diff --git a/resolvers/create/collab.py b/resolvers/create/collab.py
index df509452..c51c9be2 100644
--- a/resolvers/create/collab.py
+++ b/resolvers/create/collab.py
@@ -20,7 +20,7 @@ async def get_collabs(_, info):
 
 @mutation.field("inviteCoauthor")
 @login_required
-async def invite_coauthor(_, info, author: str, shout: int):
+async def invite_coauthor(_, info, author: int = 0, shout: int = 0):
     auth: AuthCredentials = info.context["request"].auth
 
     with local_session() as session:
@@ -43,21 +43,19 @@ async def invite_coauthor(_, info, author: str, shout: int):
 
 @mutation.field("removeCoauthor")
 @login_required
-async def remove_coauthor(_, info, author: str, shout: int):
+async def remove_coauthor(_, info, author: int = 0, shout: int = 0):
     auth: AuthCredentials = info.context["request"].auth
 
     with local_session() as session:
-        s = session.query(Shout).where(Shout.id == shout).one()
-        if not s:
-            raise ObjectNotExist("invalid shout id")
-        if auth.user_id != s.createdBy:
+        s = session.query(Shout).where(Shout.id == shout).one()  # raises Error when not found
+        if auth.user_id not in s.authors:
             raise BaseHttpException("only owner can remove coauthors")
         else:
             c = session.query(Collab).where(Collab.shout == shout).one()
-            ca = session.query(CollabAuthor).join(User).where(c.shout == shout, User.slug == author).one()
+            ca = session.query(CollabAuthor).join(User).where(c.shout == shout, User.id == author).one()
             session.remve(ca)
-            c.invites = filter(lambda x: x.slug == author, c.invites)
-            c.authors = filter(lambda x: x.slug == author, c.authors)
+            c.invites = filter(lambda x: x.id == author, c.invites)
+            c.authors = filter(lambda x: x.id == author, c.authors)
             session.add(c)
             session.commit()
 
diff --git a/resolvers/zine/reactions.py b/resolvers/zine/reactions.py
index a6e0f0dd..55b4e095 100644
--- a/resolvers/zine/reactions.py
+++ b/resolvers/zine/reactions.py
@@ -14,9 +14,9 @@ def add_reaction_stat_columns(q):
     return add_common_stat_columns(q)
 
 
-def reactions_follow(user_id, slug: str, auto=False):
+def reactions_follow(user_id, shout_id: int, auto=False):
     with local_session() as session:
-        shout = session.query(Shout).where(Shout.slug == slug).one()
+        shout = session.query(Shout).where(Shout.id == shout_id).one()
 
         following = (
             session.query(ShoutReactionsFollower).where(and_(
@@ -35,9 +35,9 @@ def reactions_follow(user_id, slug: str, auto=False):
             session.commit()
 
 
-def reactions_unfollow(user_id, slug):
+def reactions_unfollow(user_id: int, shout_id: int):
     with local_session() as session:
-        shout = session.query(Shout).where(Shout.slug == slug).one()
+        shout = session.query(Shout).where(Shout.id == shout_id).one()
 
         following = (
             session.query(ShoutReactionsFollower).where(and_(
@@ -129,7 +129,7 @@ def set_hidden(session, shout_id):
 @login_required
 async def create_reaction(_, info, reaction={}):
     auth: AuthCredentials = info.context["request"].auth
-
+    reaction['createdBy'] = auth.user_id
     with local_session() as session:
         r = Reaction.create(**reaction)
         session.add(r)
diff --git a/schema.graphql b/schema.graphql
index 839e9ebb..015f2b02 100644
--- a/schema.graphql
+++ b/schema.graphql
@@ -129,7 +129,7 @@ input TopicInput {
 }
 
 input ReactionInput {
-  kind: Int!
+  kind: ReactionKind!
   shout: Int!
   range: String
   body: String