fix(api): replace UUID type with str for Better-Auth nanoid user IDs (#98)

Better-Auth uses nanoid strings for user IDs, not UUIDs. Changed all
user_id parameter/return types in the API layer from UUID to str,
removed the obsolete UUID import where unused, and updated the
_validate_session_token return type accordingly.

Co-authored-by: CartSnitch Engineer Bot <cartnoreply@cartsnitch.com>
Co-authored-by: Paperclip <noreply@paperclip.ing>

api/src/cartsnitch_api/routes/alerts.py

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

api/src/cartsnitch_api/routes/scraping.py

@@ -1,7 +1,5 @@
 """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
 
@@ -13,7 +11,7 @@ router = APIRouter(prefix="/scraping", tags=["scraping"])
 
 
 @router.post("/{store_slug}/sync", response_model=SyncTriggerResponse)
-async def trigger_sync(store_slug: str, user_id: UUID = Depends(get_current_user)):
+async def trigger_sync(store_slug: str, user_id: str = Depends(get_current_user)):
     client = ReceiptWitnessClient()
     try:
         result = await client.trigger_sync(str(user_id), store_slug)
@@ -31,7 +29,7 @@ async def trigger_sync(store_slug: str, user_id: UUID = Depends(get_current_user
 
 
 @router.get("/status", response_model=list[SyncStatusResponse])
-async def sync_status(user_id: UUID = Depends(get_current_user)):
+async def sync_status(user_id: str = Depends(get_current_user)):
     client = ReceiptWitnessClient()
     try:
         return await client.get_sync_status(str(user_id))

api/src/cartsnitch_api/routes/shopping.py

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

api/src/cartsnitch_api/routes/stores.py

@@ -1,7 +1,5 @@
 """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
 
@@ -21,7 +19,7 @@ async def list_stores(db: AsyncSession = Depends(get_db)):
 
 @router.get("/me/stores", response_model=list[StoreAccountResponse])
 async def list_user_stores(
-    user_id: UUID = Depends(get_current_user),
+    user_id: str = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = StoreService(db)
@@ -36,7 +34,7 @@ async def list_user_stores(
 async def connect_store(
     store_slug: str,
     body: ConnectStoreRequest,
-    user_id: UUID = Depends(get_current_user),
+    user_id: str = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = StoreService(db)
@@ -51,7 +49,7 @@ 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: UUID = Depends(get_current_user),
+    user_id: str = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     svc = StoreService(db)