diff --git a/invokeai/app/services/batch_manager.py b/invokeai/app/services/batch_manager.py
index 956d5ff610..64d9ce8649 100644
--- a/invokeai/app/services/batch_manager.py
+++ b/invokeai/app/services/batch_manager.py
@@ -1,3 +1,4 @@
+from typing import Optional, Union
 import networkx as nx
 import copy
 
@@ -27,7 +28,7 @@ class BatchProcessResponse(BaseModel):
 
 class BatchManagerBase(ABC):
     @abstractmethod
-    def start(self, invoker: Invoker):
+    def start(self, invoker: Invoker) -> None:
         pass
 
     @abstractmethod
@@ -35,11 +36,11 @@ class BatchManagerBase(ABC):
         pass
 
     @abstractmethod
-    def run_batch_process(self, batch_id: str):
+    def run_batch_process(self, batch_id: str) -> None:
         pass
 
     @abstractmethod
-    def cancel_batch_process(self, batch_process_id: str):
+    def cancel_batch_process(self, batch_process_id: str) -> None:
         pass
 
 
@@ -68,11 +69,11 @@ class BatchManager(BatchManagerBase):
 
         return event
 
-    async def process(self, event: Event, err: bool):
+    async def process(self, event: Event, err: bool) -> None:
         data = event[1]["data"]
         batch_session = self.__batch_process_storage.get_session(data["graph_execution_state_id"])
         if not batch_session:
-            return
+            return None
         updateSession = BatchSessionChanges(state="error" if err else "completed")
         batch_session = self.__batch_process_storage.update_session_state(
             batch_session.batch_id,
@@ -83,7 +84,7 @@ class BatchManager(BatchManagerBase):
         if not batch_process.canceled:
             self.run_batch_process(batch_process.batch_id)
 
-    def _create_batch_session(self, batch_process: BatchProcess, batch_indices: list[int]) -> GraphExecutionState:
+    def _create_batch_session(self, batch_process: BatchProcess, batch_indices: tuple[int]) -> GraphExecutionState:
         graph = batch_process.graph.copy(deep=True)
         batch = batch_process.batch
         g = graph.nx_graph_flat()
@@ -103,7 +104,7 @@ class BatchManager(BatchManagerBase):
 
         return GraphExecutionState(graph=graph)
 
-    def run_batch_process(self, batch_id: str):
+    def run_batch_process(self, batch_id: str) -> None:
         self.__batch_process_storage.start(batch_id)
         try:
             created_session = self.__batch_process_storage.get_created_session(batch_id)
@@ -137,5 +138,5 @@ class BatchManager(BatchManagerBase):
             sessions.append(self.__batch_process_storage.create_session(batch_session))
         return sessions
 
-    def cancel_batch_process(self, batch_process_id: str):
+    def cancel_batch_process(self, batch_process_id: str) -> None:
         self.__batch_process_storage.cancel(batch_process_id)