diff --git a/lang_agent/graphs/graph_state.py b/lang_agent/graphs/graph_state.py
new file mode 100644
index 0000000..665c754
--- /dev/null
+++ b/lang_agent/graphs/graph_state.py
@@ -0,0 +1,12 @@
+from typing import Type, TypedDict, Literal, Dict, List, Tuple, Any
+
+from langchain_core.messages import SystemMessage, HumanMessage
+
+class State(TypedDict):
+    inp: Tuple[Dict[str, List[SystemMessage | HumanMessage]], 
+               Dict[str, Dict[str, str|int]]]
+    messages: List[SystemMessage | HumanMessage]
+    decision: str
+    subgraph_states: Dict[str, Any]   # NOTE: Naively assuming subgraphs
+                                      #       won't be so complicated
+