncode, 0)
+
+            # Check permissions were fixed
+            expected_mode = 0o664  # 0666 & ~0002
+            self.assertEqual(
+                self.get_file_permissions(self.test_file),
+                expected_mode,
+                f"Expected {oct(expected_mode)}, got {oct(self.get_file_permissions(self.test_file))}",
+            )
+        finally:
+            os.umask(old_umask)
+
+    def test_preserves_permissions_matching_umask(self):
+        """Test that permissions already matching umask are not changed."""
+        old_umask = os.umask(0o022)
+        try:
+            # Create file with correct permissions already
+            self.create_file_with_permissions(self.test_file, 0o644)
+
+            # Run the hook
+            result = self.run_hook("Write", self.test_file)
+            self.assertEqual(result.returncode, 0)
+
+            # Permissions should be unchanged
+            self.assertEqual(self.get_file_permissions(self.test_file), 0o644)
+        finally:
+            os.umask(old_umask)
+
+    def test_respects_umask_077(self):
+        """Test that umask 077 results in 0600 (no change needed)."""
+        old_umask = os.umask(0o077)
+        try:
+            # Create file with 0600 permissions
+            self.create_file_with_permissions(self.test_file, 0o600)
+
+            # Run the hook
+            result = self.run_hook("Write", self.test_file)
+            self.assertEqual(result.returncode, 0)
+
+            # With umask 077, 0600 is correct - should remain unchanged
+            self.assertEqual(self.get_file_permissions(self.test_file), 0o600)
+        finally:
+            os.umask(old_umask)
+
+    def test_handles_edit_tool(self):
+        """Test that the hook also works for the Edit tool."""
+        old_umask = os.umask(0o022)
+        try:
+            self.create_file_with_permissions(self.test_file, 0o600)
+
+            result = self.run_hook("Edit", self.test_file)
+            self.assertEqual(result.returncode, 0)
+
+            self.assertEqual(self.get_file_permissions(self.test_file), 0o644)
+        finally:
+            os.umask(old_umask)
+
+    def test_ignores_other_tools(self):
+        """Test that the hook ignores non-Write/Edit tools."""
+        old_umask = os.umask(0o022)
+        try:
+            self.create_file_with_permissions(self.test_file, 0o600)
+
+            result = self.run_hook("Read", self.test_file)
+            self.assertEqual(result.returncode, 0)
+
+            # Permissions should be unchanged for Read tool
+            self.assertEqual(self.get_file_permissions(self.test_file), 0o600)
+        finally:
+            os.umask(old_umask)
+
+    def test_handles_nonexistent_file(self):
+        """Test that the hook handles non-existent files gracefully."""
+        result = self.run_hook("Write", "/nonexistent/path/file.txt")
+        self.assertEqual(result.returncode, 0)
+
+    def test_handles_empty_file_path(self):
+        """Test that the hook handles empty file path gracefully."""
+        input_data = {
+            "tool_name": "Write",
+            "tool_input": {},
+            "session_id": "test-session",
+        }
+
+        result = subprocess.run(
+            [sys.executable, str(HOOK_SCRIPT)],
+            input=json.dumps(input_data),
+            capture_output=True,
+            text=True,
+        )
+        self.assertEqual(result.returncode, 0)
+
+    def test_handles_invalid_json(self):
+        """Test that the hook handles invalid JSON input gracefully."""
+        result = subprocess.run(
+            [sys.executable, str(HOOK_SCRIPT)],
+            input="not valid json",
+            capture_output=True,
+            text=True,
+        )
+        # Should exit 0 even with invalid input (don't block the workflow)
+        self.assertEqual(result.returncode, 0)
+        self.assertIn("Invalid JSON", result.stderr)
+
+    def test_handles_directory_path(self):
+        """Test that the hook ignores directory paths."""
+        result = self.run_hook("Write", self.temp_dir)
+        self.assertEqual(result.returncode, 0)
+
+    def test_outputs_system_message_on_fix(self):
+        """Test that the hook outputs a systemMessage when fixing permissions."""
+        old_umask = os.umask(0o022)
+        try:
+            self.create_file_with_permissions(self.test_file, 0o600)
+
+            result = self.run_hook("Write", self.test_file)
+            self.assertEqual(result.returncode, 0)
+
+            # Check that stdout contains the systemMessage JSON
+            if result.stdout.strip():
+                output = json.loads(result.stdout)
+                self.assertIn("systemMessage", output)
+                self.assertIn("Fixed file permissions", output["systemMessage"])
+        finally:
+            os.umask(old_umask)
+
+
+class TestCalculateFilePermissions(unittest.TestCase):
+    """Test the calculate_file_permissions function directly."""
+
+    def test_umask_022(self):
+        """Test permission calculation with umask 022."""
+        # Import the function from the hook script
+        import importlib.util
+
+        spec = importlib.util.spec_from_file_location("hook", HOOK_SCRIPT)
+        hook = importlib.util.module_from_spec(spec)
+        spec.loader.exec_module(hook)
+
+        result = hook.calculate_file_permissions(0o022)
+        self.assertEqual(result, 0o644)
+
+    def test_umask_002(self):
+        """Test permission calculation with umask 002."""
+        import importlib.util
+
+        spec = importlib.util.spec_from_file_location("hook", HOOK_SCRIPT)
+        hook = importlib.util.module_from_spec(spec)
+        spec.loader.exec_module(hook)
+
+        result = hook.calculate_file_permissions(0o002)
+        self.assertEqual(result, 0o664)
+
+    def test_umask_077(self):
+        """Test permission calculation with umask 077."""
+        import importlib.util
+
+        spec = importlib.util.spec_from_file_location("hook", HOOK_SCRIPT)
+        hook = importlib.util.module_from_spec(spec)
+        spec.loader.exec_module(hook)
+
+        result = hook.calculate_file_permissions(0o077)
+        self.assertEqual(result, 0o600)
+
+    def test_umask_000(self):
+        """Test permission calculation with umask 000."""
+        import importlib.util
+
+        spec = importlib.util.spec_from_file_location("hook", HOOK_SCRIPT)
+        hook = importlib.util.module_from_spec(spec)
+        spec.loader.exec_module(hook)
+
+        result = hook.calculate_file_permissions(0o000)
+        self.assertEqual(result, 0o666)
+
+
+if __name__ == "__main__":
+    unittest.main()