Add state arg to modify hook

libs/langgraph/langgraph/agent/__init__.py

@@ -135,7 +135,7 @@ def _make_model_request_node(
         )
         # visit middleware in order
         for mw in middleware:
-            request = mw.modify_model_request(request)
+            request = mw.modify_model_request(request, state)
         # prepare messages
         if request.system_prompt:
             messages = [SystemMessage(request.system_prompt)] + request.messages

libs/langgraph/langgraph/agent/types.py

@@ -31,7 +31,9 @@ class AgentMiddleware:
     def before_model(self, state: AgentState) -> AgentState | None:
         pass
 
-    def modify_model_request(self, request: ModelRequest) -> ModelRequest:
+    def modify_model_request(
+        self, request: ModelRequest, state: AgentState
+    ) -> ModelRequest:
         return request
 
     def after_model(self, state: AgentState) -> AgentState | None:

libs/langgraph/tests/test_agent.py

@@ -156,6 +156,10 @@ def test_create_agent_invoke(
         def before_model(self, state):
             calls.append("NoopSeven.before_model")
 
+        def modify_model_request(self, request, state):
+            calls.append("NoopSeven.modify_model_request")
+            return request
+
         def after_model(self, state):
             calls.append("NoopSeven.after_model")
 
@@ -163,6 +167,10 @@ def test_create_agent_invoke(
         def before_model(self, state):
             calls.append("NoopEight.before_model")
 
+        def modify_model_request(self, request, state):
+            calls.append("NoopEight.modify_model_request")
+            return request
+
         def after_model(self, state):
             calls.append("NoopEight.after_model")
 
@@ -216,11 +224,15 @@ def test_create_agent_invoke(
     assert calls == [
         "NoopSeven.before_model",
         "NoopEight.before_model",
+        "NoopSeven.modify_model_request",
+        "NoopEight.modify_model_request",
         "NoopEight.after_model",
         "NoopSeven.after_model",
         "my_tool",
         "NoopSeven.before_model",
         "NoopEight.before_model",
+        "NoopSeven.modify_model_request",
+        "NoopEight.modify_model_request",
         "NoopEight.after_model",
         "NoopSeven.after_model",
     ]