Fix: Set crew attribute on planning agent to prevent EventBus errors

- Added crew parameter to CrewPlanner.__init__() to accept crew reference
- Modified _create_planning_agent() to set crew attribute on planning agent
- Updated Crew._handle_crew_planning() to pass crew reference to CrewPlanner
- Added test to verify planning agent has crew attribute set
- Renamed test class from InternalCrewPlanner to TestCrewPlanner for pytest compatibility

Fixes #3782

Co-Authored-By: João <joao@crewai.com>

lib/crewai/src/crewai/crew.py

@@ -779,7 +779,7 @@ class Crew(FlowTrackable, BaseModel):
         """Handles the Crew planning."""
         self._logger.log("info", "Planning the crew execution")
         result = CrewPlanner(
-            tasks=self.tasks, planning_agent_llm=self.planning_llm
+            tasks=self.tasks, planning_agent_llm=self.planning_llm, crew=self
         )._handle_crew_planning()
 
         for task, step_plan in zip(

lib/crewai/src/crewai/utilities/planning_handler.py

@@ -37,19 +37,25 @@ class CrewPlanner:
     Attributes:
         tasks: List of tasks to be planned.
         planning_agent_llm: Optional LLM model for the planning agent.
+        crew: Optional reference to the crew instance.
     """
 
     def __init__(
-        self, tasks: list[Task], planning_agent_llm: str | BaseLLM | None = None
+        self,
+        tasks: list[Task],
+        planning_agent_llm: str | BaseLLM | None = None,
+        crew: "Any" = None,
     ) -> None:
         """Initialize CrewPlanner with tasks and optional planning agent LLM.
 
         Args:
             tasks: List of tasks to be planned.
             planning_agent_llm: Optional LLM model for the planning agent. Defaults to None.
+            crew: Optional reference to the crew instance. Defaults to None.
         """
         self.tasks = tasks
         self.planning_agent_llm = planning_agent_llm or "gpt-4o-mini"
+        self.crew = crew
 
     def _handle_crew_planning(self) -> PlannerTaskPydanticOutput:
         """Handles the Crew planning by creating detailed step-by-step plans for each task.
@@ -80,7 +86,7 @@ class CrewPlanner:
         Returns:
             An Agent instance configured for planning tasks.
         """
-        return Agent(
+        planning_agent = Agent(
             role="Task Execution Planner",
             goal=(
                 "Your goal is to create an extremely detailed, step-by-step plan based on the tasks and tools "
@@ -89,6 +95,9 @@ class CrewPlanner:
             backstory="Planner agent for crew planning",
             llm=self.planning_agent_llm,
         )
+        if self.crew:
+            planning_agent.crew = self.crew
+        return planning_agent
 
     @staticmethod
     def _create_planner_task(planning_agent: Agent, tasks_summary: str) -> Task:

lib/crewai/tests/utilities/test_planning_handler.py

@@ -13,7 +13,7 @@ from crewai.utilities.planning_handler import (
 )
 
 
-class InternalCrewPlanner:
+class TestCrewPlanner:
     @pytest.fixture
     def crew_planner(self):
         tasks = [
@@ -177,3 +177,25 @@ class InternalCrewPlanner:
                 crew_planner_different_llm.tasks
             )
             execute.assert_called_once()
+
+    def test_planning_agent_has_crew_attribute(self):
+        """Test that planning agent has crew attribute set to avoid EventBus errors."""
+        from crewai.crew import Crew
+
+        # Create a crew with planning enabled
+        agent = Agent(role="Test Agent", goal="Test Goal", backstory="Test Backstory")
+        task = Task(
+            description="Test task",
+            expected_output="Test output",
+            agent=agent,
+        )
+        crew = Crew(agents=[agent], tasks=[task], planning=True)
+
+        planner = CrewPlanner(tasks=[task], planning_agent_llm="gpt-4o-mini", crew=crew)
+        planning_agent = planner._create_planning_agent()
+
+        # Verify the planning agent has crew attribute set
+        assert planning_agent.crew is not None
+        assert planning_agent.crew == crew
+        # Verify that accessing agent.crew.key doesn't raise an error
+        assert planning_agent.crew.key is not None