add toolset base class and allow llm agent to accept toolset as tools

PiperOrigin-RevId: 756605470

src/google/adk/agents/callback_context.py

@@ -60,11 +60,6 @@ class CallbackContext(ReadonlyContext):
     """
     return self._state
 
-  @property
-  def user_content(self) -> Optional[types.Content]:
-    """The user content that started this invocation. READONLY field."""
-    return self._invocation_context.user_content
-
   async def load_artifact(
       self, filename: str, version: Optional[int] = None
   ) -> Optional[types.Part]:

src/google/adk/agents/llm_agent.py

@@ -15,7 +15,15 @@
 from __future__ import annotations
 
 import logging
-from typing import Any, AsyncGenerator, Awaitable, Callable, Literal, Optional, Union
+from typing import (
+    Any,
+    AsyncGenerator,
+    Awaitable,
+    Callable,
+    Literal,
+    Optional,
+    Union,
+)
 
 from google.genai import types
 from pydantic import BaseModel
@@ -38,6 +46,7 @@ from ..models.llm_response import LlmResponse
 from ..models.registry import LLMRegistry
 from ..planners.base_planner import BasePlanner
 from ..tools.base_tool import BaseTool
+from ..tools.base_toolset import BaseToolset
 from ..tools.function_tool import FunctionTool
 from ..tools.tool_context import ToolContext
 from .base_agent import BaseAgent
@@ -89,18 +98,19 @@ AfterToolCallback: TypeAlias = Union[
 
 InstructionProvider: TypeAlias = Callable[[ReadonlyContext], str]
 
-ToolUnion: TypeAlias = Union[Callable, BaseTool]
+ToolUnion: TypeAlias = Union[Callable, BaseTool, BaseToolset]
 ExamplesUnion = Union[list[Example], BaseExampleProvider]
 
 
-def _convert_tool_union_to_tool(
-    tool_union: ToolUnion,
-) -> BaseTool:
-  return (
-      tool_union
-      if isinstance(tool_union, BaseTool)
-      else FunctionTool(tool_union)
-  )
+async def _convert_tool_union_to_tools(
+    tool_union: ToolUnion, ctx: ReadonlyContext
+) -> list[BaseTool]:
+  if isinstance(tool_union, BaseTool):
+    return [tool_union]
+  if isinstance(tool_union, Callable):
+    return [FunctionTool(func=tool_union)]
+
+  return await tool_union.get_tools(ctx)
 
 
 class LlmAgent(BaseAgent):
@@ -312,13 +322,17 @@ class LlmAgent(BaseAgent):
     else:
       return self.global_instruction(ctx)
 
-  @property
-  def canonical_tools(self) -> list[BaseTool]:
-    """The resolved self.tools field as a list of BaseTool.
+  async def canonical_tools(
+      self, ctx: ReadonlyContext = None
+  ) -> list[BaseTool]:
+    """The resolved self.tools field as a list of BaseTool based on the context.
 
     This method is only for use by Agent Development Kit.
     """
-    return [_convert_tool_union_to_tool(tool) for tool in self.tools]
+    resolved_tools = []
+    for tool_union in self.tools:
+      resolved_tools.extend(await _convert_tool_union_to_tools(tool_union, ctx))
+    return resolved_tools
 
   @property
   def canonical_before_model_callbacks(

src/google/adk/agents/readonly_context.py

@@ -15,10 +15,11 @@
 from __future__ import annotations
 
 from types import MappingProxyType
-from typing import Any
+from typing import Any, Optional
 from typing import TYPE_CHECKING
 
 if TYPE_CHECKING:
+  from google.genai import types
   from .invocation_context import InvocationContext
 
 
@@ -30,6 +31,11 @@ class ReadonlyContext:
   ) -> None:
     self._invocation_context = invocation_context
 
+  @property
+  def user_content(self) -> Optional[types.Content]:
+    """The user content that started this invocation. READONLY field."""
+    return self._invocation_context.user_content
+
   @property
   def invocation_id(self) -> str:
     """The current invocation id."""