state: get_value unwraps MutableProxy first

reflex/state.py

@@ -1008,6 +1008,21 @@ def _clean(self):
         self.dirty_vars = set()
         self.dirty_substates = set()
 
+    def get_value(self, key: str) -> Any:
+        """Get the value of a field (without proxying).
+
+        The returned value will NOT track dirty state updates.
+
+        Args:
+            key: The key of the field.
+
+        Returns:
+            The value of the field.
+        """
+        if isinstance(key, MutableProxy):
+            return super().get_value(key.__wrapped__)
+        return super().get_value(key)
+
     def dict(self, include_computed: bool = True, **kwargs) -> dict[str, Any]:
         """Convert the object to a dictionary.
 

tests/test_state.py

@@ -2109,3 +2109,21 @@ def test_mutable_copy_vars(mutable_state, copy_func):
 def test_duplicate_substate_class(duplicate_substate):
     with pytest.raises(ValueError):
         duplicate_substate()
+
+
+class Foo(Base):
+    """A class containing a list of str."""
+
+    tags: List[str] = ["123", "456"]
+
+
+def test_json_dumps_with_mutables():
+    """Test that json.dumps works with Base vars inside mutable types."""
+
+    class MutableContainsBase(State):
+        items: List[Foo] = [Foo()]
+
+    dict_val = MutableContainsBase().dict()
+    assert isinstance(dict_val["items"][0], dict)
+    val = format.json_dumps(dict_val)
+    assert val == '{"is_hydrated": false, "items": [{"tags": ["123", "456"]}]}'