Creating the concept of a group_id for the function calls.

src/pipecat/frames/frames.py

@@ -1921,6 +1921,9 @@ class FunctionCallInProgressFrame(ControlFrame, UninterruptibleFrame):
         is_async: Whether this function call runs asynchronously. When True,
             the LLM continues the conversation immediately without waiting for
             the result. The result is injected later via a developer message.
+        group_id: Identifier shared by all function calls originating from the
+            same LLM response batch. Used to determine when the last call in a
+            group completes so the LLM can be triggered exactly once.
     """
 
     function_name: str
@@ -1928,6 +1931,7 @@ class FunctionCallInProgressFrame(ControlFrame, UninterruptibleFrame):
     arguments: Any
     cancel_on_interruption: bool = False
     is_async: bool = False
+    group_id: Optional[str] = None
 
 
 @dataclass

src/pipecat/processors/aggregators/llm_response_universal.py

@@ -1077,6 +1077,8 @@ class LLMAssistantAggregator(LLMContextAggregator):
 
         in_progress_frame = self._function_calls_in_progress[frame.tool_call_id]
         is_async = in_progress_frame.is_async if in_progress_frame else False
+        group_id = in_progress_frame.group_id if in_progress_frame else None
+
         del self._function_calls_in_progress[frame.tool_call_id]
 
         properties = frame.properties
@@ -1115,8 +1117,16 @@ class LLMAssistantAggregator(LLMContextAggregator):
                 # If the frame is indicating we should run the LLM, do it.
                 run_llm = frame.run_llm
             else:
-                # If this is the last function call in progress, run the LLM.
-                run_llm = not bool(self._function_calls_in_progress)
+                # Run the LLM when this is the last function call in the group
+                # to complete. If group_id is set, only consider sibling calls;
+                # otherwise always execute as soon as we receive the result.
+                if group_id:
+                    run_llm = not any(
+                        f is not None and f.group_id == group_id
+                        for f in self._function_calls_in_progress.values()
+                    )
+                else:
+                    run_llm = True
 
         if run_llm and not self._user_speaking:
             await self.push_context_frame(FrameDirection.UPSTREAM)

src/pipecat/services/llm_service.py

@@ -7,8 +7,8 @@
 """Base classes for Large Language Model services with function calling support."""
 
 import asyncio
-import inspect
 import json
+import uuid
 import warnings
 from dataclasses import dataclass
 from typing import (
@@ -151,6 +151,9 @@ class FunctionCallRunnerItem:
         arguments: The arguments for the function.
         context: The LLM context.
         run_llm: Optional flag to control LLM execution after function call.
+        group_id: Shared identifier for all function calls from the same LLM
+            response batch. Used to trigger the LLM exactly once when the last
+            call in the group completes.
     """
 
     registry_item: FunctionCallRegistryItem
@@ -159,6 +162,7 @@ class FunctionCallRunnerItem:
     arguments: Mapping[str, Any]
     context: OpenAILLMContext | LLMContext
     run_llm: Optional[bool] = None
+    group_id: Optional[str] = None
 
 
 class LLMService(UserTurnCompletionLLMServiceMixin, AIService):
@@ -695,6 +699,10 @@ class LLMService(UserTurnCompletionLLMServiceMixin, AIService):
 
         await self.broadcast_frame(FunctionCallsStartedFrame, function_calls=function_calls)
 
+        # All function calls from the same LLM response share a group_id so the
+        # aggregator can trigger the LLM exactly once when the last one completes.
+        group_id = str(uuid.uuid4())
+
         runner_items = []
         for function_call in function_calls:
             if function_call.function_name in self._functions.keys():
@@ -714,6 +722,7 @@ class LLMService(UserTurnCompletionLLMServiceMixin, AIService):
                     tool_call_id=function_call.tool_call_id,
                     arguments=function_call.arguments,
                     context=function_call.context,
+                    group_id=group_id,
                 )
             )
 
@@ -783,6 +792,7 @@ class LLMService(UserTurnCompletionLLMServiceMixin, AIService):
             arguments=runner_item.arguments,
             cancel_on_interruption=item.cancel_on_interruption,
             is_async=item.is_async,
+            group_id=runner_item.group_id,
         )
 
         timeout_task: Optional[asyncio.Task] = None