diff --git a/client.ts b/client.ts
index b4f9a20..bec91dc 100644
--- a/client.ts
+++ b/client.ts
@@ -23,11 +23,11 @@ export class SpotifyError extends Error {
 		super(message, options);
 	}
 
-	get url() {
+	get url(): string {
 		return this.response.url;
 	}
 
-	get status() {
+	get status(): number {
 		return this.response.status;
 	}
 }
@@ -142,7 +142,7 @@ export class SpotifyClient implements HTTPClient {
 			: "https://api.spotify.com/";
 	}
 
-	fetch(path: string, opts: FetchLikeOptions = {}) {
+	fetch(path: string, opts: FetchLikeOptions = {}): Promise<Response> {
 		const url = new URL(path, this.baseUrl);
 		if (opts.query) {
 			for (const key in opts.query) {
diff --git a/endpoints/album/album.endpoints.ts b/endpoints/album/album.endpoints.ts
index a2ba76f..860bcc0 100644
--- a/endpoints/album/album.endpoints.ts
+++ b/endpoints/album/album.endpoints.ts
@@ -15,7 +15,7 @@ export const getAlbum = async (
 	client: HTTPClient,
 	albumId: string,
 	market?: string,
-) => {
+): Promise<Album> => {
 	const res = await client.fetch("/v1/albums/" + albumId, {
 		query: { market },
 	});
@@ -33,7 +33,7 @@ export const getAlbums = async (
 	client: HTTPClient,
 	albumIds: string[],
 	market?: string,
-) => {
+): Promise<Album[]> => {
 	const res = await client.fetch("/v1/albums", {
 		query: { market, ids: albumIds },
 	});
@@ -62,7 +62,7 @@ export const getAlbumTracks = async (
 	client: HTTPClient,
 	albumId: string,
 	options?: GetAlbumTrackOpts,
-) => {
+): Promise<PagingObject<SimplifiedTrack>> => {
 	const res = await client.fetch(`/v1/albums/${albumId}/tracks`, {
 		query: options,
 	});
@@ -88,7 +88,7 @@ export type GetSavedAlbumsOpts = Prettify<
 export const getSavedAlbums = async (
 	client: HTTPClient,
 	options?: GetSavedAlbumsOpts,
-) => {
+): Promise<PagingObject<SavedAlbum>> => {
 	const res = await client.fetch("/v1/me/albums", { query: options });
 	return res.json() as Promise<PagingObject<SavedAlbum>>;
 };
@@ -99,7 +99,10 @@ export const getSavedAlbums = async (
  * @param client Spotify HTTPClient
  * @param albumIds List of the Spotify IDs for the albums. Maximum: 20 IDs
  */
-export const saveAlbums = (client: HTTPClient, albumIds: string[]) => {
+export const saveAlbums = (
+	client: HTTPClient,
+	albumIds: string[],
+): Promise<Response> => {
 	return client.fetch("/v1/me/albums", {
 		method: "PUT",
 		query: { ids: albumIds },
@@ -112,7 +115,10 @@ export const saveAlbums = (client: HTTPClient, albumIds: string[]) => {
  * @param client Spotify HTTPClient
  * @param albums_id The Spotify ID of the album
  */
-export const saveAlbum = (client: HTTPClient, albumId: string) => {
+export const saveAlbum = (
+	client: HTTPClient,
+	albumId: string,
+): Promise<Response> => {
 	return saveAlbums(client, [albumId]);
 };
 
@@ -122,7 +128,10 @@ export const saveAlbum = (client: HTTPClient, albumId: string) => {
  * @param client Spotify HTTPClient
  * @param albumIds List of the Spotify IDs for the albums. Maximum: 20 IDs
  */
-export const removeSavedAlbums = (client: HTTPClient, albumIds: string[]) => {
+export const removeSavedAlbums = (
+	client: HTTPClient,
+	albumIds: string[],
+): Promise<Response> => {
 	return client.fetch("/v1/me/albums", {
 		method: "DELETE",
 		query: { ids: albumIds },
@@ -135,7 +144,10 @@ export const removeSavedAlbums = (client: HTTPClient, albumIds: string[]) => {
  * @param client Spotify HTTPClient
  * @param albumId The Spotify ID of the album
  */
-export const removeSavedAlbum = (client: HTTPClient, albumId: string) => {
+export const removeSavedAlbum = (
+	client: HTTPClient,
+	albumId: string,
+): Promise<Response> => {
 	return removeSavedAlbums(client, [albumId]);
 };
 
@@ -148,7 +160,7 @@ export const removeSavedAlbum = (client: HTTPClient, albumId: string) => {
 export const checkIfAlbumsSaved = async (
 	client: HTTPClient,
 	albumIds: string[],
-) => {
+): Promise<boolean[]> => {
 	const res = await client.fetch("/v1/me/albums/contains", {
 		query: { ids: albumIds },
 	});
@@ -164,7 +176,7 @@ export const checkIfAlbumsSaved = async (
 export const checkIfAlbumSaved = async (
 	client: HTTPClient,
 	albumId: string,
-) => {
+): Promise<boolean> => {
 	return (await checkIfAlbumsSaved(client, [albumId]))[0]!;
 };
 
@@ -188,7 +200,7 @@ export type GetNewReleasesOpts = Prettify<
 export const getNewReleases = async (
 	client: HTTPClient,
 	options?: GetNewReleasesOpts,
-) => {
+): Promise<PagingObject<SimplifiedAlbum>> => {
 	const res = await client.fetch("/v1/browse/new-releases", { query: options });
 	return ((await res.json()) as { albums: PagingObject<SimplifiedAlbum> })
 		.albums;
diff --git a/endpoints/artist/artist.endpoints.ts b/endpoints/artist/artist.endpoints.ts
index 2725db9..88285b5 100644
--- a/endpoints/artist/artist.endpoints.ts
+++ b/endpoints/artist/artist.endpoints.ts
@@ -11,7 +11,10 @@ import type { Artist } from "./artist.types.ts";
  * @param client Spotify HTTPClient
  * @param artistId Spotify artist ID
  */
-export const getArtist = async (client: HTTPClient, artistId: string) => {
+export const getArtist = async (
+	client: HTTPClient,
+	artistId: string,
+): Promise<Artist> => {
 	const res = await client.fetch("/v1/artists/" + artistId);
 	return res.json() as Promise<Artist>;
 };
@@ -25,7 +28,7 @@ export const getArtist = async (client: HTTPClient, artistId: string) => {
 export const getArtists = async (
 	client: HTTPClient,
 	artistIds: string[],
-) => {
+): Promise<Artist[]> => {
 	const res = await client.fetch("/v1/artists", { query: { ids: artistIds } });
 	return ((await res.json()) as { artists: Artist[] }).artists;
 };
@@ -55,7 +58,7 @@ export const getArtistAlbums = async (
 	client: HTTPClient,
 	artistId: string,
 	options?: GetArtistAlbumsOpts,
-) => {
+): Promise<PagingObject<SimplifiedAlbum>> => {
 	const res = await client.fetch(`/v1/artists/${artistId}/albums`, {
 		query: options,
 	});
@@ -73,7 +76,7 @@ export const getArtistTopTracks = async (
 	client: HTTPClient,
 	artistId: string,
 	market?: string,
-) => {
+): Promise<Track[]> => {
 	const res = await client.fetch(`/v1/artists/${artistId}/top-tracks`, {
 		query: { market },
 	});
@@ -90,7 +93,7 @@ export const getArtistTopTracks = async (
 export const getArtistRelatedArtists = async (
 	client: HTTPClient,
 	artistId: string,
-) => {
+): Promise<Artist[]> => {
 	const res = await client.fetch(`/v1/artists/${artistId}/related-artists`);
 	return ((await res.json()) as { artists: Artist[] }).artists;
 };
diff --git a/endpoints/audiobook/audiobook.endpoints.ts b/endpoints/audiobook/audiobook.endpoints.ts
index 26a7600..221510f 100644
--- a/endpoints/audiobook/audiobook.endpoints.ts
+++ b/endpoints/audiobook/audiobook.endpoints.ts
@@ -2,7 +2,7 @@ import type { SimplifiedChapter } from "../chapter/chapter.types.ts";
 import type { HTTPClient } from "../../client.ts";
 import type { Prettify } from "../../shared.ts";
 import type { PagingObject, PagingOptions } from "../general.types.ts";
-import type { Audiobook, SimplifiedAudiobook } from "./audiobook.types.ts";
+import type { Audiobook, SavedAudiobook } from "./audiobook.types.ts";
 
 /**
  * Get Spotify catalog information for a single Audiobook.
@@ -15,7 +15,7 @@ export const getAudiobook = async (
 	client: HTTPClient,
 	audiobookId: string,
 	market?: string,
-) => {
+): Promise<Audiobook> => {
 	const res = await client.fetch("/v1/audiobooks/" + audiobookId, {
 		query: { market },
 	});
@@ -33,7 +33,7 @@ export const getAudiobooks = async (
 	client: HTTPClient,
 	audiobookIds: string[],
 	market?: string,
-) => {
+): Promise<Audiobook[]> => {
 	const res = await client.fetch("/v1/audiobooks", {
 		query: { market, ids: audiobookIds },
 	});
@@ -62,7 +62,7 @@ export const getAudiobookChapters = async (
 	client: HTTPClient,
 	audiobookId: string,
 	options?: GetAudiobookChapterOpts,
-) => {
+): Promise<PagingObject<SimplifiedChapter>> => {
 	const res = await client.fetch(`/v1/audiobooks/${audiobookId}/chapters`, {
 		query: options,
 	});
@@ -88,20 +88,9 @@ export type GetSavedAudiobooksOpts = Prettify<
 export const getSavedAudiobooks = async (
 	client: HTTPClient,
 	options?: GetSavedAudiobooksOpts,
-) => {
+): Promise<PagingObject<SavedAudiobook>> => {
 	const res = await client.fetch("/v1/me/audiobooks", { query: options });
-	return res.json() as Promise<
-		PagingObject<{
-			/**
-			 * The date and time the audiobook was saved Timestamps are returned in ISO 8601 format as Coordinated Universal Time (UTC) with a zero offset: YYYY-MM-DDTHH:MM:SSZ.
-			 */
-			added_at: string;
-			/**
-			 * Information about the audiobook.
-			 */
-			audiobook: SimplifiedAudiobook;
-		}>
-	>;
+	return res.json() as Promise<PagingObject<SavedAudiobook>>;
 };
 
 /**
@@ -113,7 +102,7 @@ export const getSavedAudiobooks = async (
 export const saveAudiobooks = (
 	client: HTTPClient,
 	audiobookIds: string[],
-) => {
+): Promise<Response> => {
 	return client.fetch("/v1/me/audiobooks", {
 		method: "PUT",
 		query: { ids: audiobookIds },
@@ -129,7 +118,7 @@ export const saveAudiobooks = (
 export const saveAudiobook = (
 	client: HTTPClient,
 	audiobookId: string,
-) => {
+): Promise<Response> => {
 	return saveAudiobooks(client, [audiobookId]);
 };
 
@@ -142,7 +131,7 @@ export const saveAudiobook = (
 export const removeSavedAudiobooks = (
 	client: HTTPClient,
 	audiobookIds: string[],
-) => {
+): Promise<Response> => {
 	return client.fetch("/v1/me/audiobooks", {
 		method: "DELETE",
 		query: { ids: audiobookIds },
@@ -158,7 +147,7 @@ export const removeSavedAudiobooks = (
 export const removeSavedAudiobook = (
 	client: HTTPClient,
 	audiobookId: string,
-) => {
+): Promise<Response> => {
 	return removeSavedAudiobooks(client, [audiobookId]);
 };
 
@@ -171,7 +160,7 @@ export const removeSavedAudiobook = (
 export const checkIfAudiobooksSaved = async (
 	client: HTTPClient,
 	audiobookIds: string[],
-) => {
+): Promise<boolean[]> => {
 	const res = await client.fetch("/v1/me/audiobooks/contains", {
 		query: { ids: audiobookIds },
 	});
@@ -187,6 +176,6 @@ export const checkIfAudiobooksSaved = async (
 export const checkIfAudiobookSaved = async (
 	client: HTTPClient,
 	audiobookId: string,
-) => {
+): Promise<boolean> => {
 	return (await checkIfAudiobooksSaved(client, [audiobookId]))[0]!;
 };
diff --git a/endpoints/audiobook/audiobook.types.ts b/endpoints/audiobook/audiobook.types.ts
index bad5ea6..8cf465c 100644
--- a/endpoints/audiobook/audiobook.types.ts
+++ b/endpoints/audiobook/audiobook.types.ts
@@ -90,3 +90,14 @@ export interface Audiobook extends SimplifiedAudiobook {
 	 */
 	chapters: PagingObject<SimplifiedChapter>;
 }
+
+export type SavedAudiobook = {
+	/**
+	 * The date and time the audiobook was saved Timestamps are returned in ISO 8601 format as Coordinated Universal Time (UTC) with a zero offset: YYYY-MM-DDTHH:MM:SSZ.
+	 */
+	added_at: string;
+	/**
+	 * Information about the audiobook.
+	 */
+	audiobook: SimplifiedAudiobook;
+};
\ No newline at end of file
diff --git a/endpoints/category/category.endpoints.ts b/endpoints/category/category.endpoints.ts
index d2d6edb..d804f7d 100644
--- a/endpoints/category/category.endpoints.ts
+++ b/endpoints/category/category.endpoints.ts
@@ -40,7 +40,7 @@ export type GetBrowseCategoriesOpts = {
 export const getBrowseCategories = async (
 	client: HTTPClient,
 	options?: GetBrowseCategoriesOpts,
-) => {
+): Promise<PagingObject<Category>> => {
 	const res = await client.fetch("/v1/browse/categories", {
 		query: options,
 	});
@@ -73,7 +73,7 @@ export const getBrowseCategory = async (
 	client: HTTPClient,
 	categoryId: string,
 	options?: GetBrowseCategoryOpts,
-) => {
+): Promise<Category> => {
 	const res = await client.fetch("/v1/browse/categories/" + categoryId, {
 		query: options,
 	});
diff --git a/endpoints/chapter/chapter.endpoints.ts b/endpoints/chapter/chapter.endpoints.ts
index 3ad3956..0350757 100644
--- a/endpoints/chapter/chapter.endpoints.ts
+++ b/endpoints/chapter/chapter.endpoints.ts
@@ -10,7 +10,7 @@ export const getChapter = async (
 	client: HTTPClient,
 	chapterId: string,
 	market?: string,
-) => {
+): Promise<Chapter> => {
 	const res = await client.fetch("/v1/chapters/" + chapterId, {
 		query: { market },
 	});
@@ -27,7 +27,7 @@ export const getChapters = async (
 	client: HTTPClient,
 	chapterIds: string[],
 	market?: string,
-) => {
+): Promise<Chapter[]> => {
 	const res = await client.fetch("/v1/chapters", {
 		query: { market, ids: chapterIds },
 	});
diff --git a/endpoints/episode/episode.endpoints.ts b/endpoints/episode/episode.endpoints.ts
index 25de606..1e4909b 100644
--- a/endpoints/episode/episode.endpoints.ts
+++ b/endpoints/episode/episode.endpoints.ts
@@ -2,6 +2,7 @@ import type { HTTPClient } from "../../client.ts";
 import type { Episode } from "./episode.types.ts";
 import type { PagingObject, PagingOptions } from "../general.types.ts";
 import type { Prettify } from "../../shared.ts";
+import { SavedEpisode } from "./episode.types.ts";
 
 /**
  * Get Spotify catalog informnation for a single episode.
@@ -14,7 +15,7 @@ export const getEpisode = async (
 	client: HTTPClient,
 	episodeId: string,
 	market?: string,
-) => {
+): Promise<Episode> => {
 	const res = await client.fetch("/v1/episodes/" + episodeId, {
 		query: { market },
 	});
@@ -32,7 +33,7 @@ export const getEpisodes = async (
 	client: HTTPClient,
 	episodeIds: string[],
 	market?: string,
-) => {
+): Promise<Episode[]> => {
 	const res = await client.fetch("/v1/episodes", {
 		query: { market, ids: episodeIds },
 	});
@@ -58,20 +59,9 @@ export type GetSavedEpisodesOpts = Prettify<
 export const getSavedEpisodes = async (
 	client: HTTPClient,
 	options?: GetSavedEpisodesOpts,
-) => {
+): Promise<PagingObject<SavedEpisode>> => {
 	const res = await client.fetch("/v1/me/episodes", { query: options });
-	return res.json() as Promise<
-		PagingObject<{
-			/**
-			 * The date and time the episode was saved Timestamps are returned in ISO 8601 format as Coordinated Universal Time (UTC) with a zero offset: YYYY-MM-DDTHH:MM:SSZ.
-			 */
-			added_at: string;
-			/**
-			 * Information about the episode.
-			 */
-			episode: Episode;
-		}>
-	>;
+	return res.json();
 };
 
 /**
@@ -83,7 +73,7 @@ export const getSavedEpisodes = async (
 export const saveEpisodes = (
 	client: HTTPClient,
 	episodeIds: string[],
-) => {
+): Promise<Response> => {
 	return client.fetch(`/v1/me/episodes`, {
 		method: "PUT",
 		query: { ids: episodeIds },
@@ -96,7 +86,7 @@ export const saveEpisodes = (
  * @param client Spotify HTTPClient
  * @param episodeId The Spotify ID of the episode
  */
-export const saveEpisode = (client: HTTPClient, episodeId: string) => {
+export const saveEpisode = (client: HTTPClient, episodeId: string): Promise<Response> => {
 	return saveEpisodes(client, [episodeId]);
 };
 
@@ -109,7 +99,7 @@ export const saveEpisode = (client: HTTPClient, episodeId: string) => {
 export const removeSavedEpisodes = (
 	client: HTTPClient,
 	episodeIds: string[],
-) => {
+): Promise<Response> => {
 	return client.fetch("/v1/me/episodes", {
 		query: { ids: episodeIds },
 	});
@@ -124,7 +114,7 @@ export const removeSavedEpisodes = (
 export const removeSavedEpisode = (
 	client: HTTPClient,
 	episodeId: string,
-) => {
+): Promise<Response> => {
 	return removeSavedEpisodes(client, [episodeId]);
 };
 
@@ -137,7 +127,7 @@ export const removeSavedEpisode = (
 export const checkIfEpisodesSaved = async (
 	client: HTTPClient,
 	episodeIds: string[],
-) => {
+): Promise<boolean[]> => {
 	const res = await client.fetch("/v1/me/episodes/contains", {
 		query: { ids: episodeIds },
 	});
@@ -153,6 +143,6 @@ export const checkIfEpisodesSaved = async (
 export const checkIfEpisodeSaved = async (
 	client: HTTPClient,
 	episodeId: string,
-) => {
+): Promise<boolean> => {
 	return (await checkIfEpisodesSaved(client, [episodeId]))[0]!;
 };
diff --git a/endpoints/episode/episode.types.ts b/endpoints/episode/episode.types.ts
index 09ad869..1418547 100644
--- a/endpoints/episode/episode.types.ts
+++ b/endpoints/episode/episode.types.ts
@@ -95,3 +95,14 @@ export interface Episode extends SimplifiedEpisode {
 	 */
 	show: SimplifiedShow;
 }
+
+export type SavedEpisode = {
+	/**
+	 * The date and time the episode was saved Timestamps are returned in ISO 8601 format as Coordinated Universal Time (UTC) with a zero offset: YYYY-MM-DDTHH:MM:SSZ.
+	 */
+	added_at: string;
+	/**
+	 * Information about the episode.
+	 */
+	episode: Episode;
+}
diff --git a/endpoints/genre/genre.endpoints.ts b/endpoints/genre/genre.endpoints.ts
index 91b01f4..4f5a0d4 100644
--- a/endpoints/genre/genre.endpoints.ts
+++ b/endpoints/genre/genre.endpoints.ts
@@ -5,7 +5,7 @@ import type { HTTPClient } from "../../client.ts";
  *
  * @param client Spotify HTTPClient
  */
-export const getAvailableGenreSeeds = async (client: HTTPClient) => {
+export const getAvailableGenreSeeds = async (client: HTTPClient): Promise<string[]> => {
 	const res = await client.fetch("/v1/recommendations/available-genre-seeds");
 	return ((await res.json()) as { genres: string[] }).genres;
 };
diff --git a/endpoints/market/market.endpoints.ts b/endpoints/market/market.endpoints.ts
index 8d4d3d8..34822ef 100644
--- a/endpoints/market/market.endpoints.ts
+++ b/endpoints/market/market.endpoints.ts
@@ -5,7 +5,7 @@ import type { HTTPClient } from "../../client.ts";
  *
  * @param client Spotify HTTPClient
  */
-export const getAvailableMarkets = async (client: HTTPClient) => {
+export const getAvailableMarkets = async (client: HTTPClient): Promise<string[]> => {
 	const res = await client.fetch("/v1/markets");
 	return (await res.json() as { markets: string[] }).markets;
 };
diff --git a/endpoints/player/player.endpoints.ts b/endpoints/player/player.endpoints.ts
index a1010d5..d305d96 100644
--- a/endpoints/player/player.endpoints.ts
+++ b/endpoints/player/player.endpoints.ts
@@ -30,7 +30,7 @@ export type GetPlaybackStateOpts = {
 export const getPlaybackState = async (
 	client: HTTPClient,
 	options: GetPlaybackStateOpts = {},
-) => {
+): Promise<PlaybackState | null> => {
 	const res = await client.fetch("/v1/me/player", {
 		query: {
 			market: options.market,
@@ -38,7 +38,7 @@ export const getPlaybackState = async (
 		},
 	});
 	if (res.status === 204) return null;
-	return res.json() as Promise<PlaybackState>;
+	return res.json();
 };
 
 export type TransferPlaybackBody = {
@@ -63,7 +63,7 @@ export type TransferPlaybackBody = {
 export const transferPlayback = (
 	client: HTTPClient,
 	body: TransferPlaybackBody,
-) => {
+): Promise<Response> => {
 	return client.fetch("/v1/me/player", { method: "PUT", body });
 };
 
@@ -72,7 +72,9 @@ export const transferPlayback = (
  *
  * @requires `user-read-playback-state`
  */
-export const getAvailableDevices = async (client: HTTPClient) => {
+export const getAvailableDevices = async (
+	client: HTTPClient,
+): Promise<Device[]> => {
 	const res = await client.fetch("/v1/me/player/devices");
 	return (await res.json() as { devices: Device[] }).devices;
 };
@@ -96,7 +98,7 @@ export type GetCurrentPlayingTrackOpts = {
 export const getCurrentPlayingTrack = async (
 	client: HTTPClient,
 	options?: GetCurrentPlayingTrackOpts,
-) => {
+): Promise<PlaybackState | null> => {
 	const res = await client.fetch("/v1/me/player/currently-playing", {
 		query: options,
 	});
@@ -152,7 +154,7 @@ export type StartResumePlaybackBody = {
 export const startPlayback = (
 	client: HTTPClient,
 	options: StartResumePlaybackBody = {},
-) => {
+): Promise<Response> => {
 	const { device_id, ...body } = options;
 	return client.fetch("/v1/me/player/play", {
 		method: "PUT",
@@ -179,7 +181,7 @@ export const resumePlayback = startPlayback;
 export const pausePlayback = (
 	client: HTTPClient,
 	deviceId?: string,
-) => {
+): Promise<Response> => {
 	return client.fetch("/v1/me/player/pause", {
 		method: "PUT",
 		query: { device_id: deviceId },
@@ -197,7 +199,7 @@ export const pausePlayback = (
 export const skipToNext = (
 	client: HTTPClient,
 	deviceId?: string,
-) => {
+): Promise<Response> => {
 	return client.fetch("/v1/me/player/next", {
 		method: "POST",
 		query: { device_id: deviceId },
@@ -215,7 +217,7 @@ export const skipToNext = (
 export const skipToPrevious = (
 	client: HTTPClient,
 	deviceId?: string,
-) => {
+): Promise<Response> => {
 	return client.fetch("/v1/me/player/previous", {
 		method: "POST",
 		query: { device_id: deviceId },
@@ -235,7 +237,7 @@ export const seekToPosition = (
 	client: HTTPClient,
 	positionMs: number,
 	deviceId?: string,
-) => {
+): Promise<Response> => {
 	return client.fetch("/v1/me/player/seek", {
 		method: "PUT",
 		query: { position_ms: positionMs, device_id: deviceId },
@@ -258,7 +260,7 @@ export const setRepeatMode = (
 	client: HTTPClient,
 	state: RepeatMode,
 	deviceId?: string,
-) => {
+): Promise<Response> => {
 	return client.fetch("/v1/me/player/repeat", {
 		method: "PUT",
 		query: { state, device_id: deviceId },
@@ -278,7 +280,7 @@ export const togglePlaybackShuffle = (
 	client: HTTPClient,
 	state: boolean,
 	deviceId?: string,
-) => {
+): Promise<Response> => {
 	return client.fetch("/v1/me/player/shuffle", {
 		method: "PUT",
 		query: { state, device_id: deviceId },
@@ -311,11 +313,11 @@ export type GetRecentlyPlayedTracksOpts = {
 export const getRecentPlayedTracks = async (
 	client: HTTPClient,
 	options?: GetRecentlyPlayedTracksOpts,
-) => {
+): Promise<CursorPagingObject<PlayHistoryObject>> => {
 	const res = await client.fetch("/v1/me/player/recently-played", {
 		query: options,
 	});
-	return res.json() as Promise<CursorPagingObject<PlayHistoryObject>>;
+	return res.json();
 };
 
 /**
@@ -324,7 +326,7 @@ export const getRecentPlayedTracks = async (
  * @requires `user-read-currently-playing`,
 `user-read-playback-state`
  */
-export const getUserQueue = async (client: HTTPClient) => {
+export const getUserQueue = async (client: HTTPClient): Promise<Queue> => {
 	const res = await client.fetch("/v1/me/player/queue");
 	return res.json() as Promise<Queue>;
 };
@@ -342,7 +344,7 @@ export const addItemToPlaybackQueue = (
 	client: HTTPClient,
 	uri: string,
 	deviceId?: string,
-) => {
+): Promise<Response> => {
 	return client.fetch("/v1/me/player/queue", {
 		method: "POST",
 		query: { uri, device_id: deviceId },
diff --git a/endpoints/playlist/playlist.endpoints.ts b/endpoints/playlist/playlist.endpoints.ts
index 355c40f..ff1ebce 100644
--- a/endpoints/playlist/playlist.endpoints.ts
+++ b/endpoints/playlist/playlist.endpoints.ts
@@ -42,7 +42,7 @@ export const getPlaylist = async (
 	client: HTTPClient,
 	playlistId: string,
 	options?: GetPlaylistOpts,
-) => {
+): Promise<Playlist> => {
 	const res = await client.fetch("/v1/playlists/" + playlistId, {
 		query: options,
 	});
@@ -81,7 +81,7 @@ export const changePlaylistDetails = (
 	client: HTTPClient,
 	playlistId: string,
 	body: ChangePlaylistDetailsBody,
-) => {
+): Promise<Response> => {
 	return client.fetch("/v1/playlist/" + playlistId, { method: "PUT", body });
 };
 
@@ -108,7 +108,7 @@ export const getPlaylistTracks = async (
 	client: HTTPClient,
 	playlistId: string,
 	options?: GetPlaylistTracksOpts,
-) => {
+): Promise<PagingObject<PlaylistTrack>> => {
 	const res = await client.fetch(`/v1/playlists/${playlistId}/tracks`, {
 		query: options,
 	});
@@ -128,7 +128,7 @@ export const addItemsToPlaylist = async (
 	playlistId: string,
 	uris: string[],
 	position?: number,
-) => {
+): Promise<SnapshotResponse> => {
 	const res = await client.fetch(`/v1/playlists/${playlistId}/tracks`, {
 		method: "POST",
 		query: { uris, position },
@@ -149,7 +149,7 @@ export const addItemToPlaylist = (
 	playlistId: string,
 	uri: string,
 	position?: number,
-) => {
+): Promise<SnapshotResponse> => {
 	return addItemsToPlaylist(client, playlistId, [uri], position);
 };
 
@@ -184,7 +184,7 @@ export const reorderPlaylistItems = async (
 	client: HTTPClient,
 	playlistId: string,
 	options?: ReorderPlaylistItemsOpts,
-) => {
+): Promise<SnapshotResponse> => {
 	const res = await client.fetch(`/v1/playlists/${playlistId}/tracks`, {
 		method: "PUT",
 		body: options,
@@ -204,7 +204,7 @@ export const replacePlaylistItems = async (
 	client: HTTPClient,
 	playlistId: string,
 	uris: string[],
-) => {
+): Promise<SnapshotResponse> => {
 	const res = await client.fetch(`/v1/playlists/${playlistId}/tracks`, {
 		method: "PUT",
 		body: { uris },
@@ -225,7 +225,7 @@ export const removePlaylistItems = async (
 	playlistId: string,
 	uris: string[],
 	snapshotId?: string,
-) => {
+): Promise<SnapshotResponse> => {
 	const res = await client.fetch(`/v1/playlists/${playlistId}/tracks`, {
 		method: "DELETE",
 		body: {
@@ -249,7 +249,7 @@ export const removePlaylistItem = (
 	playlistId: string,
 	uri: string,
 	snapshotId?: string,
-) => {
+): Promise<SnapshotResponse> => {
 	return removePlaylistItems(client, playlistId, [uri], snapshotId);
 };
 
@@ -262,7 +262,7 @@ export const removePlaylistItem = (
 export const getCurrentUsersPlaylists = async (
 	client: HTTPClient,
 	options?: PagingOptions,
-) => {
+): Promise<PagingObject<SimplifiedPlaylist>> => {
 	const res = await client.fetch("/v1/me/playlists", { query: options });
 	return res.json() as Promise<PagingObject<SimplifiedPlaylist>>;
 };
@@ -278,7 +278,7 @@ export const getUsersPlaylists = async (
 	client: HTTPClient,
 	userId: string,
 	options?: PagingOptions,
-) => {
+): Promise<PagingObject<SimplifiedPlaylist>> => {
 	const res = await client.fetch(`/v1/users/${userId}/playlists`, {
 		query: options,
 	});
@@ -315,7 +315,7 @@ export const createPlaylist = async (
 	client: HTTPClient,
 	userId: string,
 	body: CreatePlaylistBody,
-) => {
+): Promise<Playlist> => {
 	const res = await client.fetch(`/v1/users/${userId}/playlists`, {
 		method: "POST",
 		body,
@@ -353,7 +353,7 @@ export type GetFeaturedPlaylistsOpts = Prettify<
 export const getFeaturedPlaylists = async (
 	client: HTTPClient,
 	options?: GetFeaturedPlaylistsOpts,
-) => {
+): Promise<FeaturedPlaylists> => {
 	const res = await client.fetch("/v1/browse/featured-playlists", {
 		query: options,
 	});
@@ -381,7 +381,7 @@ export const getCategoryPlaylists = async (
 	client: HTTPClient,
 	categoryId: string,
 	options?: GetCategorysPlaylistsOpts,
-) => {
+): Promise<FeaturedPlaylists> => {
 	const res = await client.fetch(
 		`/v1/browse/categories/${categoryId}/playlists`,
 		{ query: options },
@@ -397,7 +397,7 @@ export const getCategoryPlaylists = async (
 export const getPlaylistCoverImage = async (
 	client: HTTPClient,
 	playlistId: string,
-) => {
+): Promise<NonNullableObject<Image>[]> => {
 	const res = await client.fetch(`/v1/playlists/${playlistId}/images`);
 	return res.json() as Promise<NonNullableObject<Image>[]>;
 };
@@ -412,7 +412,7 @@ export const uploadPlaylistCoverImage = (
 	client: HTTPClient,
 	playlistId: string,
 	image: string,
-) => {
+): Promise<Response> => {
 	return client.fetch(`/v1/playlists/${playlistId}/images`, {
 		method: "PUT",
 		headers: {
diff --git a/endpoints/show/show.endpoints.ts b/endpoints/show/show.endpoints.ts
index 9b284d8..2d6a69e 100644
--- a/endpoints/show/show.endpoints.ts
+++ b/endpoints/show/show.endpoints.ts
@@ -2,7 +2,7 @@ import type { HTTPClient } from "../../client.ts";
 import type { Prettify } from "../../shared.ts";
 import type { SimplifiedEpisode } from "../episode/episode.types.ts";
 import type { PagingObject, PagingOptions } from "../general.types.ts";
-import type { Show, SimplifiedShow } from "./show.types.ts";
+import type { SavedShow, Show, SimplifiedShow } from "./show.types.ts";
 
 /**
  * Get spotify catalog information for a single show by its unique Spotify ID.
@@ -15,7 +15,7 @@ export const getShow = async (
 	client: HTTPClient,
 	showId: string,
 	market?: string,
-) => {
+): Promise<Show> => {
 	const res = await client.fetch("/v1/shows/" + showId, { query: { market } });
 	return res.json() as Promise<Show>;
 };
@@ -31,7 +31,7 @@ export const getShows = async (
 	client: HTTPClient,
 	showIds: string[],
 	market?: string,
-) => {
+): Promise<SimplifiedShow> => {
 	const res = await client.fetch("/v1/shows", {
 		query: { market, ids: showIds },
 	});
@@ -60,7 +60,7 @@ export const getShowEpisodes = async (
 	client: HTTPClient,
 	showId: string,
 	options?: GetShowEpisodesOpts,
-) => {
+): Promise<PagingObject<SimplifiedEpisode>> => {
 	const res = await client.fetch(`/v1/shows/${showId}/episodes`, {
 		query: options,
 	});
@@ -86,20 +86,9 @@ export type GetSavedShowsOpts = Prettify<
 export const getSavedShows = async (
 	client: HTTPClient,
 	options?: GetSavedShowsOpts,
-) => {
+): Promise<PagingObject<SavedShow>> => {
 	const res = await client.fetch("/v1/me/shows", { query: options });
-	return res.json() as Promise<
-		PagingObject<{
-			/**
-			 * The date and time the album was saved Timestamps are returned in ISO 8601 format as Coordinated Universal Time (UTC) with a zero offset: YYYY-MM-DDTHH:MM:SSZ.
-			 */
-			added_at: string;
-			/**
-			 * Information about the show.
-			 */
-			show: Show;
-		}>
-	>;
+	return res.json() as Promise<PagingObject<SavedShow>>;
 };
 
 /**
@@ -108,7 +97,10 @@ export const getSavedShows = async (
  * @param client Spotify HTTPClient
  * @param showIds List of the Spotify IDs for the shows. Maximum: 20
  */
-export const saveShows = (client: HTTPClient, showIds: string[]) => {
+export const saveShows = (
+	client: HTTPClient,
+	showIds: string[],
+): Promise<Response> => {
 	return client.fetch("/v1/me/shows", {
 		method: "PUT",
 		query: { ids: showIds },
@@ -121,7 +113,10 @@ export const saveShows = (client: HTTPClient, showIds: string[]) => {
  * @param client  Spotify HTTPClient
  * @param showId The Spotify ID of the show
  */
-export const saveShow = (client: HTTPClient, showId: string) => {
+export const saveShow = (
+	client: HTTPClient,
+	showId: string,
+): Promise<Response> => {
 	return saveShows(client, [showId]);
 };
 
@@ -131,7 +126,10 @@ export const saveShow = (client: HTTPClient, showId: string) => {
  * @param client Spotify HTTPClient
  * @param showIds List of the Spotify IDs for the shows. Maximum: 20
  */
-export const removeSavedShows = (client: HTTPClient, showIds: string[]) => {
+export const removeSavedShows = (
+	client: HTTPClient,
+	showIds: string[],
+): Promise<Response> => {
 	return client.fetch("/v1/me/shows", {
 		method: "DELETE",
 		query: {
@@ -146,7 +144,10 @@ export const removeSavedShows = (client: HTTPClient, showIds: string[]) => {
  * @param client Spotify HTTPClient
  * @param showId The Spotify ID of the show
  */
-export const removeSavedShow = (client: HTTPClient, showId: string) => {
+export const removeSavedShow = (
+	client: HTTPClient,
+	showId: string,
+): Promise<Response> => {
 	return removeSavedShows(client, [showId]);
 };
 
@@ -159,7 +160,7 @@ export const removeSavedShow = (client: HTTPClient, showId: string) => {
 export const checkIfShowsSaved = async (
 	client: HTTPClient,
 	showIds: string[],
-) => {
+): Promise<boolean[]> => {
 	const res = await client.fetch("/v1/me/shows/contains", {
 		query: {
 			ids: showIds,
@@ -174,6 +175,9 @@ export const checkIfShowsSaved = async (
  * @param client Spotify HTTPClient
  * @param showId The Spotify ID of the show
  */
-export const checkIfShowSaved = async (client: HTTPClient, showId: string) => {
+export const checkIfShowSaved = async (
+	client: HTTPClient,
+	showId: string,
+): Promise<boolean> => {
 	return (await checkIfShowsSaved(client, [showId]))[0]!;
 };
diff --git a/endpoints/show/show.types.ts b/endpoints/show/show.types.ts
index fbe615b..032e773 100644
--- a/endpoints/show/show.types.ts
+++ b/endpoints/show/show.types.ts
@@ -80,3 +80,14 @@ export interface Show extends SimplifiedShow {
 	 */
 	episodes: PagingObject<SimplifiedEpisode>;
 }
+
+export type SavedShow = {
+	/**
+	 * The date and time the album was saved Timestamps are returned in ISO 8601 format as Coordinated Universal Time (UTC) with a zero offset: YYYY-MM-DDTHH:MM:SSZ.
+	 */
+	added_at: string;
+	/**
+	 * Information about the show.
+	 */
+	show: Show;
+};
diff --git a/endpoints/track/track.endpoints.ts b/endpoints/track/track.endpoints.ts
index 020b8df..b8290db 100644
--- a/endpoints/track/track.endpoints.ts
+++ b/endpoints/track/track.endpoints.ts
@@ -21,7 +21,7 @@ export const getTrack = async (
 	client: HTTPClient,
 	trackId: string,
 	market?: string,
-) => {
+): Promise<Track> => {
 	const res = await client.fetch("/v1/tracks/" + trackId, {
 		query: { market },
 	});
@@ -39,7 +39,7 @@ export const getTracks = async (
 	client: HTTPClient,
 	trackIds: string[],
 	market?: string,
-) => {
+): Promise<Track[]> => {
 	const res = await client.fetch("/v1/tracks", {
 		query: {
 			ids: trackIds,
@@ -68,7 +68,7 @@ export type GetSavedTracksOpts = Prettify<
 export const getSavedTracks = async (
 	client: HTTPClient,
 	options: GetSavedTracksOpts,
-) => {
+): Promise<PagingObject<Track>> => {
 	const res = await client.fetch("/v1/me/tracks", {
 		query: options,
 	});
@@ -81,7 +81,10 @@ export const getSavedTracks = async (
  * @param client Spotify HTTPClient
  * @param trackIds List of the Spotify track IDs. Maximum 50 IDs
  */
-export const saveTracks = (client: HTTPClient, trackIds: string[]) => {
+export const saveTracks = (
+	client: HTTPClient,
+	trackIds: string[],
+): Promise<Response> => {
 	return client.fetch("/v1/me/tracks", {
 		method: "PUT",
 		query: {
@@ -96,7 +99,10 @@ export const saveTracks = (client: HTTPClient, trackIds: string[]) => {
  * @param client Spotify HTTPClient
  * @param trackId Spotify track ID
  */
-export const saveTrack = (client: HTTPClient, trackId: string) => {
+export const saveTrack = (
+	client: HTTPClient,
+	trackId: string,
+): Promise<Response> => {
 	return saveTracks(client, [trackId]);
 };
 
@@ -106,7 +112,10 @@ export const saveTrack = (client: HTTPClient, trackId: string) => {
  * @param client Spotify HTTPClient
  * @param trackIds List of the Spotify track IDs. Maximum 50 IDs
  */
-export const removeSavedTracks = (client: HTTPClient, trackIds: string[]) => {
+export const removeSavedTracks = (
+	client: HTTPClient,
+	trackIds: string[],
+): Promise<Response> => {
 	return client.fetch("/v1/me/tracks", {
 		method: "DELETE",
 		query: {
@@ -121,7 +130,10 @@ export const removeSavedTracks = (client: HTTPClient, trackIds: string[]) => {
  * @param client Spotify HTTPClient
  * @param trackId Spotify track ID
  */
-export const removeSavedTrack = (client: HTTPClient, trackId: string) => {
+export const removeSavedTrack = (
+	client: HTTPClient,
+	trackId: string,
+): Promise<Response> => {
 	return removeSavedTracks(client, [trackId]);
 };
 
@@ -134,7 +146,7 @@ export const removeSavedTrack = (client: HTTPClient, trackId: string) => {
 export const checkIfTracksSaved = async (
 	client: HTTPClient,
 	track_ids: string[],
-) => {
+): Promise<boolean[]> => {
 	const res = await client.fetch("/v1/me/tracks/contains", {
 		query: {
 			ids: track_ids,
@@ -152,7 +164,7 @@ export const checkIfTracksSaved = async (
 export const checkIfTrackSaved = async (
 	client: HTTPClient,
 	trackId: string,
-) => {
+): Promise<boolean> => {
 	return (await checkIfTracksSaved(client, [trackId]))[0];
 };
 
@@ -165,7 +177,7 @@ export const checkIfTrackSaved = async (
 export const getTracksAudioFeatures = async (
 	client: HTTPClient,
 	track_ids: string[],
-) => {
+): Promise<AudioFeatures[]> => {
 	const res = await client.fetch("/v1/audio-features", {
 		query: {
 			ids: track_ids,
@@ -184,7 +196,7 @@ export const getTracksAudioFeatures = async (
 export const getTrackAudioFeatures = async (
 	client: HTTPClient,
 	trackId: string,
-) => {
+): Promise<AudioFeatures> => {
 	const res = await client.fetch("/v1/audio-features/" + trackId);
 	return res.json() as Promise<AudioFeatures>;
 };
@@ -199,7 +211,7 @@ export const getTrackAudioFeatures = async (
 export const getTracksAudioAnalysis = async (
 	client: HTTPClient,
 	trackId: string,
-) => {
+): Promise<AudioAnalysis> => {
 	const res = await client.fetch("/v1/audio-analysis/" + trackId);
 	return res.json() as Promise<AudioAnalysis>;
 };
@@ -213,7 +225,7 @@ export const getTracksAudioAnalysis = async (
 export const getRecommendations = async (
 	client: HTTPClient,
 	options: RecommendationsOptions,
-) => {
+): Promise<Recomendations> => {
 	const res = await client.fetch("/v1/recommendations", {
 		query: options,
 	});
diff --git a/endpoints/user/user.endpoints.ts b/endpoints/user/user.endpoints.ts
index c3c78b9..50cb264 100644
--- a/endpoints/user/user.endpoints.ts
+++ b/endpoints/user/user.endpoints.ts
@@ -14,9 +14,11 @@ import type { Prettify } from "../../shared.ts";
  *
  * @param client Spotify HTTPClient
  */
-export const getCurrentUser = async (client: HTTPClient) => {
+export const getCurrentUser = async (
+	client: HTTPClient,
+): Promise<UserPrivate> => {
 	const res = await client.fetch("/v1/me");
-	return res.json() as Promise<UserPrivate>;
+	return res.json();
 };
 
 export type GetUserTopItemsOpts = Prettify<
@@ -51,13 +53,13 @@ interface UserTopItemMap extends Record<UserTopItemType, UserTopItem> {
  * @param type The type of entity to return. ("artists" or "tracks")
  * @param opts Additional option for request
  */
-export const getUserTopItems = async <T extends UserTopItemType>(
+export const getUserTopItems = async <TItem extends UserTopItemType>(
 	client: HTTPClient,
-	type: T,
+	type: TItem,
 	options?: GetUserTopItemsOpts,
-) => {
+): Promise<PagingObject<UserTopItemMap[TItem]>> => {
 	const res = await client.fetch("/v1/me/top/" + type, { query: options });
-	return res.json() as Promise<PagingObject<UserTopItemMap[T]>>;
+	return res.json() as Promise<PagingObject<UserTopItemMap[TItem]>>;
 };
 
 /**
@@ -71,7 +73,7 @@ export const getUserTopItems = async <T extends UserTopItemType>(
 export const getUserTopArtists = async (
 	client: HTTPClient,
 	opts?: GetUserTopItemsOpts,
-) => {
+): Promise<PagingObject<Artist>> => {
 	return await getUserTopItems(client, "artists", opts);
 };
 
@@ -86,7 +88,7 @@ export const getUserTopArtists = async (
 export const getUserTopTracks = async (
 	client: HTTPClient,
 	opts?: GetUserTopItemsOpts,
-) => {
+): Promise<PagingObject<Track>> => {
 	return await getUserTopItems(client, "tracks", opts);
 };
 
@@ -96,7 +98,10 @@ export const getUserTopTracks = async (
  * @param client Spotify HTTPClient
  * @param userId Spotify user ID
  */
-export const getUser = async (client: HTTPClient, userId: string) => {
+export const getUser = async (
+	client: HTTPClient,
+	userId: string,
+): Promise<UserPublic> => {
 	const res = await client.fetch("/v1/users/" + userId);
 	return res.json() as Promise<UserPublic>;
 };
@@ -111,12 +116,12 @@ export const getUser = async (client: HTTPClient, userId: string) => {
  * @param isPublic If true the playlist will be included in user's public
  * playlists, if false it will remain private. By default - true
  */
-export const followPlaylist = async (
+export const followPlaylist = (
 	client: HTTPClient,
 	playlistId: string,
 	isPublic?: boolean,
-) => {
-	await client.fetch(`/v1/playlists/${playlistId}/followers`, {
+): Promise<Response> => {
+	return client.fetch(`/v1/playlists/${playlistId}/followers`, {
 		method: "PUT",
 		body: { public: isPublic },
 	});
@@ -130,11 +135,11 @@ export const followPlaylist = async (
  * @param client Spotify HTTPClient
  * @param playlistId Spotify playlist ID
  */
-export const unfollowPlaylist = async (
+export const unfollowPlaylist = (
 	client: HTTPClient,
 	playlistId: string,
-) => {
-	await client.fetch(`/v1/playlists/${playlistId}/followers`, {
+): Promise<Response> => {
+	return client.fetch(`/v1/playlists/${playlistId}/followers`, {
 		method: "DELETE",
 	});
 };
@@ -162,7 +167,7 @@ export type GetFollowedArtistsOpts = {
 export const getFollowedArtists = async (
 	client: HTTPClient,
 	options?: GetFollowedArtistsOpts,
-) => {
+): Promise<CursorPagingObject<Artist>> => {
 	const res = await client.fetch("/v1/me/following", {
 		query: {
 			...options,
@@ -181,7 +186,10 @@ export const getFollowedArtists = async (
  * @param client Spotify HTTPClient
  * @param artistIds List of Spotify artist IDs. Maximum 50
  */
-export const followArtists = (client: HTTPClient, artistIds: string[]) => {
+export const followArtists = (
+	client: HTTPClient,
+	artistIds: string[],
+): Promise<Response> => {
 	return client.fetch("/v1/me/following", {
 		method: "PUT",
 		query: {
@@ -199,7 +207,10 @@ export const followArtists = (client: HTTPClient, artistIds: string[]) => {
  * @param client Spotify HTTPClient
  * @param artistId Spotify artist ID
  */
-export const followArtist = (client: HTTPClient, artistId: string) => {
+export const followArtist = (
+	client: HTTPClient,
+	artistId: string,
+): Promise<Response> => {
 	return followArtists(client, [artistId]);
 };
 
@@ -211,7 +222,10 @@ export const followArtist = (client: HTTPClient, artistId: string) => {
  * @param client Spotify HTTPClient
  * @param userIds List of Spotify user IDs. Maximum 50
  */
-export const followUsers = (client: HTTPClient, userIds: string[]) => {
+export const followUsers = (
+	client: HTTPClient,
+	userIds: string[],
+): Promise<Response> => {
 	return client.fetch("/v1/me/following", {
 		method: "PUT",
 		query: {
@@ -229,7 +243,10 @@ export const followUsers = (client: HTTPClient, userIds: string[]) => {
  * @param client Spotify HTTPClient
  * @param artist_id Spotify user ID
  */
-export const followUser = (client: HTTPClient, userId: string) => {
+export const followUser = (
+	client: HTTPClient,
+	userId: string,
+): Promise<Response> => {
 	return followUsers(client, [userId]);
 };
 
@@ -241,7 +258,10 @@ export const followUser = (client: HTTPClient, userId: string) => {
  * @param client Spotify HTTPClient
  * @param artistIds List of Spotify artist IDs. Maximum 50
  */
-export const unfollowArtists = (client: HTTPClient, artistIds: string[]) => {
+export const unfollowArtists = (
+	client: HTTPClient,
+	artistIds: string[],
+): Promise<Response> => {
 	return client.fetch("/v1/me/following", {
 		method: "DELETE",
 		query: {
@@ -259,7 +279,10 @@ export const unfollowArtists = (client: HTTPClient, artistIds: string[]) => {
  * @param client Spotify HTTPClient
  * @param artistId Spotify artist ID
  */
-export const unfollowArtist = (client: HTTPClient, artistId: string) => {
+export const unfollowArtist = (
+	client: HTTPClient,
+	artistId: string,
+): Promise<Response> => {
 	return unfollowArtists(client, [artistId]);
 };
 
@@ -271,7 +294,10 @@ export const unfollowArtist = (client: HTTPClient, artistId: string) => {
  * @param client Spotify HTTPClient
  * @param userIds List of Spotify user IDs. Maximum 50
  */
-export const unfollowUsers = (client: HTTPClient, userIds: string[]) => {
+export const unfollowUsers = (
+	client: HTTPClient,
+	userIds: string[],
+): Promise<Response> => {
 	return client.fetch("/v1/me/following", {
 		method: "DELETE",
 		query: {
@@ -289,7 +315,10 @@ export const unfollowUsers = (client: HTTPClient, userIds: string[]) => {
  * @param client Spotify HTTPClient
  * @param artist_id Spotify user ID
  */
-export const unfollowUser = (client: HTTPClient, userId: string) => {
+export const unfollowUser = (
+	client: HTTPClient,
+	userId: string,
+): Promise<Response> => {
 	return unfollowUsers(client, [userId]);
 };
 
@@ -304,7 +333,7 @@ export const unfollowUser = (client: HTTPClient, userId: string) => {
 export const checkIfUserFollowsArtists = async (
 	client: HTTPClient,
 	artistIds: string[],
-) => {
+): Promise<boolean[]> => {
 	const res = await client.fetch("/v1/me/following/contains", {
 		query: {
 			type: "artist",
@@ -325,7 +354,7 @@ export const checkIfUserFollowsArtists = async (
 export const checkIfUserFollowsArtist = async (
 	client: HTTPClient,
 	artistId: string,
-) => {
+): Promise<boolean> => {
 	return (await checkIfUserFollowsArtists(client, [artistId]))[0]!;
 };
 
@@ -340,7 +369,7 @@ export const checkIfUserFollowsArtist = async (
 export const checkIfUserFollowsUsers = async (
 	client: HTTPClient,
 	userIds: string[],
-) => {
+): Promise<boolean[]> => {
 	const res = await client.fetch("/v1/me/following/contains", {
 		query: {
 			type: "user",
@@ -361,7 +390,7 @@ export const checkIfUserFollowsUsers = async (
 export const checkIfUserFollowsUser = async (
 	client: HTTPClient,
 	userId: string,
-) => {
+): Promise<boolean> => {
 	return (await checkIfUserFollowsUsers(client, [userId]))[0]!;
 };
 
@@ -376,7 +405,7 @@ export const checkIfUsersFollowPlaylist = async (
 	client: HTTPClient,
 	userIds: string[],
 	playlistId: string,
-) => {
+): Promise<boolean[]> => {
 	const res = await client.fetch(
 		`/v1/playlists/${playlistId}/followers/contains`,
 		{
@@ -399,6 +428,6 @@ export const checkIfUserFollowsPlaylist = async (
 	client: HTTPClient,
 	userId: string,
 	playlistId: string,
-) => {
+): Promise<boolean> => {
 	return (await checkIfUsersFollowPlaylist(client, [userId], playlistId))[0]!;
 };
diff --git a/pagination.ts b/pagination.ts
index 0eef0d3..0c45c1b 100644
--- a/pagination.ts
+++ b/pagination.ts
@@ -33,7 +33,11 @@ export class ChunkIterator<TItem> {
 		this.defaults = { ...DEFAULTS, ...defaults };
 	}
 
-	asyncIterator() {
+	asyncIterator(): AsyncIterator<
+		TItem[],
+		TItem[],
+		NextPageOptions | undefined
+	> {
 		return this[Symbol.asyncIterator]();
 	}
 
@@ -78,7 +82,7 @@ export class PageIterator<TItem> {
 		this.defaults = { ...DEFAULTS, ...defaults };
 	}
 
-	asyncIterator() {
+	asyncIterator(): AsyncGenerator<TItem, TItem, unknown> {
 		return this[Symbol.asyncIterator]();
 	}
 
@@ -104,7 +108,7 @@ export class PageIterator<TItem> {
 		}
 	}
 
-	async collect() {
+	async collect(): Promise<TItem[]> {
 		const items: TItem[] = [];
 		for await (const item of this) {
 			items.push(item);
diff --git a/tsconfig.json b/tsconfig.json
index 0633539..2d7cdc8 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -12,6 +12,7 @@
 		"module": "ESNext",
 		"target": "ESNext",
 		"outDir": "dist",
+		"declaration": true,
 		"emitDeclarationOnly": true,
 		"allowImportingTsExtensions": true,
 		"forceConsistentCasingInFileNames": true,
@@ -26,4 +27,4 @@
 		"allowUnusedLabels": false,
 		"skipLibCheck": true
 	}
-}
+}
\ No newline at end of file