diff --git a/backend/app/api/v1/endpoints/analytics.py b/backend/app/api/v1/endpoints/analytics.py
index d677bba..14f3dec 100644
--- a/backend/app/api/v1/endpoints/analytics.py
+++ b/backend/app/api/v1/endpoints/analytics.py
@@ -8,7 +8,7 @@ from sqlmodel import Session, func, select
 
 from app.auth import get_current_user
 from app.db import get_session
-from app.models.models import Category, Transaction
+from app.models.models import Category, Transaction, TransactionType
 from app.services.budget_projection import get_cycle_range
 from app.services.exchange_rate import get_converted_amount_expr
 
@@ -53,7 +53,7 @@ def spending_by_category(
             func.sum(amount_crc).label("total"),
             func.count().label("count"),
         )
-        .where(Transaction.transaction_type == "COMPRA")
+        .where(Transaction.transaction_type == TransactionType.COMPRA)
         .group_by(Transaction.category_id)
     )
 
@@ -123,7 +123,7 @@ def monthly_trend(
                 ),
             )
             .where(
-                Transaction.transaction_type == "COMPRA",
+                Transaction.transaction_type == TransactionType.COMPRA,
                 Transaction.date >= start,
                 Transaction.date < end,
             )
@@ -171,7 +171,7 @@ def daily_spending(
             func.sum(amount_crc).label("total"),
             func.count().label("count"),
         )
-        .where(Transaction.transaction_type == "COMPRA")
+        .where(Transaction.transaction_type == TransactionType.COMPRA)
         .group_by(func.date(Transaction.date))
         .order_by(func.date(Transaction.date))
     )
diff --git a/backend/app/api/v1/endpoints/budget.py b/backend/app/api/v1/endpoints/budget.py
index 76a86c8..5ac770b 100644
--- a/backend/app/api/v1/endpoints/budget.py
+++ b/backend/app/api/v1/endpoints/budget.py
@@ -248,9 +248,9 @@ def upsert_balance_override(
     _user: str = Depends(get_current_user),
 ):
     if year < MIN_YEAR or year > MAX_YEAR:
-        raise HTTPException(400, f"Year must be between {MIN_YEAR} and {MAX_YEAR}")
+        raise HTTPException(status_code=400, detail=f"Year must be between {MIN_YEAR} and {MAX_YEAR}")
     if year == FRESH_START_YEAR and month < FRESH_START_MONTH:
-        raise HTTPException(400, f"Cannot override before {FRESH_START_YEAR}-{FRESH_START_MONTH:02d}")
+        raise HTTPException(status_code=400, detail=f"Cannot override before {FRESH_START_YEAR}-{FRESH_START_MONTH:02d}")
 
     existing = session.exec(
         select(BalanceOverride).where(
@@ -288,6 +288,6 @@ def delete_balance_override(
         )
     ).first()
     if not existing:
-        raise HTTPException(404, "No override found for this month")
+        raise HTTPException(status_code=404, detail="No override found for this month")
     session.delete(existing)
     session.commit()
diff --git a/backend/app/api/v1/endpoints/transactions.py b/backend/app/api/v1/endpoints/transactions.py
index ee8dba1..ceb53ec 100644
--- a/backend/app/api/v1/endpoints/transactions.py
+++ b/backend/app/api/v1/endpoints/transactions.py
@@ -3,6 +3,7 @@ from typing import Optional
 
 from fastapi import APIRouter, Depends, HTTPException, Query
 from pydantic import BaseModel
+from sqlalchemy import and_, or_
 from sqlmodel import Session, col, func, select
 
 from app.auth import get_current_user
@@ -73,7 +74,6 @@ def list_transactions(
         prev_y, prev_m = get_previous_cycle(cycle_year, cycle_month)
         prev_start, prev_end = get_cycle_range(prev_y, prev_m)
         # Normal transactions in this cycle (not deferred) + deferred from previous cycle
-        from sqlalchemy import or_, and_
         query = query.where(
             or_(
                 and_(
diff --git a/backend/app/auth.py b/backend/app/auth.py
index ad00612..5e321a2 100644
--- a/backend/app/auth.py
+++ b/backend/app/auth.py
@@ -12,6 +12,8 @@ from jose import JWTError, jwt
 from sqlmodel import Session, select
 
 from app.config import settings
+from app.db import get_session
+from app.models.models import APIToken
 from app.timeutil import utcnow
 
 oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/v1/auth/login")
@@ -91,9 +93,6 @@ def _validate_token(token: str) -> str:
         pass
 
     # Fallback: check API token
-    from app.db import get_session
-    from app.models.models import APIToken
-
     token_hash = hash_token(token)
     with next(get_session()) as session:
         api_token = session.exec(
diff --git a/backend/app/main.py b/backend/app/main.py
index 5d768e6..1738c08 100644
--- a/backend/app/main.py
+++ b/backend/app/main.py
@@ -1,7 +1,7 @@
 import asyncio
 import json
-import re
 import uuid
+from http.cookies import SimpleCookie
 from contextlib import asynccontextmanager
 
 from agent_framework_ag_ui import add_agent_framework_fastapi_endpoint
@@ -105,10 +105,10 @@ async def agent_auth_and_session(request: Request, call_next):
     if auth_header.lower().startswith("bearer "):
         token = auth_header.split(" ", 1)[1].strip()
     else:
-        cookie_header = request.headers.get("cookie", "")
-        m = re.search(r"(?:^|;\s*)ws_token=([^;]+)", cookie_header)
-        if m:
-            token = m.group(1)
+        cookies = SimpleCookie()
+        cookies.load(request.headers.get("cookie", ""))
+        if "ws_token" in cookies:
+            token = cookies["ws_token"].value
 
     if not token:
         return Response(status_code=401, content="Missing auth")