diff --git a/platformio/home/rpc/handlers/base.py b/platformio/home/rpc/handlers/base.py
index 7b3f5d8f46..97a1ec606a 100644
--- a/platformio/home/rpc/handlers/base.py
+++ b/platformio/home/rpc/handlers/base.py
@@ -13,5 +13,58 @@
 # limitations under the License.
 
 
+import inspect
+import os
+
+
 class BaseRPCHandler:
+    PATH_ARGUMENT_MARKERS = (
+        "path",
+        "paths",
+        "dir",
+        "dirs",
+        "directory",
+        "directories",
+        "file",
+        "files",
+        "folder",
+        "folders",
+    )
+
     factory = None
+
+    def __getattribute__(self, name):
+        attr = super().__getattribute__(name)
+        if name.startswith("_") or not callable(attr):
+            return attr
+
+        def wrapped(*args, **kwargs):
+            args, kwargs = self._normalize_path_arguments(attr, args, kwargs)
+            return attr(*args, **kwargs)
+
+        return wrapped
+
+    def _normalize_path_arguments(self, method, args, kwargs):
+        bound_args = inspect.signature(method).bind_partial(*args, **kwargs)
+        for param_name, value in bound_args.arguments.items():
+            if not self._is_path_argument(param_name):
+                continue
+            bound_args.arguments[param_name] = self._normalize_path_value(value)
+        return bound_args.args, bound_args.kwargs
+
+    def _is_path_argument(self, param_name):
+        parts = param_name.lower().split("_")
+        return any(marker in parts for marker in self.PATH_ARGUMENT_MARKERS)
+
+    def _normalize_path_value(self, value):
+        if not value:
+            return value
+        if isinstance(value, str):
+            return os.path.normpath(value)
+        if isinstance(value, list):
+            return [self._normalize_path_value(item) for item in value]
+        if isinstance(value, tuple):
+            return tuple(self._normalize_path_value(item) for item in value)
+        if isinstance(value, set):
+            return {self._normalize_path_value(item) for item in value}
+        return value