diff --git a/src/elekf/api/auth/models.gleam b/src/elekf/api/auth/models.gleam
index 53a77bd..f74f025 100644
--- a/src/elekf/api/auth/models.gleam
+++ b/src/elekf/api/auth/models.gleam
@@ -1,7 +1,9 @@
+/// Information of the logged in user.
 pub type User {
   User(id: Int, token: String, session_uuid: String)
 }
 
+/// Information of the user's device.
 pub type Device {
   Device(name: String)
 }
diff --git a/src/elekf/api/auth/storage.gleam b/src/elekf/api/auth/storage.gleam
index 38622ca..40ab8de 100644
--- a/src/elekf/api/auth/storage.gleam
+++ b/src/elekf/api/auth/storage.gleam
@@ -1,3 +1,6 @@
+//// The auth storage stores the user's authentication credentials for future
+//// use, i.e. when refreshing the page.
+
 import gleam/dynamic
 import gleam/json
 import plinth/javascript/storage
@@ -6,22 +9,27 @@ import elekf/api/auth/models
 
 const storage_key = "__elektrofoni_auth_storage"
 
+/// Storage format of the authentication data in local storage.
 pub type StorageFormat {
   StorageFormat(user: models.User, device: models.Device)
 }
 
+/// The local storage API used for storing authentication details.
 pub type AuthStorage =
   varasto.TypedStorage(StorageFormat)
 
+/// Gets the `varasto` instance to use for reading and writing auth storage.
 pub fn get() {
   let assert Ok(local) = storage.local()
   varasto.new(local, reader(), writer())
 }
 
+/// Reads the previously stored value, if available.
 pub fn read(storage: AuthStorage) {
   varasto.get(storage, storage_key)
 }
 
+/// Writes new value to the storage.
 pub fn write(storage: AuthStorage, data: StorageFormat) {
   varasto.set(storage, storage_key, data)
 }
diff --git a/src/elekf/api/base_request_config.gleam b/src/elekf/api/base_request_config.gleam
index 000921a..866e913 100644
--- a/src/elekf/api/base_request_config.gleam
+++ b/src/elekf/api/base_request_config.gleam
@@ -3,6 +3,7 @@ import ibroadcast/device_info.{DeviceInfo}
 import ibroadcast/request.{RequestConfig}
 import elekf/utils/navigator
 
+/// Gets the base request config to use for all requests, authenticated and raw.
 pub fn base_request_config(device_name: String) {
   RequestConfig(
     app_info: elektrofoni.app_info,
diff --git a/src/elekf/library.gleam b/src/elekf/library.gleam
index a1393a6..6edf2ef 100644
--- a/src/elekf/library.gleam
+++ b/src/elekf/library.gleam
@@ -1,3 +1,5 @@
+//// The library stores the music library retrieved from iBroadcast.
+
 import gleam/map.{Map}
 import elekf/library/track.{Track}
 import elekf/library/album.{Album}
@@ -11,28 +13,34 @@ pub type Library {
   )
 }
 
+/// Gets an album from the library based on ID.
 pub fn get_album(library: Library, id: Int) {
   map.get(library.albums, id)
 }
 
+/// Gets an artist from the library based on ID.
 pub fn get_artist(library: Library, id: Int) {
   map.get(library.artists, id)
 }
 
+/// Gets a track from the library based on ID.
 pub fn get_track(library: Library, id: Int) {
   map.get(library.tracks, id)
 }
 
+/// Gets an album from the library, asserting that it exists.
 pub fn assert_album(library: Library, id: Int) {
   let assert Ok(album) = map.get(library.albums, id)
   album
 }
 
+/// Gets an artist from the library, asserting that it exists.
 pub fn assert_artist(library: Library, id: Int) {
   let assert Ok(artist) = map.get(library.artists, id)
   artist
 }
 
+/// Gets a track from the library, asserting that it exists.
 pub fn assert_track(library: Library, id: Int) {
   let assert Ok(track) = map.get(library.tracks, id)
   track
diff --git a/src/elekf/library/track.gleam b/src/elekf/library/track.gleam
index 70630f8..47362ad 100644
--- a/src/elekf/library/track.gleam
+++ b/src/elekf/library/track.gleam
@@ -1,3 +1,7 @@
+/// A track in the music library.
+///
+/// The `title_lower` contains the track title in lowercase, which is an
+/// optimisation for searching.
 pub type Track {
   Track(
     number: Int,
diff --git a/src/elekf/transfer/album.gleam b/src/elekf/transfer/album.gleam
index 54fa5bf..4e44c32 100644
--- a/src/elekf/transfer/album.gleam
+++ b/src/elekf/transfer/album.gleam
@@ -1,6 +1,7 @@
 import ibroadcast/library/library.{Album as APIAlbum}
 import elekf/library/album.{Album}
 
+/// Converts API album response to library format.
 pub fn from(album: APIAlbum) {
   Album(
     name: album.name,
diff --git a/src/elekf/transfer/artist.gleam b/src/elekf/transfer/artist.gleam
index 0cb8dfc..a428066 100644
--- a/src/elekf/transfer/artist.gleam
+++ b/src/elekf/transfer/artist.gleam
@@ -1,6 +1,7 @@
 import ibroadcast/library/library.{Artist as APIArtist}
 import elekf/library/artist.{Artist}
 
+/// Converts API artist response to library format.
 pub fn from(artist: APIArtist) {
   Artist(
     name: artist.name,
diff --git a/src/elekf/transfer/library.gleam b/src/elekf/transfer/library.gleam
index 917b6d8..bc286f2 100644
--- a/src/elekf/transfer/library.gleam
+++ b/src/elekf/transfer/library.gleam
@@ -6,6 +6,7 @@ import elekf/transfer/album
 import elekf/transfer/artist
 import elekf/transfer/track
 
+/// Converts API library response to library format.
 pub fn from(library: APILibrary) {
   let albums = transfer_map(library.albums, album.from)
   let artists = transfer_map(library.artists, artist.from)
diff --git a/src/elekf/transfer/track.gleam b/src/elekf/transfer/track.gleam
index 8545d3b..c0f81bf 100644
--- a/src/elekf/transfer/track.gleam
+++ b/src/elekf/transfer/track.gleam
@@ -2,6 +2,7 @@ import gleam/string
 import ibroadcast/library/library.{Track as APITrack}
 import elekf/library/track.{Track}
 
+/// Converts API track response to library format.
 pub fn from(track: APITrack) {
   Track(
     number: track.number,
diff --git a/src/elekf/utils/date.gleam b/src/elekf/utils/date.gleam
index b622d2d..3631ffd 100644
--- a/src/elekf/utils/date.gleam
+++ b/src/elekf/utils/date.gleam
@@ -28,7 +28,7 @@ pub fn equals(a: Date, b: Date) -> Bool
 @external(javascript, "../../date_ffi.mjs", "bigger_than")
 pub fn bigger_than(a: Date, b: Date) -> Bool
 
-/// Compare given dates, returning `Gt` if `a` > `b`
+/// Compares given dates, returning `Gt` if `a` > `b`
 pub fn compare(a: Date, b: Date) -> Order {
   case equals(a, b) {
     True -> Eq
@@ -41,6 +41,7 @@ pub fn compare(a: Date, b: Date) -> Order {
   }
 }
 
+/// Decodes a dynamic value as an ISO 8601 formatted datetime string.
 pub fn decode(value: Dynamic) -> Result(Date, List(DecodeError)) {
   use str <- result.try(dynamic.string(value))
   use date <- result.try(
diff --git a/src/elekf/utils/http.gleam b/src/elekf/utils/http.gleam
index 09cd861..9df52a8 100644
--- a/src/elekf/utils/http.gleam
+++ b/src/elekf/utils/http.gleam
@@ -4,9 +4,11 @@ import gleam/javascript/promise
 import ibroadcast/request as ibroadcast_request
 import ibroadcast/http as ibroadcast_http
 
+/// Error returned by an HTTP request.
 pub type ResponseError =
   ibroadcast_request.ResponseError(fetch.FetchError)
 
+/// Returns an HTTP request function based on `fetch`.
 pub fn requestor() -> ibroadcast_http.Requestor(fetch.FetchError) {
   fn(req: request.Request(String)) {
     use resp <- promise.try_await(fetch.send(req))
diff --git a/src/elekf/utils/navigator.gleam b/src/elekf/utils/navigator.gleam
index dbc07b4..94e092a 100644
--- a/src/elekf/utils/navigator.gleam
+++ b/src/elekf/utils/navigator.gleam
@@ -1,2 +1,3 @@
+/// Returns the current browser's user agent.
 @external(javascript, "../../navigator_ffi.mjs", "userAgent")
 pub fn user_agent() -> String
diff --git a/src/elekf/web/authed_view.gleam b/src/elekf/web/authed_view.gleam
index 3ec1dcf..b79f576 100644
--- a/src/elekf/web/authed_view.gleam
+++ b/src/elekf/web/authed_view.gleam
@@ -1,3 +1,6 @@
+//// The authed view manages the user's request config and displays the base
+//// view for the app.
+
 import gleam/io
 import gleam/int
 import gleam/list
diff --git a/src/elekf/web/common.gleam b/src/elekf/web/common.gleam
index 2fd5bf0..2b0764b 100644
--- a/src/elekf/web/common.gleam
+++ b/src/elekf/web/common.gleam
@@ -1,9 +1,11 @@
 import elekf/api/auth/models as auth_models
 
+/// Authentication data for the user.
 pub type AuthData {
   AuthData(user: auth_models.User, device: auth_models.Device)
 }
 
+/// Settings of the iBroadcast API.
 pub type Settings {
   Settings(artwork_server: String, streaming_server: String)
 }
diff --git a/src/elekf/web/components/player.gleam b/src/elekf/web/components/player.gleam
index 8e5eeb1..8cc490b 100644
--- a/src/elekf/web/components/player.gleam
+++ b/src/elekf/web/components/player.gleam
@@ -1,3 +1,5 @@
+//// The player view renders the media player UI element and its controls.
+
 import gleam/list
 import gleam/uri
 import lustre/element.{text}
diff --git a/src/elekf/web/components/search.gleam b/src/elekf/web/components/search.gleam
index 79d3fb6..947d74e 100644
--- a/src/elekf/web/components/search.gleam
+++ b/src/elekf/web/components/search.gleam
@@ -1,3 +1,6 @@
+//// The search view renders a search bar, other views must do the searching
+//// based on the emitted messages.
+
 import lustre/element.{text}
 import lustre/element/html.{button, div, input}
 import lustre/attribute
diff --git a/src/elekf/web/login_view.gleam b/src/elekf/web/login_view.gleam
index 0b4d61f..1e7cf06 100644
--- a/src/elekf/web/login_view.gleam
+++ b/src/elekf/web/login_view.gleam
@@ -1,3 +1,5 @@
+//// The login view displays the login form and starts the login operation.
+
 import gleam/string
 import gleam/javascript/promise
 import lustre/element.{text}
diff --git a/src/elekf/web/main.gleam b/src/elekf/web/main.gleam
index a36647a..1f88579 100644
--- a/src/elekf/web/main.gleam
+++ b/src/elekf/web/main.gleam
@@ -1,3 +1,5 @@
+//// The main view sets up everything and shows the login or authed view.
+
 import gleam/io
 import gleam/option
 import lustre
diff --git a/src/elekf/web/view.gleam b/src/elekf/web/view.gleam
index 859cc5f..a6f8d3e 100644
--- a/src/elekf/web/view.gleam
+++ b/src/elekf/web/view.gleam
@@ -1,3 +1,4 @@
+/// Views that can be rendered on the main level.
 pub type View {
   LoginView
   AuthedView
diff --git a/src/elektrofoni.gleam b/src/elektrofoni.gleam
index a235d24..58b9bd8 100644
--- a/src/elektrofoni.gleam
+++ b/src/elektrofoni.gleam
@@ -1,13 +1,20 @@
 import ibroadcast/app_info.{AppInfo}
 
+/// Name of the application.
 pub const app_name = "elektrofoni"
 
+/// Version of the application.
 pub const app_version = "1.0.0"
 
+/// ID of the application.
 pub const app_id = 1098
 
+/// Constant app info to use in application.
 pub const app_info = AppInfo(app_name, app_version)
 
+/// The bitrate to use for streaming by default.
 pub const bitrate = 256
 
+/// The expiry of the MP3 URLs generated for streaming, from the current moment
+/// onwards, in milliseconds.
 pub const track_expiry_length = 10_800_000