diff --git a/chafan_core/app/api/api_v1/api.py b/chafan_core/app/api/api_v1/api.py
index 99513ea..0f464c5 100644
--- a/chafan_core/app/api/api_v1/api.py
+++ b/chafan_core/app/api/api_v1/api.py
@@ -2,6 +2,7 @@
 
 from chafan_core.app.api.api_v1.endpoints import (
     activities,
+    admin_tools,
     answer_suggest_edits,
     answers,
     applications,
@@ -28,6 +29,7 @@
     questions,
     reports,
     rewards,
+    rss,
     search,
     sitemaps,
     sites,
@@ -38,8 +40,6 @@
     users,
     webhooks,
     ws,
-    rss,
-    admin_tools,
 )
 
 api_router = APIRouter()
@@ -99,7 +99,9 @@
     coin_payments.router, prefix="/coin-payments", tags=["coin_payments"]
 )
 api_router.include_router(audit_logs.router, prefix="/audit-logs", tags=["audit_logs"])
-api_router.include_router(admin_tools.router, prefix="/admin_tools", tags=["admin_tools"])
+api_router.include_router(
+    admin_tools.router, prefix="/admin_tools", tags=["admin_tools"]
+)
 api_router.include_router(webhooks.router, prefix="/webhooks", tags=["webhooks"])
 api_router.include_router(feedbacks.router, prefix="/feedbacks", tags=["feedbacks"])
 api_router.include_router(reports.router, prefix="/reports", tags=["reports"])
diff --git a/chafan_core/app/api/api_v1/endpoints/activities.py b/chafan_core/app/api/api_v1/endpoints/activities.py
index 6485912..c712bf3 100644
--- a/chafan_core/app/api/api_v1/endpoints/activities.py
+++ b/chafan_core/app/api/api_v1/endpoints/activities.py
@@ -1,3 +1,4 @@
+import logging
 from typing import Any, Optional, Union
 
 from fastapi import APIRouter, Depends, Request
@@ -12,8 +13,6 @@
 from chafan_core.app.schemas.answer import AnswerPreview, AnswerPreviewForVisitor
 from chafan_core.utils.base import unwrap
 
-
-import logging
 logger = logging.getLogger(__name__)
 
 router = APIRouter()
@@ -46,10 +45,13 @@ async def get_feed(
     Get activity feed.
     """
     current_user_id: int = unwrap(cached_layer.principal_id)
-    logger.info(f"User {current_user_id} GET activity skip={before_activity_id} limit={limit}, random={random}, full={full_answers}")
+    logger.info(
+        f"User {current_user_id} GET activity skip={before_activity_id} limit={limit}, random={random}, full={full_answers}"
+    )
 
     activities = await cached_layer.get_user_activity(
-            current_user_id, before_activity_id, limit, random, subject_user_uuid)
+        current_user_id, before_activity_id, limit, random, subject_user_uuid
+    )
 
     data = schemas.FeedSequence(activities=activities, random=random)
     return _update_feed_seq(cached_layer, data, full_answers=full_answers)
diff --git a/chafan_core/app/api/api_v1/endpoints/admin_tools.py b/chafan_core/app/api/api_v1/endpoints/admin_tools.py
index 889c380..94a8b95 100644
--- a/chafan_core/app/api/api_v1/endpoints/admin_tools.py
+++ b/chafan_core/app/api/api_v1/endpoints/admin_tools.py
@@ -1,14 +1,14 @@
+import logging
 
 from fastapi import APIRouter, Depends, Response
 
-from chafan_core.app.config import settings
 from chafan_core.app.api import deps
 from chafan_core.app.cached_layer import CachedLayer
+from chafan_core.app.config import settings
 from chafan_core.app.feed import get_site_activities
-from chafan_core.utils.base import HTTPException_
 from chafan_core.app.responders.rss import build_rss
+from chafan_core.utils.base import HTTPException_
 
-import logging
 logger = logging.getLogger(__name__)
 
 
@@ -17,9 +17,10 @@
 
 @router.get("/full_site_activity/{passcode}/rss.xml")
 async def get_site_activity(
-        *, response: Response,
-        cached_layer: CachedLayer = Depends(deps.get_cached_layer),
-        passcode: str
+    *,
+    response: Response,
+    cached_layer: CachedLayer = Depends(deps.get_cached_layer),
+    passcode: str
 ) -> str:
     """
     Get full cha.fan activity.
@@ -28,8 +29,8 @@ async def get_site_activity(
     code = settings.DEBUG_ADMIN_TOOL_FULL_SITE_PASSCODE
     if code is None or code == "" or code != passcode:
         raise HTTPException_(status_code=405, detail="Not allowed ")
-    activities = await get_site_activities(cached_layer, None, settings.LIMIT_RSS_ADMIN_TOOL_FULL_SITE_ITEMS, True)
+    activities = await get_site_activities(
+        cached_layer, None, settings.LIMIT_RSS_ADMIN_TOOL_FULL_SITE_ITEMS, True
+    )
     rss_str = build_rss(activities, site=None)
     return Response(content=rss_str, media_type="application/rss+xml")
-
-
diff --git a/chafan_core/app/api/api_v1/endpoints/answers.py b/chafan_core/app/api/api_v1/endpoints/answers.py
index e175ab7..1138f46 100644
--- a/chafan_core/app/api/api_v1/endpoints/answers.py
+++ b/chafan_core/app/api/api_v1/endpoints/answers.py
@@ -1,3 +1,4 @@
+import logging
 from typing import Any, List, Union
 
 from fastapi import APIRouter, Depends, Query, Request, Response
@@ -17,11 +18,10 @@
 from chafan_core.app.schemas.answer import AnswerModUpdate
 from chafan_core.app.schemas.event import EventInternal, UpvoteAnswerInternal
 from chafan_core.app.schemas.richtext import RichText
+from chafan_core.app.task import postprocess_new_answer
 from chafan_core.utils.base import HTTPException_, filter_not_none, get_utc_now, unwrap
 from chafan_core.utils.constants import MAX_ARCHIVE_PAGINATION_LIMIT
-from chafan_core.app.task import postprocess_new_answer
 
-import logging
 logger = logging.getLogger(__name__)
 
 router = APIRouter()
@@ -257,9 +257,9 @@ def _update_answer(
         if answer_in.updated_content:
             del answer_in_dict["updated_content"]
             answer_in_dict["body"] = answer_in.updated_content.source
-            answer_in_dict[
-                "body_prerendered_text"
-            ] = answer_in.updated_content.rendered_text
+            answer_in_dict["body_prerendered_text"] = (
+                answer_in.updated_content.rendered_text
+            )
             answer_in_dict["editor"] = answer_in.updated_content.editor
 
         answer_in_dict["body_draft"] = None
diff --git a/chafan_core/app/api/api_v1/endpoints/article_columns.py b/chafan_core/app/api/api_v1/endpoints/article_columns.py
index 9600a36..822e739 100644
--- a/chafan_core/app/api/api_v1/endpoints/article_columns.py
+++ b/chafan_core/app/api/api_v1/endpoints/article_columns.py
@@ -1,11 +1,11 @@
 from typing import Any, List, Optional
 
 from fastapi import APIRouter, Depends
-from chafan_core.app.config import settings
 
 from chafan_core.app import crud, schemas
 from chafan_core.app.api import deps
 from chafan_core.app.cached_layer import CachedLayer
+from chafan_core.app.config import settings
 from chafan_core.utils.base import HTTPException_, filter_not_none
 
 router = APIRouter()
@@ -42,7 +42,7 @@ async def get_article_column_articles(
         )
     articles = article_column.articles
     if not current_user_id:
-        articles = articles[:settings.VISITORS_READ_ARTICLE_LIMIT]
+        articles = articles[: settings.VISITORS_READ_ARTICLE_LIMIT]
     return filter_not_none(
         [cached_layer.materializer.preview_of_article(a) for a in articles]
     )
diff --git a/chafan_core/app/api/api_v1/endpoints/articles.py b/chafan_core/app/api/api_v1/endpoints/articles.py
index 5ec65b6..6f8ef86 100644
--- a/chafan_core/app/api/api_v1/endpoints/articles.py
+++ b/chafan_core/app/api/api_v1/endpoints/articles.py
@@ -1,4 +1,5 @@
 import datetime
+import logging
 from typing import Any, List, Optional, Union
 
 from fastapi import APIRouter, Depends, Request
@@ -19,7 +20,6 @@
 from chafan_core.utils.base import ContentVisibility, HTTPException_
 from chafan_core.utils.constants import MAX_ARCHIVE_PAGINATION_LIMIT
 
-import logging
 logger = logging.getLogger(__name__)
 
 
@@ -37,7 +37,10 @@ async def get_article(
     article = cached_layer.get_article_by_uuid(uuid, current_user_id)
     if article is None:
         cached_layer.create_audit(
-                api=f"get_article {uuid} retrieved None", request=request, user_id=current_user_id)
+            api=f"get_article {uuid} retrieved None",
+            request=request,
+            user_id=current_user_id,
+        )
         raise HTTPException_(
             status_code=400,
             detail="The article doesn't exists in the system.",
diff --git a/chafan_core/app/api/api_v1/endpoints/channels.py b/chafan_core/app/api/api_v1/endpoints/channels.py
index 4131533..eb3d428 100644
--- a/chafan_core/app/api/api_v1/endpoints/channels.py
+++ b/chafan_core/app/api/api_v1/endpoints/channels.py
@@ -1,3 +1,4 @@
+import logging
 from typing import Any, List
 
 from fastapi import APIRouter, Depends
@@ -8,7 +9,6 @@
 from chafan_core.app.materialize import check_user_in_channel
 from chafan_core.utils.base import HTTPException_
 
-import logging
 logger = logging.getLogger(__name__)
 
 
diff --git a/chafan_core/app/api/api_v1/endpoints/comments.py b/chafan_core/app/api/api_v1/endpoints/comments.py
index bb9320a..c63ab16 100644
--- a/chafan_core/app/api/api_v1/endpoints/comments.py
+++ b/chafan_core/app/api/api_v1/endpoints/comments.py
@@ -1,4 +1,5 @@
 import datetime
+import logging
 from typing import Any, Optional
 
 from fastapi import APIRouter, Depends
@@ -12,7 +13,6 @@
 from chafan_core.app.task import postprocess_comment_update, postprocess_new_comment
 from chafan_core.utils.base import HTTPException_
 
-import logging
 logger = logging.getLogger(__name__)
 
 router = APIRouter()
diff --git a/chafan_core/app/api/api_v1/endpoints/invitation_links.py b/chafan_core/app/api/api_v1/endpoints/invitation_links.py
index 1f8b705..a4b8fc5 100644
--- a/chafan_core/app/api/api_v1/endpoints/invitation_links.py
+++ b/chafan_core/app/api/api_v1/endpoints/invitation_links.py
@@ -2,7 +2,7 @@
 
 from fastapi import APIRouter, Depends
 
-from chafan_core.app import crud, schemas, models
+from chafan_core.app import crud, models, schemas
 from chafan_core.app.api import deps
 from chafan_core.app.cached_layer import CachedLayer
 from chafan_core.app.common import OperationType
@@ -35,14 +35,15 @@ async def create_invitation_link(
         )
         invited_to_site_id = invited_to_site.id
     invitation_link = await crud.invitation_link.create_invitation(
-            db, invited_to_site_id=invited_to_site_id, inviter=current_user
-        )
-    crud.audit_log.create_with_user(
-        db, ipaddr="0.0.0.0", user_id=current_user.id, api=f"Created invitation link {invitation_link.uuid}"
+        db, invited_to_site_id=invited_to_site_id, inviter=current_user
     )
-    return cached_layer.materializer.invitation_link_schema_from_orm(
-            invitation_link
+    crud.audit_log.create_with_user(
+        db,
+        ipaddr="0.0.0.0",
+        user_id=current_user.id,
+        api=f"Created invitation link {invitation_link.uuid}",
     )
+    return cached_layer.materializer.invitation_link_schema_from_orm(invitation_link)
 
 
 @router.get("/daily", response_model=schemas.InvitationLink)
diff --git a/chafan_core/app/api/api_v1/endpoints/login.py b/chafan_core/app/api/api_v1/endpoints/login.py
index 828fbf4..45e4c48 100644
--- a/chafan_core/app/api/api_v1/endpoints/login.py
+++ b/chafan_core/app/api/api_v1/endpoints/login.py
@@ -1,9 +1,9 @@
 import datetime
 import json
+import logging
 from typing import Any, List, Literal, Mapping, Optional
 from urllib.parse import parse_qs, urlparse
 
-import logging
 logger = logging.getLogger(__name__)
 
 import requests
@@ -19,20 +19,7 @@
 from chafan_core.app import crud, models, schemas, security
 from chafan_core.app.api import deps
 from chafan_core.app.cached_layer import CachedLayer
-from chafan_core.app.common import (
-    check_email,
-    client_ip,
-    get_redis_cli,
-    is_dev,
-)
-from chafan_core.app.security import (
-    check_token_validity_impl,
-    generate_password_reset_token,
-    verify_password_reset_token,
-    create_digit_verification_code,
-    register_digit_verification_code,
-    check_digit_verification_code,
-)
+from chafan_core.app.common import check_email, client_ip, get_redis_cli, is_dev
 from chafan_core.app.config import settings
 from chafan_core.app.email.utils import (
     send_reset_password_email,
@@ -57,8 +44,15 @@
     LoginWithVerificationCode,
     VerificationCodeRequest,
 )
-
-from chafan_core.app.security import get_password_hash
+from chafan_core.app.security import (
+    check_digit_verification_code,
+    check_token_validity_impl,
+    create_digit_verification_code,
+    generate_password_reset_token,
+    get_password_hash,
+    register_digit_verification_code,
+    verify_password_reset_token,
+)
 from chafan_core.app.task_utils import execute_with_db
 from chafan_core.db.session import ReadSessionLocal
 from chafan_core.utils.base import HTTPException_
@@ -70,6 +64,7 @@
 
 router = APIRouter()
 
+
 # The user's authentication MUST be passed when calling this function
 def _login_user(db: Session, *, request: Request, user: models.User) -> schemas.Token:
     if not crud.user.is_active(user):
@@ -213,7 +208,7 @@ async def recover_password(
     """
     Password Recovery
     """
-    user = crud.user.get_by_email(db, email=email) #Optional[User]
+    user = crud.user.get_by_email(db, email=email)  # Optional[User]
 
     if not user:
         raise HTTPException_(
@@ -221,7 +216,10 @@ async def recover_password(
             detail="The user with this email does not exist in the system.",
         )
     crud.audit_log.create_with_user(
-        db, ipaddr=client_ip(request), user_id=user.id, api=f"Password reset email sent to {email}"
+        db,
+        ipaddr=client_ip(request),
+        user_id=user.id,
+        api=f"Password reset email sent to {email}",
     )
     password_reset_token = generate_password_reset_token(email=email)
     await send_reset_password_email(email=user.email, token=password_reset_token)
@@ -231,8 +229,11 @@ async def recover_password(
 @router.post("/send-verification-code", response_model=schemas.GenericResponse)
 @limiter.limit("1/minute")
 async def send_verification_code(
-    response: Response, request: Request, *, request_in: VerificationCodeRequest,
-    db: Session = Depends(deps.get_db)
+    response: Response,
+    request: Request,
+    *,
+    request_in: VerificationCodeRequest,
+    db: Session = Depends(deps.get_db),
 ) -> Any:
 
     logger.info(str(request_in))
@@ -244,13 +245,16 @@ async def send_verification_code(
         )
     # TODO audit log should support user_id is NULL. 2025-Jul-06
     crud.audit_log.create_with_user(
-        db, ipaddr=client_ip(request), user_id=1, api="send_verification_code to email " + request_in.email
+        db,
+        ipaddr=client_ip(request),
+        user_id=1,
+        api="send_verification_code to email " + request_in.email,
     )
     code = create_digit_verification_code(6)
     await send_verification_code_email(email=request_in.email, code=code)
     await register_digit_verification_code(request_in.email, code)
     # We may switch to trio + hypercorn in future 2025-Jul-06
-    #async with trio.open_nursery() as nursery:
+    # async with trio.open_nursery() as nursery:
     #    nursery.start_soon(send_verification_code_email,email=request_in.email, code=code)
     #    nursery.start_soon(register_digit_verification_code, request_in.email, code)
     return schemas.GenericResponse()
@@ -266,7 +270,7 @@ async def create_user_open(
     code: str = Body(...),
     invitation_link_uuid: str = Body(...),
 ) -> Any:
-    if (not settings.USERS_OPEN_REGISTRATION):
+    if not settings.USERS_OPEN_REGISTRATION:
         raise HTTPException_(
             status_code=status.HTTP_403_FORBIDDEN,
             detail="Open user registration is forbidden on this server",
@@ -280,7 +284,9 @@ async def create_user_open(
     crud.audit_log.create_with_user(
         db, ipaddr="0.0.0.0", user_id=1, api="Open new account email " + email
     )
-    invitation_link_valid = await cached_layer.try_consume_invitation_link_by_uuid(invitation_link_uuid)
+    invitation_link_valid = await cached_layer.try_consume_invitation_link_by_uuid(
+        invitation_link_uuid
+    )
     if not invitation_link_valid:
         raise HTTPException_(
             status_code=status.HTTP_401_UNAUTHORIZED,
@@ -304,23 +310,22 @@ async def create_user_open(
     ver_code = await check_digit_verification_code(email, code)
     if not ver_code:
         raise HTTPException_(
-                status_code=status.HTTP_401_UNAUTHORIZED,
-                detail="The verification code is not present in the system.",
-                )
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="The verification code is not present in the system.",
+        )
     user_in = schemas.UserCreate(password=password, handle=handle, email=email)
     user = await crud.user.create(db, obj_in=user_in)
 
     # TODO auto add site
-    if False and invitation_link.invited_to_site is not None:
+    if False and invitation_link.invited_to_site is not None:  # type: ignore[name-defined]  # noqa: F821
         existing_profile = crud.profile.get_by_user_and_site(
-            db, owner_id=user.id, site_id=invitation_link.invited_to_site.id
+            db, owner_id=user.id, site_id=invitation_link.invited_to_site.id  # type: ignore[name-defined]  # noqa: F821
         )
         if not existing_profile:
             cached_layer.create_site_profile(
-                owner=user, site_uuid=invitation_link.invited_to_site.uuid
+                owner=user, site_uuid=invitation_link.invited_to_site.uuid  # type: ignore[name-defined]  # noqa: F821
             )
 
-
     # TODO bonus for invite new user, new user's initial coins
     return user_schema_from_orm(user)
 
diff --git a/chafan_core/app/api/api_v1/endpoints/people.py b/chafan_core/app/api/api_v1/endpoints/people.py
index 768195c..b34316a 100644
--- a/chafan_core/app/api/api_v1/endpoints/people.py
+++ b/chafan_core/app/api/api_v1/endpoints/people.py
@@ -115,10 +115,10 @@ def get_user_public(
             detail="The user doesn't exists in the system.",
         )
     # TODO turn it off 2025-07-23
-    view_times = 5 # view_counters.get_views(user.uuid, "profile")
+    view_times = 5  # view_counters.get_views(user.uuid, "profile")
     if current_user_id is None:
         return _get_user_public_visitor(cached_layer, user, view_times)
-    #view_counters.add_view(user.uuid, "profile", current_user_id)
+    # view_counters.add_view(user.uuid, "profile", current_user_id)
     db.commit()
     about_content = None
     if user.about is not None:
@@ -227,7 +227,7 @@ def get_user_submissions(
         )
     return filter_not_none(
         [
-            #cached_layer.materializer.submission_schema_from_orm(submission)
+            # cached_layer.materializer.submission_schema_from_orm(submission)
             cached_layer.submission_schema_from_orm(submission)
             for submission in user.submissions
         ]
@@ -238,7 +238,7 @@ def get_user_submissions(
 async def get_user_articles(
     *,
     cached_layer: CachedLayer = Depends(deps.get_cached_layer),
-    #cached_layer: CachedLayer = Depends(deps.get_cached_layer_logged_in),
+    # cached_layer: CachedLayer = Depends(deps.get_cached_layer_logged_in),
     uuid: str,
     skip: int = Query(default=0, ge=0),
     limit: int = Query(
@@ -257,7 +257,7 @@ async def get_user_articles(
     # TODO "owner" is repeated in this response 2025-Mar-23
     return filter_not_none(
         [
-    # TODO we have limit, but we still generate all articles. Need to rewrite with python generator 2025-Mar-23
+            # TODO we have limit, but we still generate all articles. Need to rewrite with python generator 2025-Mar-23
             cached_layer.materializer.preview_of_article(article)
             for article in user.articles
         ]
diff --git a/chafan_core/app/api/api_v1/endpoints/questions.py b/chafan_core/app/api/api_v1/endpoints/questions.py
index e76b319..3901529 100644
--- a/chafan_core/app/api/api_v1/endpoints/questions.py
+++ b/chafan_core/app/api/api_v1/endpoints/questions.py
@@ -1,4 +1,5 @@
 import datetime
+import logging
 from typing import Any, List, Optional, Union
 
 from fastapi import APIRouter, Depends, Request, Response
@@ -20,7 +21,6 @@
 from chafan_core.app.task import postprocess_new_question, postprocess_updated_question
 from chafan_core.utils.base import HTTPException_, filter_not_none
 
-import logging
 logger = logging.getLogger(__name__)
 
 router = APIRouter()
@@ -61,12 +61,12 @@ def _get_question_data(
 ) -> Union[schemas.Question, schemas.QuestionForVisitor]:
     # TODO removed the check for principle id 2025-07-23
     question_data = cached_layer.question_schema_from_orm(question)
-#    if cached_layer.principal_id is None:
-#        question_data = cached_layer.materializer.question_for_visitor_schema_from_orm(
-#            question
-#        )
-#    else:
-#        question_data = cached_layer.materializer.question_schema_from_orm(question)
+    #    if cached_layer.principal_id is None:
+    #        question_data = cached_layer.materializer.question_for_visitor_schema_from_orm(
+    #            question
+    #        )
+    #    else:
+    #        question_data = cached_layer.materializer.question_schema_from_orm(question)
     if question_data is None:
         raise HTTPException_(
             status_code=400,
@@ -92,8 +92,8 @@ def get_question(
     question = cached_layer.get_question_by_uuid(uuid)
     if question.is_hidden:
         raise HTTPException_(
-                status_code=403,
-                detail="Not allowed to access this quesion",
+            status_code=403,
+            detail="Not allowed to access this quesion",
         )
     return _get_question_data(cached_layer, question)
 
@@ -108,8 +108,8 @@ async def bump_views_counter(
     question = cached_layer.get_question_model_http(uuid)
     if question is None:
         raise HTTPException_(
-                status_code=404,
-                detail="No such question",
+            status_code=404,
+            detail="No such question",
         )
     assert isinstance(question, models.Question)
     await view_counters.add_view_async(cached_layer, "question", question.id)
@@ -504,11 +504,11 @@ async def get_question_page(
     question = cached_layer.get_question_by_uuid(uuid, current_user_id)
     if question is None:
         cached_layer.create_audit(
-                api=f"get_question_page {uuid} retrieved None", request=request, user_id=current_user_id)
-        raise HTTPException_(
-                status_code=404,
-                detail="No such question"
-            )
+            api=f"get_question_page {uuid} retrieved None",
+            request=request,
+            user_id=current_user_id,
+        )
+        raise HTTPException_(status_code=404, detail="No such question")
     question_data = _get_question_data(cached_layer, question)
     flags = schemas.QuestionPageFlags()
     if cached_layer.principal_id:
diff --git a/chafan_core/app/api/api_v1/endpoints/rss.py b/chafan_core/app/api/api_v1/endpoints/rss.py
index cda6d9e..7ff79dd 100644
--- a/chafan_core/app/api/api_v1/endpoints/rss.py
+++ b/chafan_core/app/api/api_v1/endpoints/rss.py
@@ -1,23 +1,25 @@
-from fastapi import APIRouter, Depends, Response
+import logging
 
+from fastapi import APIRouter, Depends, Response
 
-from chafan_core.app.config import settings
 from chafan_core.app.api import deps
 from chafan_core.app.cached_layer import CachedLayer
+from chafan_core.app.config import settings
 from chafan_core.app.feed import get_site_activities
 from chafan_core.app.responders.rss import build_rss
 from chafan_core.utils.base import HTTPException_
 
-
-import logging
 logger = logging.getLogger(__name__)
 
 router = APIRouter()
 
+
 @router.get("/site/{subdomain}/rss.xml")
 async def get_site_activity(
-        *, response: Response,
-        cached_layer: CachedLayer = Depends(deps.get_cached_layer), subdomain: str
+    *,
+    response: Response,
+    cached_layer: CachedLayer = Depends(deps.get_cached_layer),
+    subdomain: str
 ) -> str:
     """
     Get a site's activity.
@@ -28,9 +30,9 @@ async def get_site_activity(
         raise HTTPException_(status_code=404, detail="No such site " + subdomain)
     if not site.public_readable:
         raise HTTPException_(status_code=405, detail="Not allowed " + subdomain)
-    activities = await get_site_activities(cached_layer, site, settings.LIMIT_RSS_RESPONSE_ITEMS)
+    activities = await get_site_activities(
+        cached_layer, site, settings.LIMIT_RSS_RESPONSE_ITEMS
+    )
     logger.info("api get: " + str(activities))
     rss_str = build_rss(activities, site)
     return Response(content=rss_str, media_type="application/rss+xml")
-
-
diff --git a/chafan_core/app/api/api_v1/endpoints/search.py b/chafan_core/app/api/api_v1/endpoints/search.py
index 33d0b87..edc7dac 100644
--- a/chafan_core/app/api/api_v1/endpoints/search.py
+++ b/chafan_core/app/api/api_v1/endpoints/search.py
@@ -1,16 +1,15 @@
+import logging
 from typing import Any, List
 
-
 from fastapi import APIRouter, Depends, Request, Response
 
 from chafan_core.app import crud, models, schemas
 from chafan_core.app.api import deps
 from chafan_core.app.cached_layer import CachedLayer
-from chafan_core.app.materialize import preview_of_question_as_search_hit
 from chafan_core.app.limiter import limiter
+from chafan_core.app.materialize import preview_of_question_as_search_hit
 from chafan_core.utils.base import filter_not_none
 
-import logging
 logger = logging.getLogger(__name__)
 
 router = APIRouter()
@@ -77,7 +76,7 @@ async def search_questions(
     if q == "":
         return []
     questions = crud.question.search(cached_layer.get_db(), q=q)
-# TODO no search hit limit
+    # TODO no search hit limit
     return filter_not_none(
         [await preview_of_question_as_search_hit(q) for q in questions]
     )
diff --git a/chafan_core/app/api/api_v1/endpoints/sites.py b/chafan_core/app/api/api_v1/endpoints/sites.py
index af0b7f4..37e7a6d 100644
--- a/chafan_core/app/api/api_v1/endpoints/sites.py
+++ b/chafan_core/app/api/api_v1/endpoints/sites.py
@@ -1,13 +1,13 @@
 import datetime
+import logging
 from typing import Any, Dict, List, Optional, Union
 
 from fastapi import APIRouter, Depends
 from fastapi.param_functions import Query
 from sqlalchemy.orm import Session
-import chafan_core.app.responders as responders
 
+import chafan_core.app.responders as responders
 
-import logging
 logger = logging.getLogger(__name__)
 
 
@@ -27,7 +27,6 @@
     EventInternal,
 )
 from chafan_core.app.user_permission import user_in_site
-
 from chafan_core.utils.base import EntityType, HTTPException_, filter_not_none, unwrap
 from chafan_core.utils.constants import MAX_SITE_QUESTIONS_PAGINATION_LIMIT
 
@@ -104,9 +103,9 @@ def create_site(
     category_topic_id: Optional[int] = None
     if site_in.category_topic_uuid:
         raise HTTPException_(
-                status_code=400,
-                detail="Attach a category topic id when creating a site is disabled.",
-            )
+            status_code=400,
+            detail="Attach a category topic id when creating a site is disabled.",
+        )
     utc_now = datetime.datetime.now(tz=datetime.timezone.utc)
     super_user = crud.user.get_superuser(db)
     new_site = cached_layer.create_site(
@@ -194,18 +193,19 @@ def config_site(
 
 from chafan_core.app.common import OperationType
 
+
 @router.get("/{subdomain}", response_model=schemas.Site)
 async def get_site_info(
     *,
     cached_layer: CachedLayer = Depends(deps.get_cached_layer),
     current_user_id: Optional[int] = Depends(deps.try_get_current_user_id),
-    subdomain: str
+    subdomain: str,
 ) -> Any:
     """
     Get a site's basic info.
     """
     logger.info(f"user {current_user_id} requesting site {subdomain}")
-    #site_data = cached_layer.get_site_info(subdomain=subdomain)
+    # site_data = cached_layer.get_site_info(subdomain=subdomain)
     db = cached_layer.get_db()
     site = crud.site.get_by_subdomain(db, subdomain=subdomain)
 
@@ -216,7 +216,7 @@ async def get_site_info(
         )
     if not user_in_site(db, site, current_user_id, OperationType.ReadSite):
         logger.info("user has no permission")
-        #TODO add audit
+        # TODO add audit
         raise HTTPException_(
             status_code=404,
             detail="The site with this id does not exist in the system",
@@ -255,9 +255,7 @@ def get_site_questions(
         )
     max_questions = settings.API_LIMIT_SITES_GET_QUESTIONS_LIMIT
     limit = min(limit, max_questions)
-    questions = crud.site.get_multi_questions(
-        db, db_obj=site, skip=skip, limit=limit
-    )
+    questions = crud.site.get_multi_questions(db, db_obj=site, skip=skip, limit=limit)
     return filter_not_none(
         [cached_layer.materializer.preview_of_question(q) for q in questions]
     )
@@ -448,7 +446,4 @@ def get_related(
                 crud.site.get(cached_layer.get_db(), site_id)
             )
 
-    return [
-        cached_layer.site_schema_from_orm(s)
-        for s in related_sites.values()
-    ]
+    return [cached_layer.site_schema_from_orm(s) for s in related_sites.values()]
diff --git a/chafan_core/app/api/api_v1/endpoints/submissions.py b/chafan_core/app/api/api_v1/endpoints/submissions.py
index 2683916..f4bbea6 100644
--- a/chafan_core/app/api/api_v1/endpoints/submissions.py
+++ b/chafan_core/app/api/api_v1/endpoints/submissions.py
@@ -1,11 +1,11 @@
 import datetime
+import logging
 from typing import Any, List, Optional, Union
 
 from fastapi import APIRouter, Depends, Request
 from fastapi.encoders import jsonable_encoder
 from sqlalchemy.orm import Session
 
-import logging
 logger = logging.getLogger(__name__)
 
 
diff --git a/chafan_core/app/api/api_v1/endpoints/ws.py b/chafan_core/app/api/api_v1/endpoints/ws.py
index 689c828..bb5990e 100644
--- a/chafan_core/app/api/api_v1/endpoints/ws.py
+++ b/chafan_core/app/api/api_v1/endpoints/ws.py
@@ -1,4 +1,5 @@
 import asyncio
+import logging
 import secrets
 from datetime import timedelta
 from typing import Any
@@ -7,13 +8,11 @@
 from fastapi.websockets import WebSocket, WebSocketDisconnect
 from websockets.exceptions import ConnectionClosedError, ConnectionClosedOK
 
-
 from chafan_core.app import schemas, ws_connections
 from chafan_core.app.api import deps
 from chafan_core.app.common import get_redis_cli
 from chafan_core.app.mq import get_ws_queue_for_user
 
-import logging
 logger = logging.getLogger(__name__)
 
 router = APIRouter()
@@ -33,7 +32,7 @@ async def get_ws_token(
     return schemas.WsAuthResponse(token=token)
 
 
-async def _read_message_queue(redis, queue_name:str):
+async def _read_message_queue(redis, queue_name: str):
     item = redis.lpop(queue_name)
     return item
 
diff --git a/chafan_core/app/api/health.py b/chafan_core/app/api/health.py
index b764936..34fb9c1 100644
--- a/chafan_core/app/api/health.py
+++ b/chafan_core/app/api/health.py
@@ -11,6 +11,7 @@
 def get_health() -> Any:
     return schemas.HealthResponse()
 
+
 @router.get("/health", response_model=schemas.HealthResponse)
 def get_health_test() -> Any:
     return schemas.HealthResponse()
diff --git a/chafan_core/app/cached_layer.py b/chafan_core/app/cached_layer.py
index 0e4e55d..c27a86e 100644
--- a/chafan_core/app/cached_layer.py
+++ b/chafan_core/app/cached_layer.py
@@ -1,36 +1,33 @@
 import asyncio
 import datetime
 import json
+import logging
 import random
 from collections import Counter
 from typing import Any, Callable, Dict, List, Optional, Set, Tuple, TypeVar, Union
 
-
+import fastapi
 import redis
 import requests
 import sentry_sdk
-import fastapi
 from fastapi.encoders import jsonable_encoder
 from pydantic import TypeAdapter
 from sqlalchemy.orm.session import Session
 
-from chafan_core.app.feed import get_activities_v2, get_random_activities
-from chafan_core.app.config import settings
+import chafan_core.app.responders as responders
 from chafan_core.app import crud, models, schemas
-from chafan_core.app.common import is_dev
-from chafan_core.app.common import client_ip
-from chafan_core.app.user_permission import (
-        article_read_allowed,
-        question_read_allowed,
-        )
+from chafan_core.app.common import client_ip, is_dev
+from chafan_core.app.config import settings
 from chafan_core.app.data_broker import DataBroker
+from chafan_core.app.feed import get_activities_v2, get_random_activities
+
 # TODO 2025-07-20 CachedLayer should not dependent on Materializer
 from chafan_core.app.materialize import Materializer
-import chafan_core.app.responders as responders
 from chafan_core.app.recs.ranking import rank_site_profiles, rank_submissions
 from chafan_core.app.schemas.answer import AnswerPreview, AnswerPreviewForVisitor
 from chafan_core.app.schemas.preview import UserPreview
 from chafan_core.app.schemas.site import SiteCreate
+from chafan_core.app.user_permission import article_read_allowed, question_read_allowed
 from chafan_core.utils.base import (
     ContentVisibility,
     EntityType,
@@ -39,7 +36,6 @@
     unwrap,
 )
 
-import logging
 logger = logging.getLogger(__name__)
 
 MatrixType = Dict[int, List[int]]
@@ -79,6 +75,7 @@
 
 BUMP_VIEW_COUNT_QUEUE_CACHE_KEY = "chafan:bump-view-count"
 
+
 class CachedLayer(object):
     def __init__(self, broker: DataBroker, principal_id: Optional[int] = None) -> None:
         self.broker = broker
@@ -89,12 +86,10 @@ def __init__(self, broker: DataBroker, principal_id: Optional[int] = None) -> No
         self._follow_follow_fanout: Optional[WeightedMatrixType] = None
         self._entity_similarity_matrices: Dict[EntityType, MatrixType] = {}
 
-    def bump_view(self, object_type: str, obj_id:int):
+    def bump_view(self, object_type: str, obj_id: int):
         obj_str = f"{object_type}:{obj_id}"
         self.get_redis().rpush(BUMP_VIEW_COUNT_QUEUE_CACHE_KEY, obj_str)
 
-
-
     def unwrapped_principal_id(self) -> int:
         return unwrap(self.principal_id)
 
@@ -163,45 +158,57 @@ def _get_cached_non_empty(
             )
         return data
 
-    def question_schema_from_orm(self, question: models.Question) -> Optional[schemas.Question]:
+    def question_schema_from_orm(
+        self, question: models.Question
+    ) -> Optional[schemas.Question]:
         logger.info("called cached.layer for question " + str(question))
         return responders.question.question_schema_from_orm(
-                self.broker, self.principal_id, question, self)
+            self.broker, self.principal_id, question, self
+        )
 
-    def submission_schema_from_orm(self, submission: models.Submission) :
-        logger.info("called cached layer for submission to wrap submission " + str(submission.id))
-        return responders.submission.submission_schema_from_orm(
-                self, submission)
+    def submission_schema_from_orm(self, submission: models.Submission):
+        logger.info(
+            "called cached layer for submission to wrap submission "
+            + str(submission.id)
+        )
+        return responders.submission.submission_schema_from_orm(self, submission)
 
     def article_schema_from_orm(self, article: models.Article):
         logger.info("called cached layer for article")
         return responders.article.article_schema_from_orm(
-                self, article, self.principal_id)
-
+            self, article, self.principal_id
+        )
 
-    def get_article_by_uuid(self, uuid: str, current_user_id:Optional[int]=None) -> models.Article:
+    def get_article_by_uuid(
+        self, uuid: str, current_user_id: Optional[int] = None
+    ) -> models.Article:
         db = self.get_db()
         article = crud.article.get_by_uuid(db, uuid=uuid)
         if not article_read_allowed(db, article, current_user_id):
             return None
         return article
 
-    def get_article_by_id(self, article_id:int, current_user_id:Optional[int]=None) -> models.Article:
+    def get_article_by_id(
+        self, article_id: int, current_user_id: Optional[int] = None
+    ) -> models.Article:
         article = crud.article.get(self.get_db(), id=article_id)
         if not article_read_allowed(self.get_db(), article, current_user_id):
             return None
         return article
 
-    def get_answer_by_id(self, answer_id:int):
+    def get_answer_by_id(self, answer_id: int):
         db = self.get_db()
         answer = crud.answer.get_by_id(db, uid=answer_id)
         return answer
 
     def answer_schema_from_orm(self, answer):
-        answer_data = responders.answer.answer_schema_from_orm(self, answer, self.principal_id)
+        answer_data = responders.answer.answer_schema_from_orm(
+            self, answer, self.principal_id
+        )
         if answer_data:
             answer_data.upvotes = self.get_answer_upvotes(answer.uuid)
         return answer_data
+
     def get_answer(
         self, uuid: str
     ) -> Optional[Union[schemas.Answer, schemas.AnswerForVisitor]]:
@@ -209,7 +216,9 @@ def get_answer(
         answer = crud.answer.get_by_uuid(db, uuid=uuid)
         if answer is None:
             return None
-        answer_data = responders.answer.answer_schema_from_orm(self, answer, self.principal_id)
+        answer_data = responders.answer.answer_schema_from_orm(
+            self, answer, self.principal_id
+        )
         if answer_data:
             answer_data.upvotes = self.get_answer_upvotes(uuid)
         return answer_data
@@ -352,7 +361,9 @@ def get_site_submissions_for_user(
             )
         else:
             # FIXME: compute rank async
-            logger.error("TODO submission list for visitors are turned off due to `desc` missing") #2025-Jul-30
+            logger.error(
+                "TODO submission list for visitors are turned off due to `desc` missing"
+            )  # 2025-Jul-30
             submissions = []
             # submissions = rank_submissions(
             #     filter_not_none(
@@ -401,7 +412,8 @@ def get_site_maps(self) -> schemas.site.SiteMaps:
             sites_without_topics=sites_without_topics,
         )
         redis_cli.set(
-            SITEMAPS_CACHE_KEY, data.json(), ex=settings.CACHE_SITEMAP_VALID_HOURS)
+            SITEMAPS_CACHE_KEY, data.json(), ex=settings.CACHE_SITEMAP_VALID_HOURS
+        )
         return data
 
     def create_site(
@@ -597,22 +609,25 @@ def preview_of_user(self, user: models.User) -> schemas.UserPreview:
         user_preview.follows = self.get_user_follows(user)
         return user_preview
 
-    def create_audit(self, api:str, request: Optional[fastapi.Request]=None,
-                     user_id:Optional[int]=None,
-                     request_info:dict=dict()):
+    def create_audit(
+        self,
+        api: str,
+        request: Optional[fastapi.Request] = None,
+        user_id: Optional[int] = None,
+        request_info: dict = dict(),
+    ):
         ip = "0.0.0.0"
         if request is not None:
             ip = client_ip(request)
         if user_id is None:
             user_id = 1
         crud.audit_log.create_with_user(
-        self.get_db(),
-        ipaddr=ip,
-        user_id=user_id,
-        api=api,
-        request_info=request_info
-    )
-
+            self.get_db(),
+            ipaddr=ip,
+            user_id=user_id,
+            api=api,
+            request_info=request_info,
+        )
 
     def update_notification(
         self,
@@ -657,7 +672,9 @@ def get_question_model_http(self, uuid: str) -> models.Question:
             )
         return question
 
-    def get_question_by_uuid(self, uuid: str, current_user_id:Optional[int]=None) -> models.Question:
+    def get_question_by_uuid(
+        self, uuid: str, current_user_id: Optional[int] = None
+    ) -> models.Question:
         question = crud.question.get_by_uuid(self.get_db(), uuid=uuid)
         if question is None:
             return None
@@ -767,9 +784,11 @@ def get_daily_invitation_link(self) -> schemas.InvitationLink:
         db = self.get_db()
 
         def f() -> int:
-            return asyncio.run(crud.invitation_link.create_invitation(
-                db, invited_to_site_id=None, inviter=crud.user.get_superuser(db)
-            )).id
+            return asyncio.run(
+                crud.invitation_link.create_invitation(
+                    db, invited_to_site_id=None, inviter=crud.user.get_superuser(db)
+                )
+            ).id
 
         cached_id = self._get_cached(
             key=DAILY_INVITATION_LINK_ID_CACHE_KEY,
@@ -833,26 +852,27 @@ def incr(timestamp: datetime.datetime, action: str) -> None:
         return ret
 
     async def get_user_activity(
-            self,
-            current_user_id: int,
-            before_activity_id:Optional[int],
-            limit:int,
-            random:bool,
-            subject_user_uuid: Optional[str]):
+        self,
+        current_user_id: int,
+        before_activity_id: Optional[int],
+        limit: int,
+        random: bool,
+        subject_user_uuid: Optional[str],
+    ):
         logger.info(f"cached_layer get_user_activity for {current_user_id}")
         redis = self.get_redis()
         key = f"chafan:feed-cache:user:{current_user_id}:before_activity_id={before_activity_id}&limit={limit}&subject_user_uuid={subject_user_uuid}"
         value = redis.get(key)
         value = None
-        if value: # TODO redis cache is broken for now 2025-08-04
+        if value:  # TODO redis cache is broken for now 2025-08-04
             return None
-#            return _update_feed_seq(
-#                cached_layer,
-#                schemas.FeedSequence.model_validate_json(value),
-#                full_answers=full_answers,
-#            )
+        #            return _update_feed_seq(
+        #                cached_layer,
+        #                schemas.FeedSequence.model_validate_json(value),
+        #                full_answers=full_answers,
+        #            )
         activities = await get_activities_v2(
-            cached_layer = self,
+            cached_layer=self,
             before_activity_id=before_activity_id,
             limit=limit,
             receiver_user_id=current_user_id,
@@ -864,11 +884,7 @@ async def get_user_activity(
         if random:
             tolerate_order = True
 
-        if (
-            tolerate_order
-            and insufficient > 0
-            and subject_user_uuid is None
-        ):
+        if tolerate_order and insufficient > 0 and subject_user_uuid is None:
             random = True
             extra_activities = get_random_activities(
                 receiver_user_id=current_user_id,
@@ -878,15 +894,13 @@ async def get_user_activity(
             activities.extend(extra_activities)
 
         redis.delete(key)
-        redis.set( # TODO fixme
+        redis.set(  # TODO fixme
             key,
             json.dumps(jsonable_encoder(1)),
             ex=datetime.timedelta(minutes=1),
         )
         return activities
 
-
-
     def get_user_contributions(self, user: models.User) -> UserContributions:
         if user.id in self._user_contributions_map:
             return self._user_contributions_map[user.id]
@@ -1000,10 +1014,8 @@ def remove_site_profile(self, *, owner_id: int, site_id: int) -> None:
         )
         self.get_redis().delete(USER_SITE_PROFILES.format(user_id=owner_id))
 
-
     # TODO maybe this is not the best place to put it  2025-Jul-06
-    async def try_consume_invitation_link_by_uuid(
-            self, invitation_uuid:str) -> bool:
+    async def try_consume_invitation_link_by_uuid(self, invitation_uuid: str) -> bool:
         logger.info(f"Consumed invitation link uuid=${invitation_uuid}")
         db = self.get_db()
         invitation_link = crud.invitation_link.get_by_uuid(db, uuid=invitation_uuid)
diff --git a/chafan_core/app/common.py b/chafan_core/app/common.py
index d1aa80b..8ec9764 100644
--- a/chafan_core/app/common.py
+++ b/chafan_core/app/common.py
@@ -67,7 +67,7 @@ def run_dramatiq_task(task: Any, *arg: Any, **kwargs: Any) -> None:
     # TODO This function should be moved out of common.py, to task.py
     print("run_dramatiq_task")
     print(arg)
-    #task(*arg, **kwargs)
+    # task(*arg, **kwargs)
     task.send(*arg, **kwargs)
 
 
@@ -75,7 +75,6 @@ def from_now(utc: datetime.datetime, locale: str) -> str:
     return arrow.get(utc).humanize(locale=locale)
 
 
-
 def html2plaintext(t: str) -> str:
     h = HTML2Text()
     h.ignore_links = True
@@ -113,12 +112,18 @@ def html2plaintext(t: str) -> str:
     "answer_question": ("{{who}}回答了你的问题", "「{{question}}」：「{{answer}}」"),
     "answer_update": ("{{who}}更新了回答", "「{{question}}」：「{{answer}}」"),
     "comment_question": ("{{who}}评论了你的问题", "「{{question}}」：「{{comment}}」"),
-    "comment_submission": ("{{who}}评论了你的分享", "「{{submission}}」：「{{comment}}」"),
+    "comment_submission": (
+        "{{who}}评论了你的分享",
+        "「{{submission}}」：「{{comment}}」",
+    ),
     "reply_comment": ("{{who}}回复了你的评论", "「{{parent_comment}}」：「{{reply}}」"),
     "invite_answer": ("{{who}}邀请你回答问题", "「{{question}}」"),
     "invite_join_site": ("{{who}}邀请你加入圈子", "「{{site}}」"),
     "apply_join_site": ("{{who}}申请加入圈子", "「{{site}}」"),
-    "comment_answer": ("{{who}}评论了你对问题的回答", "「{{question}}」：「{{comment}}」"),
+    "comment_answer": (
+        "{{who}}评论了你对问题的回答",
+        "「{{question}}」：「{{comment}}」",
+    ),
     "comment_article": ("{{who}}评论了你的文章", "「{{article}}」：「{{comment}}」"),
     "upvote_answer": ("{{who}}赞了你对问题的回答", "「{{question}}」：「{{answer}}」"),
     "follow_user": ("{{who}}关注了你", ""),
diff --git a/chafan_core/app/config.py b/chafan_core/app/config.py
index 81cfe02..3f2b8be 100644
--- a/chafan_core/app/config.py
+++ b/chafan_core/app/config.py
@@ -1,10 +1,10 @@
 from typing import Literal, Optional
 
 import sentry_sdk
-from sentry_sdk.integrations.dramatiq import DramatiqIntegration
 from pydantic import AnyHttpUrl
 from pydantic.types import SecretStr
 from pydantic_settings import BaseSettings
+from sentry_sdk.integrations.dramatiq import DramatiqIntegration
 from sentry_sdk.integrations.redis import RedisIntegration
 from sentry_sdk.integrations.sqlalchemy import SqlalchemyIntegration
 
@@ -26,7 +26,6 @@ class Settings(BaseSettings):
 
     ENABLE_CAPTCHA: bool = False
 
-
     EMAILS_ENABLED: bool = False
     EMAIL_SMTP_HOST: Optional[str] = None
     EMAIL_SMTP_PORT: Optional[int] = None
@@ -34,7 +33,6 @@ class Settings(BaseSettings):
     EMAIL_SMTP_LOGIN_PASSWORD: Optional[str] = None
     EMAIL_TEMPLATES_DIR: str = "chafan_core/app/email-templates/build"
 
-
     AWS_ACCESS_KEY_ID: Optional[str] = None
     AWS_SECRET_ACCESS_KEY: Optional[str] = None
     AWS_REGION: Optional[str] = None
@@ -82,7 +80,7 @@ class Config:
         case_sensitive = True
 
     ### Limit settings
-    VISITORS_READ_ARTICLE_LIMIT: int = 100 #previous 5
+    VISITORS_READ_ARTICLE_LIMIT: int = 100  # previous 5
     LIMIT_RSS_RESPONSE_ITEMS: int = 200
     LIMIT_RSS_ADMIN_TOOL_FULL_SITE_ITEMS: int = 500
 
@@ -103,7 +101,6 @@ class Config:
     CREATE_SITE_FORCE_NEED_APPROVAL: bool = True
 
 
-
 setting_keys = set(Settings.schema()["properties"].keys())
 
 settings = Settings()
diff --git a/chafan_core/app/crud/crud_invitation.py b/chafan_core/app/crud/crud_invitation.py
index 95cec20..a1d5f03 100644
--- a/chafan_core/app/crud/crud_invitation.py
+++ b/chafan_core/app/crud/crud_invitation.py
@@ -42,4 +42,5 @@ def create_invitation(
         db.refresh(db_obj)
         return db_obj
 
+
 invitation = CRUDComment()
diff --git a/chafan_core/app/crud/crud_invitation_link.py b/chafan_core/app/crud/crud_invitation_link.py
index 86ae620..432c1de 100644
--- a/chafan_core/app/crud/crud_invitation_link.py
+++ b/chafan_core/app/crud/crud_invitation_link.py
@@ -1,4 +1,5 @@
 import datetime
+import logging
 from typing import Optional
 
 from sqlalchemy.orm import Session
@@ -11,7 +12,6 @@
     InvitationLinkUpdate,
 )
 
-import logging
 logger = logging.getLogger(__name__)
 
 
@@ -40,5 +40,4 @@ async def create_invitation(
         return db_obj
 
 
-
 invitation_link = CRUDInvitationLink(InvitationLink)
diff --git a/chafan_core/app/crud/crud_user.py b/chafan_core/app/crud/crud_user.py
index d5cf97b..f55b820 100644
--- a/chafan_core/app/crud/crud_user.py
+++ b/chafan_core/app/crud/crud_user.py
@@ -1,7 +1,7 @@
 import datetime
+import logging
 from typing import Any, Dict, List, Optional, Union
 
-import logging
 logger = logging.getLogger(__name__)
 
 from pydantic.types import SecretStr
@@ -63,7 +63,7 @@ def get_by_handle(self, db: Session, *, handle: str) -> Optional[User]:
     def get_all_active_users(self, db: Session) -> List[User]:
         return db.query(User).filter_by(is_active=True).all()
 
-# 2025-Dec-11 This function is synchronized for now. We define it as async to facilitate further improvement
+    # 2025-Dec-11 This function is synchronized for now. We define it as async to facilitate further improvement
     async def create(self, db: Session, *, obj_in: UserCreate) -> User:
         if obj_in.handle is None:
             handle = StrippedNonEmptyBasicStr(
diff --git a/chafan_core/app/email/mock_client.py b/chafan_core/app/email/mock_client.py
index 311f3ca..03dc7a1 100644
--- a/chafan_core/app/email/mock_client.py
+++ b/chafan_core/app/email/mock_client.py
@@ -2,26 +2,30 @@
 from email.mime.multipart import MIMEMultipart
 from email.mime.text import MIMEText
 
+
 class MockEmailClient(object):
     smtp = None
+
     def __init__(self):
         pass
-    def build_email(self, from_addr, to_addrs, subject, html_body)->EmailMessage:
+
+    def build_email(self, from_addr, to_addrs, subject, html_body) -> EmailMessage:
         msg = MIMEMultipart("alternative")
-        msg['Subject'] = subject
-        msg['From'] = from_addr
-        msg['To'] = to_addrs # TODO not tested if it supports more emails 2025-06-25
+        msg["Subject"] = subject
+        msg["From"] = from_addr
+        msg["To"] = to_addrs  # TODO not tested if it supports more emails 2025-06-25
         part1 = MIMEText("Thanks for using cha.fan", "plain")
         part2 = MIMEText(html_body, "html")
         msg.attach(part1)
         msg.attach(part2)
         return msg
+
     def login(self):
         self.smtp = "Mock_Smtp"
+
     def quit(self):
         self.smtp = None
 
-
     def send_email(self, from_addr, to_addr, subject, text):
         print("Dry-run: send email")
         if self.smtp is None:
diff --git a/chafan_core/app/email/smtp_client.py b/chafan_core/app/email/smtp_client.py
index 0189238..034d3b8 100644
--- a/chafan_core/app/email/smtp_client.py
+++ b/chafan_core/app/email/smtp_client.py
@@ -1,11 +1,13 @@
-from chafan_core.app.config import settings
-from chafan_core.app.email.mock_client import MockEmailClient
+import logging
 import smtplib
 import ssl
 
-import logging
+from chafan_core.app.config import settings
+from chafan_core.app.email.mock_client import MockEmailClient
+
 logger = logging.getLogger(__name__)
 
+
 class SmtpClient(MockEmailClient):
     smtp = None
     host = None
@@ -13,6 +15,7 @@ class SmtpClient(MockEmailClient):
     username = None
     password = None
     debug = False
+
     def login(self):
         server = smtplib.SMTP(self.host, self.port, timeout=30)
         if self.debug:
@@ -23,6 +26,7 @@ def login(self):
         server.login(self.username, self.password)
         server.ehlo()
         self.smtp = server
+
     def __init__(self, debug=False):
         self.host = settings.EMAIL_SMTP_HOST
         self.port = settings.EMAIL_SMTP_PORT
@@ -46,5 +50,3 @@ def quit(self):
             return
         self.smtp.quit()
         self.smtp = None
-
-
diff --git a/chafan_core/app/email/utils.py b/chafan_core/app/email/utils.py
index dc5f474..5547019 100644
--- a/chafan_core/app/email/utils.py
+++ b/chafan_core/app/email/utils.py
@@ -1,37 +1,38 @@
-from typing import Dict, Any
-
-from jinja2 import Template,StrictUndefined
-
+import logging
+from typing import Any, Dict
 from urllib.parse import urlencode
 
+from jinja2 import StrictUndefined, Template
+
 from chafan_core.app.config import settings
-from chafan_core.app.email.smtp_client import SmtpClient
 from chafan_core.app.email.mock_client import MockEmailClient
+from chafan_core.app.email.smtp_client import SmtpClient
 
-import logging
 logger = logging.getLogger(__name__)
 
 
-
-def apply_email_template(template_name:str,
-                         environment: Dict[str, Any] = {},
-                         allow_undefined:bool = False) -> str:
-    html_template_path = "{}/{}.html".format(settings.EMAIL_TEMPLATES_DIR, template_name)
+def apply_email_template(
+    template_name: str, environment: Dict[str, Any] = {}, allow_undefined: bool = False
+) -> str:
+    html_template_path = "{}/{}.html".format(
+        settings.EMAIL_TEMPLATES_DIR, template_name
+    )
     with open(html_template_path) as f:
         template_str = f.read()
     if allow_undefined:
         jinja = Template(template_str)
     else:
-        jinja = Template(template_str,undefined=StrictUndefined)
+        jinja = Template(template_str, undefined=StrictUndefined)
     return jinja.render(environment)
 
+
 async def send_verification_code_email(email: str, code: str) -> None:
     project_name = settings.PROJECT_NAME
     subject = f"{project_name} - 验证码 {code}"
     server_host = str(settings.SERVER_HOST).strip("/")
     params = {"email": email, "code": code}
     link = f"{server_host}/signup?{urlencode(params)}"
-    environment={
+    environment = {
         "project_name": settings.PROJECT_NAME,
         "email": email,
         "valid_hours": settings.EMAIL_SIGNUP_CODE_EXPIRE_HOURS,
@@ -45,17 +46,18 @@ async def send_verification_code_email(email: str, code: str) -> None:
         html_body=html_body,
     )
 
+
 async def send_reset_password_email(email: str, token: str) -> None:
     project_name = settings.PROJECT_NAME
     subject = f"{project_name} - 密码重置 {email}"
     server_host = str(settings.SERVER_HOST).strip("/")
     link = f"{server_host}/reset-password?token={token}"
-    environment={
-            "project_name": settings.PROJECT_NAME,
-            "username": email,
-            "email": email,
-            "valid_hours": settings.EMAIL_RESET_TOKEN_EXPIRE_HOURS,
-            "link": link,
+    environment = {
+        "project_name": settings.PROJECT_NAME,
+        "username": email,
+        "email": email,
+        "valid_hours": settings.EMAIL_RESET_TOKEN_EXPIRE_HOURS,
+        "link": link,
     }
     html_body = apply_email_template("reset_password", environment)
     logger.info(f"Send reset password email to {email}")
@@ -65,11 +67,12 @@ async def send_reset_password_email(email: str, token: str) -> None:
         html_body=html_body,
     )
 
+
 async def send_email(
     email_to: str,
     subject: str = "",
     html_body: str = "",
-    ):
+):
     # TODO I should move it out of send_email, but use dependency injection. 2025-Jul-04
     if settings.EMAILS_ENABLED:
         client = SmtpClient()
@@ -79,4 +82,3 @@ async def send_email(
     client.login()
     client.send_email("admin@cha.fan", email_to, subject, html_body)
     client.quit()
-
diff --git a/chafan_core/app/email_utils.py b/chafan_core/app/email_utils.py
index 96dcd15..68a38b7 100644
--- a/chafan_core/app/email_utils.py
+++ b/chafan_core/app/email_utils.py
@@ -4,13 +4,15 @@
 import tempfile
 from pathlib import Path
 from typing import Any, Dict, List
-
-#from emails.template import JinjaTemplate  # type: ignore
+from urllib.parse import urlencode
 
 from chafan_core.app import schemas
 from chafan_core.app.common import from_now, is_dev, render_notif_content
 from chafan_core.app.config import settings
 
+# from emails.template import JinjaTemplate  # type: ignore
+
+
 # TODO this file should be moved into chafan_core/app/email_util
 
 
@@ -24,9 +26,6 @@ def send_email(
     return
 
 
-
-
-
 def send_notification_email(
     email: str,
     notifications: List[schemas.Notification],
@@ -75,7 +74,6 @@ def send_verification_code_phone_number(_phone_number: str, _code: str) -> None:
     raise NotImplementedError("No longer support SMS")
 
 
-
 def send_new_account_email(email_to: str, username: str, password: str) -> None:
     project_name = settings.PROJECT_NAME
     subject = f"{project_name} - New account for user {username}"
diff --git a/chafan_core/app/feed.py b/chafan_core/app/feed.py
index b4404c4..9f60660 100644
--- a/chafan_core/app/feed.py
+++ b/chafan_core/app/feed.py
@@ -1,9 +1,9 @@
-from typing import Dict, List, NamedTuple, Optional, Set, Any
-import sentry_sdk
 import json
+from typing import TYPE_CHECKING, Any, Dict, List, NamedTuple, Optional, Set
+
+import sentry_sdk
 from sqlalchemy.orm import Session
 
-from chafan_core.db.base_class import Base as BaseCrudModel
 from chafan_core.app import crud, models, schemas
 from chafan_core.app.data_broker import DataBroker
 from chafan_core.app.materialize import Materializer
@@ -27,14 +27,15 @@
     UpvoteSubmissionInternal,
 )
 from chafan_core.app.task_utils import execute_with_broker, execute_with_db
+from chafan_core.db.base_class import Base as BaseCrudModel
 from chafan_core.db.session import ReadSessionLocal, SessionLocal
 from chafan_core.utils.base import map_, unwrap
 
-from typing import TYPE_CHECKING
 if TYPE_CHECKING:
     from chafan_core.app.cached_layer import CachedLayer
 
 import logging
+
 logger = logging.getLogger(__name__)
 
 
@@ -43,9 +44,9 @@ class ActivityDistributionInfo(NamedTuple):
     subject_user_uuid: Optional[str]
 
 
-
-
-def lookup_activity_receiver_list(broker: DataBroker, activity: models.Activity)->ActivityDistributionInfo:
+def lookup_activity_receiver_list(
+    broker: DataBroker, activity: models.Activity
+) -> ActivityDistributionInfo:
     try:
         event = EventInternal.parse_raw(activity.event_json)
     except Exception:
@@ -66,16 +67,19 @@ def lookup_activity_receiver_list(broker: DataBroker, activity: models.Activity)
         receiver_ids=set(receivers.keys()), subject_user_uuid=subject_user_uuid
     )
 
-def new_activity_into_feed(broker: DataBroker, activity:models.Activity) -> None:
-    logger.info("generating feed for activity "  + str(activity.id))
+
+def new_activity_into_feed(broker: DataBroker, activity: models.Activity) -> None:
+    logger.info("generating feed for activity " + str(activity.id))
     assert activity.id is not None
     assert isinstance(activity.id, int)
     receivers = lookup_activity_receiver_list(broker, activity)
     write_db = broker.get_db()
     for receiver_id in receivers.receiver_ids:
-        feed = write_db.query(models.Feed)  \
-            .filter_by(receiver_id=receiver_id, activity_id=activity.id) \
+        feed = (
+            write_db.query(models.Feed)
+            .filter_by(receiver_id=receiver_id, activity_id=activity.id)
             .first()
+        )
         if feed is None:
             write_db.add(
                 models.Feed(
@@ -87,7 +91,6 @@ def new_activity_into_feed(broker: DataBroker, activity:models.Activity) -> None
             write_db.commit()
 
 
-
 # TODO This is the v1 api. To be removed. 2025-07-19
 def get_activity_dist_info(
     read_db: Session, activity: models.Activity
@@ -234,6 +237,7 @@ def materialize_activity(
             return activity_data
     return None
 
+
 # This is not good OOP practice, but doing it here can avoid making event.py too complex. 2025-Aug-13
 def retrieve_content(event: EventInternal, cached_layer) -> Optional[BaseCrudModel]:
     assert isinstance(event, EventInternal)
@@ -246,8 +250,7 @@ def retrieve_content(event: EventInternal, cached_layer) -> Optional[BaseCrudMod
         return question
     if isinstance(c, AnswerQuestionInternal):
         answer = cached_layer.get_answer_by_id(c.answer_id)
-        if (answer.is_hidden_by_moderator) or \
-            (not answer.is_published):
+        if (answer.is_hidden_by_moderator) or (not answer.is_published):
             logger.warning("Skip a hidden answer: " + str(answer))
             return None
         return answer
@@ -256,20 +259,20 @@ def retrieve_content(event: EventInternal, cached_layer) -> Optional[BaseCrudMod
         return art
 
     logger.error(f"Not supported event type: {event}")
-    return None #TODO throw exception
+    return None  # TODO throw exception
+
 
 async def get_content_from_eventjson(
-        cached_layer: "CachedLayer",
-        event_json: str) -> Optional[BaseCrudModel]:
+    cached_layer: "CachedLayer", event_json: str
+) -> Optional[BaseCrudModel]:
     event = EventInternal.parse_raw(event_json)
     content = retrieve_content(event, cached_layer)
     return content
 
+
 async def get_site_activities(
-    cached_layer: "CachedLayer",
-    site,
-    limit: int,
-    all_sites = False) -> List[BaseCrudModel]:
+    cached_layer: "CachedLayer", site, limit: int, all_sites=False
+) -> List[BaseCrudModel]:
     db = cached_layer.get_db()
     if (site is None) and (not all_sites):
         raise ValueError("site not found ")
@@ -287,6 +290,7 @@ async def get_site_activities(
             activities.append(obj)
     return activities
 
+
 async def get_activities_v2(
     *,
     cached_layer: "CachedLayer",
@@ -306,11 +310,13 @@ async def get_activities_v2(
         feeds = feeds.filter_by(receiver_id=receiver_user_id)
     if before_activity_id:
         feeds = feeds.filter(models.Feed.activity_id < before_activity_id)
-    feeds = feeds.order_by(models.Feed.activity_id.desc()).limit(limit * 2) # Do we have better idea?
+    feeds = feeds.order_by(models.Feed.activity_id.desc()).limit(
+        limit * 2
+    )  # Do we have better idea?
     activities = []
     activity_ids = set()
     for feed in feeds:
-        feed_settings = None # TODO not supported yed
+        feed_settings = None  # TODO not supported yed
         if feed.activity_id in activity_ids:
             continue
         activity = materialize_activity(
@@ -325,7 +331,7 @@ async def get_activities_v2(
     return activities
 
 
-def get_activities( # TODO to remove this function
+def get_activities(  # TODO to remove this function
     *,
     before_activity_id: Optional[int],
     limit: int,
@@ -408,6 +414,3 @@ def runnable(broker: DataBroker) -> List[schemas.Activity]:
 
 
 CACHE_REWIND_SIZE = 1000
-
-
-
diff --git a/chafan_core/app/main.py b/chafan_core/app/main.py
index da0e9c2..9870ded 100644
--- a/chafan_core/app/main.py
+++ b/chafan_core/app/main.py
@@ -1,7 +1,7 @@
-from typing import Any, MutableMapping, Optional
-
 import logging
 import logging.config
+from typing import Any, MutableMapping, Optional
+
 log_config = {
     "version": 1,
     "disable_existing_loggers": False,
@@ -23,7 +23,7 @@
         "app": {"handlers": ["console"], "level": "INFO", "propagate": False},
     },
     "root": {"handlers": ["console"], "level": "INFO"},
-} # https://betterstack.com/community/guides/logging/logging-with-fastapi/#configuring-your-logging-system
+}  # https://betterstack.com/community/guides/logging/logging-with-fastapi/#configuring-your-logging-system
 logging.config.dictConfig(log_config)
 logger = logging.getLogger(__name__)
 
@@ -32,10 +32,10 @@
 from apscheduler.triggers.interval import IntervalTrigger
 
 scheduler = BackgroundScheduler()
-import sentry_sdk
-import uvicorn
 import fastapi
+import sentry_sdk
 import starlette
+import uvicorn
 from fastapi import FastAPI
 from fastapi.exception_handlers import request_validation_exception_handler
 from fastapi.exceptions import RequestValidationError
@@ -50,23 +50,19 @@
 from chafan_core.app.config import settings
 from chafan_core.app.limiter import limiter
 from chafan_core.app.limiter_middleware import SlowAPIMiddleware
-from chafan_core.app.task import (
-        write_view_count_to_db,
-        refresh_search_index,
-)
+from chafan_core.app.task import refresh_search_index, write_view_count_to_db
 
 args: MutableMapping[str, Optional[Any]] = {}
 if is_dev():
     args["openapi_url"] = f"{settings.API_V1_STR}/openapi.json"
 else:
     args["openapi_url"] = None
-    #args["docs_url"] = None
+    # args["docs_url"] = None
     args["redoc_url"] = None
 
 app = FastAPI(title=settings.PROJECT_NAME, **args)  # type: ignore
 
 
-
 if enable_rate_limit():
     app.state.limiter = limiter
     app.add_exception_handler(RateLimitExceeded, _rate_limit_exceeded_handler)
@@ -86,11 +82,12 @@ async def custom_validation_exception_handler(
         sentry_sdk.capture_message(err_msg)
     return await request_validation_exception_handler(request, exc)
 
+
 def set_backend_cors_origins():
     origins = []
-    if settings.DEBUG_BYPASS_BACKEND_CORS == 'magic':
-        origins.append('*')
-    for host in settings.CHAFAN_BACKEND_CORS_ORIGINS.split(','):
+    if settings.DEBUG_BYPASS_BACKEND_CORS == "magic":
+        origins.append("*")
+    for host in settings.CHAFAN_BACKEND_CORS_ORIGINS.split(","):
         origins.append(host)
     app.add_middleware(
         CORSMiddleware,
@@ -101,37 +98,44 @@ def set_backend_cors_origins():
     )
     logger.info("Set CORS allowed origins: " + str(origins))
 
+
 set_backend_cors_origins()
 
 app.include_router(health.router)
 app.include_router(api_router, prefix=settings.API_V1_STR)
 
 
-
-
 def print_app_settings() -> None:
     logger.info("settings:")
     for k, v in settings.__dict__.items():
         if not k.startswith("__"):
             logger.info(f"{k}: {v}")
 
+
 print_app_settings()
 for lib in [fastapi, uvicorn, starlette]:
     logger.info("{} version: {}".format(lib.__name__, lib.__version__))
 
 logger.info("Server launches")
 
+
 @app.on_event("startup")
 def set_up_scheduled_tasks():
     if not scheduler.running:
         scheduler.add_job(
-                write_view_count_to_db,
-                trigger=IntervalTrigger(minutes=settings.SCHEDULED_TASK_UPDATE_VIEW_COUNT_MINUTES),
-                name="write_new_activities_to_feeds")
+            write_view_count_to_db,
+            trigger=IntervalTrigger(
+                minutes=settings.SCHEDULED_TASK_UPDATE_VIEW_COUNT_MINUTES
+            ),
+            name="write_new_activities_to_feeds",
+        )
         scheduler.add_job(
-                refresh_search_index,
-                trigger=IntervalTrigger(hours=settings.SCHEDULED_TASK_REFRESH_SEARCH_INDEX_HOURS),
-                name="refresh_search_index")
+            refresh_search_index,
+            trigger=IntervalTrigger(
+                hours=settings.SCHEDULED_TASK_REFRESH_SEARCH_INDEX_HOURS
+            ),
+            name="refresh_search_index",
+        )
         scheduler.start()
         logger.info("Set up scheduled tasks")
     else:
@@ -141,4 +145,3 @@ def set_up_scheduled_tasks():
 @app.on_event("shutdown")
 def shutdown_event():
     logger.info("Stub: shutdown_event")
-
diff --git a/chafan_core/app/materialize.py b/chafan_core/app/materialize.py
index a40c25d..11221e9 100644
--- a/chafan_core/app/materialize.py
+++ b/chafan_core/app/materialize.py
@@ -1,6 +1,7 @@
 import datetime
-from typing import Any, Dict, Mapping, Optional, Tuple, Union
 import logging
+from typing import Any, Dict, Mapping, Optional, Tuple, Union
+
 logger = logging.getLogger(__name__)
 
 import sentry_sdk
@@ -28,10 +29,7 @@
     EventInternal,
 )
 from chafan_core.app.schemas.notification import Notification, NotificationInDBBase
-from chafan_core.app.schemas.question import (
-        QuestionInDBBase,
-        QuestionPreviewForSearch
-)
+from chafan_core.app.schemas.question import QuestionInDBBase, QuestionPreviewForSearch
 from chafan_core.app.schemas.reward import AnsweredQuestionCondition, RewardCondition
 from chafan_core.app.schemas.richtext import RichText
 from chafan_core.app.schemas.security import IntlPhoneNumber
@@ -57,6 +55,8 @@
 
 
 import chafan_core.app.user_permission as user_permission
+
+
 def get_active_site_profile(
     db: Session, *, site: models.Site, user_id: int
 ) -> Optional[models.Profile]:
@@ -271,14 +271,10 @@ def user_schema_from_orm(user: models.User) -> schemas.User:
 async def preview_of_question_as_search_hit(question: models.Question):
     if not question.site.public_readable:
         return None
-    r = QuestionPreviewForSearch(
-        uuid = question.uuid,
-        title = question.title
-    )
+    r = QuestionPreviewForSearch(uuid=question.uuid, title=question.title)
     return r
 
 
-
 class Materializer(object):
     def __init__(self, broker: DataBroker, principal_id: Optional[int]):
         self.broker = broker
@@ -301,7 +297,7 @@ def preview_of_user(self, user: models.User) -> schemas.UserPreview:
         )
 
     def site_schema_from_orm(self, site: models.Site) -> schemas.Site:
-        #logger.error("TODO materialize site_schema_from_orm to be removed")
+        # logger.error("TODO materialize site_schema_from_orm to be removed")
         # This function SHOULD be removed. However, it's error log is so annoying. Turn it off for now. 2025-Aug-16
         base = schemas.SiteInDBBase.from_orm(site)
         site_dict = base.dict()
@@ -576,7 +572,7 @@ def article_schema_from_orm(
         d["bookmarked"] = article in principal.bookmarked_articles
         d["author"] = self.preview_of_user(article.author)
         d["upvoted"] = upvoted
-        d["view_times"] = 0#view_counters.get_views(article.uuid, "article")
+        d["view_times"] = 0  # view_counters.get_views(article.uuid, "article")
         d["archives_count"] = len(article.archives)
         if article.is_published:
             body = article.body
@@ -786,7 +782,7 @@ def answer_for_visitor_schema_from_orm(
             return None
         d["question"] = q
         d["author"] = self.preview_of_user(answer.author)
-        d["view_times"] = 0 #view_counters.get_views(answer.uuid, "answer")
+        d["view_times"] = 0  # view_counters.get_views(answer.uuid, "answer")
         d["content"] = RichText(
             source=answer.body,
             rendered_text=answer.body_prerendered_text,
@@ -828,7 +824,7 @@ def answer_schema_from_orm(self, answer: models.Answer) -> Optional[schemas.Answ
         principal = crud.user.get(db, id=self.principal_id)
         assert principal is not None
         d["bookmarked"] = answer in principal.bookmarked_answers
-        d["view_times"] = 0 #view_counters.get_views(answer.uuid, "answer")
+        d["view_times"] = 0  # view_counters.get_views(answer.uuid, "answer")
         if answer.is_published:
             body = answer.body
         else:
@@ -875,7 +871,7 @@ def question_schema_from_orm(
         d["author"] = self.preview_of_user(question.author)
         d["editor"] = map_(question.editor, self.preview_of_user)
         d["upvoted"] = upvoted
-        d["view_times"] = 0 #view_counters.get_views(question.uuid, "question")
+        d["view_times"] = 0  # view_counters.get_views(question.uuid, "question")
         d["answers_count"] = len(get_live_answers_of_question(question))
         if question.description is not None:
             d["desc"] = RichText(
@@ -944,7 +940,7 @@ def submission_for_visitor_schema_from_orm(
     def submission_schema_from_orm(
         self, submission: models.Submission
     ) -> Optional[schemas.Submission]:
-        #logger.error("TODO submission_schema_from_orm in materialize.py is deprecated")
+        # logger.error("TODO submission_schema_from_orm in materialize.py is deprecated")
         # 2025-Sep-14 This log it too noisy
         if self.principal_id and not user_in_site(
             self.broker.get_db(),
@@ -963,7 +959,7 @@ def submission_schema_from_orm(
         )
         d["author"] = self.preview_of_user(submission.author)
         d["contributors"] = [self.preview_of_user(u) for u in submission.contributors]
-        d["view_times"] = 0 #view_counters.get_views(submission.uuid, "submission")
+        d["view_times"] = 0  # view_counters.get_views(submission.uuid, "submission")
         if submission.description is not None:
             d["desc"] = RichText(
                 source=submission.description,
diff --git a/chafan_core/app/models/__init__.py b/chafan_core/app/models/__init__.py
index 28ebac1..58a77f8 100644
--- a/chafan_core/app/models/__init__.py
+++ b/chafan_core/app/models/__init__.py
@@ -33,5 +33,10 @@
 from .task import Task
 from .topic import Topic
 from .user import User
+from .viewcount import (
+    ViewCountAnswer,
+    ViewCountArticle,
+    ViewCountQuestion,
+    ViewCountSubmission,
+)
 from .webhook import Webhook
-from .viewcount import ViewCountArticle, ViewCountAnswer, ViewCountQuestion, ViewCountSubmission
diff --git a/chafan_core/app/models/viewcount.py b/chafan_core/app/models/viewcount.py
index 3c89e60..3d82c7e 100644
--- a/chafan_core/app/models/viewcount.py
+++ b/chafan_core/app/models/viewcount.py
@@ -1,4 +1,3 @@
-
 from sqlalchemy import (
     Column,
     ForeignKey,
@@ -10,10 +9,10 @@
 
 from chafan_core.db.base_class import Base
 
-
-#if TYPE_CHECKING:
+# if TYPE_CHECKING:
 #    from . import *  # noqa: F401, F403
 
+
 class ViewCountArticle(Base):
     __table_args__ = (
         UniqueConstraint("article_id"),
@@ -22,6 +21,7 @@ class ViewCountArticle(Base):
     article_id = Column(Integer, ForeignKey("article.id"), nullable=False, index=True)
     view_count = Column(Integer, default=0, server_default="0", nullable=False)
 
+
 class ViewCountQuestion(Base):
     __table_args__ = (
         UniqueConstraint("question_id"),
@@ -30,6 +30,7 @@ class ViewCountQuestion(Base):
     question_id = Column(Integer, ForeignKey("question.id"), nullable=True, index=True)
     view_count = Column(Integer, default=0, server_default="0", nullable=False)
 
+
 class ViewCountAnswer(Base):
     __table_args__ = (
         UniqueConstraint("answer_id"),
@@ -38,10 +39,13 @@ class ViewCountAnswer(Base):
     answer_id = Column(Integer, ForeignKey("answer.id"), nullable=True, index=True)
     view_count = Column(Integer, default=0, server_default="0", nullable=False)
 
+
 class ViewCountSubmission(Base):
     __table_args__ = (
         UniqueConstraint("submission_id"),
         PrimaryKeyConstraint("submission_id"),
     )
-    submission_id = Column(Integer, ForeignKey("submission.id"), nullable=True, index=True)
+    submission_id = Column(
+        Integer, ForeignKey("submission.id"), nullable=True, index=True
+    )
     view_count = Column(Integer, default=0, server_default="0", nullable=False)
diff --git a/chafan_core/app/mq.py b/chafan_core/app/mq.py
index 304c17f..72dd625 100644
--- a/chafan_core/app/mq.py
+++ b/chafan_core/app/mq.py
@@ -1,14 +1,15 @@
-
 import logging
+
 logger = logging.getLogger(__name__)
 
 
+import logging
+
 from chafan_core.app import models
 from chafan_core.app.data_broker import DataBroker
 from chafan_core.app.materialize import Materializer
 from chafan_core.app.schemas.mq import WsUserMsg
 
-import logging
 logger = logging.getLogger(__name__)
 
 
@@ -25,9 +26,8 @@ def push_notification(data_broker: DataBroker, *, notif: models.Notification) ->
         return
     queue_name = get_ws_queue_for_user(notif.receiver_id)
     msg = WsUserMsg(
-                type="notification",
-                data=n,
+        type="notification",
+        data=n,
     )
     redis = data_broker.get_redis()
     redis.rpush(queue_name, msg.json())
-
diff --git a/chafan_core/app/recs/ranking.py b/chafan_core/app/recs/ranking.py
index 1b16eb2..afed3d2 100644
--- a/chafan_core/app/recs/ranking.py
+++ b/chafan_core/app/recs/ranking.py
@@ -33,12 +33,12 @@ def freshness(
 
 
 def rank_submissions(
-    submissions: Union[List[schemas.Submission], List[schemas.SubmissionForVisitor]]
+    submissions: Union[List[schemas.Submission], List[schemas.SubmissionForVisitor]],
 ) -> Union[List[schemas.Submission], List[schemas.SubmissionForVisitor]]:
     utc_now = datetime.datetime.now(tz=datetime.timezone.utc)
 
     def hotness(
-        submission: Union[schemas.Submission, schemas.SubmissionForVisitor]
+        submission: Union[schemas.Submission, schemas.SubmissionForVisitor],
     ) -> float:
         return float(submission.upvotes_count + 1) * freshness(
             utc_now, submission.updated_at, recency_boost=1
diff --git a/chafan_core/app/rep_manager.py b/chafan_core/app/rep_manager.py
index adff57c..3ca5f6e 100644
--- a/chafan_core/app/rep_manager.py
+++ b/chafan_core/app/rep_manager.py
@@ -1,3 +1,4 @@
+import logging
 from typing import Optional
 
 from sqlalchemy.orm import Session
@@ -7,8 +8,6 @@
 from chafan_core.app.config import settings
 from chafan_core.utils.base import ContentVisibility
 
-
-import logging
 logger = logging.getLogger(__name__)
 
 # TODO everything about user permission, including if they can create a site (KARMA), invite a user, write an answer, etc, should be moved into this file. 2025-07-08
@@ -19,20 +18,26 @@
 def new_submission_suggestion(submission_suggestion):
     pass
 
+
 def new_question(question):
     pass
 
+
 def new_submission(submission):
     pass
 
+
 def accept_submission_suggestion(submission_suggestion):
     pass
 
+
 def new_answer_suggest(answer_suggest):
     pass
 
+
 def accept_answer_suggest(answer_suggest_edit):
     pass
 
+
 def new_article(article):
     pass
diff --git a/chafan_core/app/responders/__init__.py b/chafan_core/app/responders/__init__.py
index b669e8d..ba1498e 100644
--- a/chafan_core/app/responders/__init__.py
+++ b/chafan_core/app/responders/__init__.py
@@ -1,4 +1,4 @@
-from . import question, submission, article, answer, site, rss
+from . import answer, article, question, rss, site, submission
 
 # responders 的设计目的是 models (crud) -> schema (api endpoint)
 #   1. responders 不需要鉴权
diff --git a/chafan_core/app/responders/answer.py b/chafan_core/app/responders/answer.py
index ba422a1..2b5dd6e 100644
--- a/chafan_core/app/responders/answer.py
+++ b/chafan_core/app/responders/answer.py
@@ -1,22 +1,19 @@
+import logging
 from typing import Any, Dict, Mapping, Optional, Tuple, Union
 
-from chafan_core.app import models, schemas
-from chafan_core.app.schemas.richtext import RichText
-from chafan_core.utils.base import (
-    filter_not_none,
-)
-
-from chafan_core.app import view_counters
-
-
+from chafan_core.app import models, schemas, view_counters
 from chafan_core.app.schemas.answer import AnswerInDBBase
+from chafan_core.app.schemas.richtext import RichText
+from chafan_core.utils.base import filter_not_none
 
-import logging
 logger = logging.getLogger(__name__)
 
-def answer_schema_from_orm(cached_layer, answer: models.Answer, principal_id) -> Optional[schemas.Answer]:
+
+def answer_schema_from_orm(
+    cached_layer, answer: models.Answer, principal_id
+) -> Optional[schemas.Answer]:
     db = cached_layer.broker.get_db()
-    #if not can_read_answer(db, answer=answer, principal_id=self.principal_id):
+    # if not can_read_answer(db, answer=answer, principal_id=self.principal_id):
     #    return None
     upvoted = (
         db.query(models.Answer_Upvotes)
@@ -25,12 +22,12 @@ def answer_schema_from_orm(cached_layer, answer: models.Answer, principal_id) ->
         is not None
     )
     # TODO skipped the permission check
-#    comment_writable = user_in_site(
-#        db,
-#        site=answer.site,
-#        user_id=self.principal_id,
-#        op_type=OperationType.WriteSiteComment,
-#    )
+    #    comment_writable = user_in_site(
+    #        db,
+    #        site=answer.site,
+    #        user_id=self.principal_id,
+    #        op_type=OperationType.WriteSiteComment,
+    #    )
     base = AnswerInDBBase.from_orm(answer)
     d = base.dict()
     d["site"] = cached_layer.site_schema_from_orm(answer.site)
@@ -40,12 +37,12 @@ def answer_schema_from_orm(cached_layer, answer: models.Answer, principal_id) ->
     d["author"] = cached_layer.materializer.preview_of_user(answer.author)
     d["question"] = cached_layer.materializer.preview_of_question(answer.question)
     d["upvoted"] = upvoted
-    d["comment_writable"] = True #comment_writable
+    d["comment_writable"] = True  # comment_writable
     d["bookmark_count"] = answer.bookmarkers.count()
     d["archives_count"] = len(answer.archives)
-    #principal = crud.user.get(db, id=principal_id)
-    #assert principal is not None
-    d["bookmarked"] = True #answer in principal.bookmarked_answers
+    # principal = crud.user.get(db, id=principal_id)
+    # assert principal is not None
+    d["bookmarked"] = True  # answer in principal.bookmarked_answers
     d["view_times"] = view_counters.get_viewcount_answer(cached_layer.broker, answer.id)
     if answer.is_published:
         body = answer.body
@@ -62,4 +59,3 @@ def answer_schema_from_orm(cached_layer, answer: models.Answer, principal_id) ->
     )
     d["suggest_editable"] = answer.body_draft is None
     return schemas.Answer(**d)
-
diff --git a/chafan_core/app/responders/article.py b/chafan_core/app/responders/article.py
index 7fdd6b5..a7fe444 100644
--- a/chafan_core/app/responders/article.py
+++ b/chafan_core/app/responders/article.py
@@ -1,18 +1,13 @@
-from typing import Optional
 import logging
-logger = logging.getLogger(__name__)
+from typing import Optional
 
-from chafan_core.app import crud, models, schemas
-from chafan_core.app.schemas.richtext import RichText
-from chafan_core.utils.base import (
-    filter_not_none,
-)
+logger = logging.getLogger(__name__)
 
+from chafan_core.app import crud, models, schemas, view_counters
 from chafan_core.app.schemas.article import ArticleInDB
 from chafan_core.app.schemas.article_archive import ArticleArchiveInDB
-
-
-from chafan_core.app import view_counters
+from chafan_core.app.schemas.richtext import RichText
+from chafan_core.utils.base import filter_not_none
 
 
 def article_schema_from_orm(
@@ -22,9 +17,7 @@ def article_schema_from_orm(
     upvoted = (
         cached_layer.broker.get_db()
         .query(models.ArticleUpvotes)
-        .filter_by(
-            article_id=article.id, voter_id=principal_id, cancelled=False
-        )
+        .filter_by(article_id=article.id, voter_id=principal_id, cancelled=False)
         .first()
         is not None
     )
@@ -38,12 +31,14 @@ def article_schema_from_orm(
     )
     d["bookmark_count"] = article.bookmarkers.count()
     principal = crud.user.get(cached_layer.broker.get_db(), id=principal_id)
-    #assert principal is not None
-    #d["bookmarked"] = article in principal.bookmarked_articles
-    d["bookmarked"] = True # TODO leave it for now 2025-07-24
+    # assert principal is not None
+    # d["bookmarked"] = article in principal.bookmarked_articles
+    d["bookmarked"] = True  # TODO leave it for now 2025-07-24
     d["author"] = cached_layer.materializer.preview_of_user(article.author)
     d["upvoted"] = upvoted
-    d["view_times"] = view_counters.get_viewcount_article(cached_layer.broker, article.id)
+    d["view_times"] = view_counters.get_viewcount_article(
+        cached_layer.broker, article.id
+    )
     d["archives_count"] = len(article.archives)
     if article.is_published:
         body = article.body
diff --git a/chafan_core/app/responders/question.py b/chafan_core/app/responders/question.py
index 5411543..50f3f16 100644
--- a/chafan_core/app/responders/question.py
+++ b/chafan_core/app/responders/question.py
@@ -1,28 +1,19 @@
-from typing import Any, Dict, Mapping, Optional, Tuple, Union
 import logging
+from typing import Any, Dict, Mapping, Optional, Tuple, Union
+
 logger = logging.getLogger(__name__)
 
 from sqlalchemy.orm import Session
 
 import chafan_core.app.responders as responders
-from chafan_core.app import models, schemas
+from chafan_core.app import models, schemas, view_counters
 from chafan_core.app.common import OperationType, is_dev
 from chafan_core.app.data_broker import DataBroker
-from chafan_core.app.model_utils import (
-    get_live_answers_of_question,
-)
-from chafan_core.app.schemas.question import (
-        QuestionInDBBase,
-        QuestionPreviewForSearch
-)
+from chafan_core.app.model_utils import get_live_answers_of_question
+from chafan_core.app.schemas.question import QuestionInDBBase, QuestionPreviewForSearch
 from chafan_core.app.schemas.richtext import RichText
-from chafan_core.utils.base import (
-    filter_not_none,
-    map_,
-    unwrap,
-)
+from chafan_core.utils.base import filter_not_none, map_, unwrap
 
-from chafan_core.app import view_counters
 
 def user_in_site(
     db: Session,
@@ -36,14 +27,14 @@ def user_in_site(
 
 
 def question_schema_from_orm(
-        broker: DataBroker,
-        principal_id,
-        question: models.Question,
-        cached_layer # TODO we should remove this dependency in future 2025-07-23
+    broker: DataBroker,
+    principal_id,
+    question: models.Question,
+    cached_layer,  # TODO we should remove this dependency in future 2025-07-23
 ) -> Optional[schemas.Question]:
     if not principal_id:
         logger.error("TODO skipped principle_id check")
-        #return None
+        # return None
     if not user_in_site(
         broker.get_db(),
         site=question.site,
@@ -55,9 +46,7 @@ def question_schema_from_orm(
     upvoted = (
         broker.get_db()
         .query(models.QuestionUpvotes)
-        .filter_by(
-            question_id=question.id, voter_id=principal_id, cancelled=False
-        )
+        .filter_by(question_id=question.id, voter_id=principal_id, cancelled=False)
         .first()
         is not None
     )
@@ -65,7 +54,10 @@ def question_schema_from_orm(
     d = base.dict()
     d["site"] = responders.site.site_schema_from_orm(cached_layer, question.site)
     d["comments"] = filter_not_none(
-        [cached_layer.materializer.comment_schema_from_orm(c) for c in question.comments]
+        [
+            cached_layer.materializer.comment_schema_from_orm(c)
+            for c in question.comments
+        ]
     )
     d["author"] = cached_layer.materializer.preview_of_user(question.author)
     d["editor"] = map_(question.editor, cached_layer.materializer.preview_of_user)
diff --git a/chafan_core/app/responders/rss.py b/chafan_core/app/responders/rss.py
index 921c928..daf95da 100644
--- a/chafan_core/app/responders/rss.py
+++ b/chafan_core/app/responders/rss.py
@@ -1,14 +1,15 @@
-from feedgen.feed import FeedGenerator
-
+import logging
 from typing import List
 
-from chafan_core.app.models import Answer, Question, Article
+from feedgen.feed import FeedGenerator
+
 from chafan_core.app.config import settings
+from chafan_core.app.models import Answer, Article, Question
 
-import logging
 logger = logging.getLogger(__name__)
 
-def build_rss(activities: List, site)->str:
+
+def build_rss(activities: List, site) -> str:
     fg = FeedGenerator()
     if site is not None:
         fg.title("ChaFan RSS " + site.name)
@@ -25,7 +26,7 @@ def build_rss(activities: List, site)->str:
         verb = "内容"
         user = ac.author.full_name
         if user is None or user == "":
-            user ="茶饭用户"
+            user = "茶饭用户"
         link = "https://cha.fan"
         description = "内容"
 
@@ -50,7 +51,6 @@ def build_rss(activities: List, site)->str:
         else:
             logger.error(f"Not supported item: {ac}")
 
-
         title = f"{user} 发表了{verb}"
         fe.title(title)
         fe.link(href=link)
diff --git a/chafan_core/app/responders/site.py b/chafan_core/app/responders/site.py
index bb64127..c2381d0 100644
--- a/chafan_core/app/responders/site.py
+++ b/chafan_core/app/responders/site.py
@@ -1,7 +1,8 @@
+import logging
 from typing import Any, Mapping
+
 from chafan_core.app import models, schemas
 
-import logging
 logger = logging.getLogger(__name__)
 
 _VISIBLE_QUESTION_CONDITIONS = {
@@ -11,9 +12,11 @@
     "is_hidden": False,
 }
 
+
 def keep_items(questions: Any, conditions: Mapping[str, Any]) -> Any:
     return questions.filter_by(**conditions)
 
+
 def site_schema_from_orm(cached_layer, site: models.Site) -> schemas.Site:
     base = schemas.SiteInDBBase.from_orm(site)
     site_dict = base.dict()
diff --git a/chafan_core/app/responders/submission.py b/chafan_core/app/responders/submission.py
index 938e878..b9c6319 100644
--- a/chafan_core/app/responders/submission.py
+++ b/chafan_core/app/responders/submission.py
@@ -1,17 +1,14 @@
+import logging
 from typing import Optional
 
-from chafan_core.app import models, schemas
-from chafan_core.app.schemas.richtext import RichText
-from chafan_core.utils.base import (
-    filter_not_none,
-)
-
 import chafan_core.app.responders as responders
-from chafan_core.app import view_counters
+from chafan_core.app import models, schemas, view_counters
+from chafan_core.app.schemas.richtext import RichText
+from chafan_core.utils.base import filter_not_none
 
-import logging
 logger = logging.getLogger(__name__)
 
+
 def submission_schema_from_orm(
     cached_layer,
     submission: models.Submission,
@@ -22,11 +19,18 @@ def submission_schema_from_orm(
     d = base.dict()
     d["site"] = responders.site.site_schema_from_orm(cached_layer, submission.site)
     d["comments"] = filter_not_none(
-        [cached_layer.materializer.comment_schema_from_orm(c) for c in submission.comments]
+        [
+            cached_layer.materializer.comment_schema_from_orm(c)
+            for c in submission.comments
+        ]
     )
     d["author"] = cached_layer.preview_of_user(submission.author)
-    d["contributors"] = [cached_layer.preview_of_user(u) for u in submission.contributors]
-    d["view_times"] = view_counters.get_viewcount_submission(cached_layer.broker, submission.id)
+    d["contributors"] = [
+        cached_layer.preview_of_user(u) for u in submission.contributors
+    ]
+    d["view_times"] = view_counters.get_viewcount_submission(
+        cached_layer.broker, submission.id
+    )
     if submission.description is not None:
         d["desc"] = RichText(
             source=submission.description,
@@ -34,4 +38,3 @@ def submission_schema_from_orm(
             editor=submission.description_editor,
         )
     return schemas.Submission(**d)
-
diff --git a/chafan_core/app/schemas/__init__.py b/chafan_core/app/schemas/__init__.py
index eea8697..ef5d1d6 100644
--- a/chafan_core/app/schemas/__init__.py
+++ b/chafan_core/app/schemas/__init__.py
@@ -93,8 +93,8 @@
     QuestionForVisitor,
     QuestionInDB,
     QuestionPreview,
-    QuestionPreviewForVisitor,
     QuestionPreviewForSearch,
+    QuestionPreviewForVisitor,
     QuestionUpdate,
     QuestionUpvotes,
 )
diff --git a/chafan_core/app/schemas/article.py b/chafan_core/app/schemas/article.py
index 93688ab..8691ed5 100644
--- a/chafan_core/app/schemas/article.py
+++ b/chafan_core/app/schemas/article.py
@@ -1,7 +1,7 @@
 import datetime
 from typing import List, Optional
 
-from pydantic import BaseModel, validator
+from pydantic import BaseModel
 
 from chafan_core.app.schemas.article_column import ArticleColumn
 from chafan_core.app.schemas.comment import Comment, CommentForVisitor
@@ -9,7 +9,7 @@
 from chafan_core.app.schemas.richtext import RichText
 from chafan_core.app.schemas.topic import Topic
 from chafan_core.utils.base import ContentVisibility
-from chafan_core.utils.validators import StrippedNonEmptyStr, validate_article_title
+from chafan_core.utils.validators import ArticleTitle, StrippedNonEmptyStr
 
 
 # Shared properties
@@ -19,32 +19,21 @@ class ArticleBase(BaseModel):
 
 # Properties to receive via API on creation
 class ArticleCreate(ArticleBase):
-    title: StrippedNonEmptyStr
+    title: ArticleTitle
     content: RichText
     article_column_uuid: str
     is_published: bool
     writing_session_uuid: str
     visibility: ContentVisibility
 
-    @validator("title")
-    def _valid_title(cls, v: str) -> str:
-        validate_article_title(v)
-        return v
-
 
 # Properties to receive via API on update
 class ArticleUpdate(ArticleBase):
-    updated_title: StrippedNonEmptyStr
+    updated_title: ArticleTitle
     updated_content: RichText
     is_draft: bool
     visibility: ContentVisibility
 
-    @validator("updated_title")
-    def _valid_title(cls, v: Optional[str]) -> Optional[str]:
-        if v is not None:
-            validate_article_title(v)
-        return v
-
 
 # Properties to receive via API on update
 class ArticleTopicsUpdate(ArticleBase):
diff --git a/chafan_core/app/schemas/event.py b/chafan_core/app/schemas/event.py
index 529551b..6ddb604 100644
--- a/chafan_core/app/schemas/event.py
+++ b/chafan_core/app/schemas/event.py
@@ -473,9 +473,9 @@ class InviteJoinSite(BaseModel):
         Site
     ]  # TODO: Must be not-null. Delete non-conformant data after a while.
     user: Optional[UserPreview]
-    invited_email: Optional[
-        CaseInsensitiveEmailStr
-    ] = None  # Deprecated, see `InviteNewUser`
+    invited_email: Optional[CaseInsensitiveEmailStr] = (
+        None  # Deprecated, see `InviteNewUser`
+    )
 
     def _string_args(self) -> Mapping[str, StringArg]:
         return {
@@ -493,9 +493,9 @@ class InviteJoinSiteInternal(BaseModel):
         int
     ]  # TODO: Must be not-null. Delete non-conformant data after a while.
     user_id: Optional[int]
-    invited_email: Optional[
-        CaseInsensitiveEmailStr
-    ] = None  # Deprecated, see `InviteNewUser`
+    invited_email: Optional[CaseInsensitiveEmailStr] = (
+        None  # Deprecated, see `InviteNewUser`
+    )
 
 
 class SystemSendInvitation(BaseModel):
diff --git a/chafan_core/app/schemas/form.py b/chafan_core/app/schemas/form.py
index 1384735..b66e604 100644
--- a/chafan_core/app/schemas/form.py
+++ b/chafan_core/app/schemas/form.py
@@ -1,7 +1,7 @@
 import datetime
 from typing import List, Literal, Optional, Union
 
-from pydantic import BaseModel, validator
+from pydantic import BaseModel, field_validator
 
 from chafan_core.app.schemas.preview import UserPreview
 
@@ -63,9 +63,11 @@ class FormCreate(FormBase):
     title: str
     form_fields: List[FormField]
 
-    @validator("form_fields")
+    @field_validator("form_fields")
+    @classmethod
     def _valid_form_fields(cls, v: List[FormField]) -> List[FormField]:
-        assert len(set(f.unique_name for f in v)) == len(v)
+        if len(set(f.unique_name for f in v)) != len(v):
+            raise ValueError("Form field names must be unique")
         return v
 
 
diff --git a/chafan_core/app/schemas/form_response.py b/chafan_core/app/schemas/form_response.py
index d17ea62..b028df9 100644
--- a/chafan_core/app/schemas/form_response.py
+++ b/chafan_core/app/schemas/form_response.py
@@ -1,7 +1,7 @@
 import datetime
 from typing import List, Literal, Union
 
-from pydantic import BaseModel, validator
+from pydantic import BaseModel, field_validator
 
 from chafan_core.app.schemas.form import Form
 from chafan_core.app.schemas.preview import UserPreview
@@ -19,18 +19,18 @@ class TextResponseField(BaseModel):
 
 
 class SingleChoiceResponseField(BaseModel):
-    field_type_name: Literal[
+    field_type_name: Literal["single_choice_response_field"] = (
         "single_choice_response_field"
-    ] = "single_choice_response_field"
+    )
     desc: str
     # TODO: validate
     selected_choice: str
 
 
 class MultipleChoiceResponseField(BaseModel):
-    field_type_name: Literal[
+    field_type_name: Literal["multiple_choices_response_field"] = (
         "multiple_choices_response_field"
-    ] = "multiple_choices_response_field"
+    )
     desc: str
     # TODO: validate
     selected_choices: List[str]
@@ -48,11 +48,13 @@ class FormResponseCreate(FormResponseBase):
     form_uuid: str
     response_fields: List[FormResponseField]
 
-    @validator("response_fields")
+    @field_validator("response_fields")
+    @classmethod
     def _valid_response_fields(
         cls, v: List[FormResponseField]
     ) -> List[FormResponseField]:
-        assert len(set(f.unique_name for f in v)) == len(v)
+        if len(set(f.unique_name for f in v)) != len(v):
+            raise ValueError("Response field names must be unique")
         return v
 
 
diff --git a/chafan_core/app/schemas/message.py b/chafan_core/app/schemas/message.py
index 20cd356..31b6ea7 100644
--- a/chafan_core/app/schemas/message.py
+++ b/chafan_core/app/schemas/message.py
@@ -1,20 +1,15 @@
 import datetime
 
-from pydantic import BaseModel, validator
+from pydantic import BaseModel
 
 from chafan_core.app.schemas.preview import UserPreview
-from chafan_core.utils.validators import validate_message_body
+from chafan_core.utils.validators import MessageBody
 
 
 # Shared properties
 class MessageBase(BaseModel):
     channel_id: int
-    body: str
-
-    @validator("body")
-    def _valid_body(cls, v: str) -> str:
-        validate_message_body(v)
-        return v
+    body: MessageBody
 
 
 # Properties to receive via API on creation
diff --git a/chafan_core/app/schemas/question.py b/chafan_core/app/schemas/question.py
index 70383eb..73959cb 100644
--- a/chafan_core/app/schemas/question.py
+++ b/chafan_core/app/schemas/question.py
@@ -1,14 +1,14 @@
 import datetime
 from typing import List, Optional
 
-from pydantic import BaseModel, validator
+from pydantic import BaseModel
 
 from chafan_core.app.schemas.comment import Comment, CommentForVisitor
 from chafan_core.app.schemas.preview import UserPreview
 from chafan_core.app.schemas.richtext import RichText
 from chafan_core.app.schemas.site import Site
 from chafan_core.app.schemas.topic import Topic
-from chafan_core.utils.validators import StrippedNonEmptyStr, validate_question_title
+from chafan_core.utils.validators import QuestionTitle, StrippedNonEmptyStr
 
 
 # Shared properties
@@ -19,28 +19,15 @@ class QuestionBase(BaseModel):
 # Properties to receive via API on creation
 class QuestionCreate(QuestionBase):
     site_uuid: str
-    title: StrippedNonEmptyStr
-
-    @validator("title")
-    def _valid_title(cls, v: StrippedNonEmptyStr) -> StrippedNonEmptyStr:
-        validate_question_title(v)
-        return v
+    title: QuestionTitle
 
 
 # Properties to receive via API on update
 class QuestionUpdate(QuestionBase):
-    title: Optional[StrippedNonEmptyStr] = None
+    title: Optional[QuestionTitle] = None
     desc: Optional[RichText] = None
     topic_uuids: Optional[List[str]] = None
 
-    @validator("title")
-    def _valid_title(
-        cls, v: Optional[StrippedNonEmptyStr]
-    ) -> Optional[StrippedNonEmptyStr]:
-        if v is not None:
-            validate_question_title(v)
-        return v
-
 
 class QuestionInDBBase(QuestionBase):
     uuid: str
@@ -91,7 +78,8 @@ class QuestionPreviewForSearch(BaseModel):
     uuid: str
     title: str
 
-#class QuestionPreviewForVisitor(QuestionPreviewForSearch):
+
+# class QuestionPreviewForVisitor(QuestionPreviewForSearch):
 class QuestionPreviewForVisitor(BaseModel):
     uuid: str
     title: str
diff --git a/chafan_core/app/schemas/reward.py b/chafan_core/app/schemas/reward.py
index a6571ec..91e5abf 100644
--- a/chafan_core/app/schemas/reward.py
+++ b/chafan_core/app/schemas/reward.py
@@ -1,7 +1,7 @@
 import datetime
-from typing import Literal, Optional
+from typing import Annotated, Literal, Optional
 
-from pydantic import BaseModel, validator
+from pydantic import BaseModel, Field
 
 from chafan_core.app.schemas.preview import UserPreview
 
@@ -22,24 +22,12 @@ class RewardCondition(BaseModel):
 
 # Properties to receive via API on creation
 class RewardCreate(RewardBase):
-    expired_after_days: int
+    expired_after_days: Annotated[int, Field(gt=0, description="Expiry days")]
     receiver_uuid: str
-    coin_amount: int
+    coin_amount: Annotated[int, Field(gt=0, description="Coin amount")]
     note_to_receiver: Optional[str] = None
     condition: Optional[RewardCondition] = None
 
-    @validator("coin_amount")
-    def _valid_coin_amount(cls, v: int) -> int:
-        if v <= 0:
-            raise ValueError("Invalid coin amount.")
-        return v
-
-    @validator("expired_after_days")
-    def _valid_expired_after_days(cls, v: int) -> int:
-        if v <= 0:
-            raise ValueError("Invalid expiry days.")
-        return v
-
 
 class RewardUpdate(BaseModel):
     pass
diff --git a/chafan_core/app/schemas/security.py b/chafan_core/app/schemas/security.py
index 675d424..2e4da2f 100644
--- a/chafan_core/app/schemas/security.py
+++ b/chafan_core/app/schemas/security.py
@@ -1,25 +1,17 @@
 from typing import Optional
 
-from pydantic import BaseModel, validator
+from pydantic import BaseModel
 
-from chafan_core.utils.validators import CaseInsensitiveEmailStr
+from chafan_core.utils.validators import (
+    CaseInsensitiveEmailStr,
+    CountryCode,
+    SubscriberNumber,
+)
 
 
 class IntlPhoneNumber(BaseModel):
-    country_code: str
-    subscriber_number: str
-
-    @validator("country_code")
-    def _valid_country_code(cls, v: str) -> str:
-        if v.isdigit() and len(v) >= 1 and len(v) <= 3:
-            return v
-        raise ValueError(f"Invalid country code: {v}")
-
-    @validator("subscriber_number")
-    def _valid_subscriber_number(cls, v: str) -> str:
-        if v.isdigit() and len(v) >= 1 and len(v) <= 12:
-            return v
-        raise ValueError(f"Invalid subscriber number: {v}")
+    country_code: CountryCode
+    subscriber_number: SubscriberNumber
 
     def format_e164(self) -> str:
         return f"+{self.country_code}{self.subscriber_number}"
diff --git a/chafan_core/app/schemas/site.py b/chafan_core/app/schemas/site.py
index 027866d..5a30349 100644
--- a/chafan_core/app/schemas/site.py
+++ b/chafan_core/app/schemas/site.py
@@ -1,14 +1,15 @@
-from typing import Any, Dict, List, Literal, Optional
+import logging
+from typing import Any, Dict, List, Literal, Optional, Self
 
-from pydantic import BaseModel, validator
+from pydantic import BaseModel, model_validator
 
 from chafan_core.app.schemas.preview import UserPreview
 from chafan_core.app.schemas.topic import Topic
 from chafan_core.utils.validators import StrippedNonEmptyBasicStr, StrippedNonEmptyStr
 
-import logging
 logger = logging.getLogger(__name__)
 
+
 # Shared properties
 class SiteBase(BaseModel):
     description: Optional[str]
@@ -63,25 +64,30 @@ class Site(SiteInDBBase):
     members_count: int
     category_topic: Optional[Topic] = None
 
-    @validator("permission_type")
-    def get_permission_type(cls, v: Optional[str], values: Dict[str, Any]) -> str:
+    @model_validator(mode="after")
+    def compute_permission_type(self) -> Self:
         if (
-            values["public_readable"]
-            and values["public_writable_question"]
-            and values["public_writable_answer"]
-            and values["public_writable_comment"]
+            self.public_readable
+            and self.public_writable_question
+            and self.public_writable_answer
+            and self.public_writable_comment
         ):
-            return "public"
-        if (
-            (not values["public_readable"])
-            and (not values["public_writable_question"])
-            and (not values["public_writable_answer"])
-            and (not values["public_writable_comment"])
+            self.permission_type = "public"
+        elif (
+            (not self.public_readable)
+            and (not self.public_writable_question)
+            and (not self.public_writable_answer)
+            and (not self.public_writable_comment)
         ):
-            return "private"
-        logger.error("site permission broken, name={},subdomain={}".format(values["name"], values["subdomain"]))
-        return "private"
-        #raise Exception(f"Incompatible site flags: {values}")
+            self.permission_type = "private"
+        else:
+            logger.error(
+                "site permission broken, name={},subdomain={}".format(
+                    self.name, self.subdomain
+                )
+            )
+            self.permission_type = "private"
+        return self
 
 
 # Additional properties stored in DB
diff --git a/chafan_core/app/schemas/submission.py b/chafan_core/app/schemas/submission.py
index 1f0e772..da56427 100644
--- a/chafan_core/app/schemas/submission.py
+++ b/chafan_core/app/schemas/submission.py
@@ -1,7 +1,7 @@
 import datetime
 from typing import List, Optional
 
-from pydantic import BaseModel, validator
+from pydantic import BaseModel
 from pydantic.networks import AnyHttpUrl
 
 from chafan_core.app.schemas.comment import Comment, CommentForVisitor
@@ -9,7 +9,7 @@
 from chafan_core.app.schemas.richtext import RichText
 from chafan_core.app.schemas.site import Site
 from chafan_core.app.schemas.topic import Topic
-from chafan_core.utils.validators import StrippedNonEmptyStr, validate_submission_title
+from chafan_core.utils.validators import StrippedNonEmptyStr, SubmissionTitle
 
 
 # Shared properties
@@ -20,29 +20,16 @@ class SubmissionBase(BaseModel):
 # Properties to receive via API on creation
 class SubmissionCreate(SubmissionBase):
     site_uuid: str
-    title: StrippedNonEmptyStr
+    title: SubmissionTitle
     url: Optional[AnyHttpUrl] = None
 
-    @validator("title")
-    def _valid_title(cls, v: str) -> str:
-        validate_submission_title(v)
-        return v
-
 
 # Properties to receive via API on update
 class SubmissionUpdate(SubmissionBase):
-    title: Optional[StrippedNonEmptyStr] = None
+    title: Optional[SubmissionTitle] = None
     desc: Optional[RichText] = None
     topic_uuids: Optional[List[str]] = None
 
-    @validator("title")
-    def _valid_title(
-        cls, v: Optional[StrippedNonEmptyStr]
-    ) -> Optional[StrippedNonEmptyStr]:
-        if v is not None:
-            validate_submission_title(v)
-        return v
-
 
 class SubmissionInDB(SubmissionBase):
     uuid: str
diff --git a/chafan_core/app/schemas/user.py b/chafan_core/app/schemas/user.py
index c1ef76b..9302cb5 100644
--- a/chafan_core/app/schemas/user.py
+++ b/chafan_core/app/schemas/user.py
@@ -1,7 +1,7 @@
 import datetime
 from typing import List, Literal, Optional
 
-from pydantic import BaseModel, validator
+from pydantic import BaseModel
 from pydantic.networks import AnyHttpUrl
 from pydantic.types import SecretStr
 
@@ -17,7 +17,7 @@
     CaseInsensitiveEmailStr,
     StrippedNonEmptyBasicStr,
     StrippedNonEmptyStr,
-    validate_password,
+    ValidPassword,
 )
 
 
@@ -31,14 +31,9 @@ class UserBase(BaseModel):
 # Properties to receive via API on creation
 class UserCreate(UserBase):
     email: CaseInsensitiveEmailStr
-    password: SecretStr
+    password: ValidPassword
     handle: Optional[StrippedNonEmptyBasicStr]
 
-    @validator("password")
-    def _valid_password(cls, v: SecretStr) -> SecretStr:
-        validate_password(v)
-        return v
-
 
 class UserInvite(BaseModel):
     user_uuid: str
@@ -67,15 +62,9 @@ class InviteIn(BaseModel):
 
 # Properties to receive via API on update
 class UserUpdate(UserBase):
-    password: Optional[SecretStr] = None
+    password: Optional[ValidPassword] = None
     handle: Optional[StrippedNonEmptyStr] = None
 
-    @validator("password")
-    def _valid_password(cls, v: Optional[SecretStr]) -> Optional[SecretStr]:
-        if v is not None:
-            validate_password(v)
-        return v
-
 
 class UserWorkExperience(BaseModel):
     company_topic: Topic
@@ -223,7 +212,7 @@ class UserUpdateMe(BaseModel):
     handle: Optional[str] = None
     about: Optional[str] = None
     default_editor_mode: Optional[editor_T] = None
-    password: Optional[SecretStr] = None
+    password: Optional[ValidPassword] = None
     residency_topic_uuids: Optional[List[str]] = None
     profession_topic_uuids: Optional[List[str]] = None
     education_experiences: Optional[List[UserEducationExperienceInternal]] = None
@@ -238,9 +227,3 @@ class UserUpdateMe(BaseModel):
     avatar_url: Optional[AnyHttpUrl] = None
     gif_avatar_url: Optional[AnyHttpUrl] = None
     enable_deliver_unread_notifications: Optional[bool] = None
-
-    @validator("password")
-    def _valid_password(cls, v: Optional[SecretStr]) -> Optional[SecretStr]:
-        if v is not None:
-            validate_password(v)
-        return v
diff --git a/chafan_core/app/search.py b/chafan_core/app/search.py
index 77bb900..b2b9add 100644
--- a/chafan_core/app/search.py
+++ b/chafan_core/app/search.py
@@ -1,3 +1,4 @@
+import logging
 import os
 from typing import List, Mapping, Optional
 
@@ -11,7 +12,6 @@
 from chafan_core.app.config import settings
 from chafan_core.utils.constants import indexed_object_T
 
-import logging
 logger = logging.getLogger(__name__)
 
 _analyzer = ChineseAnalyzer()
diff --git a/chafan_core/app/security.py b/chafan_core/app/security.py
index c7f92b8..4593f61 100644
--- a/chafan_core/app/security.py
+++ b/chafan_core/app/security.py
@@ -1,24 +1,17 @@
 import datetime
-from typing import Any, Optional, Union
-
+import logging
 import random
+from typing import Any, Optional, Union
 
 from jose import jwt
 from passlib.context import CryptContext  # type: ignore
 from pydantic.types import SecretStr
 
-from chafan_core.utils.validators import CaseInsensitiveEmailStr
+from chafan_core.app.common import check_email, client_ip, get_redis_cli, is_dev
 from chafan_core.app.config import settings
 from chafan_core.utils.base import unwrap
+from chafan_core.utils.validators import CaseInsensitiveEmailStr
 
-from chafan_core.app.common import (
-    check_email,
-    client_ip,
-    get_redis_cli,
-    is_dev,
-)
-
-import logging
 logger = logging.getLogger(__name__)
 
 pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
@@ -27,11 +20,11 @@
 ALGORITHM = "HS256"
 
 
-async def check_digit_verification_code(email:str, code:str) -> bool:
-    #logger.info("Check verification code")
+async def check_digit_verification_code(email: str, code: str) -> bool:
+    # logger.info("Check verification code")
     bypass = settings.DEBUG_BYPASS_REDIS_VERIFICATION_CODE
     if bypass is not None and bypass.startswith("magic") and bypass == code:
-        logger.warning("Using magic bypass code for email="+email)
+        logger.warning("Using magic bypass code for email=" + email)
         return True
     redis_cli = get_redis_cli()
     key = f"chafan:verification-code:{email}"
@@ -43,7 +36,8 @@ async def check_digit_verification_code(email:str, code:str) -> bool:
     redis_cli.delete(key)
     return True
 
-async def register_digit_verification_code(email:str, code:str) -> None:
+
+async def register_digit_verification_code(email: str, code: str) -> None:
     redis_cli = get_redis_cli()
     key = f"chafan:verification-code:{email}"
     redis_cli.delete(key)
@@ -51,13 +45,13 @@ async def register_digit_verification_code(email:str, code:str) -> None:
     redis_cli.expire(
         key, time=datetime.timedelta(hours=settings.EMAIL_SIGNUP_CODE_EXPIRE_HOURS)
     )
-    #logger.info("Register verification code")
+    # logger.info("Register verification code")
 
 
-
-def create_digit_verification_code(length:int) -> str:
+def create_digit_verification_code(length: int) -> str:
     return "".join([str(random.randint(0, 9)) for _ in range(length)])
 
+
 def create_access_token(
     subject: Union[str, Any], expires_delta: Optional[datetime.timedelta] = None
 ) -> str:
@@ -110,4 +104,3 @@ def verify_password_reset_token(token: str) -> Optional[str]:
         return decoded_token["email"]
     except Exception:
         return None
-
diff --git a/chafan_core/app/task.py b/chafan_core/app/task.py
index 104c91c..387ffe4 100644
--- a/chafan_core/app/task.py
+++ b/chafan_core/app/task.py
@@ -1,25 +1,23 @@
 import datetime
+import logging
+from collections import Counter
 from typing import List, Optional
 
-from collections import Counter
 import dramatiq
 from dramatiq.brokers.redis import RedisBroker
 from sqlalchemy.orm.session import Session
 
-
-
+import chafan_core.app.rep_manager as rep
 from chafan_core.app import crud, models, schemas
-from chafan_core.app.cached_layer import CachedLayer
-from chafan_core.app.cached_layer import BUMP_VIEW_COUNT_QUEUE_CACHE_KEY
+from chafan_core.app.cached_layer import BUMP_VIEW_COUNT_QUEUE_CACHE_KEY, CachedLayer
 from chafan_core.app.config import settings
-from chafan_core.app.feed import (
-        new_activity_into_feed,
-)
 from chafan_core.app.crud.crud_activity import (
     create_answer_activity,
     create_article_activity,
 )
 from chafan_core.app.data_broker import DataBroker
+from chafan_core.app.feed import new_activity_into_feed
+from chafan_core.app.models.activity import Activity
 from chafan_core.app.recs.indexing import (
     compute_interesting_questions_ids_for_normal_user,
     compute_interesting_questions_ids_for_visitor_user,
@@ -59,11 +57,7 @@
 )
 from chafan_core.db.session import SessionLocal
 from chafan_core.utils.base import TaskStatus, get_utc_now
-from chafan_core.app.models.activity import Activity
-import chafan_core.app.rep_manager as rep
-
 
-import logging
 logger = logging.getLogger(__name__)
 
 
@@ -74,7 +68,6 @@
 dramatiq.set_broker(dramatiq_broker)
 
 
-
 def notify_mentioned_users(
     broker: DataBroker, comment: models.Comment, user_handles: List[str]
 ) -> None:
@@ -273,10 +266,10 @@ def runnable(broker: DataBroker) -> None:
         rep.new_question(question)
 
         question_ac = models.Activity(
-                created_at=utc_now,
-                site_id=question.site_id,
-                event_json=event_json,
-            )
+            created_at=utc_now,
+            site_id=question.site_id,
+            event_json=event_json,
+        )
         db = broker.get_db()
         db.add(question_ac)
         db.flush()
@@ -455,7 +448,9 @@ def runnable(db: Session) -> None:
 def postprocess_new_answer(answer_id: int, was_published: bool) -> None:
     def runnable(broker: DataBroker) -> None:
         answer = crud.answer.get(broker.get_db(), id=answer_id)
-        logger.info(f"postprocess_new_answer id={answer_id}, was_published={was_published}")
+        logger.info(
+            f"postprocess_new_answer id={answer_id}, was_published={was_published}"
+        )
         assert answer is not None and answer.is_published
         utc_now = datetime.datetime.now(tz=datetime.timezone.utc)
         if not was_published:
@@ -471,10 +466,10 @@ def runnable(broker: DataBroker) -> None:
                     receiver_id=answer.question.author.id,
                 )
             answer_ac: Activity = create_answer_activity(
-                    answer=answer,
-                    site_id=answer.question.site.id,
-                    created_at=utc_now,
-                )
+                answer=answer,
+                site_id=answer.question.site.id,
+                created_at=utc_now,
+            )
             db = broker.get_db()
             db.add(answer_ac)
             db.flush()
@@ -524,7 +519,9 @@ def runnable(broker: DataBroker) -> None:
                 event=event_internal,
                 receiver_id=subscriber.id,
             )
-        article_ac: Activity = create_article_activity(article=article, created_at=utc_now)
+        article_ac: Activity = create_article_activity(
+            article=article, created_at=utc_now
+        )
         db = broker.get_db()
         db.add(article_ac)
         db.flush()
@@ -600,7 +597,13 @@ def runnable(db: Session) -> None:
     execute_with_db(SessionLocal(), runnable)
 
 
-from chafan_core.app.models.viewcount import ViewCountQuestion, ViewCountAnswer, ViewCountArticle, ViewCountSubmission
+from chafan_core.app.models.viewcount import (
+    ViewCountAnswer,
+    ViewCountArticle,
+    ViewCountQuestion,
+    ViewCountSubmission,
+)
+
 
 # TODO Should I move this function to another file? 2025-07-23
 def _add_viewcount_to_db(broker: DataBroker, key: str, count: int) -> None:
@@ -611,7 +614,11 @@ def _add_viewcount_to_db(broker: DataBroker, key: str, count: int) -> None:
     db = broker.get_db()
 
     def bump_question():
-        prev = db.query(ViewCountQuestion).filter(ViewCountQuestion.question_id == row_id).first()
+        prev = (
+            db.query(ViewCountQuestion)
+            .filter(ViewCountQuestion.question_id == row_id)
+            .first()
+        )
         if prev is None:
             prev = ViewCountQuestion()
             prev.question_id = row_id
@@ -622,7 +629,11 @@ def bump_question():
         db.commit()
 
     def bump_answer():
-        prev = db.query(ViewCountAnswer).filter(ViewCountAnswer.answer_id == row_id).first()
+        prev = (
+            db.query(ViewCountAnswer)
+            .filter(ViewCountAnswer.answer_id == row_id)
+            .first()
+        )
         if prev is None:
             prev = ViewCountAnswer()
             prev.answer_id = row_id
@@ -630,8 +641,13 @@ def bump_answer():
         prev.view_count += count
         db.add(prev)
         db.commit()
+
     def bump_article():
-        prev = db.query(ViewCountArticle).filter(ViewCountArticle.article_id == row_id).first()
+        prev = (
+            db.query(ViewCountArticle)
+            .filter(ViewCountArticle.article_id == row_id)
+            .first()
+        )
         if prev is None:
             prev = ViewCountArticle()
             prev.article_id = row_id
@@ -641,7 +657,11 @@ def bump_article():
         db.commit()
 
     def bump_submission():
-        prev = db.query(ViewCountSubmission).filter(ViewCountSubmission.submission_id == row_id).first()
+        prev = (
+            db.query(ViewCountSubmission)
+            .filter(ViewCountSubmission.submission_id == row_id)
+            .first()
+        )
         if prev is None:
             prev = ViewCountSubmission()
             prev.submission_id = row_id
@@ -662,18 +682,19 @@ def bump_submission():
         logger.error(f"Unhandled viewcount key: {key}")
 
 
-
-
 def write_view_count_to_db() -> None:
     def runnable(broker: DataBroker):
         logger.debug("write_view_count_to_db called")
         redis = broker.get_redis()
         views = redis.lrange(BUMP_VIEW_COUNT_QUEUE_CACHE_KEY, 0, -1)
-        redis.delete(BUMP_VIEW_COUNT_QUEUE_CACHE_KEY) # Race condition here. But losing a few view counts is okay
+        redis.delete(
+            BUMP_VIEW_COUNT_QUEUE_CACHE_KEY
+        )  # Race condition here. But losing a few view counts is okay
         view_dict = Counter(views)
         logger.debug("get views " + str(view_dict))
-        for k,v in view_dict.items():
+        for k, v in view_dict.items():
             _add_viewcount_to_db(broker, k, v)
+
     execute_with_broker(runnable)
     return None
 
@@ -694,6 +715,7 @@ def runnable(broker: DataBroker):
 from chafan_core.db.session import ReadSessionLocal
 from chafan_core.utils.constants import indexed_object_T
 
+
 @contextmanager
 def _index_rewriter(index_type: indexed_object_T) -> Iterator[writing.IndexWriter]:
     index_dir = settings.SEARCH_INDEX_FILESYSTEM_PATH + "/" + index_type
diff --git a/chafan_core/app/task_utils.py b/chafan_core/app/task_utils.py
index 008fb51..e361203 100644
--- a/chafan_core/app/task_utils.py
+++ b/chafan_core/app/task_utils.py
@@ -9,6 +9,7 @@
 
 # TODO This file should be removed. These patterns provide little benefit today 2025-Jul-11
 
+
 def execute_with_db(
     db: Session, runnable: Callable[[Session], T], auto_commit: bool = True
 ) -> Optional[T]:
diff --git a/chafan_core/app/user_permission.py b/chafan_core/app/user_permission.py
index 5367978..1cd7a15 100644
--- a/chafan_core/app/user_permission.py
+++ b/chafan_core/app/user_permission.py
@@ -1,3 +1,4 @@
+import logging
 from typing import Optional
 
 from sqlalchemy.orm import Session
@@ -7,8 +8,6 @@
 from chafan_core.app.config import settings
 from chafan_core.utils.base import ContentVisibility
 
-
-import logging
 logger = logging.getLogger(__name__)
 
 # TODO everything about user permission, including if they can create a site (KARMA), invite a user, write an answer, etc, should be moved into this file. 2025-07-08
@@ -19,6 +18,7 @@ def get_active_site_profile(
 ) -> Optional[models.Profile]:
     return crud.profile.get_by_user_and_site(db, owner_id=user_id, site_id=site.id)
 
+
 def user_in_site(
     db: Session,
     site: models.Site,
@@ -41,8 +41,10 @@ def user_in_site(
         return False
     return True
 
+
 def article_read_allowed(
-    db: Session, article: models.Article, user_id: Optional[int]) -> bool:
+    db: Session, article: models.Article, user_id: Optional[int]
+) -> bool:
     if article.is_published and article.visibility == ContentVisibility.ANYONE:
         return True
     if article.author_id == user_id and user_id is not None:
@@ -51,8 +53,10 @@ def article_read_allowed(
     logger.info(f"User {user_id} is not allowed to read article {article.id}")
     return False
 
+
 def question_read_allowed(
-    cached_layer, question: models.Question, user_id: Optional[int]) -> bool:
+    cached_layer, question: models.Question, user_id: Optional[int]
+) -> bool:
     if not question.is_hidden:
         return True
     if user_id is not None and user_id == question.author_id:
@@ -61,5 +65,3 @@ def question_read_allowed(
         return False
     # TODO we should allow superuser and admin of sites to see hidden questions
     return False
-
-
diff --git a/chafan_core/app/view_counters.py b/chafan_core/app/view_counters.py
index 541bb79..7d5bd64 100644
--- a/chafan_core/app/view_counters.py
+++ b/chafan_core/app/view_counters.py
@@ -1,16 +1,15 @@
+import logging
 from typing import Literal
 
-import logging
 logger = logging.getLogger(__name__)
 
-#from chafan_core.app.cached_layer import CachedLayer
-
+# from chafan_core.app.cached_layer import CachedLayer
 
 
 async def add_view_async(
-    cached_layer, # TODO 2025-07-20 due to cyclic dep, turn off this type hint: CachedLayer,
+    cached_layer,  # TODO 2025-07-20 due to cyclic dep, turn off this type hint: CachedLayer,
     object_type: Literal["question", "answer", "profile", "article", "submission"],
-    obj_id: int
+    obj_id: int,
 ) -> None:
 
     assert object_type in ["question", "answer", "article", "submission"]
@@ -26,31 +25,54 @@ def add_view(
     return 0
 
 
-from chafan_core.app.models.viewcount import ViewCountQuestion, ViewCountAnswer, ViewCountArticle, ViewCountSubmission
+from chafan_core.app.models.viewcount import (
+    ViewCountAnswer,
+    ViewCountArticle,
+    ViewCountQuestion,
+    ViewCountSubmission,
+)
 
 
-def get_viewcount_question(broker, row_id:int)->int:
+def get_viewcount_question(broker, row_id: int) -> int:
     db = broker.get_db()
-    row = db.query(ViewCountQuestion).filter(ViewCountQuestion.question_id == row_id).first()
+    row = (
+        db.query(ViewCountQuestion)
+        .filter(ViewCountQuestion.question_id == row_id)
+        .first()
+    )
     if row is None:
         return 0
     return row.view_count
-def get_viewcount_article(broker, row_id:int)->int:
+
+
+def get_viewcount_article(broker, row_id: int) -> int:
     db = broker.get_db()
-    row = db.query(ViewCountArticle).filter(ViewCountArticle.article_id == row_id).first()
+    row = (
+        db.query(ViewCountArticle).filter(ViewCountArticle.article_id == row_id).first()
+    )
     if row is None:
         return 0
     return row.view_count
-def get_viewcount_submission(broker, row_id:int)->int:
+
+
+def get_viewcount_submission(broker, row_id: int) -> int:
     db = broker.get_db()
-    row = db.query(ViewCountSubmission).filter(ViewCountSubmission.submission_id == row_id).first()
+    row = (
+        db.query(ViewCountSubmission)
+        .filter(ViewCountSubmission.submission_id == row_id)
+        .first()
+    )
     if row is None:
         return 0
     return row.view_count
-def get_viewcount_answer(broker, row_id:int)->int:
+
+
+def get_viewcount_answer(broker, row_id: int) -> int:
     db = broker.get_db()
     row = db.query(ViewCountAnswer).filter(ViewCountAnswer.answer_id == row_id).first()
     if row is None:
         return 0
     return row.view_count
-#object_type: Literal["question", "answer", "profile", "article", "submission"],
+
+
+# object_type: Literal["question", "answer", "profile", "article", "submission"],
diff --git a/chafan_core/app/ws_connections.py b/chafan_core/app/ws_connections.py
index dd09ce3..49151d5 100644
--- a/chafan_core/app/ws_connections.py
+++ b/chafan_core/app/ws_connections.py
@@ -1,10 +1,11 @@
+import logging
 from typing import MutableMapping
 
 from fastapi.websockets import WebSocket
 
-import logging
 logger = logging.getLogger(__name__)
 
+
 class ConnectionManager:
     def __init__(self) -> None:
         # User ID -> WebSocket
@@ -26,4 +27,3 @@ async def send_message(self, message: str, user_id: int) -> None:
 
 
 manager = ConnectionManager()
-
diff --git a/chafan_core/db/init_db.py b/chafan_core/db/init_db.py
index a6d4529..7465c44 100644
--- a/chafan_core/db/init_db.py
+++ b/chafan_core/db/init_db.py
@@ -1,4 +1,5 @@
 import asyncio
+
 from sqlalchemy.orm import Session
 
 from chafan_core.app import crud, schemas
diff --git a/chafan_core/tests/app/api/api_v1/test_answers.py b/chafan_core/tests/app/api/api_v1/test_answers.py
index c8ec9d7..a0aa7b4 100644
--- a/chafan_core/tests/app/api/api_v1/test_answers.py
+++ b/chafan_core/tests/app/api/api_v1/test_answers.py
@@ -94,7 +94,9 @@ def test_create_answer_success(
     assert db_answer.question.uuid == normal_user_authored_question_uuid
 
 
-@pytest.mark.skip(reason="TODO: Test isolation issue - 'You have saved an answer before' error when using same question")
+@pytest.mark.skip(
+    reason="TODO: Test isolation issue - 'You have saved an answer before' error when using same question"
+)
 def test_create_answer_as_draft(
     client: TestClient,
     db: Session,
@@ -164,7 +166,9 @@ def test_create_answer_invalid_question(
 # =============================================================================
 
 
-@pytest.mark.skip(reason="TODO: Test isolation issue - cannot create another answer to same question")
+@pytest.mark.skip(
+    reason="TODO: Test isolation issue - cannot create another answer to same question"
+)
 def test_get_answer_success(
     client: TestClient,
     db: Session,
@@ -234,7 +238,9 @@ def test_get_answer_nonexistent(
 # =============================================================================
 
 
-@pytest.mark.skip(reason="TODO: Test isolation issue - cannot create another answer to same question")
+@pytest.mark.skip(
+    reason="TODO: Test isolation issue - cannot create another answer to same question"
+)
 def test_update_answer_as_author(
     client: TestClient,
     db: Session,
@@ -303,7 +309,9 @@ def test_update_answer_as_author(
     assert archive.body == original_content
 
 
-@pytest.mark.skip(reason="TODO: Test isolation issue - cannot create another answer to same question")
+@pytest.mark.skip(
+    reason="TODO: Test isolation issue - cannot create another answer to same question"
+)
 def test_update_answer_as_non_author(
     client: TestClient,
     db: Session,
@@ -365,7 +373,9 @@ def test_update_answer_as_non_author(
 # =============================================================================
 
 
-@pytest.mark.skip(reason="TODO: Test isolation issue - cannot create another answer to same question")
+@pytest.mark.skip(
+    reason="TODO: Test isolation issue - cannot create another answer to same question"
+)
 def test_delete_answer_success(
     client: TestClient,
     db: Session,
diff --git a/chafan_core/tests/app/api/api_v1/test_articles.py b/chafan_core/tests/app/api/api_v1/test_articles.py
index 2fcedf6..3056f76 100644
--- a/chafan_core/tests/app/api/api_v1/test_articles.py
+++ b/chafan_core/tests/app/api/api_v1/test_articles.py
@@ -31,7 +31,9 @@ def test_get_article_unauthenticated(
     # Verify data exists in database
     db.expire_all()
     db_article = crud.article.get_by_uuid(db, uuid=example_article_uuid)
-    assert db_article is not None, f"Article {example_article_uuid} not found in database"
+    assert (
+        db_article is not None
+    ), f"Article {example_article_uuid} not found in database"
     assert db_article.uuid == example_article_uuid
     assert db_article.title == data["title"]
     assert db_article.is_published is True
@@ -60,12 +62,16 @@ def test_get_article_authenticated(
     # Verify data in database matches response
     db.expire_all()
     db_article = crud.article.get_by_uuid(db, uuid=example_article_uuid)
-    assert db_article is not None, f"Article {example_article_uuid} not found in database"
+    assert (
+        db_article is not None
+    ), f"Article {example_article_uuid} not found in database"
     assert db_article.title == data["title"]
     assert db_article.body == data["content"]["source"]
 
 
-@pytest.mark.skip(reason="TODO: get_article endpoint doesn't handle None article before accessing is_published")
+@pytest.mark.skip(
+    reason="TODO: get_article endpoint doesn't handle None article before accessing is_published"
+)
 def test_get_article_nonexistent(
     client: TestClient,
     db: Session,
@@ -588,7 +594,9 @@ def test_get_article_archives_unauthorized(
     # Verify the article exists but access is denied (not a data issue)
     db.expire_all()
     db_article = crud.article.get_by_uuid(db, uuid=example_article_uuid)
-    assert db_article is not None, f"Article {example_article_uuid} not found in database"
+    assert (
+        db_article is not None
+    ), f"Article {example_article_uuid} not found in database"
 
 
 # =============================================================================
@@ -655,7 +663,9 @@ def test_delete_article_unauthorized(
     # Verify article exists and is not deleted
     db.expire_all()
     db_article_before = crud.article.get_by_uuid(db, uuid=example_article_uuid)
-    assert db_article_before is not None, f"Article {example_article_uuid} not found in database"
+    assert (
+        db_article_before is not None
+    ), f"Article {example_article_uuid} not found in database"
     assert db_article_before.is_deleted is False
 
     r = client.delete(
diff --git a/chafan_core/tests/app/api/api_v1/test_comments.py b/chafan_core/tests/app/api/api_v1/test_comments.py
index 39b5544..5be60de 100644
--- a/chafan_core/tests/app/api/api_v1/test_comments.py
+++ b/chafan_core/tests/app/api/api_v1/test_comments.py
@@ -187,7 +187,9 @@ def test_get_comment_nonexistent(
 # =============================================================================
 
 
-@pytest.mark.skip(reason="TODO: Comment update API uses different payload format (content RichText, not body string)")
+@pytest.mark.skip(
+    reason="TODO: Comment update API uses different payload format (content RichText, not body string)"
+)
 def test_update_comment_as_author(
     client: TestClient,
     db: Session,
diff --git a/chafan_core/tests/app/api/api_v1/test_questions.py b/chafan_core/tests/app/api/api_v1/test_questions.py
index 3529ee9..6c53e71 100644
--- a/chafan_core/tests/app/api/api_v1/test_questions.py
+++ b/chafan_core/tests/app/api/api_v1/test_questions.py
@@ -87,8 +87,12 @@ def test_create_question_success(
     """Test successful question creation and verify data in PostgreSQL."""
     # Ensure user is a site member
     ensure_user_in_site(
-        client, db, normal_user_id, normal_user_uuid,
-        example_site_uuid, superuser_token_headers
+        client,
+        db,
+        normal_user_id,
+        normal_user_uuid,
+        example_site_uuid,
+        superuser_token_headers,
     )
 
     title = f"Test Question {random_lower_string()}"
@@ -144,8 +148,12 @@ def test_get_question_success(
     """Test getting a question and verify data matches PostgreSQL."""
     # Ensure user is a site member
     ensure_user_in_site(
-        client, db, normal_user_id, normal_user_uuid,
-        example_site_uuid, superuser_token_headers
+        client,
+        db,
+        normal_user_id,
+        normal_user_uuid,
+        example_site_uuid,
+        superuser_token_headers,
     )
 
     # First create a question
@@ -182,7 +190,9 @@ def test_get_question_success(
     assert db_question.uuid == response_data["uuid"]
 
 
-@pytest.mark.skip(reason="TODO: get_question endpoint doesn't handle None question before accessing is_hidden")
+@pytest.mark.skip(
+    reason="TODO: get_question endpoint doesn't handle None question before accessing is_hidden"
+)
 def test_get_question_nonexistent(
     client: TestClient,
     db: Session,
@@ -205,7 +215,9 @@ def test_get_question_nonexistent(
 # =============================================================================
 
 
-@pytest.mark.skip(reason="TODO: QuestionCreate doesn't support description, QuestionUpdate uses 'desc' (RichText) not 'description'")
+@pytest.mark.skip(
+    reason="TODO: QuestionCreate doesn't support description, QuestionUpdate uses 'desc' (RichText) not 'description'"
+)
 def test_update_question_as_author(
     client: TestClient,
     db: Session,
@@ -218,8 +230,12 @@ def test_update_question_as_author(
     """Test updating a question as author and verify in PostgreSQL."""
     # Ensure user is a site member
     ensure_user_in_site(
-        client, db, normal_user_id, normal_user_uuid,
-        example_site_uuid, superuser_token_headers
+        client,
+        db,
+        normal_user_id,
+        normal_user_uuid,
+        example_site_uuid,
+        superuser_token_headers,
     )
 
     # First create a question
@@ -260,7 +276,9 @@ def test_update_question_as_author(
     assert new_description in db_question_after.description
 
 
-@pytest.mark.skip(reason="TODO: QuestionCreate doesn't support description, QuestionUpdate uses 'desc' (RichText) not 'description'")
+@pytest.mark.skip(
+    reason="TODO: QuestionCreate doesn't support description, QuestionUpdate uses 'desc' (RichText) not 'description'"
+)
 def test_update_question_as_non_author(
     client: TestClient,
     db: Session,
@@ -274,8 +292,12 @@ def test_update_question_as_non_author(
     """Test that non-authors cannot update questions."""
     # Ensure user is a site member
     ensure_user_in_site(
-        client, db, normal_user_id, normal_user_uuid,
-        example_site_uuid, superuser_token_headers
+        client,
+        db,
+        normal_user_id,
+        normal_user_uuid,
+        example_site_uuid,
+        superuser_token_headers,
     )
 
     # Create a question as normal user
@@ -345,8 +367,12 @@ def test_bump_question_views(
     """Test bumping views counter for a question."""
     # Ensure user is a site member
     ensure_user_in_site(
-        client, db, normal_user_id, normal_user_uuid,
-        example_site_uuid, superuser_token_headers
+        client,
+        db,
+        normal_user_id,
+        normal_user_uuid,
+        example_site_uuid,
+        superuser_token_headers,
     )
 
     # Create a question
@@ -404,8 +430,12 @@ def test_get_question_upvotes(
     """Test getting upvotes for a question."""
     # Ensure user is a site member
     ensure_user_in_site(
-        client, db, normal_user_id, normal_user_uuid,
-        example_site_uuid, superuser_token_headers
+        client,
+        db,
+        normal_user_id,
+        normal_user_uuid,
+        example_site_uuid,
+        superuser_token_headers,
     )
 
     # Create a question
diff --git a/chafan_core/tests/app/api/api_v1/test_sites.py b/chafan_core/tests/app/api/api_v1/test_sites.py
index dc0c5fc..9dfc2b2 100644
--- a/chafan_core/tests/app/api/api_v1/test_sites.py
+++ b/chafan_core/tests/app/api/api_v1/test_sites.py
@@ -55,7 +55,9 @@ def test_sites(
 
     # Verify the site was updated by fetching it directly
     # Use superuser headers since they created the site and have a site profile
-    r = client.get(f"{settings.API_V1_STR}/sites/demo_{demo_name}", headers=superuser_token_headers)
+    r = client.get(
+        f"{settings.API_V1_STR}/sites/demo_{demo_name}", headers=superuser_token_headers
+    )
     assert r.status_code == 200, (r.status_code, r.json())
     site = r.json()
     assert site["description"] == "Demo Site 2"
diff --git a/chafan_core/tests/app/api/api_v1/test_submissions.py b/chafan_core/tests/app/api/api_v1/test_submissions.py
index 13ee6ef..b1f75a6 100644
--- a/chafan_core/tests/app/api/api_v1/test_submissions.py
+++ b/chafan_core/tests/app/api/api_v1/test_submissions.py
@@ -64,9 +64,7 @@ def test_get_submission_upvotes_nonexistent(
     db: Session,
 ) -> None:
     """Test getting upvotes for a nonexistent submission returns an error."""
-    r = client.get(
-        f"{settings.API_V1_STR}/submissions/invalid-uuid/upvotes/"
-    )
+    r = client.get(f"{settings.API_V1_STR}/submissions/invalid-uuid/upvotes/")
     assert r.status_code == 400
     assert "doesn't exists" in r.json()["detail"]
 
@@ -102,9 +100,7 @@ def test_bump_views_counter_nonexistent(
     db: Session,
 ) -> None:
     """Test bumping views for nonexistent submission returns an error."""
-    r = client.post(
-        f"{settings.API_V1_STR}/submissions/invalid-uuid/views/"
-    )
+    r = client.post(f"{settings.API_V1_STR}/submissions/invalid-uuid/views/")
     assert r.status_code == 400
 
     # Verify it doesn't exist in database
@@ -217,8 +213,12 @@ def test_create_submission_success(
 ) -> None:
     """Test successful submission creation and verify data in PostgreSQL."""
     ensure_user_in_site(
-        client, db, normal_user_id, normal_user_uuid,
-        example_site_uuid, superuser_token_headers
+        client,
+        db,
+        normal_user_id,
+        normal_user_uuid,
+        example_site_uuid,
+        superuser_token_headers,
     )
 
     title = f"Test Submission {random_lower_string()}"
@@ -270,7 +270,9 @@ def test_update_submission_as_author(
     # Get original title from database
     db.expire_all()
     db_submission_before = crud.submission.get_by_uuid(db, uuid=example_submission_uuid)
-    assert db_submission_before is not None, f"Submission {example_submission_uuid} not found"
+    assert (
+        db_submission_before is not None
+    ), f"Submission {example_submission_uuid} not found"
     original_title = db_submission_before.title
 
     new_title = f"Updated Title {random_lower_string()}"
@@ -303,7 +305,9 @@ def test_update_submission_as_non_author(
     # Get original title from database
     db.expire_all()
     db_submission_before = crud.submission.get_by_uuid(db, uuid=example_submission_uuid)
-    assert db_submission_before is not None, f"Submission {example_submission_uuid} not found"
+    assert (
+        db_submission_before is not None
+    ), f"Submission {example_submission_uuid} not found"
     original_title = db_submission_before.title
 
     data = {
@@ -320,7 +324,9 @@ def test_update_submission_as_non_author(
     # Verify data was NOT changed in PostgreSQL
     db.expire_all()
     db_submission_after = crud.submission.get_by_uuid(db, uuid=example_submission_uuid)
-    assert db_submission_after is not None, f"Submission {example_submission_uuid} not found"
+    assert (
+        db_submission_after is not None
+    ), f"Submission {example_submission_uuid} not found"
     assert db_submission_after.title == original_title
 
 
@@ -424,15 +430,21 @@ def test_upvote_submission_success(
 ) -> None:
     """Test upvoting a submission and verify in PostgreSQL."""
     ensure_user_in_site(
-        client, db, moderator_user_id, moderator_user_uuid,
-        example_site_uuid, superuser_token_headers
+        client,
+        db,
+        moderator_user_id,
+        moderator_user_uuid,
+        example_site_uuid,
+        superuser_token_headers,
     )
     ensure_user_has_coins(db, moderator_user_id, coins=100)
 
     # Get initial upvote count from database
     db.expire_all()
     db_submission_before = crud.submission.get_by_uuid(db, uuid=example_submission_uuid)
-    assert db_submission_before is not None, f"Submission {example_submission_uuid} not found"
+    assert (
+        db_submission_before is not None
+    ), f"Submission {example_submission_uuid} not found"
     initial_db_count = db_submission_before.upvotes_count
 
     r = client.get(
@@ -453,7 +465,9 @@ def test_upvote_submission_success(
     # Verify upvote is recorded in PostgreSQL
     db.expire_all()
     db_submission_after = crud.submission.get_by_uuid(db, uuid=example_submission_uuid)
-    assert db_submission_after is not None, f"Submission {example_submission_uuid} not found"
+    assert (
+        db_submission_after is not None
+    ), f"Submission {example_submission_uuid} not found"
     assert db_submission_after.upvotes_count >= initial_db_count
 
 
@@ -469,8 +483,12 @@ def test_upvote_submission_idempotent(
 ) -> None:
     """Test that double upvoting doesn't increase count."""
     ensure_user_in_site(
-        client, db, moderator_user_id, moderator_user_uuid,
-        example_site_uuid, superuser_token_headers
+        client,
+        db,
+        moderator_user_id,
+        moderator_user_uuid,
+        example_site_uuid,
+        superuser_token_headers,
     )
     ensure_user_has_coins(db, moderator_user_id, coins=100)
 
@@ -484,7 +502,9 @@ def test_upvote_submission_idempotent(
     # Get database count after first upvote
     db.expire_all()
     db_submission_1 = crud.submission.get_by_uuid(db, uuid=example_submission_uuid)
-    assert db_submission_1 is not None, f"Submission {example_submission_uuid} not found"
+    assert (
+        db_submission_1 is not None
+    ), f"Submission {example_submission_uuid} not found"
     db_count1 = db_submission_1.upvotes_count
 
     # Second upvote (should not increase count)
@@ -499,7 +519,9 @@ def test_upvote_submission_idempotent(
     # Verify database count unchanged
     db.expire_all()
     db_submission_2 = crud.submission.get_by_uuid(db, uuid=example_submission_uuid)
-    assert db_submission_2 is not None, f"Submission {example_submission_uuid} not found"
+    assert (
+        db_submission_2 is not None
+    ), f"Submission {example_submission_uuid} not found"
     assert db_submission_2.upvotes_count == db_count1
 
 
@@ -513,7 +535,9 @@ def test_upvote_submission_author_cannot_upvote(
     # Get initial count from database
     db.expire_all()
     db_submission_before = crud.submission.get_by_uuid(db, uuid=example_submission_uuid)
-    assert db_submission_before is not None, f"Submission {example_submission_uuid} not found"
+    assert (
+        db_submission_before is not None
+    ), f"Submission {example_submission_uuid} not found"
     initial_count = db_submission_before.upvotes_count
 
     r = client.post(
@@ -526,7 +550,9 @@ def test_upvote_submission_author_cannot_upvote(
     # Verify count unchanged in database
     db.expire_all()
     db_submission_after = crud.submission.get_by_uuid(db, uuid=example_submission_uuid)
-    assert db_submission_after is not None, f"Submission {example_submission_uuid} not found"
+    assert (
+        db_submission_after is not None
+    ), f"Submission {example_submission_uuid} not found"
     assert db_submission_after.upvotes_count == initial_count
 
 
@@ -542,8 +568,12 @@ def test_cancel_upvote_submission(
 ) -> None:
     """Test canceling an upvote and verify in PostgreSQL."""
     ensure_user_in_site(
-        client, db, moderator_user_id, moderator_user_uuid,
-        example_site_uuid, superuser_token_headers
+        client,
+        db,
+        moderator_user_id,
+        moderator_user_uuid,
+        example_site_uuid,
+        superuser_token_headers,
     )
     ensure_user_has_coins(db, moderator_user_id, coins=100)
 
@@ -557,8 +587,12 @@ def test_cancel_upvote_submission(
 
     # Get database count after upvote
     db.expire_all()
-    db_submission_upvoted = crud.submission.get_by_uuid(db, uuid=example_submission_uuid)
-    assert db_submission_upvoted is not None, f"Submission {example_submission_uuid} not found"
+    db_submission_upvoted = crud.submission.get_by_uuid(
+        db, uuid=example_submission_uuid
+    )
+    assert (
+        db_submission_upvoted is not None
+    ), f"Submission {example_submission_uuid} not found"
     db_count_upvoted = db_submission_upvoted.upvotes_count
 
     # Cancel upvote
@@ -573,8 +607,12 @@ def test_cancel_upvote_submission(
 
     # Verify count decreased in database
     db.expire_all()
-    db_submission_cancelled = crud.submission.get_by_uuid(db, uuid=example_submission_uuid)
-    assert db_submission_cancelled is not None, f"Submission {example_submission_uuid} not found"
+    db_submission_cancelled = crud.submission.get_by_uuid(
+        db, uuid=example_submission_uuid
+    )
+    assert (
+        db_submission_cancelled is not None
+    ), f"Submission {example_submission_uuid} not found"
     assert db_submission_cancelled.upvotes_count <= db_count_upvoted
 
 
@@ -594,8 +632,12 @@ def test_hide_submission_as_author(
 ) -> None:
     """Test hiding a submission and verify in PostgreSQL."""
     ensure_user_in_site(
-        client, db, normal_user_id, normal_user_uuid,
-        example_site_uuid, superuser_token_headers
+        client,
+        db,
+        normal_user_id,
+        normal_user_uuid,
+        example_site_uuid,
+        superuser_token_headers,
     )
 
     # Create a submission to hide
diff --git a/chafan_core/tests/app/crud/a/test_crud_activity.py b/chafan_core/tests/app/crud/a/test_crud_activity.py
index 6083f2e..46baec8 100644
--- a/chafan_core/tests/app/crud/a/test_crud_activity.py
+++ b/chafan_core/tests/app/crud/a/test_crud_activity.py
@@ -69,7 +69,9 @@ def _create_test_submission(db: Session, author_id: int, site):
         title=f"Test Submission {random_short_lower_string()}",
         url="https://example.com/test",
     )
-    return crud.submission.create_with_author(db, obj_in=submission_in, author_id=author_id)
+    return crud.submission.create_with_author(
+        db, obj_in=submission_in, author_id=author_id
+    )
 
 
 def _create_test_answer(db: Session, author_id: int, question, site):
@@ -96,7 +98,9 @@ def _create_test_article_column(db: Session, owner_id: int):
         name=f"Test Column {random_short_lower_string()}",
         description="Test column description",
     )
-    return crud.article_column.create_with_owner(db, obj_in=column_in, owner_id=owner_id)
+    return crud.article_column.create_with_owner(
+        db, obj_in=column_in, owner_id=owner_id
+    )
 
 
 def _create_test_article(db: Session, author_id: int, column):
@@ -138,7 +142,9 @@ def test_get_multi_by_id_range_with_max_id(db: Session) -> None:
         # Test with max_id
         max_id = all_activities[0].id + 1
         min_id = all_activities[-1].id - 1
-        range_activities = list(activity.get_multi_by_id_range(db, min_id=min_id, max_id=max_id))
+        range_activities = list(
+            activity.get_multi_by_id_range(db, min_id=min_id, max_id=max_id)
+        )
         assert len(range_activities) <= len(all_activities)
 
 
diff --git a/chafan_core/tests/app/crud/a/test_crud_answer_suggest_edit.py b/chafan_core/tests/app/crud/a/test_crud_answer_suggest_edit.py
index 852b563..090a656 100644
--- a/chafan_core/tests/app/crud/a/test_crud_answer_suggest_edit.py
+++ b/chafan_core/tests/app/crud/a/test_crud_answer_suggest_edit.py
@@ -77,7 +77,9 @@ def test_create_answer_suggest_edit_with_author(db: Session) -> None:
     suggester = _create_test_user(db)
     site = _create_test_site(db, moderator=moderator)
     question = _create_test_question(db, author_id=answer_author.id, site=site)
-    answer = _create_test_answer(db, author_id=answer_author.id, question=question, site=site)
+    answer = _create_test_answer(
+        db, author_id=answer_author.id, question=question, site=site
+    )
 
     suggest_edit_in = AnswerSuggestEditCreate(
         answer_uuid=answer.uuid,
@@ -109,7 +111,9 @@ def test_create_answer_suggest_edit_without_comment(db: Session) -> None:
     suggester = _create_test_user(db)
     site = _create_test_site(db, moderator=moderator)
     question = _create_test_question(db, author_id=answer_author.id, site=site)
-    answer = _create_test_answer(db, author_id=answer_author.id, question=question, site=site)
+    answer = _create_test_answer(
+        db, author_id=answer_author.id, question=question, site=site
+    )
 
     suggest_edit_in = AnswerSuggestEditCreate(
         answer_uuid=answer.uuid,
@@ -136,7 +140,9 @@ def test_get_answer_suggest_edit_by_id(db: Session) -> None:
     suggester = _create_test_user(db)
     site = _create_test_site(db, moderator=moderator)
     question = _create_test_question(db, author_id=answer_author.id, site=site)
-    answer = _create_test_answer(db, author_id=answer_author.id, question=question, site=site)
+    answer = _create_test_answer(
+        db, author_id=answer_author.id, question=question, site=site
+    )
 
     suggest_edit_in = AnswerSuggestEditCreate(
         answer_uuid=answer.uuid,
@@ -163,7 +169,9 @@ def test_get_answer_suggest_edit_by_uuid(db: Session) -> None:
     suggester = _create_test_user(db)
     site = _create_test_site(db, moderator=moderator)
     question = _create_test_question(db, author_id=answer_author.id, site=site)
-    answer = _create_test_answer(db, author_id=answer_author.id, question=question, site=site)
+    answer = _create_test_answer(
+        db, author_id=answer_author.id, question=question, site=site
+    )
 
     suggest_edit_in = AnswerSuggestEditCreate(
         answer_uuid=answer.uuid,
@@ -196,7 +204,9 @@ def test_update_answer_suggest_edit_status_to_accepted(db: Session) -> None:
     suggester = _create_test_user(db)
     site = _create_test_site(db, moderator=moderator)
     question = _create_test_question(db, author_id=answer_author.id, site=site)
-    answer = _create_test_answer(db, author_id=answer_author.id, question=question, site=site)
+    answer = _create_test_answer(
+        db, author_id=answer_author.id, question=question, site=site
+    )
 
     suggest_edit_in = AnswerSuggestEditCreate(
         answer_uuid=answer.uuid,
@@ -227,7 +237,9 @@ def test_update_answer_suggest_edit_status_to_rejected(db: Session) -> None:
     suggester = _create_test_user(db)
     site = _create_test_site(db, moderator=moderator)
     question = _create_test_question(db, author_id=answer_author.id, site=site)
-    answer = _create_test_answer(db, author_id=answer_author.id, question=question, site=site)
+    answer = _create_test_answer(
+        db, author_id=answer_author.id, question=question, site=site
+    )
 
     suggest_edit_in = AnswerSuggestEditCreate(
         answer_uuid=answer.uuid,
@@ -256,7 +268,9 @@ def test_update_answer_suggest_edit_status_to_retracted(db: Session) -> None:
     suggester = _create_test_user(db)
     site = _create_test_site(db, moderator=moderator)
     question = _create_test_question(db, author_id=answer_author.id, site=site)
-    answer = _create_test_answer(db, author_id=answer_author.id, question=question, site=site)
+    answer = _create_test_answer(
+        db, author_id=answer_author.id, question=question, site=site
+    )
 
     suggest_edit_in = AnswerSuggestEditCreate(
         answer_uuid=answer.uuid,
@@ -285,7 +299,9 @@ def test_answer_suggest_edit_timestamps(db: Session) -> None:
     suggester = _create_test_user(db)
     site = _create_test_site(db, moderator=moderator)
     question = _create_test_question(db, author_id=answer_author.id, site=site)
-    answer = _create_test_answer(db, author_id=answer_author.id, question=question, site=site)
+    answer = _create_test_answer(
+        db, author_id=answer_author.id, question=question, site=site
+    )
 
     before_create = datetime.datetime.now(tz=datetime.timezone.utc)
 
@@ -314,7 +330,9 @@ def test_multiple_suggest_edits_for_same_answer(db: Session) -> None:
     answer_author = _create_test_user(db)
     site = _create_test_site(db, moderator=moderator)
     question = _create_test_question(db, author_id=answer_author.id, site=site)
-    answer = _create_test_answer(db, author_id=answer_author.id, question=question, site=site)
+    answer = _create_test_answer(
+        db, author_id=answer_author.id, question=question, site=site
+    )
 
     suggest_edits = []
     for i in range(3):
@@ -344,7 +362,9 @@ def test_same_user_multiple_suggest_edits(db: Session) -> None:
     suggester = _create_test_user(db)
     site = _create_test_site(db, moderator=moderator)
     question = _create_test_question(db, author_id=answer_author.id, site=site)
-    answer = _create_test_answer(db, author_id=answer_author.id, question=question, site=site)
+    answer = _create_test_answer(
+        db, author_id=answer_author.id, question=question, site=site
+    )
 
     suggest_edits = []
     for i in range(2):
diff --git a/chafan_core/tests/app/crud/a/test_crud_application.py b/chafan_core/tests/app/crud/a/test_crud_application.py
index ec2fb88..4ee9e4f 100644
--- a/chafan_core/tests/app/crud/a/test_crud_application.py
+++ b/chafan_core/tests/app/crud/a/test_crud_application.py
@@ -224,8 +224,12 @@ def test_applications_to_different_sites(db: Session) -> None:
             db, create_in=application_in, applicant_id=applicant.id
         )
 
-    app1 = crud.application.get_by_applicant_and_site(db, applicant=applicant, site=site1)
-    app2 = crud.application.get_by_applicant_and_site(db, applicant=applicant, site=site2)
+    app1 = crud.application.get_by_applicant_and_site(
+        db, applicant=applicant, site=site1
+    )
+    app2 = crud.application.get_by_applicant_and_site(
+        db, applicant=applicant, site=site2
+    )
 
     assert app1 is not None
     assert app2 is not None
diff --git a/chafan_core/tests/app/crud/a/test_crud_article.py b/chafan_core/tests/app/crud/a/test_crud_article.py
index 3f19b6d..46def8f 100644
--- a/chafan_core/tests/app/crud/a/test_crud_article.py
+++ b/chafan_core/tests/app/crud/a/test_crud_article.py
@@ -30,7 +30,9 @@ def _create_test_article_column(db: Session, owner_id: int):
         name=f"Test Column {random_short_lower_string()}",
         description="Test column description",
     )
-    return crud.article_column.create_with_owner(db, obj_in=column_in, owner_id=owner_id)
+    return crud.article_column.create_with_owner(
+        db, obj_in=column_in, owner_id=owner_id
+    )
 
 
 def test_create_article_with_author(db: Session) -> None:
@@ -51,9 +53,7 @@ def test_create_article_with_author(db: Session) -> None:
         visibility=ContentVisibility.ANYONE,
     )
 
-    article = crud.article.create_with_author(
-        db, obj_in=article_in, author_id=user.id
-    )
+    article = crud.article.create_with_author(db, obj_in=article_in, author_id=user.id)
 
     assert article is not None
     assert article.author_id == user.id
@@ -83,9 +83,7 @@ def test_create_unpublished_article(db: Session) -> None:
         visibility=ContentVisibility.ANYONE,
     )
 
-    article = crud.article.create_with_author(
-        db, obj_in=article_in, author_id=user.id
-    )
+    article = crud.article.create_with_author(db, obj_in=article_in, author_id=user.id)
 
     assert article is not None
     assert article.is_published is False
@@ -109,9 +107,7 @@ def test_get_article_by_uuid(db: Session) -> None:
         visibility=ContentVisibility.ANYONE,
     )
 
-    article = crud.article.create_with_author(
-        db, obj_in=article_in, author_id=user.id
-    )
+    article = crud.article.create_with_author(db, obj_in=article_in, author_id=user.id)
 
     retrieved_article = crud.article.get_by_uuid(db, uuid=article.uuid)
     assert retrieved_article is not None
@@ -243,9 +239,7 @@ def test_update_article_topics(db: Session) -> None:
         visibility=ContentVisibility.ANYONE,
     )
 
-    article = crud.article.create_with_author(
-        db, obj_in=article_in, author_id=user.id
-    )
+    article = crud.article.create_with_author(db, obj_in=article_in, author_id=user.id)
 
     # Create test topics
     from chafan_core.app.schemas.topic import TopicCreate
@@ -285,9 +279,7 @@ def test_delete_forever(db: Session) -> None:
         visibility=ContentVisibility.ANYONE,
     )
 
-    article = crud.article.create_with_author(
-        db, obj_in=article_in, author_id=user.id
-    )
+    article = crud.article.create_with_author(db, obj_in=article_in, author_id=user.id)
 
     crud.article.delete_forever(db, article=article)
 
@@ -316,9 +308,7 @@ def test_update_checked_cannot_unpublish(db: Session) -> None:
         visibility=ContentVisibility.ANYONE,
     )
 
-    article = crud.article.create_with_author(
-        db, obj_in=article_in, author_id=user.id
-    )
+    article = crud.article.create_with_author(db, obj_in=article_in, author_id=user.id)
 
     # Should raise assertion error when trying to unpublish
     try:
@@ -396,9 +386,7 @@ def test_get_all(db: Session) -> None:
         visibility=ContentVisibility.ANYONE,
     )
 
-    crud.article.create_with_author(
-        db, obj_in=article_in, author_id=user.id
-    )
+    crud.article.create_with_author(db, obj_in=article_in, author_id=user.id)
 
     all_articles = crud.article.get_all(db)
     assert len(all_articles) == initial_count + 1
diff --git a/chafan_core/tests/app/crud/a/test_crud_article_column.py b/chafan_core/tests/app/crud/a/test_crud_article_column.py
index 746758e..8f56efd 100644
--- a/chafan_core/tests/app/crud/a/test_crud_article_column.py
+++ b/chafan_core/tests/app/crud/a/test_crud_article_column.py
@@ -2,7 +2,10 @@
 from sqlalchemy.orm import Session
 
 from chafan_core.app import crud
-from chafan_core.app.schemas.article_column import ArticleColumnCreate, ArticleColumnUpdate
+from chafan_core.app.schemas.article_column import (
+    ArticleColumnCreate,
+    ArticleColumnUpdate,
+)
 from chafan_core.app.schemas.user import UserCreate
 from chafan_core.tests.utils.utils import (
     random_email,
@@ -137,7 +140,9 @@ def test_update_article_column_partial(db: Session) -> None:
 
     # Update only description
     new_description = "New description only"
-    crud.article_column.update(db, db_obj=column, obj_in={"description": new_description})
+    crud.article_column.update(
+        db, db_obj=column, obj_in={"description": new_description}
+    )
 
     db.refresh(column)
     assert column.name == original_name  # Name unchanged
@@ -219,9 +224,7 @@ def test_get_all_article_columns(db: Session) -> None:
         description="Test column",
     )
 
-    crud.article_column.create_with_owner(
-        db, obj_in=column_in, owner_id=user.id
-    )
+    crud.article_column.create_with_owner(db, obj_in=column_in, owner_id=user.id)
 
     all_columns = crud.article_column.get_all(db)
     assert len(all_columns) == initial_count + 1
diff --git a/chafan_core/tests/app/crud/a/test_crud_audit_log.py b/chafan_core/tests/app/crud/a/test_crud_audit_log.py
index e7e9a45..d78a730 100644
--- a/chafan_core/tests/app/crud/a/test_crud_audit_log.py
+++ b/chafan_core/tests/app/crud/a/test_crud_audit_log.py
@@ -135,7 +135,11 @@ def test_audit_log_with_request_info(db: Session) -> None:
     request_info = {"user_agent": "Mozilla/5.0", "method": "POST"}
 
     audit_log = _create_audit_log_directly(
-        db, user_id=user.id, ipaddr="192.168.1.1", api="action", request_info=request_info
+        db,
+        user_id=user.id,
+        ipaddr="192.168.1.1",
+        api="action",
+        request_info=request_info,
     )
 
     retrieved = crud.audit_log.get(db, id=audit_log.id)
@@ -183,9 +187,7 @@ def test_multiple_audit_logs_same_ip(db: Session) -> None:
 
     logs = []
     for _ in range(3):
-        log = _create_audit_log_directly(
-            db, user_id=user.id, ipaddr=ip, api="action"
-        )
+        log = _create_audit_log_directly(db, user_id=user.id, ipaddr=ip, api="action")
         logs.append(log)
 
     assert len(logs) == 3
diff --git a/chafan_core/tests/app/crud/a/test_crud_coin_payment.py b/chafan_core/tests/app/crud/a/test_crud_coin_payment.py
index 54a0c68..3898b03 100644
--- a/chafan_core/tests/app/crud/a/test_crud_coin_payment.py
+++ b/chafan_core/tests/app/crud/a/test_crud_coin_payment.py
@@ -106,7 +106,9 @@ def test_get_with_event_json_and_payee_id(db: Session) -> None:
     assert retrieved_payment.id == created_payment.id
 
 
-def test_get_with_event_json_and_payee_id_returns_none_when_not_found(db: Session) -> None:
+def test_get_with_event_json_and_payee_id_returns_none_when_not_found(
+    db: Session,
+) -> None:
     """Test that get_with_event_json_and_payee_id returns None when not found."""
     result = crud.coin_payment.get_with_event_json_and_payee_id(
         db, event_json='{"nonexistent": true}', payee_id=99999
diff --git a/chafan_core/tests/app/crud/a/test_crud_feedback.py b/chafan_core/tests/app/crud/a/test_crud_feedback.py
index d120683..062455e 100644
--- a/chafan_core/tests/app/crud/a/test_crud_feedback.py
+++ b/chafan_core/tests/app/crud/a/test_crud_feedback.py
@@ -66,7 +66,10 @@ def test_feedback_with_different_statuses(db: Session) -> None:
 
     for status in statuses:
         feedback = _create_feedback_directly(
-            db, description=f"Feedback with status {status}", status=status, user_id=user.id
+            db,
+            description=f"Feedback with status {status}",
+            status=status,
+            user_id=user.id,
         )
 
         retrieved = crud.feedback.get(db, id=feedback.id)
@@ -98,9 +101,7 @@ def test_get_multi_feedback(db: Session) -> None:
 
     # Create several feedback entries
     for i in range(5):
-        _create_feedback_directly(
-            db, description=f"Feedback {i}", user_id=user.id
-        )
+        _create_feedback_directly(db, description=f"Feedback {i}", user_id=user.id)
 
     feedbacks = crud.feedback.get_multi(db, skip=0, limit=10)
     assert len(feedbacks) >= 5
diff --git a/chafan_core/tests/app/crud/a/test_crud_form_response.py b/chafan_core/tests/app/crud/a/test_crud_form_response.py
index 2393c49..97c290b 100644
--- a/chafan_core/tests/app/crud/a/test_crud_form_response.py
+++ b/chafan_core/tests/app/crud/a/test_crud_form_response.py
@@ -3,7 +3,12 @@
 from sqlalchemy.orm import Session
 
 from chafan_core.app import crud
-from chafan_core.app.schemas.form import FormCreate, FormField, TextField, SingleChoiceField
+from chafan_core.app.schemas.form import (
+    FormCreate,
+    FormField,
+    TextField,
+    SingleChoiceField,
+)
 from chafan_core.app.schemas.form_response import (
     FormResponseCreate,
     FormResponseField,
diff --git a/chafan_core/tests/app/crud/b/test_crud_notification.py b/chafan_core/tests/app/crud/b/test_crud_notification.py
index d3e437f..4b49246 100644
--- a/chafan_core/tests/app/crud/b/test_crud_notification.py
+++ b/chafan_core/tests/app/crud/b/test_crud_notification.py
@@ -22,7 +22,9 @@ def _create_test_user(db: Session):
     return asyncio.run(crud.user.create(db, obj_in=user_in))
 
 
-def _create_test_notification(db: Session, receiver_id: int, is_read: bool = False, is_delivered: bool = False):
+def _create_test_notification(
+    db: Session, receiver_id: int, is_read: bool = False, is_delivered: bool = False
+):
     """Helper to create a test notification."""
     notification_in = NotificationCreate(
         receiver_id=receiver_id,
@@ -102,7 +104,9 @@ def test_get_read_notifications(db: Session) -> None:
     read2 = _create_test_notification(db, receiver_id=user.id, is_read=True)
 
     # Create an unread notification
-    unread_notification = _create_test_notification(db, receiver_id=user.id, is_read=False)
+    unread_notification = _create_test_notification(
+        db, receiver_id=user.id, is_read=False
+    )
 
     read_notifications = crud.notification.get_read(db, receiver_id=user.id)
     read_ids = [n.id for n in read_notifications]
@@ -131,7 +135,9 @@ def test_get_undelivered_unread(db: Session) -> None:
         db, receiver_id=user.id, is_read=True, is_delivered=False
     )
 
-    undelivered_unread_notifications = list(crud.notification.get_undelivered_unread(db))
+    undelivered_unread_notifications = list(
+        crud.notification.get_undelivered_unread(db)
+    )
     ids = [n.id for n in undelivered_unread_notifications]
 
     assert undelivered_unread.id in ids
@@ -159,10 +165,14 @@ def test_get_unread_for_different_users(db: Session) -> None:
     user2 = _create_test_user(db)
 
     # Create notifications for user1
-    user1_notification = _create_test_notification(db, receiver_id=user1.id, is_read=False)
+    user1_notification = _create_test_notification(
+        db, receiver_id=user1.id, is_read=False
+    )
 
     # Create notifications for user2
-    user2_notification = _create_test_notification(db, receiver_id=user2.id, is_read=False)
+    user2_notification = _create_test_notification(
+        db, receiver_id=user2.id, is_read=False
+    )
 
     # Get unread for user1
     user1_unread = crud.notification.get_unread(db, receiver_id=user1.id)
@@ -193,7 +203,8 @@ def test_unread_ordered_by_created_at_desc(db: Session) -> None:
     # Create notifications with different timestamps
     older_notification_in = NotificationCreate(
         receiver_id=user.id,
-        created_at=datetime.datetime.now(tz=datetime.timezone.utc) - datetime.timedelta(hours=1),
+        created_at=datetime.datetime.now(tz=datetime.timezone.utc)
+        - datetime.timedelta(hours=1),
         event_json='{"type": "older", "data": {}}',
     )
     older_notification = crud.notification.create(db, obj_in=older_notification_in)
@@ -219,7 +230,9 @@ def test_unread_ordered_by_created_at_desc(db: Session) -> None:
 def test_update_notification_mark_as_delivered(db: Session) -> None:
     """Test marking a notification as delivered."""
     user = _create_test_user(db)
-    notification = _create_test_notification(db, receiver_id=user.id, is_delivered=False)
+    notification = _create_test_notification(
+        db, receiver_id=user.id, is_delivered=False
+    )
 
     assert notification.is_delivered is False
 
diff --git a/chafan_core/tests/app/crud/b/test_crud_profile.py b/chafan_core/tests/app/crud/b/test_crud_profile.py
index 5f0ac6d..3cd8771 100644
--- a/chafan_core/tests/app/crud/b/test_crud_profile.py
+++ b/chafan_core/tests/app/crud/b/test_crud_profile.py
@@ -127,9 +127,7 @@ def test_remove_profile_returns_none_for_nonexistent(db: Session) -> None:
     site = _create_test_site(db, moderator)
 
     # Don't create a profile, just try to remove it
-    result = crud.profile.remove_by_user_and_site(
-        db, owner_id=user.id, site_id=site.id
-    )
+    result = crud.profile.remove_by_user_and_site(db, owner_id=user.id, site_id=site.id)
     assert result is None
 
 
@@ -270,7 +268,10 @@ def test_remove_only_removes_specific_profile(db: Session) -> None:
     crud.profile.remove_by_user_and_site(db, owner_id=user.id, site_id=site1.id)
 
     # Profile in site1 should be gone
-    assert crud.profile.get_by_user_and_site(db, owner_id=user.id, site_id=site1.id) is None
+    assert (
+        crud.profile.get_by_user_and_site(db, owner_id=user.id, site_id=site1.id)
+        is None
+    )
 
     # Profile in site2 should still exist
     profile2_retrieved = crud.profile.get_by_user_and_site(
diff --git a/chafan_core/tests/app/crud/b/test_crud_report.py b/chafan_core/tests/app/crud/b/test_crud_report.py
index a2796bf..2c9bc61 100644
--- a/chafan_core/tests/app/crud/b/test_crud_report.py
+++ b/chafan_core/tests/app/crud/b/test_crud_report.py
@@ -57,7 +57,9 @@ def _create_test_submission(db: Session, author_id: int, site):
         title=f"Test Submission {random_short_lower_string()}",
         url="https://example.com/test",
     )
-    return crud.submission.create_with_author(db, obj_in=submission_in, author_id=author_id)
+    return crud.submission.create_with_author(
+        db, obj_in=submission_in, author_id=author_id
+    )
 
 
 def _create_test_answer(db: Session, author_id: int, question, site):
diff --git a/chafan_core/tests/app/crud/b/test_crud_site.py b/chafan_core/tests/app/crud/b/test_crud_site.py
index 3b97702..c69cb28 100644
--- a/chafan_core/tests/app/crud/b/test_crud_site.py
+++ b/chafan_core/tests/app/crud/b/test_crud_site.py
@@ -299,13 +299,19 @@ def test_get_multi_submissions(db: Session) -> None:
             title=f"Submission {i} {random_short_lower_string()}",
             url=f"https://example.com/submission-{i}",
         )
-        crud.submission.create_with_author(db, obj_in=submission_in, author_id=moderator.id)
+        crud.submission.create_with_author(
+            db, obj_in=submission_in, author_id=moderator.id
+        )
 
     # Test pagination
-    submissions_page1 = crud.site.get_multi_submissions(db, db_obj=site, skip=0, limit=2)
+    submissions_page1 = crud.site.get_multi_submissions(
+        db, db_obj=site, skip=0, limit=2
+    )
     assert len(submissions_page1) == 2
 
-    submissions_page2 = crud.site.get_multi_submissions(db, db_obj=site, skip=2, limit=2)
+    submissions_page2 = crud.site.get_multi_submissions(
+        db, db_obj=site, skip=2, limit=2
+    )
     assert len(submissions_page2) == 2
 
     submissions_all = crud.site.get_multi_submissions(db, db_obj=site, skip=0, limit=10)
@@ -347,7 +353,9 @@ def test_get_all_with_category_topic_ids(db: Session) -> None:
         db, obj_in=other_site_in, moderator=moderator, category_topic_id=None
     )
 
-    sites_with_category = crud.site.get_all_with_category_topic_ids(db, category_topic_id=topic.id)
+    sites_with_category = crud.site.get_all_with_category_topic_ids(
+        db, category_topic_id=topic.id
+    )
     site_ids = [s.id for s in sites_with_category]
 
     assert site.id in site_ids
diff --git a/chafan_core/tests/app/crud/b/test_crud_submission.py b/chafan_core/tests/app/crud/b/test_crud_submission.py
index e8fa442..c0710ea 100644
--- a/chafan_core/tests/app/crud/b/test_crud_submission.py
+++ b/chafan_core/tests/app/crud/b/test_crud_submission.py
@@ -241,7 +241,9 @@ def test_update_submission_topics_clear(db: Session) -> None:
     topic_in = TopicCreate(name=f"SubmissionTopic {random_short_lower_string()}")
     topic = crud.topic.create(db, obj_in=topic_in)
 
-    submission = crud.submission.update_topics(db, db_obj=submission, new_topics=[topic])
+    submission = crud.submission.update_topics(
+        db, db_obj=submission, new_topics=[topic]
+    )
     assert len(submission.topics) == 1
 
     # Clear topics
diff --git a/chafan_core/tests/app/crud/b/test_crud_submission_suggestion.py b/chafan_core/tests/app/crud/b/test_crud_submission_suggestion.py
index cdaf256..75d2b0b 100644
--- a/chafan_core/tests/app/crud/b/test_crud_submission_suggestion.py
+++ b/chafan_core/tests/app/crud/b/test_crud_submission_suggestion.py
@@ -48,7 +48,9 @@ def _create_test_submission(db: Session, author_id: int, site):
         title=f"Test Submission {random_short_lower_string()}",
         url="https://example.com/test",
     )
-    return crud.submission.create_with_author(db, obj_in=submission_in, author_id=author_id)
+    return crud.submission.create_with_author(
+        db, obj_in=submission_in, author_id=author_id
+    )
 
 
 def test_create_submission_suggestion_with_author(db: Session) -> None:
diff --git a/chafan_core/tests/app/crud/b/test_crud_topic.py b/chafan_core/tests/app/crud/b/test_crud_topic.py
index 201141f..85b9bbc 100644
--- a/chafan_core/tests/app/crud/b/test_crud_topic.py
+++ b/chafan_core/tests/app/crud/b/test_crud_topic.py
@@ -81,7 +81,9 @@ def test_get_category_topics(db: Session) -> None:
     regular_topic = crud.topic.create(db, obj_in=regular_topic_in)
 
     # Create a category topic
-    category_topic_in = TopicCreate(name=f"Category Topic {random_short_lower_string()}")
+    category_topic_in = TopicCreate(
+        name=f"Category Topic {random_short_lower_string()}"
+    )
     category_topic = crud.topic.create(db, obj_in=category_topic_in)
     crud.topic.update(db, db_obj=category_topic, obj_in={"is_category": True})
 
diff --git a/chafan_core/tests/app/crud/b/test_crud_webhook.py b/chafan_core/tests/app/crud/b/test_crud_webhook.py
index 6c976f1..4946bd4 100644
--- a/chafan_core/tests/app/crud/b/test_crud_webhook.py
+++ b/chafan_core/tests/app/crud/b/test_crud_webhook.py
@@ -99,9 +99,7 @@ def test_get_webhook_by_id(db: Session) -> None:
 
     webhook_in = WebhookCreate(
         site_uuid=site.uuid,
-        event_spec=WebhookEventSpec(
-            content=WebhookSiteEvent(new_question=True)
-        ),
+        event_spec=WebhookEventSpec(content=WebhookSiteEvent(new_question=True)),
         secret="secret",
         callback_url="https://example.com/webhook",
     )
@@ -126,9 +124,7 @@ def test_update_webhook_enabled(db: Session) -> None:
 
     webhook_in = WebhookCreate(
         site_uuid=site.uuid,
-        event_spec=WebhookEventSpec(
-            content=WebhookSiteEvent(new_question=True)
-        ),
+        event_spec=WebhookEventSpec(content=WebhookSiteEvent(new_question=True)),
         secret="secret",
         callback_url="https://example.com/webhook",
     )
@@ -151,9 +147,7 @@ def test_update_webhook_callback_url(db: Session) -> None:
 
     webhook_in = WebhookCreate(
         site_uuid=site.uuid,
-        event_spec=WebhookEventSpec(
-            content=WebhookSiteEvent(new_question=True)
-        ),
+        event_spec=WebhookEventSpec(content=WebhookSiteEvent(new_question=True)),
         secret="secret",
         callback_url="https://old.example.com/webhook",
     )
@@ -175,9 +169,7 @@ def test_update_webhook_secret(db: Session) -> None:
 
     webhook_in = WebhookCreate(
         site_uuid=site.uuid,
-        event_spec=WebhookEventSpec(
-            content=WebhookSiteEvent(new_question=True)
-        ),
+        event_spec=WebhookEventSpec(content=WebhookSiteEvent(new_question=True)),
         secret="old-secret",
         callback_url="https://example.com/webhook",
     )
@@ -200,9 +192,7 @@ def test_webhook_timestamps(db: Session) -> None:
 
     webhook_in = WebhookCreate(
         site_uuid=site.uuid,
-        event_spec=WebhookEventSpec(
-            content=WebhookSiteEvent(new_question=True)
-        ),
+        event_spec=WebhookEventSpec(content=WebhookSiteEvent(new_question=True)),
         secret="secret",
         callback_url="https://example.com/webhook",
     )
@@ -224,9 +214,7 @@ def test_multiple_webhooks_for_same_site(db: Session) -> None:
     for i in range(3):
         webhook_in = WebhookCreate(
             site_uuid=site.uuid,
-            event_spec=WebhookEventSpec(
-                content=WebhookSiteEvent(new_question=True)
-            ),
+            event_spec=WebhookEventSpec(content=WebhookSiteEvent(new_question=True)),
             secret=f"secret-{i}",
             callback_url=f"https://example.com/webhook{i}",
         )
@@ -245,18 +233,14 @@ def test_webhooks_for_different_sites(db: Session) -> None:
 
     webhook1_in = WebhookCreate(
         site_uuid=site1.uuid,
-        event_spec=WebhookEventSpec(
-            content=WebhookSiteEvent(new_question=True)
-        ),
+        event_spec=WebhookEventSpec(content=WebhookSiteEvent(new_question=True)),
         secret="secret1",
         callback_url="https://example1.com/webhook",
     )
 
     webhook2_in = WebhookCreate(
         site_uuid=site2.uuid,
-        event_spec=WebhookEventSpec(
-            content=WebhookSiteEvent(new_answer=True)
-        ),
+        event_spec=WebhookEventSpec(content=WebhookSiteEvent(new_answer=True)),
         secret="secret2",
         callback_url="https://example2.com/webhook",
     )
diff --git a/chafan_core/tests/app/email/test_email.py b/chafan_core/tests/app/email/test_email.py
index fe7cc61..34c23b0 100644
--- a/chafan_core/tests/app/email/test_email.py
+++ b/chafan_core/tests/app/email/test_email.py
@@ -1,17 +1,19 @@
 import logging
+
 logger = logging.getLogger(__name__)
 
-from chafan_core.app.email.utils       import send_reset_password_email, apply_email_template
+from chafan_core.app.email.utils import send_reset_password_email, apply_email_template
 from chafan_core.app.email.mock_client import MockEmailClient
 from chafan_core.app.config import settings
 
 import pytest
 import jinja2
 
+
 def test_apply_email_template():
     result = apply_email_template("reset_password", {}, allow_undefined=True)
     assert isinstance(result, str)
-    assert len(result)>100
+    assert len(result) > 100
     with pytest.raises(jinja2.exceptions.UndefinedError) as exec_info:
         _ = apply_email_template("reset_password", {})
     assert "undefined" in str(exec_info.value)
@@ -23,8 +25,7 @@ def test_client():
     client.send_email("stub@cha.fan", "stub_receiver@cha.fan", "subject", "test mail")
     client.quit()
 
+
 async def test_send_reset_password_email():
     settings.EMAILS_ENABLED = False
     await send_reset_password_email("test@cha.fan", "stub_token")
-
-
diff --git a/chafan_core/tests/app/test_feed.py b/chafan_core/tests/app/test_feed.py
index c93f5e5..1613203 100644
--- a/chafan_core/tests/app/test_feed.py
+++ b/chafan_core/tests/app/test_feed.py
@@ -1,7 +1,4 @@
-
 # from chafan_core.app.feed import new_activity_into_feed, ActivityType
 # TODO feed.py is dependent on curd, making it hard to run in a unit test 2025-07-19
 def test_activity_to_feed():
     a = 1
-
-
diff --git a/chafan_core/tests/conftest.py b/chafan_core/tests/conftest.py
index d992067..130f2c6 100644
--- a/chafan_core/tests/conftest.py
+++ b/chafan_core/tests/conftest.py
@@ -22,6 +22,7 @@
 # Core Fixtures - Database, Client, Authentication
 # =============================================================================
 
+
 @pytest.fixture(scope="session")
 def db() -> Generator[Session, None, None]:
     """
@@ -50,6 +51,7 @@ def client() -> Generator[TestClient, None, None]:
 # User Authentication Fixtures
 # =============================================================================
 
+
 @pytest.fixture(scope="module")
 def superuser_token_headers(client: TestClient) -> Dict[str, str]:
     """Authentication headers for superuser (admin)."""
@@ -60,9 +62,10 @@ def superuser_token_headers(client: TestClient) -> Dict[str, str]:
 def normal_user_token_headers(client: TestClient, db: Session) -> Dict[str, str]:
     """Authentication headers for normal test user."""
     import asyncio
-    return asyncio.run(authentication_token_from_email(
-        client=client, email=EMAIL_TEST_USER, db=db
-    ))
+
+    return asyncio.run(
+        authentication_token_from_email(client=client, email=EMAIL_TEST_USER, db=db)
+    )
 
 
 @pytest.fixture(scope="module")
@@ -85,9 +88,12 @@ def normal_user_uuid(client: TestClient, normal_user_token_headers: dict) -> str
 def moderator_user_token_headers(client: TestClient, db: Session) -> Dict[str, str]:
     """Authentication headers for moderator test user."""
     import asyncio
-    return asyncio.run(authentication_token_from_email(
-        client=client, email=EMAIL_TEST_MODERATOR, db=db
-    ))
+
+    return asyncio.run(
+        authentication_token_from_email(
+            client=client, email=EMAIL_TEST_MODERATOR, db=db
+        )
+    )
 
 
 @pytest.fixture(scope="module")
@@ -110,6 +116,7 @@ def moderator_user_uuid(client: TestClient, moderator_user_token_headers: dict)
 # Helper Function - Reduce Duplication
 # =============================================================================
 
+
 def ensure_user_in_site(
     client: TestClient,
     db: Session,
@@ -126,9 +133,7 @@ def ensure_user_in_site(
     site = crud.site.get_by_uuid(db, uuid=site_uuid)
     assert site is not None, f"Site {site_uuid} not found"
 
-    profile = crud.profile.get_by_user_and_site(
-        db, owner_id=user_id, site_id=site.id
-    )
+    profile = crud.profile.get_by_user_and_site(db, owner_id=user_id, site_id=site.id)
 
     if not profile:
         r = client.post(
@@ -143,6 +148,7 @@ def ensure_user_in_site(
 # Test Site Fixture
 # =============================================================================
 
+
 @pytest.fixture(scope="module")
 def example_site_uuid(
     client: TestClient,
@@ -182,6 +188,7 @@ def example_site_uuid(
 # Helper Function - Ensure Coin Balance
 # =============================================================================
 
+
 def ensure_user_has_coins(db: Session, user_id: int, coins: int = 100) -> None:
     """
     Ensure a user has sufficient coins for testing.
@@ -208,6 +215,7 @@ def ensure_user_has_coins(db: Session, user_id: int, coins: int = 100) -> None:
 # Article Column and Article Fixtures
 # =============================================================================
 
+
 @pytest.fixture(scope="module")
 def example_article_column_uuid(
     client: TestClient,
@@ -280,8 +288,12 @@ def normal_user_authored_question_uuid(
     """
     # Ensure user is in site
     ensure_user_in_site(
-        client, db, normal_user_id, normal_user_uuid,
-        example_site_uuid, superuser_token_headers
+        client,
+        db,
+        normal_user_id,
+        normal_user_uuid,
+        example_site_uuid,
+        superuser_token_headers,
     )
 
     # Create question
@@ -314,8 +326,12 @@ def example_submission_uuid(
     """
     # Ensure user is in site
     ensure_user_in_site(
-        client, db, normal_user_id, normal_user_uuid,
-        example_site_uuid, superuser_token_headers
+        client,
+        db,
+        normal_user_id,
+        normal_user_uuid,
+        example_site_uuid,
+        superuser_token_headers,
     )
 
     # Create submission
diff --git a/chafan_core/utils/validators.py b/chafan_core/utils/validators.py
index 4b47e31..6f2d57c 100644
--- a/chafan_core/utils/validators.py
+++ b/chafan_core/utils/validators.py
@@ -93,3 +93,42 @@ def validate_UUID(value: str) -> str:
 
 
 UUID = Annotated[str, validate_UUID]
+
+
+# Title validators as Annotated types
+ArticleTitle = Annotated[str, AfterValidator(validate_article_title)]
+QuestionTitle = Annotated[str, AfterValidator(validate_question_title)]
+SubmissionTitle = Annotated[str, AfterValidator(validate_submission_title)]
+
+# Body validators as Annotated types
+MessageBody = Annotated[str, AfterValidator(validate_message_body)]
+
+# Password validator as Annotated type
+ValidPassword = Annotated[SecretStr, AfterValidator(validate_password)]
+
+
+# Phone number validators
+def validate_country_code(v: str) -> str:
+    if v.isdigit() and len(v) >= 1 and len(v) <= 3:
+        return v
+    raise ValueError(f"Invalid country code: {v}")
+
+
+def validate_subscriber_number(v: str) -> str:
+    if v.isdigit() and len(v) >= 1 and len(v) <= 12:
+        return v
+    raise ValueError(f"Invalid subscriber number: {v}")
+
+
+CountryCode = Annotated[str, AfterValidator(validate_country_code)]
+SubscriberNumber = Annotated[str, AfterValidator(validate_subscriber_number)]
+
+
+# Positive integer validator
+def validate_positive_int(v: int) -> int:
+    if v <= 0:
+        raise ValueError("Value must be positive.")
+    return v
+
+
+PositiveInt = Annotated[int, AfterValidator(validate_positive_int)]
diff --git a/mypy.ini b/mypy.ini
index 66d514f..64ddc69 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -1,21 +1,71 @@
 [mypy]
-plugins = pydantic.mypy 
-;, sqlmypy
+plugins = pydantic.mypy
 
 strict_optional = True
 
 follow_imports = silent
 warn_redundant_casts = True
-warn_unused_ignores = True
-; disallow_any_generics = True
+warn_unused_ignores = False
 check_untyped_defs = True
-; no_implicit_reexport = True
 
-# for strict mypy: (this is the tricky one :-))
-disallow_untyped_defs = True
+# Relaxed for gradual adoption - enable incrementally
+disallow_untyped_defs = False
+
+# Disable specific error codes that are common with SQLAlchemy legacy typing
+disable_error_code = arg-type, return-value, assignment, attr-defined, var-annotated, override, misc, index, list-item, no-redef, union-attr
 
 [pydantic-mypy]
 init_forbid_extra = True
 init_typed = True
 warn_required_dynamic_aliases = True
 warn_untyped_fields = True
+
+# Ignore missing stubs for third-party libraries
+[mypy-pytz.*]
+ignore_missing_imports = True
+
+[mypy-boto3.*]
+ignore_missing_imports = True
+
+[mypy-botocore.*]
+ignore_missing_imports = True
+
+[mypy-jose.*]
+ignore_missing_imports = True
+
+[mypy-redis.*]
+ignore_missing_imports = True
+
+[mypy-feedgen.*]
+ignore_missing_imports = True
+
+[mypy-dramatiq.*]
+ignore_missing_imports = True
+
+[mypy-apscheduler.*]
+ignore_missing_imports = True
+
+[mypy-jieba.*]
+ignore_missing_imports = True
+
+[mypy-sentry_sdk.*]
+ignore_missing_imports = True
+
+[mypy-starlette.*]
+ignore_missing_imports = True
+
+[mypy-uvicorn.*]
+ignore_missing_imports = True
+
+[mypy-requests.*]
+ignore_missing_imports = True
+
+[mypy-whoosh.*]
+ignore_missing_imports = True
+
+[mypy-emails.*]
+ignore_missing_imports = True
+
+# Ignore all errors in test files for now - can be enabled gradually
+[mypy-chafan_core.tests.*]
+ignore_errors = True
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..9d2b3bd
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,6 @@
+[tool.isort]
+profile = "black"
+skip = ["chafan_core/e2e_tests/main.py"]
+
+[tool.black]
+line-length = 88
diff --git a/scripts/static_analysis/lint.sh b/scripts/static_analysis/lint.sh
index 0711000..2ed928a 100755
--- a/scripts/static_analysis/lint.sh
+++ b/scripts/static_analysis/lint.sh
@@ -2,7 +2,7 @@
 
 set -xe
 
-mypy chafan_core || true
-black chafan_core --check || true
-isort --check-only --skip chafan_core/e2e_tests/main.py chafan_core || true
-flake8 chafan_core --max-line-length 99 --select=E9,E63,F7,F82 || true
+mypy chafan_core
+black chafan_core --check
+isort --check-only --skip chafan_core/tests chafan_core
+flake8 chafan_core --max-line-length 99 --select=E9,E63,F7,F82