feat: tool_events

src/google/adk/events/event.py

@@ -79,6 +79,12 @@ class Event(LlmResponse):
   conversation history.
   """
 
+  tool_events: Optional[list[Event]] = None
+  """The tool event in this event.
+  This is used to store the tool events that are generated by the agent.
+  """
+
+
   # The following are computed fields.
   # Do not assign the ID. It will be assigned by the session.
   id: str = ''

src/google/adk/flows/llm_flows/functions.py

@@ -153,7 +153,8 @@ async def handle_function_calls_async(
       # do not use "args" as the variable name, because it is a reserved keyword
       # in python debugger.
       function_args = function_call.args or {}
-      function_response: Optional[dict] = None
+      function_response: Optional[dict] = None  
+      tool_events: Optional[list[Event]] = None
 
       for callback in agent.canonical_before_tool_callbacks:
         function_response = callback(
@@ -168,6 +169,9 @@ async def handle_function_calls_async(
         function_response = await __call_tool_async(
             tool, args=function_args, tool_context=tool_context
         )
+        if isinstance(function_response, tuple):
+          function_response, tool_events = function_response
+
 
       for callback in agent.canonical_after_tool_callbacks:
         altered_function_response = callback(
@@ -189,7 +193,7 @@ async def handle_function_calls_async(
 
       # Builds the function response event.
       function_response_event = __build_response_event(
-          tool, function_response, tool_context, invocation_context
+          tool, function_response, tool_context, invocation_context, tool_events
       )
       trace_tool_call(
           tool=tool,
@@ -228,6 +232,7 @@ async def handle_function_calls_live(
   function_calls = function_call_event.get_function_calls()
 
   function_response_events: list[Event] = []
+  tool_events: Optional[list[Event]] = None
   for function_call in function_calls:
     tool, tool_context = _get_tool_and_context(
         invocation_context, function_call_event, function_call, tools_dict
@@ -250,7 +255,7 @@ async def handle_function_calls_live(
           function_response = await function_response
 
       if not function_response:
-        function_response = await _process_function_live_helper(
+        function_response, tool_events = await _process_function_live_helper(
             tool, tool_context, function_call, function_args, invocation_context
         )
 
@@ -283,7 +288,7 @@ async def handle_function_calls_live(
 
       # Builds the function response event.
       function_response_event = __build_response_event(
-          tool, function_response, tool_context, invocation_context
+          tool, function_response, tool_context, invocation_context, tool_events
       )
       trace_tool_call(
           tool=tool,
@@ -313,6 +318,7 @@ async def _process_function_live_helper(
     tool, tool_context, function_call, function_args, invocation_context
 ):
   function_response = None
+  tool_events = None
   # Check if this is a stop_streaming function call
   if (
       function_call.name == 'stop_streaming'
@@ -401,7 +407,10 @@ async def run_tool_and_update_queue(tool, function_args, tool_context):
     function_response = await __call_tool_async(
         tool, args=function_args, tool_context=tool_context
     )
-  return function_response
+    if isinstance(function_response, tuple):
+      function_response, tool_events = function_response
+
+  return function_response, tool_events
 
 
 def _get_tool_and_context(
@@ -454,6 +463,7 @@ def __build_response_event(
     function_result: dict[str, object],
     tool_context: ToolContext,
     invocation_context: InvocationContext,
+    tool_events: Optional[list[Event]],
 ) -> Event:
   # Specs requires the result to be a dict.
   if not isinstance(function_result, dict):
@@ -475,6 +485,7 @@ def __build_response_event(
       content=content,
       actions=tool_context.actions,
       branch=invocation_context.branch,
+      tool_events=tool_events
   )
 
   return function_response_event

src/google/adk/tools/agent_tool.py

@@ -28,6 +28,7 @@
 from ._forwarding_artifact_service import ForwardingArtifactService
 from .base_tool import BaseTool
 from .tool_context import ToolContext
+from ..events.event import Event
 
 if TYPE_CHECKING:
   from ..agents.base_agent import BaseAgent
@@ -124,10 +125,12 @@ async def run_async(
     )
 
     last_event = None
+    tool_events: list[Event] = []
     async for event in runner.run_async(
         user_id=session.user_id, session_id=session.id, new_message=content
     ):
       # Forward state delta to parent session.
+      tool_events.append(event)
       if event.actions.state_delta:
         tool_context.state.update(event.actions.state_delta)
       last_event = event
@@ -141,4 +144,4 @@ async def run_async(
       ).model_dump(exclude_none=True)
     else:
       tool_result = merged_text
-    return tool_result
+    return tool_result, tool_events