diff --git a/didier/cogs/owner.py b/didier/cogs/owner.py
index af50633..f87dc5e 100644
--- a/didier/cogs/owner.py
+++ b/didier/cogs/owner.py
@@ -3,6 +3,9 @@ from typing import Optional
 import discord
 from discord.ext import commands
 
+from database.crud import custom_commands
+from database.exceptions.constraints import DuplicateInsertException
+from database.exceptions.not_found import NoResultFoundException
 from didier import Didier
 
 
@@ -14,13 +17,51 @@ class Owner(commands.Cog):
     def __init__(self, client: Didier):
         self.client = client
 
+    async def cog_check(self, ctx: commands.Context) -> bool:
+        """Global check for every command in this cog, so we don't have to add
+        is_owner() to every single command separately
+        """
+        return await self.client.is_owner(ctx.author)
+
     @commands.command(name="Sync")
-    @commands.is_owner()
     async def sync(self, ctx: commands.Context, guild: Optional[discord.Guild] = None):
         """Sync all application-commands in Discord"""
         await self.client.tree.sync(guild=guild)
         await ctx.message.add_reaction("🔄")
 
+    @commands.group(name="Add", case_insensitive=True, invoke_without_command=False)
+    async def add(self, ctx: commands.Context):
+        """Command group for [add X] commands"""
+
+    @add.command(name="Custom")
+    async def add_custom(self, ctx: commands.Context, name: str, *, response: str):
+        """Add a new custom command"""
+        async with self.client.db_session as session:
+            try:
+                await custom_commands.create_command(session, name, response)
+                await self.client.confirm_message(ctx.message)
+            except DuplicateInsertException:
+                await ctx.reply("Er bestaat al een commando met deze naam.")
+                await self.client.reject_message(ctx.message)
+
+    @add.command(name="Alias")
+    async def add_alias(self, ctx: commands.Context, command: str, alias: str):
+        """Add a new alias for a custom command"""
+        async with self.client.db_session as session:
+            try:
+                await custom_commands.create_alias(session, command, alias)
+                await self.client.confirm_message(ctx.message)
+            except NoResultFoundException:
+                await ctx.reply(f'Geen commando gevonden voor "{command}".')
+                await self.client.reject_message(ctx.message)
+            except DuplicateInsertException:
+                await ctx.reply("Er bestaat al een commando met deze naam.")
+                await self.client.reject_message(ctx.message)
+
+    @commands.group(name="Edit")
+    async def edit(self, ctx: commands.Context):
+        """Command group for [edit X] commands"""
+
 
 async def setup(client: Didier):
     """Load the cog"""
diff --git a/didier/didier.py b/didier/didier.py
index 06786e0..3cd2648 100644
--- a/didier/didier.py
+++ b/didier/didier.py
@@ -3,7 +3,6 @@ import sys
 import traceback
 
 import discord
-from discord import Message
 from discord.ext import commands
 from sqlalchemy.ext.asyncio import AsyncSession
 
@@ -35,6 +34,11 @@ class Didier(commands.Bot):
             command_prefix=get_prefix, case_insensitive=True, intents=intents, activity=activity, status=status
         )
 
+    @property
+    def db_session(self) -> AsyncSession:
+        """Obtain a database session"""
+        return DBSession()
+
     async def setup_hook(self) -> None:
         """Hook called once the bot is initialised"""
         # Load extensions
@@ -48,11 +52,6 @@ class Didier(commands.Bot):
             self.tree.copy_global_to(guild=guild_object)
             await self.tree.sync(guild=guild_object)
 
-    @property
-    def db_session(self) -> AsyncSession:
-        """Obtain a database session"""
-        return DBSession()
-
     async def _load_initial_extensions(self):
         """Load all extensions that should  be loaded before the others"""
         for extension in self.initial_extensions:
@@ -86,11 +85,19 @@ class Didier(commands.Bot):
         channel = self.get_channel(reference.channel_id)
         return await channel.fetch_message(reference.message_id)
 
+    async def confirm_message(self, message: discord.Message):
+        """Add a checkmark to a message"""
+        await message.add_reaction("✅")
+
+    async def reject_message(self, message: discord.Message):
+        """Add an X to a message"""
+        await message.add_reaction("❌")
+
     async def on_ready(self):
         """Event triggered when the bot is ready"""
         print(settings.DISCORD_READY_MESSAGE)
 
-    async def on_message(self, message: Message, /) -> None:
+    async def on_message(self, message: discord.Message, /) -> None:
         """Event triggered when a message is sent"""
         # Ignore messages by bots
         if message.author.bot:
@@ -101,12 +108,12 @@ class Didier(commands.Bot):
             await message.add_reaction(settings.DISCORD_BOOS_REACT)
 
         # Potential custom command
-        if self._try_invoke_custom_command(message):
+        if await self._try_invoke_custom_command(message):
             return
 
         await self.process_commands(message)
 
-    async def _try_invoke_custom_command(self, message: Message) -> bool:
+    async def _try_invoke_custom_command(self, message: discord.Message) -> bool:
         """Check if the message tries to invoke a custom command
         If it does, send the reply associated with it
         """