diff --git a/nado_protocol/engine_client/query.py b/nado_protocol/engine_client/query.py
index 55c238e..b85f087 100644
--- a/nado_protocol/engine_client/query.py
+++ b/nado_protocol/engine_client/query.py
@@ -1,3 +1,4 @@
+import json
 from typing import Optional
 import requests
 
@@ -182,7 +183,10 @@ def get_order(self, product_id: int, digest: str) -> OrderData:
         )
 
     def get_subaccount_info(
-        self, subaccount: str, txs: Optional[list[QuerySubaccountInfoTx]] = None
+        self,
+        subaccount: str,
+        txs: Optional[list[QuerySubaccountInfoTx]] = None,
+        pre_state: Optional[bool] = None,
     ) -> SubaccountInfoData:
         """
         Query the engine for the state of a subaccount, including balances.
@@ -193,11 +197,26 @@ def get_subaccount_info(
             txs (list[QuerySubaccountInfoTx], optional): You can optionally provide a list of txs, to get an estimated view
             of what the subaccount state would look like if the transactions were applied.
 
+            pre_state (bool, optional): When True and txs are provided, returns the subaccount state before the
+            transactions were applied in the pre_state field. Defaults to False.
+
         Returns:
             SubaccountInfoData: Information about the specified subaccount.
         """
+        txns_str = None
+        if txs is not None:
+            txns_str = json.dumps([tx.dict() for tx in txs])
+
+        pre_state_str = None
+        if pre_state is not None:
+            pre_state_str = str(pre_state).lower()
+
         return ensure_data_type(
-            self.query(QuerySubaccountInfoParams(subaccount=subaccount, txs=txs)).data,
+            self.query(
+                QuerySubaccountInfoParams(
+                    subaccount=subaccount, txns=txns_str, pre_state=pre_state_str
+                )
+            ).data,
             SubaccountInfoData,
         )
 
diff --git a/nado_protocol/engine_client/types/__init__.py b/nado_protocol/engine_client/types/__init__.py
index 77fd199..5c60eb3 100644
--- a/nado_protocol/engine_client/types/__init__.py
+++ b/nado_protocol/engine_client/types/__init__.py
@@ -60,6 +60,7 @@ class EngineClientOpts(NadoClientOpts):
     "ContractsData",
     "NoncesData",
     "OrderData",
+    "PreState",
     "SubaccountInfoData",
     "SubaccountOpenOrdersData",
     "MarketLiquidityData",
diff --git a/nado_protocol/engine_client/types/query.py b/nado_protocol/engine_client/types/query.py
index bea7cb2..90e7553 100644
--- a/nado_protocol/engine_client/types/query.py
+++ b/nado_protocol/engine_client/types/query.py
@@ -101,7 +101,8 @@ class QuerySubaccountInfoParams(NadoBaseModel):
 
     type = EngineQueryType.SUBACCOUNT_INFO.value
     subaccount: str
-    txs: Optional[list[QuerySubaccountInfoTx]]
+    txns: Optional[str]
+    pre_state: Optional[str]
 
 
 class QuerySubaccountOpenOrdersParams(NadoBaseModel):
@@ -299,6 +300,17 @@ class OrderData(NadoBaseModel):
     placed_at: str
 
 
+class PreState(NadoBaseModel):
+    """
+    Model for subaccount state before simulated transactions were applied.
+    """
+
+    healths: list[SubaccountHealth]
+    health_contributions: list[list[str]]
+    spot_balances: list[SpotProductBalance]
+    perp_balances: list[PerpProductBalance]
+
+
 class SubaccountInfoData(NadoBaseModel):
     """
     Model for detailed info about a subaccount, including balances.
@@ -314,6 +326,7 @@ class SubaccountInfoData(NadoBaseModel):
     perp_balances: list[PerpProductBalance]
     spot_products: list[SpotProduct]
     perp_products: list[PerpProduct]
+    pre_state: Optional[PreState]
 
     def parse_subaccount_balance(
         self, product_id: int
diff --git a/pyproject.toml b/pyproject.toml
index df25ab7..ad0386e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "nado-protocol"
-version = "0.2.7"
+version = "0.2.8"
 description = "Nado Protocol SDK"
 authors = ["Jeury Mejia <jeury@inkfnd.com>"]
 homepage = "https://nado.xyz"
diff --git a/sanity/engine_client.py b/sanity/engine_client.py
index 6be0cb8..ebf76ee 100644
--- a/sanity/engine_client.py
+++ b/sanity/engine_client.py
@@ -19,6 +19,7 @@
 from nado_protocol.engine_client.types.query import (
     QueryMaxOrderSizeParams,
 )
+from nado_protocol.engine_client.types.models import ApplyDelta, ApplyDeltaTx
 from nado_protocol.utils.bytes32 import (
     bytes32_to_hex,
     str_to_hex,
@@ -79,7 +80,7 @@ def run():
     pprint(spots_apr)
 
     print("querying orderbook for BTC-PERP pair...")
-    btc_perp_book = client.get_orderbook("BTC-PERP_USDT", 10)
+    btc_perp_book = client.get_orderbook("BTC-PERP_USDT0", 10)
     pprint(btc_perp_book)
 
     order_price = 100_000
@@ -132,6 +133,29 @@ def run():
     subaccount_info = client.get_subaccount_info(sender)
     print("subaccount info:", subaccount_info.json(indent=2))
 
+    print("querying subaccount info with simulated transaction and pre_state...")
+    # Simulate applying a delta to a perp product
+    simulated_tx = ApplyDeltaTx(
+        apply_delta=ApplyDelta(
+            product_id=2,
+            subaccount=sender,
+            amount_delta="100000000000000000",
+            v_quote_delta="3033500000000000000000",
+        )
+    )
+    subaccount_info_with_pre_state = client.get_subaccount_info(
+        sender, txs=[simulated_tx], pre_state=True
+    )
+    print(
+        "subaccount info with simulation:",
+        subaccount_info_with_pre_state.json(indent=2),
+    )
+    if subaccount_info_with_pre_state.pre_state:
+        print("✓ pre_state returned successfully")
+        print("pre_state healths:", subaccount_info_with_pre_state.pre_state.healths)
+    else:
+        print("✗ Warning: pre_state was not returned")
+
     print("querying subaccount open orders...")
     subaccount_open_orders = client.get_subaccount_open_orders(product_id, sender)
     print("subaccount open orders:", subaccount_open_orders.json(indent=2))