From 5cb7ba509e79ed11de6deb28d760f9f122ae221d Mon Sep 17 00:00:00 2001
From: Yufeng He <40085740+he-yufeng@users.noreply.github.com>
Date: Sun, 7 Jun 2026 23:59:52 +0800
Subject: [PATCH] fix: handle bare dict type annotations

---
 src/openai/_models.py           |  5 ++++-
 src/openai/_utils/_transform.py | 12 ++++++++++--
 tests/test_models.py            |  4 ++++
 tests/test_transform.py         | 12 ++++++++++++
 4 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/src/openai/_models.py b/src/openai/_models.py
index ed4c1f82d6..a63e687025 100644
--- a/src/openai/_models.py
+++ b/src/openai/_models.py
@@ -657,7 +657,10 @@ 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]
+        if len(args) < 2:
+            return value
+
+        _, items_type = args  # Dict[_, items_type]
         return {key: construct_type(value=item, type_=items_type) for key, item in value.items()}
 
     if (
diff --git a/src/openai/_utils/_transform.py b/src/openai/_utils/_transform.py
index 414f38c340..cd3084a3bb 100644
--- a/src/openai/_utils/_transform.py
+++ b/src/openai/_utils/_transform.py
@@ -180,7 +180,11 @@ def _transform_recursive(
         return _transform_typeddict(data, stripped_type)
 
     if origin == dict and is_mapping(data):
-        items_type = get_args(stripped_type)[1]
+        args = get_args(stripped_type)
+        if len(args) < 2:
+            return data
+
+        items_type = args[1]
         return {key: _transform_recursive(value, annotation=items_type) for key, value in data.items()}
 
     if (
@@ -346,7 +350,11 @@ async def _async_transform_recursive(
         return await _async_transform_typeddict(data, stripped_type)
 
     if origin == dict and is_mapping(data):
-        items_type = get_args(stripped_type)[1]
+        args = get_args(stripped_type)
+        if len(args) < 2:
+            return data
+
+        items_type = args[1]
         return {key: _transform_recursive(value, annotation=items_type) for key, value in data.items()}
 
     if (
diff --git a/tests/test_models.py b/tests/test_models.py
index cc204bac1d..3577d7c90e 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -655,6 +655,10 @@ class Model(BaseModel):
     assert m.value == "foo"
 
 
+def test_construct_bare_dict_type() -> None:
+    assert construct_type(value={"key": "value"}, type_=dict) == {"key": "value"}
+
+
 def test_discriminated_unions_invalid_data() -> None:
     class A(BaseModel):
         type: Literal["a"]
diff --git a/tests/test_transform.py b/tests/test_transform.py
index bece75dfc7..80ffe90e99 100644
--- a/tests/test_transform.py
+++ b/tests/test_transform.py
@@ -397,6 +397,18 @@ class DictItems(TypedDict):
     assert await transform({"foo": {"foo_baz": "bar"}}, Dict[str, DictItems], use_async) == {"foo": {"fooBaz": "bar"}}
 
 
+class BareDictParam(TypedDict):
+    metadata: dict
+
+
+@parametrize
+@pytest.mark.asyncio
+async def test_bare_dictionary_annotation(use_async: bool) -> None:
+    data = {"metadata": {"foo_bar": "bar"}}
+
+    assert await transform(data, BareDictParam, use_async) == data
+
+
 class TypedDictIterableUnionStr(TypedDict):
     foo: Annotated[Union[str, Iterable[Baz8]], PropertyInfo(alias="FOO")]