feat: Add timezone-aware datetime support for PostgreSQL

src/backend/base/langflow/alembic/versions/c8613607a100_add_timezone_support_for_asyncpg_.py

@@ -0,0 +1,203 @@
+"""Add timezone support for asyncpg compatibility
+
+Revision ID: c8613607a100
+Revises: 182e5471b900
+Create Date: 2025-11-07 14:56:02.303392
+
+"""
+
+from collections.abc import Sequence
+
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision: str = "c8613607a100"  # pragma: allowlist secret
+down_revision: str | None = "182e5471b900"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    conn = op.get_bind()
+
+    # Only apply changes if using PostgreSQL
+    # SQLite and other databases don't have timezone-aware datetime types
+    if conn.dialect.name == "postgresql":
+        # Alter datetime columns to use TIMESTAMP WITH TIME ZONE
+
+        # User table
+        op.alter_column(
+            "user",
+            "create_at",
+            type_=sa.DateTime(timezone=True),
+            existing_type=sa.DateTime(timezone=False),
+            existing_nullable=False,
+        )
+        op.alter_column(
+            "user",
+            "updated_at",
+            type_=sa.DateTime(timezone=True),
+            existing_type=sa.DateTime(timezone=False),
+            existing_nullable=False,
+        )
+        op.alter_column(
+            "user",
+            "last_login_at",
+            type_=sa.DateTime(timezone=True),
+            existing_type=sa.DateTime(timezone=False),
+            existing_nullable=True,
+        )
+
+        # ApiKey table
+        op.alter_column(
+            "apikey",
+            "last_used_at",
+            type_=sa.DateTime(timezone=True),
+            existing_type=sa.DateTime(timezone=False),
+            existing_nullable=True,
+        )
+
+        # Flow table
+        op.alter_column(
+            "flow",
+            "updated_at",
+            type_=sa.DateTime(timezone=True),
+            existing_type=sa.DateTime(timezone=False),
+            existing_nullable=True,
+        )
+
+        # Message table
+        op.alter_column(
+            "message",
+            "timestamp",
+            type_=sa.DateTime(timezone=True),
+            existing_type=sa.DateTime(timezone=False),
+            existing_nullable=False,
+        )
+
+        # File table
+        op.alter_column(
+            "file",
+            "created_at",
+            type_=sa.DateTime(timezone=True),
+            existing_type=sa.DateTime(timezone=False),
+            existing_nullable=False,
+        )
+        op.alter_column(
+            "file",
+            "updated_at",
+            type_=sa.DateTime(timezone=True),
+            existing_type=sa.DateTime(timezone=False),
+            existing_nullable=False,
+        )
+
+        # Transaction table
+        op.alter_column(
+            "transaction",
+            "timestamp",
+            type_=sa.DateTime(timezone=True),
+            existing_type=sa.DateTime(timezone=False),
+            existing_nullable=False,
+        )
+
+        # VertexBuild table
+        op.alter_column(
+            "vertex_build",
+            "timestamp",
+            type_=sa.DateTime(timezone=True),
+            existing_type=sa.DateTime(timezone=False),
+            existing_nullable=False,
+        )
+
+
+def downgrade() -> None:
+    conn = op.get_bind()
+
+    # Only apply changes if using PostgreSQL
+    if conn.dialect.name == "postgresql":
+        # Revert datetime columns to TIMESTAMP WITHOUT TIME ZONE
+
+        # User table
+        op.alter_column(
+            "user",
+            "create_at",
+            type_=sa.DateTime(timezone=False),
+            existing_type=sa.DateTime(timezone=True),
+            existing_nullable=False,
+        )
+        op.alter_column(
+            "user",
+            "updated_at",
+            type_=sa.DateTime(timezone=False),
+            existing_type=sa.DateTime(timezone=True),
+            existing_nullable=False,
+        )
+        op.alter_column(
+            "user",
+            "last_login_at",
+            type_=sa.DateTime(timezone=False),
+            existing_type=sa.DateTime(timezone=True),
+            existing_nullable=True,
+        )
+
+        # ApiKey table
+        op.alter_column(
+            "apikey",
+            "last_used_at",
+            type_=sa.DateTime(timezone=False),
+            existing_type=sa.DateTime(timezone=True),
+            existing_nullable=True,
+        )
+
+        # Flow table
+        op.alter_column(
+            "flow",
+            "updated_at",
+            type_=sa.DateTime(timezone=False),
+            existing_type=sa.DateTime(timezone=True),
+            existing_nullable=True,
+        )
+
+        # Message table
+        op.alter_column(
+            "message",
+            "timestamp",
+            type_=sa.DateTime(timezone=False),
+            existing_type=sa.DateTime(timezone=True),
+            existing_nullable=False,
+        )
+
+        # File table
+        op.alter_column(
+            "file",
+            "created_at",
+            type_=sa.DateTime(timezone=False),
+            existing_type=sa.DateTime(timezone=True),
+            existing_nullable=False,
+        )
+        op.alter_column(
+            "file",
+            "updated_at",
+            type_=sa.DateTime(timezone=False),
+            existing_type=sa.DateTime(timezone=True),
+            existing_nullable=False,
+        )
+
+        # Transaction table
+        op.alter_column(
+            "transaction",
+            "timestamp",
+            type_=sa.DateTime(timezone=False),
+            existing_type=sa.DateTime(timezone=True),
+            existing_nullable=False,
+        )
+
+        # VertexBuild table
+        op.alter_column(
+            "vertex_build",
+            "timestamp",
+            type_=sa.DateTime(timezone=False),
+            existing_type=sa.DateTime(timezone=True),
+            existing_nullable=False,
+        )

src/backend/base/langflow/services/database/models/api_key/model.py

@@ -17,7 +17,7 @@ def utc_now():
 
 class ApiKeyBase(SQLModel):
     name: str | None = Field(index=True, nullable=True, default=None)
-    last_used_at: datetime | None = Field(default=None, nullable=True)
+    last_used_at: datetime | None = Field(sa_column=Column(DateTime(timezone=True), nullable=True), default=None)
     total_uses: int = Field(default=0)
     is_active: bool = Field(default=True)
 

src/backend/base/langflow/services/database/models/file/model.py

@@ -1,6 +1,7 @@
 from datetime import datetime, timezone
 from uuid import UUID, uuid4
 
+from sqlalchemy import Column, DateTime
 from sqlmodel import Field, SQLModel, UniqueConstraint
 
 from langflow.schema.serialize import UUIDstr
@@ -13,7 +14,11 @@ class File(SQLModel, table=True):  # type: ignore[call-arg]
     path: str = Field(nullable=False)
     size: int = Field(nullable=False)
     provider: str | None = Field(default=None)
-    created_at: datetime = Field(default_factory=lambda: datetime.now(timezone.utc))
-    updated_at: datetime = Field(default_factory=lambda: datetime.now(timezone.utc))
+    created_at: datetime = Field(
+        sa_column=Column(DateTime(timezone=True), nullable=False), default_factory=lambda: datetime.now(timezone.utc)
+    )
+    updated_at: datetime = Field(
+        sa_column=Column(DateTime(timezone=True), nullable=False), default_factory=lambda: datetime.now(timezone.utc)
+    )
 
     __table_args__ = (UniqueConstraint("name", "user_id"),)

src/backend/base/langflow/services/database/models/flow/model.py

@@ -11,8 +11,8 @@
 from fastapi import HTTPException, status
 from lfx.log.logger import logger
 from pydantic import BaseModel, ValidationInfo, field_serializer, field_validator
+from sqlalchemy import DateTime, Text, UniqueConstraint, text
 from sqlalchemy import Enum as SQLEnum
-from sqlalchemy import Text, UniqueConstraint, text
 from sqlmodel import JSON, Column, Field, Relationship, SQLModel
 
 from langflow.schema.data import Data
@@ -40,7 +40,9 @@ class FlowBase(SQLModel):
     gradient: str | None = Field(default=None, nullable=True)
     data: dict | None = Field(default=None, nullable=True)
     is_component: bool | None = Field(default=False, nullable=True)
-    updated_at: datetime | None = Field(default_factory=lambda: datetime.now(timezone.utc), nullable=True)
+    updated_at: datetime | None = Field(
+        sa_column=Column(DateTime(timezone=True), nullable=True), default_factory=lambda: datetime.now(timezone.utc)
+    )
     webhook: bool | None = Field(default=False, nullable=True, description="Can be used on the webhook endpoint")
     endpoint_name: str | None = Field(default=None, nullable=True, index=True)
     tags: list[str] | None = None

src/backend/base/langflow/services/database/models/message/model.py

@@ -4,7 +4,7 @@
 from uuid import UUID, uuid4
 
 from pydantic import ConfigDict, field_serializer, field_validator
-from sqlalchemy import Text
+from sqlalchemy import DateTime, Text
 from sqlmodel import JSON, Column, Field, SQLModel
 
 from langflow.schema.content_block import ContentBlock
@@ -17,7 +17,7 @@
 
 class MessageBase(SQLModel):
     timestamp: Annotated[datetime, str_to_timestamp_validator] = Field(
-        default_factory=lambda: datetime.now(timezone.utc)
+        sa_column=Column(DateTime(timezone=True), nullable=False), default_factory=lambda: datetime.now(timezone.utc)
     )
     sender: str
     sender_name: str

src/backend/base/langflow/services/database/models/transactions/model.py

@@ -2,13 +2,16 @@
 from uuid import UUID, uuid4
 
 from pydantic import field_serializer, field_validator
-from sqlmodel import JSON, Column, Field, SQLModel
+from sqlalchemy import Column, DateTime
+from sqlmodel import JSON, Field, SQLModel
 
 from langflow.serialization.serialization import get_max_items_length, get_max_text_length, serialize
 
 
 class TransactionBase(SQLModel):
-    timestamp: datetime = Field(default_factory=lambda: datetime.now(timezone.utc))
+    timestamp: datetime = Field(
+        sa_column=Column(DateTime(timezone=True), nullable=False), default_factory=lambda: datetime.now(timezone.utc)
+    )
     vertex_id: str = Field(nullable=False)
     target_id: str | None = Field(default=None)
     inputs: dict | None = Field(default=None, sa_column=Column(JSON))

src/backend/base/langflow/services/database/models/user/model.py

@@ -3,7 +3,7 @@
 from uuid import UUID, uuid4
 
 from pydantic import BaseModel
-from sqlalchemy import JSON, Column
+from sqlalchemy import JSON, Column, DateTime
 from sqlmodel import Field, Relationship, SQLModel
 
 from langflow.schema.serialize import UUIDstr
@@ -29,9 +29,13 @@ class User(SQLModel, table=True):  # type: ignore[call-arg]
     profile_image: str | None = Field(default=None, nullable=True)
     is_active: bool = Field(default=False)
     is_superuser: bool = Field(default=False)
-    create_at: datetime = Field(default_factory=lambda: datetime.now(timezone.utc))
-    updated_at: datetime = Field(default_factory=lambda: datetime.now(timezone.utc))
-    last_login_at: datetime | None = Field(default=None, nullable=True)
+    create_at: datetime = Field(
+        sa_column=Column(DateTime(timezone=True), nullable=False), default_factory=lambda: datetime.now(timezone.utc)
+    )
+    updated_at: datetime = Field(
+        sa_column=Column(DateTime(timezone=True), nullable=False), default_factory=lambda: datetime.now(timezone.utc)
+    )
+    last_login_at: datetime | None = Field(sa_column=Column(DateTime(timezone=True), nullable=True), default=None)
     api_keys: list["ApiKey"] = Relationship(
         back_populates="user",
         sa_relationship_kwargs={"cascade": "delete"},

src/backend/base/langflow/services/database/models/vertex_builds/model.py

@@ -2,14 +2,16 @@
 from uuid import UUID, uuid4
 
 from pydantic import BaseModel, field_serializer, field_validator
-from sqlalchemy import Text
+from sqlalchemy import DateTime, Text
 from sqlmodel import JSON, Column, Field, SQLModel
 
 from langflow.serialization.serialization import get_max_items_length, get_max_text_length, serialize
 
 
 class VertexBuildBase(SQLModel):
-    timestamp: datetime = Field(default_factory=lambda: datetime.now(timezone.utc))
+    timestamp: datetime = Field(
+        sa_column=Column(DateTime(timezone=True), nullable=False), default_factory=lambda: datetime.now(timezone.utc)
+    )
     id: str = Field(nullable=False)
     data: dict | None = Field(default=None, sa_column=Column(JSON))
     artifacts: dict | None = Field(default=None, sa_column=Column(JSON))

src/backend/tests/integration/drivers/__init__.py

@@ -0,0 +1 @@
+# This file makes the directory a Python package

src/backend/tests/integration/drivers/conftest.py

@@ -0,0 +1,18 @@
+"""Conftest for PostgreSQL driver tests.
+
+This conftest overrides the _start_app fixture from the parent integration/conftest.py
+to prevent it from loading the client fixture, which would override the database URL.
+"""
+
+import pytest
+
+
+@pytest.fixture(autouse=True)
+def _start_app():
+    """Override parent _start_app fixture to skip client loading.
+
+    PostgreSQL driver tests create their own database connections
+    and don't need the app client fixture.
+    """
+    # Do nothing - this prevents the parent fixture from running
+    return