fix(api): remove TimestampMixin from models whose DB tables lack timestamp columns

Remove TimestampMixin (created_at/updated_at) from Purchase, PurchaseItem,
PriceHistory, Coupon, and ShrinkflationEvent models since their PostgreSQL
tables do not have those columns. This was causing 500 errors on
/api/v1/purchases and /api/v1/purchases/stats.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

api/src/cartsnitch_api/auth/dependencies.py

@@ -5,6 +5,8 @@ Sessions are verified by querying the shared sessions table directly.
 """
 
 from datetime import UTC, datetime
+from hashlib import sha256
+from uuid import UUID
 
 from fastapi import Cookie, Depends, Header, HTTPException, Request, status
 from fastapi.security import HTTPAuthorizationCredentials, HTTPBearer
@@ -26,19 +28,17 @@ SESSION_COOKIE_NAMES = [
 ]
 
 
-async def _validate_session_token(token: str, db: AsyncSession) -> str:
+async def _validate_session_token(token: str, db: AsyncSession) -> UUID:
     """Validate a Better-Auth session token against the sessions table.
 
-    Returns the user_id (as str) if the session is valid and not expired.
+    Returns the user_id (as UUID) if the session is valid and not expired.
-    Better-Auth v1.5.6 stores raw tokens in the DB. The session cookie
+    Better-Auth v1.5.6+ stores tokens as SHA-256 hashes, so we hash the
-    is signed: ``rawToken.base64HMACSignature``. Strip the signature
+    incoming raw token before querying.
-    before querying.
     """
-    # Signed cookie format: rawToken.hmacSignature — split and use only the token part
+    hashed_token = sha256(token.encode("utf-8")).hexdigest()
-    raw_token = token.split(".")[0] if "." in token else token
     result = await db.execute(
         text("SELECT user_id, expires_at FROM sessions WHERE token = :token"),
-        {"token": raw_token},
+        {"token": hashed_token},
     )
     row = result.first()
 
@@ -59,14 +59,14 @@ async def _validate_session_token(token: str, db: AsyncSession) -> str:
             detail="Session expired",
         )
 
-    return str(user_id)
+    return UUID(str(user_id))
 
 
 async def get_current_user(
     request: Request,
     credentials: HTTPAuthorizationCredentials | None = Depends(bearer_scheme),
     db: AsyncSession = Depends(get_db),
-) -> str:
+) -> UUID:
     """Extract and validate the session token from cookie or Authorization header.
 
     Checks in order:

api/src/cartsnitch_api/auth/jwt.py

@@ -2,21 +2,22 @@
 
 from datetime import UTC, datetime, timedelta
 from typing import Any, cast
+from uuid import UUID
 
 from jose import JWTError, jwt
 
 from cartsnitch_api.config import settings
 
 
-def create_access_token(user_id: str) -> str:
+def create_access_token(user_id: UUID) -> str:
     expire = datetime.now(UTC) + timedelta(minutes=settings.jwt_access_token_expire_minutes)
-    payload = {"sub": user_id, "exp": expire, "type": "access"}
+    payload = {"sub": str(user_id), "exp": expire, "type": "access"}
     return cast(str, jwt.encode(payload, settings.jwt_secret_key, algorithm=settings.jwt_algorithm))
 
 
-def create_refresh_token(user_id: str) -> str:
+def create_refresh_token(user_id: UUID) -> str:
     expire = datetime.now(UTC) + timedelta(days=settings.jwt_refresh_token_expire_days)
-    payload = {"sub": user_id, "exp": expire, "type": "refresh"}
+    payload = {"sub": str(user_id), "exp": expire, "type": "refresh"}
     return cast(str, jwt.encode(payload, settings.jwt_secret_key, algorithm=settings.jwt_algorithm))
 
 

api/src/cartsnitch_api/auth/routes.py

@@ -5,6 +5,8 @@ the Better-Auth service (auth/). This router provides user profile
 endpoints that query our own user data from the shared database.
 """
 
+from uuid import UUID
+
 from fastapi import APIRouter, Depends, HTTPException, status
 from sqlalchemy.ext.asyncio import AsyncSession
 
@@ -21,7 +23,7 @@ router = APIRouter(prefix="/auth", tags=["auth"])
 
 @router.get("/me", response_model=UserResponse)
 async def get_me(
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = AuthService(db)
@@ -36,7 +38,7 @@ async def get_me(
 @router.patch("/me", response_model=UserResponse)
 async def update_me(
     body: UpdateUserRequest,
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = AuthService(db)
@@ -52,7 +54,7 @@ async def update_me(
 
 @router.delete("/me", status_code=status.HTTP_204_NO_CONTENT)
 async def delete_me(
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = AuthService(db)

api/src/cartsnitch_api/models/coupon.py

@@ -9,14 +9,14 @@ from sqlalchemy import Boolean, Date, DateTime, ForeignKey, Numeric, String
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from cartsnitch_api.constants import DiscountType
-from cartsnitch_api.models.base import Base, TimestampMixin, UUIDPrimaryKeyMixin
+from cartsnitch_api.models.base import Base, UUIDPrimaryKeyMixin
 
 if TYPE_CHECKING:
     from cartsnitch_api.models.product import NormalizedProduct
     from cartsnitch_api.models.store import Store
 
 
-class Coupon(UUIDPrimaryKeyMixin, TimestampMixin, Base):
+class Coupon(UUIDPrimaryKeyMixin, Base):
     """A coupon or deal for a product at a store."""
 
     __tablename__ = "coupons"

api/src/cartsnitch_api/models/price.py

@@ -9,7 +9,7 @@ from sqlalchemy import Date, ForeignKey, Index, Numeric, String
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from cartsnitch_api.constants import PriceSource
-from cartsnitch_api.models.base import Base, TimestampMixin, UUIDPrimaryKeyMixin
+from cartsnitch_api.models.base import Base, UUIDPrimaryKeyMixin
 
 if TYPE_CHECKING:
     from cartsnitch_api.models.product import NormalizedProduct
@@ -17,7 +17,7 @@ if TYPE_CHECKING:
     from cartsnitch_api.models.store import Store
 
 
-class PriceHistory(UUIDPrimaryKeyMixin, TimestampMixin, Base):
+class PriceHistory(UUIDPrimaryKeyMixin, Base):
     """A single price observation for a product at a store on a date."""
 
     __tablename__ = "price_history"

api/src/cartsnitch_api/models/purchase.py

@@ -18,7 +18,7 @@ from sqlalchemy import (
 )
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
-from cartsnitch_api.models.base import Base, TimestampMixin, UUIDPrimaryKeyMixin
+from cartsnitch_api.models.base import Base, UUIDPrimaryKeyMixin
 
 if TYPE_CHECKING:
     from cartsnitch_api.models.price import PriceHistory
@@ -27,7 +27,7 @@ if TYPE_CHECKING:
     from cartsnitch_api.models.user import User
 
 
-class Purchase(UUIDPrimaryKeyMixin, TimestampMixin, Base):
+class Purchase(UUIDPrimaryKeyMixin, Base):
     """A single shopping trip / receipt."""
 
     __tablename__ = "purchases"
@@ -61,7 +61,7 @@ class Purchase(UUIDPrimaryKeyMixin, TimestampMixin, Base):
     )
 
 
-class PurchaseItem(UUIDPrimaryKeyMixin, TimestampMixin, Base):
+class PurchaseItem(UUIDPrimaryKeyMixin, Base):
     """Individual line item on a receipt."""
 
     __tablename__ = "purchase_items"

api/src/cartsnitch_api/models/shrinkflation.py

@@ -9,13 +9,13 @@ from sqlalchemy import Date, ForeignKey, Numeric, String
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from cartsnitch_api.constants import SizeUnit
-from cartsnitch_api.models.base import Base, TimestampMixin, UUIDPrimaryKeyMixin
+from cartsnitch_api.models.base import Base, UUIDPrimaryKeyMixin
 
 if TYPE_CHECKING:
     from cartsnitch_api.models.product import NormalizedProduct
 
 
-class ShrinkflationEvent(UUIDPrimaryKeyMixin, TimestampMixin, Base):
+class ShrinkflationEvent(UUIDPrimaryKeyMixin, Base):
     """Detected shrinkflation event — product size changed while price held or rose."""
 
     __tablename__ = "shrinkflation_events"

api/src/cartsnitch_api/routes/alerts.py

@@ -1,5 +1,7 @@
 """Alert routes: list alerts, manage settings."""
 
+from uuid import UUID
+
 from fastapi import APIRouter, Depends, HTTPException, status
 from sqlalchemy.ext.asyncio import AsyncSession
 
@@ -13,7 +15,7 @@ router = APIRouter(prefix="/alerts", tags=["alerts"])
 
 @router.get("", response_model=list[AlertResponse])
 async def list_alerts(
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = AlertService(db)
@@ -22,7 +24,7 @@ async def list_alerts(
 
 @router.get("/settings", response_model=AlertSettingsResponse)
 async def get_alert_settings(
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = AlertService(db)
@@ -32,7 +34,7 @@ async def get_alert_settings(
 @router.put("/settings")
 async def update_alert_settings(
     body: AlertSettingsRequest,
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     raise HTTPException(

api/src/cartsnitch_api/routes/coupons.py

@@ -16,7 +16,7 @@ router = APIRouter(prefix="/coupons", tags=["coupons"])
 @router.get("", response_model=list[CouponResponse])
 async def list_coupons(
     store_id: UUID | None = Query(None),
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = CouponService(db)
@@ -25,7 +25,7 @@ async def list_coupons(
 
 @router.get("/relevant", response_model=list[CouponResponse])
 async def relevant_coupons(
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = CouponService(db)

api/src/cartsnitch_api/routes/prices.py

@@ -20,7 +20,7 @@ router = APIRouter(prefix="/prices", tags=["prices"])
 
 @router.get("/trends", response_model=list[PriceTrendResponse])
 async def price_trends(
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     category: str | None = Query(None),
     db: AsyncSession = Depends(get_db),
 ):
@@ -30,7 +30,7 @@ async def price_trends(
 
 @router.get("/increases", response_model=list[PriceIncreaseResponse])
 async def price_increases(
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = PriceService(db)
@@ -40,7 +40,7 @@ async def price_increases(
 @router.get("/comparison", response_model=list[PriceComparisonResponse])
 async def price_comparison(
     product_ids: Annotated[list[UUID], Query()],
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = PriceService(db)

api/src/cartsnitch_api/routes/products.py

@@ -15,7 +15,7 @@ router = APIRouter(prefix="/products", tags=["products"])
 
 @router.get("", response_model=list[ProductResponse])
 async def list_products(
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     q: str | None = Query(None),
     category: str | None = Query(None),
     page: int = Query(1, ge=1),
@@ -29,7 +29,7 @@ async def list_products(
 @router.get("/{product_id}", response_model=ProductDetailResponse)
 async def get_product(
     product_id: UUID,
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = ProductService(db)
@@ -44,7 +44,7 @@ async def get_product(
 @router.get("/{product_id}/prices", response_model=PriceTrendResponse)
 async def get_product_prices(
     product_id: UUID,
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = ProductService(db)

api/src/cartsnitch_api/routes/purchases.py

@@ -15,7 +15,7 @@ router = APIRouter(prefix="/purchases", tags=["purchases"])
 
 @router.get("", response_model=list[PurchaseResponse])
 async def list_purchases(
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     store_id: UUID | None = Query(None),
     page: int = Query(1, ge=1),
     page_size: int = Query(20, ge=1, le=100),
@@ -27,7 +27,7 @@ async def list_purchases(
 
 @router.get("/stats", response_model=PurchaseStatsResponse)
 async def purchase_stats(
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = PurchaseService(db)
@@ -37,7 +37,7 @@ async def purchase_stats(
 @router.get("/{purchase_id}", response_model=PurchaseDetailResponse)
 async def get_purchase(
     purchase_id: UUID,
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = PurchaseService(db)

api/src/cartsnitch_api/routes/scraping.py

@@ -1,5 +1,7 @@
 """Scraping routes: trigger sync, check status (proxy to ReceiptWitness)."""
 
+from uuid import UUID
+
 from fastapi import APIRouter, Depends, HTTPException, status
 from httpx import HTTPStatusError, RequestError
 
@@ -11,7 +13,7 @@ router = APIRouter(prefix="/scraping", tags=["scraping"])
 
 
 @router.post("/{store_slug}/sync", response_model=SyncTriggerResponse)
-async def trigger_sync(store_slug: str, user_id: str = Depends(get_current_user)):
+async def trigger_sync(store_slug: str, user_id: UUID = Depends(get_current_user)):
     client = ReceiptWitnessClient()
     try:
         result = await client.trigger_sync(str(user_id), store_slug)
@@ -29,7 +31,7 @@ async def trigger_sync(store_slug: str, user_id: str = Depends(get_current_user)
 
 
 @router.get("/status", response_model=list[SyncStatusResponse])
-async def sync_status(user_id: str = Depends(get_current_user)):
+async def sync_status(user_id: UUID = Depends(get_current_user)):
     client = ReceiptWitnessClient()
     try:
         return await client.get_sync_status(str(user_id))

api/src/cartsnitch_api/routes/shopping.py

@@ -1,5 +1,7 @@
 """Shopping routes: optimize list, saved lists."""
 
+from uuid import UUID
+
 from fastapi import APIRouter, Depends, HTTPException, status
 from httpx import HTTPStatusError, RequestError
 
@@ -11,7 +13,7 @@ router = APIRouter(prefix="/shopping", tags=["shopping"])
 
 
 @router.post("/optimize", response_model=OptimizeResponse)
-async def optimize_shopping(body: OptimizeRequest, user_id: str = Depends(get_current_user)):
+async def optimize_shopping(body: OptimizeRequest, user_id: UUID = Depends(get_current_user)):
     client = ClipArtistClient()
     try:
         result = await client.optimize(
@@ -35,7 +37,7 @@ async def optimize_shopping(body: OptimizeRequest, user_id: str = Depends(get_cu
 
 
 @router.get("/lists", response_model=list[ShoppingListResponse])
-async def list_shopping_lists(user_id: str = Depends(get_current_user)):
+async def list_shopping_lists(user_id: UUID = Depends(get_current_user)):
     client = ClipArtistClient()
     try:
         return await client.get_shopping_lists(str(user_id))

api/src/cartsnitch_api/routes/stores.py

@@ -1,5 +1,7 @@
 """Store routes: list stores, manage user store connections."""
 
+from uuid import UUID
+
 from fastapi import APIRouter, Depends, HTTPException, status
 from sqlalchemy.ext.asyncio import AsyncSession
 
@@ -19,7 +21,7 @@ async def list_stores(db: AsyncSession = Depends(get_db)):
 
 @router.get("/me/stores", response_model=list[StoreAccountResponse])
 async def list_user_stores(
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = StoreService(db)
@@ -34,7 +36,7 @@ async def list_user_stores(
 async def connect_store(
     store_slug: str,
     body: ConnectStoreRequest,
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = StoreService(db)
@@ -49,7 +51,7 @@ async def connect_store(
 @router.delete("/me/stores/{store_slug}", status_code=status.HTTP_204_NO_CONTENT)
 async def disconnect_store(
     store_slug: str,
-    user_id: str = Depends(get_current_user),
+    user_id: UUID = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = StoreService(db)

api/src/cartsnitch_api/services/alerts.py

@@ -4,6 +4,8 @@ Alerts are generated by StickerShock and ShrinkRay services and written to the D
 This service reads them for the API gateway.
 """
 
+from uuid import UUID
+
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import selectinload
@@ -13,7 +15,7 @@ class AlertService:
     def __init__(self, db: AsyncSession) -> None:
         self.db = db
 
-    async def list_alerts(self, user_id: str) -> list[dict]:
+    async def list_alerts(self, user_id: UUID) -> list[dict]:
         """List shrinkflation events for products the user has purchased."""
         from cartsnitch_api.models import Purchase, PurchaseItem, ShrinkflationEvent
 
@@ -55,7 +57,7 @@ class AlertService:
             for e in events
         ]
 
-    async def get_settings(self, user_id: str) -> dict:
+    async def get_settings(self, user_id: UUID) -> dict:
         # Alert settings would be stored in a user_settings table.
         # For now, return defaults since the table doesn't exist yet in common lib.
         return {
@@ -64,7 +66,7 @@ class AlertService:
             "email_notifications": False,
         }
 
-    async def update_settings(self, user_id: str, **fields) -> dict:
+    async def update_settings(self, user_id: UUID, **fields) -> dict:
         # Would update user_settings table. Return merged defaults for now.
         current = await self.get_settings(user_id)
         for k, v in fields.items():

api/src/cartsnitch_api/services/auth.py

@@ -5,6 +5,8 @@ handled by the Better-Auth service (auth/). This service provides
 user lookup and profile update operations for the API gateway.
 """
 
+from uuid import UUID
+
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
@@ -13,7 +15,7 @@ class AuthService:
     def __init__(self, db: AsyncSession) -> None:
         self.db = db
 
-    async def get_user(self, user_id: str) -> dict:
+    async def get_user(self, user_id: UUID) -> dict:
         from cartsnitch_api.models import User
 
         result = await self.db.execute(select(User).where(User.id == user_id))
@@ -28,7 +30,7 @@ class AuthService:
             "created_at": user.created_at,
         }
 
-    async def update_user(self, user_id: str, **fields) -> dict:
+    async def update_user(self, user_id: UUID, **fields) -> dict:
         from cartsnitch_api.models import User
 
         result = await self.db.execute(select(User).where(User.id == user_id))
@@ -56,7 +58,7 @@ class AuthService:
             "created_at": user.created_at,
         }
 
-    async def delete_user(self, user_id: str) -> None:
+    async def delete_user(self, user_id: UUID) -> None:
         from cartsnitch_api.models import User
 
         result = await self.db.execute(select(User).where(User.id == user_id))

api/src/cartsnitch_api/services/coupons.py

@@ -29,7 +29,7 @@ class CouponService:
         coupons = result.scalars().all()
         return [self._to_dict(c) for c in coupons]
 
-    async def relevant_coupons(self, user_id: str) -> list[dict]:
+    async def relevant_coupons(self, user_id: UUID) -> list[dict]:
         """Coupons for products the user has purchased."""
         from cartsnitch_api.models import Coupon, PurchaseItem
 

api/src/cartsnitch_api/services/purchases.py

@@ -13,7 +13,7 @@ class PurchaseService:
 
     async def list_purchases(
         self,
-        user_id: str,
+        user_id: UUID,
         store_id: UUID | None = None,
         page: int = 1,
         page_size: int = 20,
@@ -56,7 +56,7 @@ class PurchaseService:
             for p, item_count, store_name in result.all()
         ]
 
-    async def get_purchase(self, purchase_id: UUID, user_id: str) -> dict:
+    async def get_purchase(self, purchase_id: UUID, user_id: UUID) -> dict:
         from cartsnitch_api.models import Purchase
 
         result = await self.db.execute(
@@ -88,7 +88,7 @@ class PurchaseService:
             ],
         }
 
-    async def get_stats(self, user_id: str) -> dict:
+    async def get_stats(self, user_id: UUID) -> dict:
         from cartsnitch_api.models import Purchase
 
         result = await self.db.execute(

api/src/cartsnitch_api/services/stores.py

@@ -1,6 +1,7 @@
 """Store service — list stores, manage user store account connections."""
 
 import json
+from uuid import UUID
 
 from cryptography.fernet import Fernet
 from sqlalchemy import select
@@ -34,7 +35,7 @@ class StoreService:
             for s in stores
         ]
 
-    async def list_user_stores(self, user_id: str) -> list[dict]:
+    async def list_user_stores(self, user_id: UUID) -> list[dict]:
         from cartsnitch_api.models import UserStoreAccount
 
         result = await self.db.execute(
@@ -59,7 +60,7 @@ class StoreService:
             for a in accounts
         ]
 
-    async def connect_store(self, user_id: str, store_slug: str, credentials: dict | None) -> dict:
+    async def connect_store(self, user_id: UUID, store_slug: str, credentials: dict | None) -> dict:
         from cartsnitch_api.models import Store, UserStoreAccount
 
         result = await self.db.execute(select(Store).where(Store.slug == store_slug))
@@ -106,7 +107,7 @@ class StoreService:
             "sync_status": "active",
         }
 
-    async def disconnect_store(self, user_id: str, store_slug: str) -> None:
+    async def disconnect_store(self, user_id: UUID, store_slug: str) -> None:
         from cartsnitch_api.models import Store, UserStoreAccount
 
         result = await self.db.execute(select(Store).where(Store.slug == store_slug))