diff --git a/onchain_scout_gate/app/models.py b/onchain_scout_gate/app/models.py
index 152350d..8545077 100644
--- a/onchain_scout_gate/app/models.py
+++ b/onchain_scout_gate/app/models.py
@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from datetime import datetime
+from typing import Optional
 
 from sqlalchemy import DateTime, Float, Integer, String, Text
 from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column
@@ -54,10 +55,10 @@ class KeyMonitor(Base):
     upper: Mapped[float] = mapped_column(Float)
     lower: Mapped[float] = mapped_column(Float)
     sl_tp_mode: Mapped[str] = mapped_column(String(24), default="standard")
-    manual_take_profit: Mapped[float | None] = mapped_column(Float, nullable=True)
+    manual_take_profit: Mapped[Optional[float]] = mapped_column(Float, nullable=True)
     stop_outside_pct: Mapped[float] = mapped_column(Float, default=0.3)
     breakeven_enabled: Mapped[int] = mapped_column(Integer, default=0)
-    note: Mapped[str | None] = mapped_column(Text, nullable=True)
+    note: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
     created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, index=True)
 
 
@@ -67,7 +68,7 @@ class KeyMonitorHistory(Base):
     __tablename__ = "key_monitor_history"
 
     id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
-    key_monitor_id: Mapped[int | None] = mapped_column(Integer, nullable=True)
+    key_monitor_id: Mapped[Optional[int]] = mapped_column(Integer, nullable=True)
     symbol: Mapped[str] = mapped_column(String(32), index=True)
     inst_id: Mapped[str] = mapped_column(String(48))
     monitor_type: Mapped[str] = mapped_column(String(32))
@@ -75,15 +76,15 @@ class KeyMonitorHistory(Base):
     upper: Mapped[float] = mapped_column(Float)
     lower: Mapped[float] = mapped_column(Float)
     sl_tp_mode: Mapped[str] = mapped_column(String(24))
-    manual_take_profit: Mapped[float | None] = mapped_column(Float, nullable=True)
+    manual_take_profit: Mapped[Optional[float]] = mapped_column(Float, nullable=True)
     stop_outside_pct: Mapped[float] = mapped_column(Float)
-    confirm_close: Mapped[float | None] = mapped_column(Float, nullable=True)
-    planned_sl: Mapped[float | None] = mapped_column(Float, nullable=True)
-    planned_tp: Mapped[float | None] = mapped_column(Float, nullable=True)
-    planned_rr: Mapped[float | None] = mapped_column(Float, nullable=True)
-    executor_signal_id: Mapped[str | None] = mapped_column(String(64), nullable=True)
-    executor_status: Mapped[str | None] = mapped_column(String(64), nullable=True)
-    checks_json: Mapped[str | None] = mapped_column(Text, nullable=True)
-    last_alert_message: Mapped[str | None] = mapped_column(Text, nullable=True)
+    confirm_close: Mapped[Optional[float]] = mapped_column(Float, nullable=True)
+    planned_sl: Mapped[Optional[float]] = mapped_column(Float, nullable=True)
+    planned_tp: Mapped[Optional[float]] = mapped_column(Float, nullable=True)
+    planned_rr: Mapped[Optional[float]] = mapped_column(Float, nullable=True)
+    executor_signal_id: Mapped[Optional[str]] = mapped_column(String(64), nullable=True)
+    executor_status: Mapped[Optional[str]] = mapped_column(String(64), nullable=True)
+    checks_json: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
+    last_alert_message: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
     close_reason: Mapped[str] = mapped_column(String(48), index=True)
     closed_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, index=True)