diff --git a/resolvers/collab.py b/resolvers/collab.py
index 8271b478..7db4620e 100644
--- a/resolvers/collab.py
+++ b/resolvers/collab.py
@@ -32,16 +32,16 @@ async def invite_author(_, info, author, shout):
         authors = [a.id for a in shout.authors]
         if user_id not in authors:
             return {"error": "access denied"}
-        author = session.query(User).filter(User.slug == author).first()
-        if author.id in authors:
-            return {"error": "already added"}
-        shout.authors.append(author)
+        author = session.query(User).filter(User.id == author.id).first()
+        if author:
+            if author.id in authors:
+                return {"error": "already added"}
+            shout.authors.append(author)
         shout.updated_at = datetime.now()
         session.add(shout)
         session.commit()
 
     # TODO: email notify
-
     return {}
 
 
@@ -59,9 +59,10 @@ async def remove_author(_, info, author, shout):
         if user_id not in authors:
             return {"error": "access denied"}
         author = session.query(User).filter(User.slug == author).first()
-        if author.id not in authors:
-            return {"error": "not in authors"}
-        shout.authors.remove(author)
+        if author:
+            if author.id not in authors:
+                return {"error": "not in authors"}
+            shout.authors.remove(author)
         shout.updated_at = datetime.now()
         session.add(shout)
         session.commit()
diff --git a/resolvers/inbox/load.py b/resolvers/inbox/load.py
index 05431c68..5d7927b7 100644
--- a/resolvers/inbox/load.py
+++ b/resolvers/inbox/load.py
@@ -1,13 +1,16 @@
 import json
 from datetime import datetime, timedelta
+
+from auth.authenticate import login_required
 from base.redis import redis
 from base.resolvers import query
-from auth.authenticate import login_required
 
 
 async def get_unread_counter(chat_id: str, user_slug: str):
     try:
-        return int(await redis.execute("LLEN", f"chats/{chat_id}/unread/{user_slug}"))
+        unread = await redis.execute("LLEN", f"chats/{chat_id}/unread/{user_slug}")
+        if unread:
+            return unread
     except Exception:
         return 0
 
@@ -55,7 +58,7 @@ async def load_chats(_, info, offset: int, amount: int):
     if not chats:
         chats = []
     for c in chats:
-        c['messages'] = await load_messages(c['id'])
+        c['messages'] = await load_messages(c['id'], offset, amount)
         c['unread'] = await get_unread_counter(c['id'], user.slug)
     return {
         "chats": chats,
diff --git a/resolvers/reactions.py b/resolvers/reactions.py
index 267d40ba..abdbb46b 100644
--- a/resolvers/reactions.py
+++ b/resolvers/reactions.py
@@ -1,4 +1,5 @@
 from datetime import datetime, timedelta
+
 from sqlalchemy import and_, desc, select, text
 from sqlalchemy.orm import selectinload
 
diff --git a/schema.graphql b/schema.graphql
index 73e8762b..7e43d280 100644
--- a/schema.graphql
+++ b/schema.graphql
@@ -255,8 +255,6 @@ type Query {
   userFollowers(slug: String!): [Author]!
   userFollowedAuthors(slug: String!): [Author]!
   userFollowedTopics(slug: String!): [Topic]!
-
-
   authorsAll: [Author]!
   getAuthor(slug: String!): User!
 
diff --git a/services/stat/views.py b/services/stat/views.py
index 74434753..32c08cbf 100644
--- a/services/stat/views.py
+++ b/services/stat/views.py
@@ -1,7 +1,9 @@
-from gql import gql, Client
-from gql.transport.aiohttp import AIOHTTPTransport
 import asyncio
 import json
+
+from gql import Client, gql
+from gql.transport.aiohttp import AIOHTTPTransport
+
 from base.redis import redis
 from services.zine.topics import TopicStorage