refactor: uniform Google LLM variant and parsing logic and make contant value consistent with Google GenAI SDK : 903e0729ce/google/genai/_automatic_function_calling_util.py (L96)

PiperOrigin-RevId: 765639681

src/google/adk/tools/_automatic_function_calling_util.py

@@ -31,6 +31,7 @@ from pydantic import create_model
 from pydantic import fields as pydantic_fields
 
 from . import _function_parameter_parse_util
+from ..utils.variant_utils import GoogleLLMVariant
 
 _py_type_2_schema_type = {
     'str': types.Type.STRING,
@@ -194,7 +195,7 @@ def _get_return_type(func: Callable) -> Any:
 def build_function_declaration(
     func: Union[Callable, BaseModel],
     ignore_params: Optional[list[str]] = None,
-    variant: Literal['GOOGLE_AI', 'VERTEX_AI', 'DEFAULT'] = 'GOOGLE_AI',
+    variant: GoogleLLMVariant = GoogleLLMVariant.GEMINI_API,
 ) -> types.FunctionDeclaration:
   signature = inspect.signature(func)
   should_update_signature = False
@@ -291,16 +292,9 @@ def build_function_declaration_util(
 
 def from_function_with_options(
     func: Callable,
-    variant: Literal['GOOGLE_AI', 'VERTEX_AI', 'DEFAULT'] = 'GOOGLE_AI',
+    variant: GoogleLLMVariant = GoogleLLMVariant.GEMINI_API,
 ) -> 'types.FunctionDeclaration':
 
-  supported_variants = ['GOOGLE_AI', 'VERTEX_AI', 'DEFAULT']
-  if variant not in supported_variants:
-    raise ValueError(
-        f'Unsupported variant: {variant}. Supported variants are:'
-        f' {", ".join(supported_variants)}'
-    )
-
   parameters_properties = {}
   for name, param in inspect.signature(func).parameters.items():
     if param.kind in (
@@ -330,7 +324,7 @@ def from_function_with_options(
             declaration.parameters
         )
     )
-  if not variant == 'VERTEX_AI':
+  if variant == GoogleLLMVariant.GEMINI_API:
     return declaration
 
   return_annotation = inspect.signature(func).return_annotation

src/google/adk/tools/_function_parameter_parse_util.py

@@ -28,6 +28,8 @@ from typing import Union
 from google.genai import types
 import pydantic
 
+from ..utils.variant_utils import GoogleLLMVariant
+
 _py_builtin_type_to_schema_type = {
     str: types.Type.STRING,
     int: types.Type.INTEGER,
@@ -63,8 +65,10 @@ def _update_for_default_if_mldev(schema: types.Schema):
     )
 
 
-def _raise_if_schema_unsupported(variant: str, schema: types.Schema):
-  if not variant == 'VERTEX_AI':
+def _raise_if_schema_unsupported(
+    variant: GoogleLLMVariant, schema: types.Schema
+):
+  if variant == GoogleLLMVariant.GEMINI_API:
     _raise_for_any_of_if_mldev(schema)
     _update_for_default_if_mldev(schema)
 
@@ -116,7 +120,7 @@ def _is_default_value_compatible(
 
 
 def _parse_schema_from_parameter(
-    variant: str, param: inspect.Parameter, func_name: str
+    variant: GoogleLLMVariant, param: inspect.Parameter, func_name: str
 ) -> types.Schema:
   """parse schema from parameter.
 

src/google/adk/tools/base_tool.py

@@ -15,13 +15,14 @@
 from __future__ import annotations
 
 from abc import ABC
-import os
 from typing import Any
 from typing import Optional
 from typing import TYPE_CHECKING
 
 from google.genai import types
 
+from ..utils.variant_utils import get_google_llm_variant
+from ..utils.variant_utils import GoogleLLMVariant
 from .tool_context import ToolContext
 
 if TYPE_CHECKING:
@@ -118,12 +119,8 @@ class BaseTool(ABC):
       )
 
   @property
-  def _api_variant(self) -> str:
-    use_vertexai = os.environ.get('GOOGLE_GENAI_USE_VERTEXAI', '0').lower() in [
-        'true',
-        '1',
-    ]
-    return 'VERTEX_AI' if use_vertexai else 'GOOGLE_AI'
+  def _api_variant(self) -> GoogleLLMVariant:
+    return get_google_llm_variant()
 
 
 def _find_tool_with_function_declarations(