Tighten the pipeline_task contract for processors and tools

`FrameProcessorSetup.pipeline_task` is now mandatory and
`FrameProcessor.pipeline_task` raises if accessed before setup
instead of returning `None`. `FunctionCallParams` gains a
required `pipeline_task` field and `LLMService._run_function_call`
populates it (plus reads `app_resources` directly off the
pipeline task). Tests that build a processor or
`FunctionCallParams` outside a real pipeline stub it with a
`SimpleNamespace`.

src/pipecat/processors/frame_processor.py

@@ -75,10 +75,10 @@ class FrameProcessorSetup:
     Parameters:
         clock: The clock instance for timing operations.
         task_manager: The task manager for handling async operations.
-        observer: Optional observer for monitoring frame processing events.
         pipeline_task: The :class:`PipelineTask` running this pipeline. Stored
             on each processor as ``self.pipeline_task`` so processors can
             reach task-scoped state (e.g. ``self.pipeline_task.app_resources``).
+        observer: Optional observer for monitoring frame processing events.
         tool_resources: Deprecated. :class:`PipelineTask` continues to populate
             this with ``app_resources`` so that custom :class:`FrameProcessor`
             subclasses whose ``setup()`` overrides read ``setup.tool_resources``
@@ -93,8 +93,8 @@ class FrameProcessorSetup:
 
     clock: BaseClock
     task_manager: BaseTaskManager
+    pipeline_task: PipelineTask
     observer: BaseObserver | None = None
-    pipeline_task: PipelineTask | None = None
     tool_resources: Any = None
 
     def __getattribute__(self, name: str) -> Any:
@@ -220,8 +220,9 @@ class FrameProcessor(BaseObject):
         # Observer
         self._observer: BaseObserver | None = None
 
-        # Pipeline Task
-        self._pipeline_task: PipelineTask | None = None
+        # Pipeline Task. Populated by ``setup()``; accessing the
+        # ``pipeline_task`` property before setup raises.
+        self._pipeline_task: PipelineTask | None = None  # set in setup()
 
         # Other properties
         self._enable_metrics = False
@@ -366,7 +367,7 @@ class FrameProcessor(BaseObject):
         return self._report_only_initial_ttfb
 
     @property
-    def pipeline_task(self) -> PipelineTask | None:
+    def pipeline_task(self) -> PipelineTask:
         """Get the :class:`PipelineTask` this processor is running in.
 
         Provides access to task-scoped state from inside a processor — most
@@ -374,11 +375,10 @@ class FrameProcessor(BaseObject):
         shared bag of resources (DB handles, clients, feature flags, etc.).
 
         Returns:
-            The :class:`PipelineTask` instance that set up this processor,
-            or ``None`` if the processor has not yet been set up by one
-            (for example, before the task has started, or when the processor
-            was instantiated in isolation).
+            The :class:`PipelineTask` instance that set up this processor.
         """
+        if not self._pipeline_task:
+            raise Exception(f"{self} pipeline task is still not set.")
         return self._pipeline_task
 
     def processors_with_metrics(self):

src/pipecat/services/llm_service.py

@@ -15,6 +15,7 @@ import warnings
 from collections.abc import Awaitable, Callable, Mapping, Sequence
 from dataclasses import dataclass
 from typing import (
+    TYPE_CHECKING,
     Any,
     Generic,
     Protocol,
@@ -70,6 +71,10 @@ from pipecat.utils.context.llm_context_summarization import (
     LLMContextSummarizationUtil,
 )
 
+if TYPE_CHECKING:
+    from pipecat.pipeline.task import PipelineTask
+
+
 # Type alias for a callable that handles LLM function calls.
 FunctionCallHandler = Callable[["FunctionCallParams"], Awaitable[None]]
 
@@ -126,6 +131,7 @@ class FunctionCallParams:
     # treat it invariantly, rejecting `LLMService[XAdapter]` at the call
     # sites that build FunctionCallParams.
     llm: LLMService[Any]
+    pipeline_task: PipelineTask
     context: LLMContext
     result_callback: FunctionCallResultCallback
     app_resources: Any = None
@@ -947,9 +953,6 @@ class LLMService(UserTurnCompletionLLMServiceMixin, AIService, Generic[TAdapter]
         # it starts would leave the coroutine in a "never awaited" state.
         await asyncio.sleep(0)
 
-        # _pipeline_task may be unset when the service is driven without a PipelineTask.
-        app_resources = self._pipeline_task.app_resources if self._pipeline_task else None
-
         try:
             if isinstance(item.handler, DirectFunctionWrapper):
                 # Handler is a DirectFunctionWrapper
@@ -960,9 +963,10 @@ class LLMService(UserTurnCompletionLLMServiceMixin, AIService, Generic[TAdapter]
                         tool_call_id=runner_item.tool_call_id,
                         arguments=runner_item.arguments,
                         llm=self,
+                        pipeline_task=self.pipeline_task,
                         context=runner_item.context,
                         result_callback=function_call_result_callback,
-                        app_resources=app_resources,
+                        app_resources=self.pipeline_task.app_resources,
                     ),
                 )
             else:
@@ -972,9 +976,10 @@ class LLMService(UserTurnCompletionLLMServiceMixin, AIService, Generic[TAdapter]
                     tool_call_id=runner_item.tool_call_id,
                     arguments=runner_item.arguments,
                     llm=self,
+                    pipeline_task=self.pipeline_task,
                     context=runner_item.context,
                     result_callback=function_call_result_callback,
-                    app_resources=app_resources,
+                    app_resources=self.pipeline_task.app_resources,
                 )
                 await item.handler(params)
         except Exception as e: