diff --git a/README.md b/README.md
index d3389fd..9387d97 100644
--- a/README.md
+++ b/README.md
@@ -35,7 +35,7 @@ docker run --rm \
     -e MIXD=@heeeroooooooes:example.org
     -e ACCESSTOKEN_FILE=/heroesofthestorm \
     -e ADMIN_ROOM='!iesofojasief90429ewiofj:example.org' \
-    -e CATEGORY=heroesofthestorm
+    -e CATEGORY=heroesofthestorm,insideblizzard,battlenet
     gitea.lubiland.de/lub/snowstorm-matrix:latest
 ```
 
@@ -52,7 +52,7 @@ Or via docker-compose/swarm:
             - ACCESSTOKEN_FILE=/run/secrets/snowstorm-matrix_overwatch
             - MXID=@bastionrulez:example.com
             - ADMIN_ROOM=!jjpPluoxZoAOBQeYer:example.org
-            - CATEGORY=overwatch
+            - CATEGORY=overwatch,overwatch2
     snowstorm-matrix_worldofwarcraft:
         image: gitea.lubiland.de/lub/snowstorm-matrix:latest
         deploy:
diff --git a/scrape.py b/scrape.py
index 468b701..5dba0f9 100644
--- a/scrape.py
+++ b/scrape.py
@@ -125,6 +125,7 @@ async def main():
     # use this event type to store our url cache
     cache_event_type = 'de.lubiland.snowstorm-matrix.cache'
 
+    cache = {}
     while True:
         # do sync first to e.g. accept an admin room invite
         sync = await matrix.sync(timeout=30000, sync_filter=sync_filter)
@@ -136,20 +137,22 @@ async def main():
 
         if next_update < datetime.now():
             # refresh url cache
-            cache_state = await matrix.room_get_state_event(room_id=admin_room,
-                                                            event_type=cache_event_type,
-                                                            state_key=category)
-            if hasattr(cache_state, 'content') and 'url_list' in cache_state.content:
-                cache = cache_state.content['url_list']
-            else:
-                print('cache is empty')
-                cache = []
+            old_cache = cache
+            cache = {}
+            for category in category_list:
+                cache_state = await matrix.room_get_state_event(room_id=admin_room,
+                                                                event_type=cache_event_type,
+                                                                state_key=category)
+                if hasattr(cache_state, 'content') and 'url_list' in cache_state.content:
+                    if not hasattr(cache, category):
+                        cache[category] = []
+                    cache[category] += cache_state.content['url_list']
 
             # scrape all blog posts and process them
             blog = get_blog()
             for post in blog:
                 # check if post url is in cache and matches our category
-                if post['url'] not in cache and post['category'] == category:
+                if post['category'] in category_list and hasattr(cache, post['category']) and post['url'] not in cache[post['category']]:
                     # post url not found in cache
                     # announce new post to matrix rooms
                     print('new post: '+post['url'])
@@ -169,21 +172,24 @@ async def main():
                                                    content=content)
 
                     # add url to cache
-                    cache += [post['url']]
+                    cache[post['category']] += [post['url']]
 
                 else:
                     # no new posts found
                     pass
 
-            # trim the cache
-            while len(cache) > 100:
-                cache.remove(cache[0])
+            # cleanup cache and push it as room state
+            for category in cache.keys():
+                # trim the cache
+                while len(cache[category]) > 100:
+                    cache[category].remove(cache[category][0])
 
-            # set new cache event
-            await matrix.room_put_state(room_id=admin_room,
-                                        event_type=cache_event_type,
-                                        state_key=category,
-                                        content={'url_list': cache})
+                # set new cache event
+                if hasattr(old_cache, 'category') and old_cache[category] != cache[category]:
+                    await matrix.room_put_state(room_id=admin_room,
+                                                event_type=cache_event_type,
+                                                state_key=category,
+                                                content={'url_list': cache[category]})
 
             # wait between 15min and 30min to randomize scraping
             next_update = datetime.now() + timedelta(minutes=randrange(15, 30))
@@ -202,8 +208,9 @@ print('accesstoken_file: '+environ['ACCESSTOKEN_FILE'])
 admin_room = environ['ADMIN_ROOM']
 print('admin_room: '+admin_room)
 
-category = environ['CATEGORY']
-print('category: '+category)
+category_list = environ['CATEGORY'].split(',')
+print('categories:')
+print(category_list)
 
 
 asyncio.run(main())