fix(realtime): include tool arguments in RealtimeToolStart/RealtimeToolEnd events

src/agents/realtime/events.py

@@ -69,6 +69,10 @@ class RealtimeToolStart:
  """The agent that updated."""
 
  tool: Tool
+ """The tool being called."""
+
+ arguments: str
+ """The arguments passed to the tool as a JSON string."""
 
  info: RealtimeEventInfo
  """Common info for all events, such as the context."""
@@ -86,6 +90,9 @@ class RealtimeToolEnd:
  tool: Tool
  """The tool that was called."""
 
+ arguments: str
+ """The arguments passed to the tool as a JSON string."""
+
  output: Any
  """The output of the tool call."""
 

src/agents/realtime/session.py

@@ -411,6 +411,7 @@ async def _handle_tool_call(
  info=self._event_info,
  tool=function_map[event.name],
  agent=agent,
+ arguments=event.arguments,
  )
  )
 
@@ -436,6 +437,7 @@ async def _handle_tool_call(
  tool=func_tool,
  output=result,
  agent=agent,
+ arguments=event.arguments,
  )
  )
  elif event.name in handoff_map:

tests/realtime/test_session.py

@@ -986,13 +986,15 @@ async def test_function_tool_execution_success(
  assert isinstance(tool_start_event, RealtimeToolStart)
  assert tool_start_event.tool == mock_function_tool
  assert tool_start_event.agent == mock_agent
+ assert tool_start_event.arguments == '{"param": "value"}'
 
  # Check tool end event
  tool_end_event = await session._event_queue.get()
  assert isinstance(tool_end_event, RealtimeToolEnd)
  assert tool_end_event.tool == mock_function_tool
  assert tool_end_event.output == "function_result"
  assert tool_end_event.agent == mock_agent
+ assert tool_end_event.arguments == '{"param": "value"}'
 
  @pytest.mark.asyncio
  async def test_function_tool_with_multiple_tools_available(self, mock_model, mock_agent):
@@ -1111,6 +1113,7 @@ async def test_function_tool_exception_handling(
  assert session._event_queue.qsize() == 1
  tool_start_event = await session._event_queue.get()
  assert isinstance(tool_start_event, RealtimeToolStart)
+ assert tool_start_event.arguments == "{}"
 
  # But no tool output should have been sent and no end event queued
  assert len(mock_model.sent_tool_outputs) == 0
@@ -1133,10 +1136,20 @@ async def test_tool_call_with_complex_arguments(
 
  await session._handle_tool_call(tool_call_event)
 
- # Verify arguments were passed correctly
+ # Verify arguments were passed correctly to tool
  call_args = mock_function_tool.on_invoke_tool.call_args
  assert call_args[0][1] == complex_args
 
+ # Verify tool_start event includes arguments
+ tool_start_event = await session._event_queue.get()
+ assert isinstance(tool_start_event, RealtimeToolStart)
+ assert tool_start_event.arguments == complex_args
+
+ # Verify tool_end event includes arguments
+ tool_end_event = await session._event_queue.get()
+ assert isinstance(tool_end_event, RealtimeToolEnd)
+ assert tool_end_event.arguments == complex_args
+
  @pytest.mark.asyncio
  async def test_tool_call_with_custom_call_id(self, mock_model, mock_agent, mock_function_tool):
  """Test that tool context receives correct call_id"""