From ea47daf11c23e364419a6a9934516d1a5f15b918 Mon Sep 17 00:00:00 2001
From: lrg913427-dot <lrg913427@gmail.com>
Date: Mon, 1 Jun 2026 22:18:23 +0800
Subject: [PATCH] fix: handle bare dict annotation in construct_type()

When type_ is a bare dict without type parameters (e.g. dict instead of
dict[str, Any]), get_args(dict) returns an empty tuple. The previous code
unconditionally unpacked two values from it, causing ValueError.

Add a length check before unpacking and return the value as-is for bare
dicts since there are no type parameters to recurse into.

Fixes #3341
---
 src/openai/_models.py |  7 ++++++-
 tests/test_models.py  | 16 ++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/openai/_models.py b/src/openai/_models.py
index ed4c1f82d6..03a99729a5 100644
--- a/src/openai/_models.py
+++ b/src/openai/_models.py
@@ -657,7 +657,12 @@ 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 len(args) < 2:
+            # bare `dict` with no type parameters (e.g. `dict` instead of
+            # `dict[str, Any]`) — nothing to recurse into, return as-is.
+            return value
+        _, items_type = args
         return {key: construct_type(value=item, type_=items_type) for key, item in value.items()}
 
     if (
diff --git a/tests/test_models.py b/tests/test_models.py
index cc204bac1d..10ca835628 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -133,6 +133,22 @@ class NestedModel(BaseModel):
     assert cast(Any, m.nested) is False
 
 
+
+def test_bare_dict_annotation() -> None:
+    """construct_type should not crash on bare dict annotations without type parameters."""
+    # This was crashing with ValueError: not enough values to unpack
+    # because get_args(dict) returns () for unparameterised dict.
+    result = construct_type(value={"key": "value"}, type_=dict)
+    assert result == {"key": "value"}
+
+    result = construct_type(value={"a": 1, "b": 2}, type_=dict)
+    assert result == {"a": 1, "b": 2}
+
+    # empty dict
+    result = construct_type(value={}, type_=dict)
+    assert result == {}
+
+
 def test_nested_dictionary_model() -> None:
     class NestedModel(BaseModel):
         nested: Dict[str, BasicModel]