improve one less route

lib/crewai/src/crewai/experimental/conversational_mixin.py

@@ -46,7 +46,9 @@ from crewai.flow.conversation import (
     get_conversation_messages,
     receive_user_message as _receive_user_message,
 )
-from crewai.flow.dsl import listen, router, start
+from crewai.flow.dsl import listen, start
+from crewai.flow.dsl._utils import _set_flow_method_definition
+from crewai.flow.flow_definition import FlowMethodDefinition
 from crewai.utilities.types import LLMMessage
 
 
@@ -72,6 +74,15 @@ def _iter_condition_labels(condition: Any) -> set[str]:
     return set()
 
 
+def _conversation_start_router(func: Callable[..., Any]) -> Any:
+    wrapper = start()(func)
+    _set_flow_method_definition(
+        wrapper,
+        FlowMethodDefinition(start=True, router=True),
+    )
+    return wrapper
+
+
 class _ConversationalMixin:
     """Experimental conversational graph for ``Flow``.
 
@@ -85,10 +96,7 @@ class _ConversationalMixin:
     conversational: ClassVar[bool] = False
     conversational_config: ClassVar[ConversationConfig | None] = None
     builtin_routes: ClassVar[tuple[str, ...]] = ("converse", "end")
-    internal_routes: ClassVar[tuple[str, ...]] = (
-        "answer_from_history",
-        "conversation_start",
-    )
+    internal_routes: ClassVar[tuple[str, ...]] = ("answer_from_history",)
     builtin_route_descriptions: ClassVar[dict[str, str]] = {
         "converse": (
             "Ordinary chat, follow-ups, summaries, clarifications, and "
@@ -138,23 +146,21 @@ class _ConversationalMixin:
         def kickoff(self, *args: Any, **kwargs: Any) -> Any:
             pass
 
-    @start()
-    @_conversational_only
     def conversation_start(self) -> str | None:
-        """Internal Flow entrypoint that hands the user message to the router.
+        """Return the current user message for conversational route selection.
 
-        In conversational mode, ``Flow.kickoff_async`` runs all ``@start``
-        methods sequentially and this one is registered last, so any user
-        ``@start`` methods (e.g. permission loading) have already finished
-        before the returned value triggers ``route_conversation``.
+        This remains as a plain overridable helper for compatibility. It is not
+        registered as a Flow method; ``route_conversation`` is the synthetic
+        built-in start/router that begins a conversational turn.
         """
         state = cast(ConversationState, self.state)
         return state.current_user_message
 
-    @router(conversation_start)
+    @_conversation_start_router
     @_conversational_only
     def route_conversation(self) -> str:
         """Route the current turn to a listener label."""
+        self.conversation_start()
         state = cast(ConversationState, self.state)
         context = self.build_router_context()
         previous_intent = state.last_intent
@@ -651,16 +657,16 @@ class _ConversationalMixin:
         if not type(self)._is_conversational():
             return start_methods, False
 
-        conversation_start = "conversation_start"
-        if conversation_start not in {str(method) for method in start_methods}:
+        route_conversation = "route_conversation"
+        if route_conversation not in {str(method) for method in start_methods}:
             return start_methods, False
 
         ordered_starts = [
-            method for method in start_methods if str(method) != conversation_start
+            method for method in start_methods if str(method) != route_conversation
         ]
         ordered_starts.append(
             next(
-                method for method in start_methods if str(method) == conversation_start
+                method for method in start_methods if str(method) == route_conversation
             )
         )
         return ordered_starts, True

lib/crewai/src/crewai/flow/conversational_definition.py

@@ -39,9 +39,7 @@ class FlowConversationalDefinition(BaseModel):
     visible_agent_outputs: list[str] | Literal["all"] | None = None
     defer_trace_finalization: bool = True
     builtin_routes: list[str] = Field(default_factory=lambda: ["converse", "end"])
-    internal_routes: list[str] = Field(
-        default_factory=lambda: ["answer_from_history", "conversation_start"]
-    )
+    internal_routes: list[str] = Field(default_factory=lambda: ["answer_from_history"])
 
 
 __all__ = [

lib/crewai/src/crewai/flow/dsl/_utils.py

@@ -313,7 +313,7 @@ def _build_conversational_definition(
     internal_routes = getattr(
         flow_class,
         "internal_routes",
-        ("answer_from_history", "conversation_start"),
+        ("answer_from_history",),
     )
     if config is None:
         return FlowConversationalDefinition(

lib/crewai/tests/test_flow_conversation.py

@@ -598,9 +598,9 @@ class TestConversationalFlow:
         """Conversational flows: user ``@start`` methods finish before router fires.
 
         Non-chat flows run ``@start`` methods in parallel via ``asyncio.gather``,
-        which would race with ``conversation_start`` and let the router fire
+        which would race with ``route_conversation`` and let the router fire
         before user setup finished. In conversational mode the framework runs
-        them sequentially, with ``conversation_start`` last.
+        them sequentially, with ``route_conversation`` last.
         """
         order: list[str] = []
 
@@ -643,15 +643,10 @@ class TestConversationalFlow:
         assert "attach_bus" in order  # still fires every turn
         assert "route_turn" in order
 
-    def test_subclass_can_override_conversation_start_without_redecorating(
+    def test_subclass_can_override_conversation_start_helper(
         self,
     ) -> None:
-        """Overriding an inherited ``@start`` method must not unregister it.
-
-        Before the metaclass fix, subclasses had to re-apply ``@start()`` on
-        every override or the parent's ``conversation_start`` would silently
-        drop out of the start registry — leaving the flow with nothing to fire.
-        """
+        """The compatibility helper remains overridable without adding a Flow node."""
 
         bootstrap_calls: list[str] = []
 
@@ -673,6 +668,10 @@ class TestConversationalFlow:
         flow.handle_turn("hi")
 
         assert bootstrap_calls == ["ran"]
+        assert "conversation_start" not in BootstrapFlow.flow_definition().methods
+        route_definition = BootstrapFlow.flow_definition().methods["route_conversation"]
+        assert route_definition.start is True
+        assert route_definition.router is True
         assert flow.state.messages[-1].content == "worked"
 
     @conversational_graph_broken

lib/crewai/tests/test_flow_definition.py

@@ -223,10 +223,11 @@ def test_flow_definition_includes_conversational_builtins_when_enabled():
     assert definition.conversational.enabled is True
     assert definition.conversational.defer_trace_finalization is True
     assert definition.conversational.builtin_routes == ["converse", "end"]
-    assert "conversation_start" in methods
+    assert "conversation_start" not in methods
     assert "route_conversation" in methods
     assert "converse_turn" in methods
-    assert methods["conversation_start"].start is True
+    assert methods["route_conversation"].start is True
+    assert methods["route_conversation"].router is True
 
 
 def test_flow_definition_serializes_conversational_config():
@@ -260,7 +261,7 @@ def test_flow_definition_serializes_conversational_config():
     assert conversational.router.fallback_intent == "end"
 
 
-def test_flow_definition_preserves_undecorated_conversational_override():
+def test_flow_definition_uses_collapsed_conversational_router_start():
     class ChatFlow(Flow):
         conversational = True
 
@@ -269,8 +270,10 @@ def test_flow_definition_preserves_undecorated_conversational_override():
 
     methods = ChatFlow.flow_definition().methods
 
-    assert methods["conversation_start"].start is True
+    assert "conversation_start" not in methods
     assert "route_conversation" in methods
+    assert methods["route_conversation"].start is True
+    assert methods["route_conversation"].router is True
 
 
 def test_flow_definition_serializes_human_feedback_metadata():