Fix

libs/langgraph/langgraph/graph/branch.py

@@ -34,7 +34,7 @@ from langgraph.utils.runnable import (
 )
 
 Writer = Callable[
-    [Sequence[Union[str, Send]]],
+    [Sequence[Union[str, Send]], bool],
     Sequence[Union[ChannelWriteEntry, Send]],
 ]
 
@@ -142,7 +142,7 @@ class Branch(NamedTuple):
             ),
             list(
                 zip_longest(
-                    writer([e for e in self.ends.values()]),
+                    writer([e for e in self.ends.values()], True),
                     [str(la) for la, e in self.ends.items()],
                 )
             )
@@ -211,12 +211,11 @@ class Branch(NamedTuple):
             ]
         else:
             destinations = cast(Sequence[Union[Send, str]], result)
-        destinations = [d for d in destinations if d != END]
         if any(dest is None or dest == START for dest in destinations):
             raise ValueError("Branch did not return a valid destination")
         if any(p.node == END for p in destinations if isinstance(p, Send)):
             raise InvalidUpdateError("Cannot send a packet to the END node")
-        entries = writer(destinations)
+        entries = writer(destinations, False)
         if not entries:
             return input
         else:

libs/langgraph/langgraph/graph/graph.py

@@ -374,7 +374,7 @@ class CompiledGraph(Pregel):
 
     def attach_branch(self, start: str, name: str, branch: Branch) -> None:
         def get_writes(
-            packets: Sequence[Union[str, Send]],
+            packets: Sequence[Union[str, Send]], static: bool = False
         ) -> Sequence[Union[ChannelWriteEntry, Send]]:
             return [
                 (

libs/langgraph/langgraph/graph/state.py

@@ -843,7 +843,7 @@ class CompiledStateGraph(CompiledGraph):
         self, start: str, name: str, branch: Branch, *, with_reader: bool = True
     ) -> None:
         def get_writes(
-            packets: Sequence[Union[str, Send]],
+            packets: Sequence[Union[str, Send]], static: bool = False
         ) -> Sequence[Union[ChannelWriteEntry, Send]]:
             writes = [
                 (
@@ -852,7 +852,10 @@ class CompiledStateGraph(CompiledGraph):
                     else p
                 )
                 for p in packets
+                if (True if static else p != END)
             ]
+            if not writes:
+                return []
             if branch.then and branch.then != END:
                 writes.append(
                     ChannelWriteEntry(