add SNAP MID order type and usage example

examples/place-order-snap-mid.py

@@ -0,0 +1,48 @@
+from ib_async import IB, Future, SnapMidOrder, TimeCondition
+from datetime import datetime, timedelta, timezone
+
+ib = IB()
+ib.connect(
+    host = "127.0.0.1",
+    port = 7497,
+    clientId = 1
+)
+
+# Define the ES futures contract (E-mini S&P 500 Futures)
+# SNAP MID orders are mostly used to make better-than MKT fill
+# for highly liquid instruments, but those which don't support
+# more sophisticated IB order types.
+# Common example is Futures/CFD
+contract = Future(
+    symbol = "ES",
+    lastTradeDateOrContractMonth = "20250321",   # use actual expiration date
+    exchange = "CME"
+)
+
+# Define an execution condition for order - some time in future
+# to make sure order is not executed immediately (for testing purposes)
+future_date = datetime.now(timezone.utc) + timedelta(days = 10)
+time_condition = TimeCondition(
+    time = future_date.strftime("%Y%m%d %H:%M:%S UTC")
+)
+
+# Create order object
+order = SnapMidOrder(
+    action = "BUY",
+    totalQuantity = 1,
+    conditions = [
+        time_condition
+    ]
+)
+
+# Place the order with the time condition
+print("Placing order...")
+trade = ib.placeOrder(contract, order)
+
+print("waiting a bit...")
+ib.sleep(1)
+
+print("Order placed")
+print(f"status: {trade.orderStatus.status}")
+
+ib.disconnect()

ib_async/__init__.py

@@ -95,6 +95,7 @@
     OrderStatus,
     PercentChangeCondition,
     PriceCondition,
+    SnapMidOrder,
     StopLimitOrder,
     StopOrder,
     TimeCondition,
@@ -194,6 +195,7 @@
     "OrderStatus",
     "PercentChangeCondition",
     "PriceCondition",
+    "SnapMidOrder",
     "StopLimitOrder",
     "StopOrder",
     "TimeCondition",

ib_async/order.py

@@ -196,6 +196,13 @@ def __init__(self, action: str, totalQuantity: float, **kwargs):
         )
 
 
+class SnapMidOrder(Order):
+    def __init__(self, action: str, totalQuantity: float, **kwargs):
+        Order.__init__(
+            self, orderType="SNAP MID", action=action, totalQuantity=totalQuantity, **kwargs
+        )
+
+
 class StopOrder(Order):
     def __init__(self, action: str, totalQuantity: float, stopPrice: float, **kwargs):
         Order.__init__(