Wire household creation on registration and fix datetime handling

backend/app/auth/users.py

@@ -2,7 +2,7 @@
 from collections.abc import AsyncGenerator
 from typing import Annotated
 
-from fastapi import Depends
+from fastapi import Depends, Request
 from fastapi_users import BaseUserManager, FastAPIUsers, UUIDIDMixin
 from fastapi_users.db import BaseUserDatabase
 from fastapi_users_db_sqlalchemy import SQLAlchemyUserDatabase
@@ -11,6 +11,7 @@
 from app.auth.backend import auth_backend
 from app.config import get_settings
 from app.database import get_session
+from app.models.household import Household
 from app.models.user import User
 
 
@@ -23,16 +24,43 @@ async def get_user_db(
 
 
 class UserManager(UUIDIDMixin, BaseUserManager[User, uuid.UUID]):
-    # These secrets sign password-reset and verification tokens.
-    # Changing them invalidates all outstanding tokens.
     reset_password_token_secret = get_settings().secret_key.get_secret_value()
     verification_token_secret = get_settings().secret_key.get_secret_value()
 
+    def __init__(
+        self,
+        user_db: BaseUserDatabase[User, uuid.UUID],
+        session: AsyncSession,
+    ) -> None:
+        super().__init__(user_db)
+        self.session = session
+
+    async def on_after_register(
+        self, user: User, request: Request | None = None
+    ) -> None:
+        # FastAPI Users commits the user row before calling this hook, so true
+        # atomicity isn't possible. We use a compensating transaction: if
+        # household creation fails for any reason, we delete the orphaned user
+        # so the DB is left in a consistent state.
+        try:
+            prefix = user.email.split("@", 1)[0].strip() or "User"
+            household = Household(name=f"{prefix}'s household")
+            self.session.add(household)
+            await self.session.flush()  # writes household row and populates household.id
+            user.household_id = household.id  # session tracks this change automatically
+            await self.session.commit()
+        except Exception:
+            await self.user_db.delete(user)
+            raise
+
 
 async def get_user_manager(
     user_db: Annotated[BaseUserDatabase[User, uuid.UUID], Depends(get_user_db)],
+    session: Annotated[AsyncSession, Depends(get_session)],
 ) -> AsyncGenerator[UserManager]:
-    yield UserManager(user_db)
+    # FastAPI caches dependencies per request, so session here is the same
+    # instance already open for get_user_db — no extra connection is opened.
+    yield UserManager(user_db, session)
 
 
 fastapi_users: FastAPIUsers[User, uuid.UUID] = FastAPIUsers(

backend/app/database.py

@@ -9,7 +9,9 @@
 
 DATABASE_URL = settings.database_url.get_secret_value()
 
-engine = create_async_engine(DATABASE_URL, echo=settings.environment == "development")
+# pool_pre_ping=True tests each connection before use and reconnects if Neon
+# closed it due to inactivity (Neon drops idle connections after ~5 minutes).
+engine = create_async_engine(DATABASE_URL, echo=settings.environment == "development", pool_pre_ping=True)
 
 # keeps objects usable after commit (relevant for async sessions)
 _session_factory = async_sessionmaker(engine, expire_on_commit=False)

backend/app/models/household.py

@@ -1,10 +1,15 @@
 from datetime import UTC, datetime
 
+import sqlalchemy as sa
 from sqlmodel import Field, SQLModel
 
 
 class Household(SQLModel, table=True):
     __tablename__: str = "households"
+
     id: int | None = Field(default=None, primary_key=True)
     name: str
-    created_at: datetime = Field(default_factory=lambda: datetime.now(UTC))
+    created_at: datetime = Field(
+        default_factory=lambda: datetime.now(UTC),
+        sa_column=sa.Column(sa.DateTime(timezone=True), nullable=False),
+    )

backend/app/models/user.py

@@ -1,6 +1,7 @@
 import uuid
 from datetime import UTC, datetime
 
+import sqlalchemy as sa
 from fastapi_users import schemas
 from sqlmodel import Field, SQLModel
 
@@ -18,11 +19,13 @@ class User(SQLModel, table=True):
     is_active: bool = Field(default=True)
     is_superuser: bool = Field(default=False)
     is_verified: bool = Field(default=False)
-    # Nullable until the on_after_register hook creates and assigns a household.
     household_id: int | None = Field(
-        default=None, foreign_key="household.id", index=True
+        default=None, foreign_key="households.id", index=True
+    )
+    created_at: datetime = Field(
+        default_factory=lambda: datetime.now(UTC),
+        sa_column=sa.Column(sa.DateTime(timezone=True), nullable=False),
     )
-    created_at: datetime = Field(default_factory=lambda: datetime.now(UTC))
 
 
 class UserRead(schemas.BaseUser[uuid.UUID]):