From da0e22bc57cb4faa1a9780a6d8d470d04f26a730 Mon Sep 17 00:00:00 2001
From: Matej Aleksandrov <maleksandrov@google.com>
Date: Fri, 17 Jul 2026 02:08:42 -0700
Subject: [PATCH] fix: Fix Union types for Python 3.14

PiperOrigin-RevId: 949443636
---
 .../genai/_automatic_function_calling_util.py | 27 ++++++++++---------
 google/genai/types.py                         |  3 +++
 2 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/google/genai/_automatic_function_calling_util.py b/google/genai/_automatic_function_calling_util.py
index ec7f9a702..7de3c4e35 100644
--- a/google/genai/_automatic_function_calling_util.py
+++ b/google/genai/_automatic_function_calling_util.py
@@ -14,10 +14,9 @@
 #
 
 import inspect
-import sys
 import types as builtin_types
 import typing
-from typing import _GenericAlias, Any, Callable, get_args, get_origin, Literal, Optional, Union  # type: ignore[attr-defined]
+from typing import Any, Literal, Optional, Union, _GenericAlias, get_args, get_origin  # type: ignore[attr-defined]
 
 import pydantic
 
@@ -25,10 +24,8 @@
 from . import types
 
 
-if sys.version_info >= (3, 10):
-  VersionedUnionType = builtin_types.UnionType
-else:
-  VersionedUnionType = typing._UnionGenericAlias  # type: ignore[attr-defined]
+_UNION_CLASSES = (builtin_types.UnionType, typing._UnionGenericAlias)  # type: ignore[attr-defined]
+_UNION_ORIGINS = (typing.Union, builtin_types.UnionType)
 
 
 __all__ = [
@@ -102,10 +99,10 @@ def _is_default_value_compatible(
   if (
       isinstance(annotation, _GenericAlias)
       or isinstance(annotation, builtin_types.GenericAlias)
-      or isinstance(annotation, VersionedUnionType)
+      or isinstance(annotation, _UNION_CLASSES)
   ):
     origin = get_origin(annotation)
-    if origin in (Union, VersionedUnionType):  # type: ignore[comparison-overlap]
+    if origin in _UNION_ORIGINS:  # type: ignore[comparison-overlap]
       return any(
           _is_default_value_compatible(default_value, arg)
           for arg in get_args(annotation)
@@ -160,7 +157,7 @@ def _parse_schema_from_parameter(  # type: ignore[return]
     schema.type = _py_builtin_type_to_schema_type[param.annotation]
     return schema
   if (
-      isinstance(param.annotation, VersionedUnionType)
+      isinstance(param.annotation, _UNION_CLASSES)
       # only parse simple UnionType, example int | str | float | bool
       # complex UnionType will be invoked in raise branch
       and all(
@@ -199,8 +196,10 @@ def _parse_schema_from_parameter(  # type: ignore[return]
         raise ValueError(default_value_error_msg)
       schema.default = param.default
     return schema
-  if isinstance(param.annotation, _GenericAlias) or isinstance(
-      param.annotation, builtin_types.GenericAlias
+  if (
+      isinstance(param.annotation, _GenericAlias)
+      or isinstance(param.annotation, builtin_types.GenericAlias)
+      or isinstance(param.annotation, _UNION_CLASSES)
   ):
     origin = get_origin(param.annotation)
     args = get_args(param.annotation)
@@ -239,7 +238,11 @@ def _parse_schema_from_parameter(  # type: ignore[return]
           raise ValueError(default_value_error_msg)
         schema.default = param.default
       return schema
-    if origin is Union:
+    if origin in _UNION_ORIGINS:
+      if any(_extra_utils.is_annotation_pydantic_model(arg) for arg in args):
+        raise ValueError(
+            'Union containing Pydantic model is not supported in direct parsing'
+        )
       schema.any_of = []
       schema.type = _py_builtin_type_to_schema_type[dict]
       unique_types = set()
diff --git a/google/genai/types.py b/google/genai/types.py
index feffb5756..a13986361 100644
--- a/google/genai/types.py
+++ b/google/genai/types.py
@@ -3287,6 +3287,9 @@ def convert_json_schema(
               and field_name != 'additional_properties'
           ):
             setattr(schema, field_name, field_value)
+      if schema.any_of and not schema.type:
+        if all(s.type == 'OBJECT' for s in schema.any_of):
+          schema.type = Type('OBJECT')
 
       if (
           schema.type == 'ARRAY'