diff --git a/lenaverse_bot/commands/__init__.py b/lenaverse_bot/commands/__init__.py
new file mode 100644
index 0000000..e1d8666
--- /dev/null
+++ b/lenaverse_bot/commands/__init__.py
@@ -0,0 +1,3 @@
+from . import advent, post, verein
+
+COMMANDS = post.COMMANDS + verein.COMMANDS + advent.COMMANDS
diff --git a/lenaverse_bot/commands/advent.py b/lenaverse_bot/commands/advent.py
new file mode 100644
index 0000000..4510d5b
--- /dev/null
+++ b/lenaverse_bot/commands/advent.py
@@ -0,0 +1,97 @@
+import logging
+from io import BytesIO
+
+import aiohttp
+import discord
+
+from ..core.config import CONFIG
+
+_logger = logging.getLogger(__name__)
+
+
+@discord.app_commands.command(name=CONFIG.command_prefix + "advent")
+async def advent(interaction: discord.Interaction, day: int | None = None) -> None:
+    """
+    Türchen vom Lenaisten-Adventskalender öffnen (https://advent.lenaisten.de)
+    """
+
+    _logger.debug(
+        f"User {interaction.user.name}({interaction.user.id}) used /advent (day: {day})"
+    )
+
+    async with aiohttp.ClientSession(
+        auth=aiohttp.BasicAuth(login="", password="")
+    ) as session:
+        if day is None:
+            # Kein Tag angegeben => neuesten Tag finden
+
+            async with session.get(
+                "https://advent.lenaisten.de/api/user/doors"
+            ) as http_response:
+                if http_response.status != 200:
+                    # user/doors Anfrage hat nicht geklappt
+                    await interaction.response.send_message(
+                        content="Fehler: Ich konnte das aktuelle Türchen nicht finden :zany_face: (Probier's nochmal?)",
+                        # nur für ausführenden User
+                        ephemeral=True,
+                    )
+                    return
+
+                if not isinstance(doors := await http_response.json(), list):
+                    # user/doors Antwort falsches Format (keine Liste)
+                    await interaction.response.send_message(
+                        content="Fehler: Ich konnte das aktuelle Türchen nicht finden :sweat_smile: (Probier's nochmal?)",
+                        ephemeral=True,
+                    )
+                    return
+
+            days: list[int] = []
+            for door in doors:
+                if not isinstance(door, dict) or "day" not in door:
+                    # user/doors Antwort falsches Format (Liste enthält falsche Daten)
+                    await interaction.response.send_message(
+                        content="Fehler: Ich konnte das aktuelle Türchen nicht finden :face_with_monocle: (Probier's nochmal?)",
+                        ephemeral=True,
+                    )
+                    return
+
+                days.append(door["day"])
+
+            day = max(days)
+
+        async with session.get(
+            f"https://advent.lenaisten.de/api/user/image_{day}"
+        ) as http_response:
+            reply_ephemeral = not CONFIG.ev_info.in_allowed_channel(interaction)
+
+            if http_response.status == 401:
+                # Bild (noch) nicht verfügbar
+                await interaction.response.send_message(
+                    content=f"Fehler: Tag {day} kann ich (noch?) nicht abrufen. Netter Versuch! :woman_technologist_tone2:",
+                    ephemeral=reply_ephemeral,
+                )
+                return
+
+            if http_response.status != 200:
+                # Bild (noch) nicht verfügbar
+                await interaction.response.send_message(
+                    content="Fehler: Ich konnte das Bild nicht herunterladen :sob: (Probier's nochmal?)",
+                    ephemeral=True,
+                )
+                return
+
+            image = discord.File(
+                fp=BytesIO(await http_response.read()),
+                filename="advent.jpg",
+            )
+
+            await interaction.response.send_message(
+                content=f"Hier ist das Bild für Tag {day}!",
+                file=image,
+                ephemeral=reply_ephemeral,
+            )
+
+
+COMMANDS = [
+    advent,
+]
diff --git a/lenaverse_bot/core/post.py b/lenaverse_bot/commands/post.py
similarity index 96%
rename from lenaverse_bot/core/post.py
rename to lenaverse_bot/commands/post.py
index f2632db..077d352 100644
--- a/lenaverse_bot/core/post.py
+++ b/lenaverse_bot/commands/post.py
@@ -4,7 +4,7 @@ from enum import Enum, auto
 import discord
 from discord import ui
 
-from .config import CONFIG
+from ..core.config import CONFIG
 
 _logger = logging.getLogger(__name__)
 
@@ -111,7 +111,7 @@ async def post(interaction: discord.Interaction) -> None:
             f"User {interaction.user.name}({interaction.user.id}) tried to /post"
         )
         await interaction.response.send_message(
-            content="Du bist nicht berechtigt, den `/post`-Befehl zu benutzen!",
+            content=f"Du bist nicht berechtigt, den `/{CONFIG.command_prefix}post`-Befehl zu benutzen!",
             # nur für ausführenden User
             ephemeral=True,
         )
diff --git a/lenaverse_bot/core/verein.py b/lenaverse_bot/commands/verein.py
similarity index 75%
rename from lenaverse_bot/core/verein.py
rename to lenaverse_bot/commands/verein.py
index 6a6f282..2161f5b 100644
--- a/lenaverse_bot/core/verein.py
+++ b/lenaverse_bot/commands/verein.py
@@ -3,16 +3,11 @@ import logging
 
 import discord
 
-from .config import CONFIG, FileCommand, InfoCommand
+from ..core.config import CONFIG, FileCommand, InfoCommand
 
 _logger = logging.getLogger(__name__)
 
 
-def reply_private(interaction: discord.Interaction, name: str) -> bool:
-    _logger.debug(f"User {interaction.user.name}({interaction.user.id}) used /{name}")
-    return interaction.channel_id not in CONFIG.ev_info.channels
-
-
 @functools.singledispatch
 def make_command(command) -> discord.app_commands.Command:
     raise NotImplementedError
@@ -25,11 +20,15 @@ def _(command: FileCommand) -> discord.app_commands.Command:
         description=command.description,
     )
     async def cmd(interaction: discord.Interaction) -> None:
+        _logger.debug(
+            f"User {interaction.user.name}({interaction.user.id}) used FileCommand /{command.name}"
+        )
+
         if (file := await command.as_discord_file) is not None:
             await interaction.response.send_message(
                 content=command.content,
                 suppress_embeds=True,
-                ephemeral=reply_private(interaction, command.name),
+                ephemeral=not CONFIG.ev_info.in_allowed_channel(interaction),
                 file=file,
             )
 
@@ -49,10 +48,14 @@ def _(command: InfoCommand) -> discord.app_commands.Command:
         description=command.description,
     )
     async def cmd(interaction: discord.Interaction) -> None:
+        _logger.debug(
+            f"User {interaction.user.name}({interaction.user.id}) used InfoCommand /{command.name}"
+        )
+
         await interaction.response.send_message(
             content=command.content,
             suppress_embeds=True,
-            ephemeral=reply_private(interaction, command.name),
+            ephemeral=not CONFIG.ev_info.in_allowed_channel(interaction),
         )
 
     return cmd
diff --git a/lenaverse_bot/core/bot.py b/lenaverse_bot/core/bot.py
index 55212d5..5057f96 100644
--- a/lenaverse_bot/core/bot.py
+++ b/lenaverse_bot/core/bot.py
@@ -2,7 +2,7 @@ import logging
 
 import discord
 
-from . import post, verein
+from ..commands import COMMANDS
 from .config import CONFIG
 
 _logger = logging.getLogger(__name__)
@@ -16,8 +16,7 @@ class LenaverseBot(discord.Client):
         )
 
         self.tree = discord.app_commands.CommandTree(self)
-        commands = post.COMMANDS + verein.COMMANDS
-        for command in commands:
+        for command in COMMANDS:
             self.tree.add_command(command)
 
     async def setup_hook(self):
diff --git a/lenaverse_bot/core/config.py b/lenaverse_bot/core/config.py
index 490c54d..eb5bdcb 100644
--- a/lenaverse_bot/core/config.py
+++ b/lenaverse_bot/core/config.py
@@ -68,6 +68,18 @@ class ClubInfo(BaseModel):
     fest: InfoCommand
     aktion: InfoCommand
 
+    def in_allowed_channel(self, interaction: discord.Interaction) -> bool:
+        if interaction.channel is None:
+            return False
+
+        # öffentliche Antwort erlaubt in:
+        # - DM channels
+        # - "allowed" channels
+        is_dm_channel = isinstance(interaction.channel, discord.DMChannel)
+        is_listed = interaction.channel.id in self.channels
+
+        return is_dm_channel or is_listed
+
 
 class Config(BaseModel):
     discord_token: str