diff --git a/api/models/model.py b/api/models/model.py
index 8a8574e2fe..818021eb42 100644
--- a/api/models/model.py
+++ b/api/models/model.py
@@ -3,6 +3,7 @@ import re
 import uuid
 from collections.abc import Mapping
 from datetime import datetime
+from decimal import Decimal
 from enum import StrEnum, auto
 from typing import TYPE_CHECKING, Any, Literal, Optional, cast
 
@@ -914,34 +915,40 @@ class Message(Base):
     )
 
     id: Mapped[str] = mapped_column(StringUUID, server_default=sa.text("uuid_generate_v4()"))
-    app_id = mapped_column(StringUUID, nullable=False)
-    model_provider = mapped_column(String(255), nullable=True)
-    model_id = mapped_column(String(255), nullable=True)
-    override_model_configs = mapped_column(sa.Text)
-    conversation_id = mapped_column(StringUUID, sa.ForeignKey("conversations.id"), nullable=False)
+    app_id: Mapped[str] = mapped_column(StringUUID, nullable=False)
+    model_provider: Mapped[str | None] = mapped_column(String(255), nullable=True)
+    model_id: Mapped[str | None] = mapped_column(String(255), nullable=True)
+    override_model_configs: Mapped[str | None] = mapped_column(sa.Text)
+    conversation_id: Mapped[str] = mapped_column(StringUUID, sa.ForeignKey("conversations.id"), nullable=False)
     _inputs: Mapped[dict[str, Any]] = mapped_column("inputs", sa.JSON)
     query: Mapped[str] = mapped_column(sa.Text, nullable=False)
-    message = mapped_column(sa.JSON, nullable=False)
+    message: Mapped[dict[str, Any]] = mapped_column(sa.JSON, nullable=False)
     message_tokens: Mapped[int] = mapped_column(sa.Integer, nullable=False, server_default=sa.text("0"))
-    message_unit_price = mapped_column(sa.Numeric(10, 4), nullable=False)
-    message_price_unit = mapped_column(sa.Numeric(10, 7), nullable=False, server_default=sa.text("0.001"))
+    message_unit_price: Mapped[Decimal] = mapped_column(sa.Numeric(10, 4), nullable=False)
+    message_price_unit: Mapped[Decimal] = mapped_column(
+        sa.Numeric(10, 7), nullable=False, server_default=sa.text("0.001")
+    )
     answer: Mapped[str] = mapped_column(sa.Text, nullable=False)
     answer_tokens: Mapped[int] = mapped_column(sa.Integer, nullable=False, server_default=sa.text("0"))
-    answer_unit_price = mapped_column(sa.Numeric(10, 4), nullable=False)
-    answer_price_unit = mapped_column(sa.Numeric(10, 7), nullable=False, server_default=sa.text("0.001"))
-    parent_message_id = mapped_column(StringUUID, nullable=True)
-    provider_response_latency = mapped_column(sa.Float, nullable=False, server_default=sa.text("0"))
-    total_price = mapped_column(sa.Numeric(10, 7))
+    answer_unit_price: Mapped[Decimal] = mapped_column(sa.Numeric(10, 4), nullable=False)
+    answer_price_unit: Mapped[Decimal] = mapped_column(
+        sa.Numeric(10, 7), nullable=False, server_default=sa.text("0.001")
+    )
+    parent_message_id: Mapped[str | None] = mapped_column(StringUUID, nullable=True)
+    provider_response_latency: Mapped[float] = mapped_column(sa.Float, nullable=False, server_default=sa.text("0"))
+    total_price: Mapped[Decimal | None] = mapped_column(sa.Numeric(10, 7))
     currency: Mapped[str] = mapped_column(String(255), nullable=False)
-    status = mapped_column(String(255), nullable=False, server_default=sa.text("'normal'::character varying"))
-    error = mapped_column(sa.Text)
-    message_metadata = mapped_column(sa.Text)
+    status: Mapped[str] = mapped_column(
+        String(255), nullable=False, server_default=sa.text("'normal'::character varying")
+    )
+    error: Mapped[str | None] = mapped_column(sa.Text)
+    message_metadata: Mapped[str | None] = mapped_column(sa.Text)
     invoke_from: Mapped[str | None] = mapped_column(String(255), nullable=True)
     from_source: Mapped[str] = mapped_column(String(255), nullable=False)
     from_end_user_id: Mapped[str | None] = mapped_column(StringUUID)
     from_account_id: Mapped[str | None] = mapped_column(StringUUID)
     created_at: Mapped[datetime] = mapped_column(sa.DateTime, server_default=func.current_timestamp())
-    updated_at = mapped_column(sa.DateTime, nullable=False, server_default=func.current_timestamp())
+    updated_at: Mapped[datetime] = mapped_column(sa.DateTime, nullable=False, server_default=func.current_timestamp())
     agent_based: Mapped[bool] = mapped_column(sa.Boolean, nullable=False, server_default=sa.text("false"))
     workflow_run_id: Mapped[str | None] = mapped_column(StringUUID)
     app_mode: Mapped[str | None] = mapped_column(String(255), nullable=True)