diff --git a/core/src/cdn_url.rs b/core/src/cdn_url.rs
index 9df43ea9..e7016143 100644
--- a/core/src/cdn_url.rs
+++ b/core/src/cdn_url.rs
@@ -67,7 +67,7 @@ impl CdnUrl {
 
     pub async fn resolve_audio(&self, session: &Session) -> Result<Self, Error> {
         let file_id = self.file_id;
-        let response = session.spclient().get_audio_storage(file_id).await?;
+        let response = session.spclient().get_audio_storage(&file_id).await?;
         let msg = CdnUrlMessage::parse_from_bytes(&response)?;
         let urls = MaybeExpiringUrls::try_from(msg)?;
 
diff --git a/core/src/spclient.rs b/core/src/spclient.rs
index 479c86e0..e65e0bff 100644
--- a/core/src/spclient.rs
+++ b/core/src/spclient.rs
@@ -235,7 +235,7 @@ impl SpClient {
             HeaderValue::from_static("application/x-protobuf"),
         );
 
-        self.request(method, endpoint, Some(headers), Some(body))
+        self.request(method, endpoint, Some(headers), Some(&body))
             .await
     }
 
@@ -244,7 +244,7 @@ impl SpClient {
         method: &Method,
         endpoint: &str,
         headers: Option<HeaderMap>,
-        body: Option<String>,
+        body: Option<&str>,
     ) -> SpClientResult {
         let mut headers = headers.unwrap_or_else(HeaderMap::new);
         headers.insert(ACCEPT, HeaderValue::from_static("application/json"));
@@ -257,7 +257,7 @@ impl SpClient {
         method: &Method,
         endpoint: &str,
         headers: Option<HeaderMap>,
-        body: Option<String>,
+        body: Option<&str>,
     ) -> SpClientResult {
         let mut tries: usize = 0;
         let mut last_response;
@@ -283,7 +283,7 @@ impl SpClient {
             let mut request = Request::builder()
                 .method(method)
                 .uri(url)
-                .body(Body::from(body.clone()))?;
+                .body(Body::from(body.to_owned()))?;
 
             // Reconnection logic: keep getting (cached) tokens because they might have expired.
             let token = self
@@ -348,44 +348,44 @@ impl SpClient {
 
     pub async fn put_connect_state(
         &self,
-        connection_id: String,
-        state: PutStateRequest,
+        connection_id: &str,
+        state: &PutStateRequest,
     ) -> SpClientResult {
         let endpoint = format!("/connect-state/v1/devices/{}", self.session().device_id());
 
         let mut headers = HeaderMap::new();
         headers.insert("X-Spotify-Connection-Id", connection_id.parse()?);
 
-        self.request_with_protobuf(&Method::PUT, &endpoint, Some(headers), &state)
+        self.request_with_protobuf(&Method::PUT, &endpoint, Some(headers), state)
             .await
     }
 
-    pub async fn get_metadata(&self, scope: &str, id: SpotifyId) -> SpClientResult {
+    pub async fn get_metadata(&self, scope: &str, id: &SpotifyId) -> SpClientResult {
         let endpoint = format!("/metadata/4/{}/{}", scope, id.to_base16()?);
         self.request(&Method::GET, &endpoint, None, None).await
     }
 
-    pub async fn get_track_metadata(&self, track_id: SpotifyId) -> SpClientResult {
+    pub async fn get_track_metadata(&self, track_id: &SpotifyId) -> SpClientResult {
         self.get_metadata("track", track_id).await
     }
 
-    pub async fn get_episode_metadata(&self, episode_id: SpotifyId) -> SpClientResult {
+    pub async fn get_episode_metadata(&self, episode_id: &SpotifyId) -> SpClientResult {
         self.get_metadata("episode", episode_id).await
     }
 
-    pub async fn get_album_metadata(&self, album_id: SpotifyId) -> SpClientResult {
+    pub async fn get_album_metadata(&self, album_id: &SpotifyId) -> SpClientResult {
         self.get_metadata("album", album_id).await
     }
 
-    pub async fn get_artist_metadata(&self, artist_id: SpotifyId) -> SpClientResult {
+    pub async fn get_artist_metadata(&self, artist_id: &SpotifyId) -> SpClientResult {
         self.get_metadata("artist", artist_id).await
     }
 
-    pub async fn get_show_metadata(&self, show_id: SpotifyId) -> SpClientResult {
+    pub async fn get_show_metadata(&self, show_id: &SpotifyId) -> SpClientResult {
         self.get_metadata("show", show_id).await
     }
 
-    pub async fn get_lyrics(&self, track_id: SpotifyId) -> SpClientResult {
+    pub async fn get_lyrics(&self, track_id: &SpotifyId) -> SpClientResult {
         let endpoint = format!("/color-lyrics/v2/track/{}", track_id.to_base62()?);
 
         self.request_as_json(&Method::GET, &endpoint, None, None)
@@ -394,8 +394,8 @@ impl SpClient {
 
     pub async fn get_lyrics_for_image(
         &self,
-        track_id: SpotifyId,
-        image_id: FileId,
+        track_id: &SpotifyId,
+        image_id: &FileId,
     ) -> SpClientResult {
         let endpoint = format!(
             "/color-lyrics/v2/track/{}/image/spotify:image:{}",
@@ -407,7 +407,7 @@ impl SpClient {
             .await
     }
 
-    pub async fn get_playlist(&self, playlist_id: SpotifyId) -> SpClientResult {
+    pub async fn get_playlist(&self, playlist_id: &SpotifyId) -> SpClientResult {
         let endpoint = format!("/playlist/v2/playlist/{}", playlist_id);
 
         self.request(&Method::GET, &endpoint, None, None).await
@@ -415,7 +415,7 @@ impl SpClient {
 
     pub async fn get_user_profile(
         &self,
-        username: String,
+        username: &str,
         playlist_limit: Option<u32>,
         artist_limit: Option<u32>,
     ) -> SpClientResult {
@@ -440,14 +440,14 @@ impl SpClient {
             .await
     }
 
-    pub async fn get_user_followers(&self, username: String) -> SpClientResult {
+    pub async fn get_user_followers(&self, username: &str) -> SpClientResult {
         let endpoint = format!("/user-profile-view/v3/profile/{}/followers", username);
 
         self.request_as_json(&Method::GET, &endpoint, None, None)
             .await
     }
 
-    pub async fn get_user_following(&self, username: String) -> SpClientResult {
+    pub async fn get_user_following(&self, username: &str) -> SpClientResult {
         let endpoint = format!("/user-profile-view/v3/profile/{}/following", username);
 
         self.request_as_json(&Method::GET, &endpoint, None, None)
@@ -466,9 +466,9 @@ impl SpClient {
 
     pub async fn get_apollo_station(
         &self,
-        context: SpotifyId,
+        context_uri: &str,
         count: u32,
-        previous_tracks: Vec<SpotifyId>,
+        previous_tracks: Vec<&SpotifyId>,
         autoplay: bool,
     ) -> SpClientResult {
         let previous_track_str = previous_tracks
@@ -478,10 +478,7 @@ impl SpClient {
             .join(",");
         let endpoint = format!(
             "/radio-apollo/v3/stations/{}?count={}&prev_tracks={}&autoplay={}",
-            context.to_uri()?,
-            count,
-            previous_track_str,
-            autoplay,
+            context_uri, count, previous_track_str, autoplay,
         );
 
         self.request_as_json(&Method::GET, &endpoint, None, None)
@@ -501,7 +498,7 @@ impl SpClient {
             .await
     }
 
-    pub async fn get_audio_storage(&self, file_id: FileId) -> SpClientResult {
+    pub async fn get_audio_storage(&self, file_id: &FileId) -> SpClientResult {
         let endpoint = format!(
             "/storage-resolve/files/audio/interactive/{}",
             file_id.to_base16()?
@@ -530,7 +527,7 @@ impl SpClient {
         Ok(stream)
     }
 
-    pub async fn request_url(&self, url: String) -> SpClientResult {
+    pub async fn request_url(&self, url: &str) -> SpClientResult {
         let request = Request::builder()
             .method(&Method::GET)
             .uri(url)
@@ -554,11 +551,11 @@ impl SpClient {
         };
         let _ = write!(url, "{}cid={}", separator, self.session().client_id());
 
-        self.request_url(url).await
+        self.request_url(&url).await
     }
 
     // The first 128 kB of a track, unencrypted
-    pub async fn get_head_file(&self, file_id: FileId) -> SpClientResult {
+    pub async fn get_head_file(&self, file_id: &FileId) -> SpClientResult {
         let attribute = "head-files-url";
         let template = self
             .session()
@@ -567,10 +564,10 @@ impl SpClient {
 
         let url = template.replace("{file_id}", &file_id.to_base16()?);
 
-        self.request_url(url).await
+        self.request_url(&url).await
     }
 
-    pub async fn get_image(&self, image_id: FileId) -> SpClientResult {
+    pub async fn get_image(&self, image_id: &FileId) -> SpClientResult {
         let attribute = "image-url";
         let template = self
             .session()
@@ -578,6 +575,6 @@ impl SpClient {
             .ok_or_else(|| SpClientError::Attribute(attribute.to_string()))?;
         let url = template.replace("{file_id}", &image_id.to_base16()?);
 
-        self.request_url(url).await
+        self.request_url(&url).await
     }
 }
diff --git a/core/src/spotify_id.rs b/core/src/spotify_id.rs
index 66e3ac36..f1c1f1b8 100644
--- a/core/src/spotify_id.rs
+++ b/core/src/spotify_id.rs
@@ -329,10 +329,10 @@ impl NamedSpotifyId {
         Ok(dst)
     }
 
-    pub fn from_spotify_id(id: SpotifyId, username: String) -> Self {
+    pub fn from_spotify_id(id: SpotifyId, username: &str) -> Self {
         Self {
             inner_id: id,
-            username,
+            username: username.to_owned(),
         }
     }
 }
diff --git a/metadata/src/album.rs b/metadata/src/album.rs
index c2c439c2..45db39ea 100644
--- a/metadata/src/album.rs
+++ b/metadata/src/album.rs
@@ -76,11 +76,11 @@ impl Album {
 impl Metadata for Album {
     type Message = protocol::metadata::Album;
 
-    async fn request(session: &Session, album_id: SpotifyId) -> RequestResult {
+    async fn request(session: &Session, album_id: &SpotifyId) -> RequestResult {
         session.spclient().get_album_metadata(album_id).await
     }
 
-    fn parse(msg: &Self::Message, _: SpotifyId) -> Result<Self, Error> {
+    fn parse(msg: &Self::Message, _: &SpotifyId) -> Result<Self, Error> {
         Self::try_from(msg)
     }
 }
diff --git a/metadata/src/artist.rs b/metadata/src/artist.rs
index db297b59..1a7e1862 100644
--- a/metadata/src/artist.rs
+++ b/metadata/src/artist.rs
@@ -171,11 +171,11 @@ impl Artist {
 impl Metadata for Artist {
     type Message = protocol::metadata::Artist;
 
-    async fn request(session: &Session, artist_id: SpotifyId) -> RequestResult {
+    async fn request(session: &Session, artist_id: &SpotifyId) -> RequestResult {
         session.spclient().get_artist_metadata(artist_id).await
     }
 
-    fn parse(msg: &Self::Message, _: SpotifyId) -> Result<Self, Error> {
+    fn parse(msg: &Self::Message, _: &SpotifyId) -> Result<Self, Error> {
         Self::try_from(msg)
     }
 }
diff --git a/metadata/src/episode.rs b/metadata/src/episode.rs
index e3a5c7a3..e65a1045 100644
--- a/metadata/src/episode.rs
+++ b/metadata/src/episode.rs
@@ -60,7 +60,7 @@ impl_deref_wrapped!(Episodes, Vec<SpotifyId>);
 #[async_trait]
 impl InnerAudioItem for Episode {
     async fn get_audio_item(session: &Session, id: SpotifyId) -> AudioItemResult {
-        let episode = Self::get(session, id).await?;
+        let episode = Self::get(session, &id).await?;
         let availability = Self::available_for_user(
             &session.user_data(),
             &episode.availability,
@@ -84,11 +84,11 @@ impl InnerAudioItem for Episode {
 impl Metadata for Episode {
     type Message = protocol::metadata::Episode;
 
-    async fn request(session: &Session, episode_id: SpotifyId) -> RequestResult {
+    async fn request(session: &Session, episode_id: &SpotifyId) -> RequestResult {
         session.spclient().get_episode_metadata(episode_id).await
     }
 
-    fn parse(msg: &Self::Message, _: SpotifyId) -> Result<Self, Error> {
+    fn parse(msg: &Self::Message, _: &SpotifyId) -> Result<Self, Error> {
         Self::try_from(msg)
     }
 }
diff --git a/metadata/src/lib.rs b/metadata/src/lib.rs
index 577af387..ef8443db 100644
--- a/metadata/src/lib.rs
+++ b/metadata/src/lib.rs
@@ -42,15 +42,15 @@ pub trait Metadata: Send + Sized + 'static {
     type Message: protobuf::Message;
 
     // Request a protobuf
-    async fn request(session: &Session, id: SpotifyId) -> RequestResult;
+    async fn request(session: &Session, id: &SpotifyId) -> RequestResult;
 
     // Request a metadata struct
-    async fn get(session: &Session, id: SpotifyId) -> Result<Self, Error> {
+    async fn get(session: &Session, id: &SpotifyId) -> Result<Self, Error> {
         let response = Self::request(session, id).await?;
         let msg = Self::Message::parse_from_bytes(&response)?;
         trace!("Received metadata: {:#?}", msg);
         Self::parse(&msg, id)
     }
 
-    fn parse(msg: &Self::Message, _: SpotifyId) -> Result<Self, Error>;
+    fn parse(msg: &Self::Message, _: &SpotifyId) -> Result<Self, Error>;
 }
diff --git a/metadata/src/playlist/annotation.rs b/metadata/src/playlist/annotation.rs
index fd8863cf..9cb7f144 100644
--- a/metadata/src/playlist/annotation.rs
+++ b/metadata/src/playlist/annotation.rs
@@ -27,12 +27,12 @@ pub struct PlaylistAnnotation {
 impl Metadata for PlaylistAnnotation {
     type Message = protocol::playlist_annotate3::PlaylistAnnotation;
 
-    async fn request(session: &Session, playlist_id: SpotifyId) -> RequestResult {
+    async fn request(session: &Session, playlist_id: &SpotifyId) -> RequestResult {
         let current_user = session.username();
         Self::request_for_user(session, &current_user, playlist_id).await
     }
 
-    fn parse(msg: &Self::Message, _: SpotifyId) -> Result<Self, Error> {
+    fn parse(msg: &Self::Message, _: &SpotifyId) -> Result<Self, Error> {
         Ok(Self {
             description: msg.get_description().to_owned(),
             picture: msg.get_picture().to_owned(), // TODO: is this a URL or Spotify URI?
@@ -47,7 +47,7 @@ impl PlaylistAnnotation {
     async fn request_for_user(
         session: &Session,
         username: &str,
-        playlist_id: SpotifyId,
+        playlist_id: &SpotifyId,
     ) -> RequestResult {
         let uri = format!(
             "hm://playlist-annotate/v1/annotation/user/{}/playlist/{}",
@@ -61,7 +61,7 @@ impl PlaylistAnnotation {
     async fn get_for_user(
         session: &Session,
         username: &str,
-        playlist_id: SpotifyId,
+        playlist_id: &SpotifyId,
     ) -> Result<Self, Error> {
         let response = Self::request_for_user(session, username, playlist_id).await?;
         let msg = <Self as Metadata>::Message::parse_from_bytes(&response)?;
diff --git a/metadata/src/playlist/list.rs b/metadata/src/playlist/list.rs
index 414e1fda..c813a14d 100644
--- a/metadata/src/playlist/list.rs
+++ b/metadata/src/playlist/list.rs
@@ -97,14 +97,14 @@ impl Playlist {
 impl Metadata for Playlist {
     type Message = protocol::playlist4_external::SelectedListContent;
 
-    async fn request(session: &Session, playlist_id: SpotifyId) -> RequestResult {
+    async fn request(session: &Session, playlist_id: &SpotifyId) -> RequestResult {
         session.spclient().get_playlist(playlist_id).await
     }
 
-    fn parse(msg: &Self::Message, id: SpotifyId) -> Result<Self, Error> {
+    fn parse(msg: &Self::Message, id: &SpotifyId) -> Result<Self, Error> {
         // the playlist proto doesn't contain the id so we decorate it
         let playlist = SelectedListContent::try_from(msg)?;
-        let id = NamedSpotifyId::from_spotify_id(id, playlist.owner_username);
+        let id = NamedSpotifyId::from_spotify_id(*id, &playlist.owner_username);
 
         Ok(Self {
             id,
diff --git a/metadata/src/show.rs b/metadata/src/show.rs
index 19e910d8..0d3acef8 100644
--- a/metadata/src/show.rs
+++ b/metadata/src/show.rs
@@ -39,11 +39,11 @@ pub struct Show {
 impl Metadata for Show {
     type Message = protocol::metadata::Show;
 
-    async fn request(session: &Session, show_id: SpotifyId) -> RequestResult {
+    async fn request(session: &Session, show_id: &SpotifyId) -> RequestResult {
         session.spclient().get_show_metadata(show_id).await
     }
 
-    fn parse(msg: &Self::Message, _: SpotifyId) -> Result<Self, Error> {
+    fn parse(msg: &Self::Message, _: &SpotifyId) -> Result<Self, Error> {
         Self::try_from(msg)
     }
 }
diff --git a/metadata/src/track.rs b/metadata/src/track.rs
index 7d416f14..f4855d8a 100644
--- a/metadata/src/track.rs
+++ b/metadata/src/track.rs
@@ -61,7 +61,7 @@ impl_deref_wrapped!(Tracks, Vec<SpotifyId>);
 #[async_trait]
 impl InnerAudioItem for Track {
     async fn get_audio_item(session: &Session, id: SpotifyId) -> AudioItemResult {
-        let track = Self::get(session, id).await?;
+        let track = Self::get(session, &id).await?;
         let alternatives = {
             if track.alternatives.is_empty() {
                 None
@@ -98,11 +98,11 @@ impl InnerAudioItem for Track {
 impl Metadata for Track {
     type Message = protocol::metadata::Track;
 
-    async fn request(session: &Session, track_id: SpotifyId) -> RequestResult {
+    async fn request(session: &Session, track_id: &SpotifyId) -> RequestResult {
         session.spclient().get_track_metadata(track_id).await
     }
 
-    fn parse(msg: &Self::Message, _: SpotifyId) -> Result<Self, Error> {
+    fn parse(msg: &Self::Message, _: &SpotifyId) -> Result<Self, Error> {
         Self::try_from(msg)
     }
 }