fix(_models): guard against empty get_args() on bare dict annotation

src/openai/_models.py

@@ -657,7 +657,11 @@ def construct_type(*, value: object, type_: object, metadata: Optional[List[Any]
         if not is_mapping(value):
             return value
 
-        _, items_type = get_args(type_)  # Dict[_, items_type]
+        args = get_args(type_)
+        if not args:
+            # bare `dict` with no type arguments — return value as-is
+            return value
+        _, items_type = args  # Dict[_, items_type]
         return {key: construct_type(value=item, type_=items_type) for key, item in value.items()}
 
     if (

tests/test_models.py

@@ -655,6 +655,12 @@ class Model(BaseModel):
     assert m.value == "foo"
 
 
+def test_construct_type_bare_dict_annotation() -> None:
+    # bare `dict` (no type args) must not raise ValueError on unpack
+    result = construct_type(value={"key": "value"}, type_=dict)
+    assert result == {"key": "value"}
+
+
 def test_discriminated_unions_invalid_data() -> None:
     class A(BaseModel):
         type: Literal["a"]