diff --git a/src/command/join.rs b/src/command/join.rs
index 35c86e7..dc3aee9 100644
--- a/src/command/join.rs
+++ b/src/command/join.rs
@@ -1,12 +1,23 @@
 use std::sync::LazyLock;
 
-use twilight_model::application::{
-    command::{Command, CommandType},
-    interaction::{Interaction, application_command::CommandData},
+use snafu::{OptionExt, Snafu};
+use twilight_model::{
+    application::{
+        command::{Command, CommandType},
+        interaction::Interaction,
+    },
+    channel::message::{Embed, MessageFlags},
+    http::interaction::{InteractionResponse, InteractionResponseType},
+    id::{
+        Id,
+        marker::{ChannelMarker, GuildMarker},
+    },
+};
+use twilight_util::builder::{
+    InteractionResponseDataBuilder, command::CommandBuilder, embed::EmbedBuilder,
 };
-use twilight_util::builder::command::CommandBuilder;
 
-use crate::command::State;
+use crate::{VCs, command::State};
 
 const NAME: &str = "join";
 const DESCRIPTION: &str = "The bot will join the same VC as you (with intention to record)";
@@ -18,24 +29,103 @@ pub static COMMAND: LazyLock<Command> = LazyLock::new(|| {
         .build()
 });
 
+#[derive(Debug, Snafu)]
+enum GetGuildAndChannelIdError {
+    /// this command was not used inside a guild (Discord server)
+    NotInGuild,
+
+    /// there is no user who invoked this command
+    NoUser,
+
+    /// there are no voice chats in this guild
+    NoVCsInGuild,
+
+    /// the user is not in a voice chat in this guild
+    UserNotInVC,
+}
+
+impl From<GetGuildAndChannelIdError> for Embed {
+    fn from(error: GetGuildAndChannelIdError) -> Embed {
+        match error {
+            GetGuildAndChannelIdError::NotInGuild => {
+                EmbedBuilder::new().title("Use this in a server").description("This bot can't find a VC to join if the command is used outside of a server (you might've used it in a DM?).").validate().unwrap().build()
+            }
+            GetGuildAndChannelIdError::NoUser => EmbedBuilder::new().title("Not invoked by a user").description("This command works by joining the same VC as the user, but this bot didn't receive any user data. So did no user invoke it?! (This error should be impossible!)").validate().unwrap().build(),
+            GetGuildAndChannelIdError::NoVCsInGuild => {
+                EmbedBuilder::new().title("No VCs in this server").description("This bot can't find a VC to join because there aren't any in this server right now.").validate().unwrap().build()
+            },
+            GetGuildAndChannelIdError::UserNotInVC => {
+
+                EmbedBuilder::new().title("You're not in a VC").description("This bot can't follow you into VC if you aren't in one in this server.").validate().unwrap().build()
+            },
+        }
+    }
+}
+
+#[tracing::instrument]
+fn get_guild_and_channel_id(
+    interaction: &Interaction,
+    vcs: &VCs,
+) -> Result<(Id<GuildMarker>, Id<ChannelMarker>), GetGuildAndChannelIdError> {
+    let guild_id = interaction.guild_id.context(NotInGuildSnafu)?;
+
+    let user_id = interaction
+        .member
+        .as_ref()
+        .and_then(|member| member.user.as_ref().map(|user| user.id))
+        .context(NoUserSnafu)?;
+
+    let guild_vcs = vcs.get(&guild_id).context(NoVCsInGuildSnafu)?;
+
+    let &channel_id = guild_vcs.get_left_for(&user_id).context(UserNotInVCSnafu)?;
+
+    Ok((guild_id, channel_id))
+}
+
 #[tracing::instrument]
 pub async fn handle(state: State, interaction: Interaction) {
     let vcs = state.vcs;
 
-    let guild_id = interaction.guild_id.expect("TODO");
-    // let user_id = data.user.map(|user| user.id).expect("TODO");
+    let (guild_id, channel_id) = match get_guild_and_channel_id(&interaction, &vcs) {
+        Ok((guild_id, channel_id)) => (guild_id, channel_id),
+        Err(error) => {
+            state
+                .discord_client
+                .interaction(state.discord_application_id)
+                .create_response(
+                    interaction.id,
+                    &interaction.token,
+                    &InteractionResponse {
+                        kind: InteractionResponseType::ChannelMessageWithSource,
+                        data: Some(
+                            InteractionResponseDataBuilder::new()
+                                .embeds([error.into()])
+                                .flags(MessageFlags::EPHEMERAL)
+                                .build(),
+                        ),
+                    },
+                )
+                .await
+                .expect("TODO");
 
-    let user_id = interaction
-        .member
-        .and_then(|member| member.user.map(|user| user.id))
+            return;
+        }
+    };
+
+    state
+        .discord_client
+        .interaction(state.discord_application_id)
+        .create_response(
+            interaction.id,
+            &interaction.token,
+            &InteractionResponse {
+                kind: InteractionResponseType::DeferredChannelMessageWithSource,
+                data: None,
+            },
+        )
+        .await
         .expect("TODO");
 
-    let guild_vcs = vcs.get(&guild_id).expect("TODO");
-    tracing::error!(?guild_vcs, "TODO");
-
-    let (&channel_id, user_in_vc_data) = guild_vcs.get_left_and_data_for(&user_id).expect("TODO");
-    tracing::error!(?user_in_vc_data, "TODO");
-
     let call = tokio::spawn({
         let songbird = state.songbird.clone();
         async move { songbird.join(guild_id, channel_id).await }
@@ -44,5 +134,20 @@ pub async fn handle(state: State, interaction: Interaction) {
     .unwrap()
     .expect("TODO");
 
+    let channel_mention = format!("<#{channel_id}>");
+
+    state
+        .discord_client
+        .interaction(state.discord_application_id)
+        .update_response(
+            &interaction.token,
+        ).embeds(Some(&[
+            EmbedBuilder::new().title("Joined VC with intent to record").description(&format!("This bot joined {channel_mention} and intends to start recording after a responsible disclosure and consent.")).validate().unwrap().build()
+        ]))
+        .await
+        .expect("TODO");
+
     tracing::error!(?call, "TODO");
+
+    let call_guard = call.lock().await;
 }
diff --git a/src/command/mod.rs b/src/command/mod.rs
index 3254fd6..1083702 100644
--- a/src/command/mod.rs
+++ b/src/command/mod.rs
@@ -1,88 +1,93 @@
-use std::{fmt::Debug, sync::Arc};
-
-use futures::future::BoxFuture;
-use patricia_tree::StringPatriciaMap;
-use songbird::Songbird;
-use twilight_model::application::{command::Command, interaction::Interaction};
-
-use crate::VCs;
-
-mod join;
-mod leave;
-mod opt_out;
-
-#[derive(Debug, Clone)]
-pub struct State {
-    pub vcs: Arc<VCs>,
-    pub songbird: Arc<Songbird>,
-}
-
-type Return = ();
-type BoxedHandler = Box<dyn Fn(State, Interaction) -> BoxFuture<'static, Return>>;
-
-fn box_handler<Handler, Fut>(handler: Handler) -> BoxedHandler
-where
-    Fut: Future<Output = Return> + Send + 'static,
-    Handler: Fn(State, Interaction) -> Fut + 'static,
-{
-    Box::new(move |state, interaction| Box::pin(handler(state, interaction)))
-}
-
-pub fn all() -> Vec<(&'static Command, BoxedHandler)> {
-    vec![
-        (&join::COMMAND, box_handler(join::handle)),
-        (&leave::COMMAND, box_handler(leave::handle)),
-        (&opt_out::COMMAND, box_handler(opt_out::handle)),
-    ]
-}
-
-#[derive(Default)]
-pub struct Router {
-    map: StringPatriciaMap<BoxedHandler>,
-}
-
-impl Router {
-    fn add_route<'s, 'a, Fut, Handler>(&'s mut self, name: &'a str, handler: Handler)
-    where
-        Fut: Future<Output = Return> + Send + 'static,
-        Handler: Fn(State, Interaction) -> Fut + 'static,
-    {
-        self.add_route_already_boxed(name, box_handler(handler));
-    }
-
-    fn add_route_already_boxed<'s, 'a>(&'s mut self, name: &'a str, boxed_handler: BoxedHandler) {
-        self.map.insert(name, boxed_handler);
-    }
-
-    pub async fn handle(
-        &self,
-        state: State,
-        command_name: &str,
-        interaction: Interaction,
-    ) -> Option<Return> {
-        let handler = self.map.get(command_name)?;
-
-        Some(handler(state, interaction).await)
-    }
-}
-
-impl<'a> FromIterator<(&'a Command, BoxedHandler)> for Router {
-    #[inline]
-    fn from_iter<T: IntoIterator<Item = (&'a Command, BoxedHandler)>>(iter: T) -> Self {
-        let mut this = Self::default();
-
-        this.extend(iter);
-
-        this
-    }
-}
-
-impl<'a> Extend<(&'a Command, BoxedHandler)> for Router {
-    #[inline]
-    fn extend<T: IntoIterator<Item = (&'a Command, BoxedHandler)>>(&mut self, iter: T) {
-        for (command, boxed_handler) in iter {
-            let name = &command.name;
-            self.add_route_already_boxed(name, boxed_handler);
-        }
-    }
-}
+use std::{fmt::Debug, sync::Arc};
+
+use futures::future::BoxFuture;
+use patricia_tree::StringPatriciaMap;
+use songbird::Songbird;
+use twilight_model::{
+    application::{command::Command, interaction::Interaction},
+    id::{Id, marker::ApplicationMarker},
+};
+
+use crate::VCs;
+
+mod join;
+mod leave;
+mod opt_out;
+
+#[derive(Debug, Clone)]
+pub struct State {
+    pub discord_client: Arc<twilight_http::Client>,
+    pub discord_application_id: Id<ApplicationMarker>,
+    pub songbird: Arc<Songbird>,
+    pub vcs: Arc<VCs>,
+}
+
+type Return = ();
+type BoxedHandler = Box<dyn Fn(State, Interaction) -> BoxFuture<'static, Return>>;
+
+fn box_handler<Handler, Fut>(handler: Handler) -> BoxedHandler
+where
+    Fut: Future<Output = Return> + Send + 'static,
+    Handler: Fn(State, Interaction) -> Fut + 'static,
+{
+    Box::new(move |state, interaction| Box::pin(handler(state, interaction)))
+}
+
+pub fn all() -> Vec<(&'static Command, BoxedHandler)> {
+    vec![
+        (&join::COMMAND, box_handler(join::handle)),
+        (&leave::COMMAND, box_handler(leave::handle)),
+        (&opt_out::COMMAND, box_handler(opt_out::handle)),
+    ]
+}
+
+#[derive(Default)]
+pub struct Router {
+    map: StringPatriciaMap<BoxedHandler>,
+}
+
+impl Router {
+    fn add_route<'s, 'a, Fut, Handler>(&'s mut self, name: &'a str, handler: Handler)
+    where
+        Fut: Future<Output = Return> + Send + 'static,
+        Handler: Fn(State, Interaction) -> Fut + 'static,
+    {
+        self.add_route_already_boxed(name, box_handler(handler));
+    }
+
+    fn add_route_already_boxed<'s, 'a>(&'s mut self, name: &'a str, boxed_handler: BoxedHandler) {
+        self.map.insert(name, boxed_handler);
+    }
+
+    pub async fn handle(
+        &self,
+        state: State,
+        command_name: &str,
+        interaction: Interaction,
+    ) -> Option<Return> {
+        let handler = self.map.get(command_name)?;
+
+        Some(handler(state, interaction).await)
+    }
+}
+
+impl<'a> FromIterator<(&'a Command, BoxedHandler)> for Router {
+    #[inline]
+    fn from_iter<T: IntoIterator<Item = (&'a Command, BoxedHandler)>>(iter: T) -> Self {
+        let mut this = Self::default();
+
+        this.extend(iter);
+
+        this
+    }
+}
+
+impl<'a> Extend<(&'a Command, BoxedHandler)> for Router {
+    #[inline]
+    fn extend<T: IntoIterator<Item = (&'a Command, BoxedHandler)>>(&mut self, iter: T) {
+        for (command, boxed_handler) in iter {
+            let name = &command.name;
+            self.add_route_already_boxed(name, boxed_handler);
+        }
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index 4eaef2e..ab3c88e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -132,7 +132,7 @@ async fn main() -> Result<(), MainError> {
         .await
         .expect("couldn't get current Discord application"); // TODO
 
-    let application_id = current_application.id;
+    let discord_application_id = current_application.id;
 
     let shard_id = ShardId::new(0, 1);
     let intents = Intents::GUILD_VOICE_STATES;
@@ -150,7 +150,7 @@ async fn main() -> Result<(), MainError> {
     let event_types = EventTypeFlags::GUILD_VOICE_STATES | EventTypeFlags::INTERACTION_CREATE;
     let mut next_event = shard.next_event(event_types);
 
-    let interaction_client = discord_client.interaction(application_id);
+    let interaction_client = discord_client.interaction(discord_application_id);
 
     let commands = all_commands();
 
@@ -172,11 +172,17 @@ async fn main() -> Result<(), MainError> {
     let command_router = CommandRouter::from_iter(commands);
 
     let vcs = initialize_vcs(&discord_client).await;
+
+    let discord_client = Arc::new(discord_client);
+    let songbird = Arc::new(songbird);
     let vcs = Arc::new(vcs);
 
-    let songbird = Arc::new(songbird);
-
-    let state = State { vcs, songbird };
+    let state = State {
+        discord_application_id,
+        discord_client,
+        songbird,
+        vcs,
+    };
 
     while let Some(event_res) = next_event.await {
         match event_res {