diff --git a/api/src/auth.ts b/api/src/auth.ts
index 19af106..c1c1a2a 100644
--- a/api/src/auth.ts
+++ b/api/src/auth.ts
@@ -3,10 +3,16 @@ import { drizzleAdapter } from "better-auth/adapters/drizzle";
 import { db } from "./db";
 import Elysia, { status, type Context } from "elysia";
 import * as schema from "./db/auth-schema";
+import { SpotifyApi } from "@spotify/web-api-ts-sdk";
 
 export const SPOTIFY_CLIENT_ID = process.env.SPOTIFY_CLIENT_ID!;
 export const SPOTIFY_CLIENT_SECRET = process.env.SPOTIFY_CLIENT_SECRET!;
 
+export const defaultSdk = SpotifyApi.withClientCredentials(
+  SPOTIFY_CLIENT_ID,
+  SPOTIFY_CLIENT_SECRET,
+);
+
 export const auth = betterAuth({
   database: drizzleAdapter(db, {
     provider: "pg",
diff --git a/api/src/db/index.ts b/api/src/db/index.ts
index 1e58183..f89c2b9 100644
--- a/api/src/db/index.ts
+++ b/api/src/db/index.ts
@@ -1,4 +1,4 @@
 import { drizzle } from "drizzle-orm/node-postgres";
-import "./schema";
+import { relations } from "./schema";
 
-export const db = drizzle(process.env.DATABASE_URL!);
+export const db = drizzle(process.env.DATABASE_URL!, { relations });
diff --git a/api/src/db/schema.ts b/api/src/db/schema.ts
index ec59a44..435f5d8 100644
--- a/api/src/db/schema.ts
+++ b/api/src/db/schema.ts
@@ -1,3 +1,4 @@
+import { defineRelations } from "drizzle-orm";
 import {
   boolean,
   index,
@@ -7,6 +8,7 @@ import {
   primaryKey,
   text,
   timestamp,
+  uniqueIndex,
   uuid,
   varchar,
 } from "drizzle-orm/pg-core";
@@ -26,6 +28,7 @@ export const artist = pgTable("artist", {
 
 export const genre = pgTable("genre", {
   id: uuid().defaultRandom().primaryKey().notNull(),
+  name: text().notNull().unique(),
 });
 
 export const artistGenre = pgTable(
@@ -45,13 +48,20 @@ export const artistGenre = pgTable(
   ],
 );
 
-export const platformImage = pgTable("platform_image", {
-  id: uuid().defaultRandom().primaryKey().notNull(),
-  platform: platform().notNull(),
-  url: text(),
-  height: integer(),
-  width: integer(),
-});
+export const platformImage = pgTable(
+  "platform_image",
+  {
+    id: uuid().defaultRandom().primaryKey().notNull(),
+    platform: platform().notNull(),
+    url: text(),
+    height: integer(),
+    width: integer(),
+  },
+  (platformImage) => [
+    uniqueIndex().on(platformImage.platform, platformImage.url),
+    index().on(platformImage.url),
+  ],
+);
 
 export const artistImage = pgTable(
   "artist_image",
@@ -98,6 +108,40 @@ export const albumImage = pgTable(
   ],
 );
 
+export const albumArtist = pgTable(
+  "album_artist",
+  {
+    album: uuid()
+      .references(() => album.id)
+      .notNull(),
+    artist: uuid()
+      .references(() => artist.id)
+      .notNull(),
+  },
+  (albumArtist) => [
+    primaryKey({
+      columns: [albumArtist.album, albumArtist.artist],
+    }),
+  ],
+);
+
+export const albumGenre = pgTable(
+  "album_genre",
+  {
+    album: uuid()
+      .references(() => album.id)
+      .notNull(),
+    genre: uuid()
+      .references(() => genre.id)
+      .notNull(),
+  },
+  (albumGenre) => [
+    primaryKey({
+      columns: [albumGenre.album, albumGenre.genre],
+    }),
+  ],
+);
+
 export const track = pgTable(
   "track",
   {
@@ -252,3 +296,230 @@ export const playbackHistory = pgTable(
   },
   (playbackHistory) => [index().on([playbackHistory.user])],
 );
+
+export const relations = defineRelations(
+  {
+    album,
+    albumImage,
+    albumArtist,
+    albumGenre,
+    artist,
+    artistGenre,
+    artistImage,
+    followedArtist,
+    genre,
+    platformImage,
+    playbackHistory,
+    savedAlbum,
+    savedTrack,
+    topArtist,
+    topTrack,
+    track,
+    trackArtist,
+    user,
+  },
+  (r) => ({
+    artist: {
+      artistGenres: r.many.artistGenre(),
+      artistImages: r.many.artistImage(),
+      trackArtists: r.many.trackArtist(),
+      albumArtists: r.many.albumArtist(),
+      topArtists: r.many.topArtist(),
+      followedArtists: r.many.followedArtist(),
+      albumGenres: r.many.albumGenre(),
+      genres: r.many.genre({
+        from: r.artist.id.through(r.artistGenre.artist),
+        to: r.genre.id.through(r.artistGenre.genre),
+      }),
+      images: r.many.platformImage({
+        from: r.artist.id.through(r.artistImage.artist),
+        to: r.platformImage.id.through(r.artistImage.image),
+      }),
+      albums: r.many.album({
+        from: r.artist.id.through(r.albumArtist.artist),
+        to: r.album.id.through(r.albumArtist.album),
+      }),
+      tracks: r.many.track({
+        from: r.artist.id.through(r.trackArtist.artist),
+        to: r.track.id.through(r.trackArtist.track),
+      }),
+    },
+    genre: {
+      artistGenres: r.many.artistGenre(),
+      albumGenres: r.many.albumGenre(),
+      artists: r.many.artist({
+        from: r.genre.id.through(r.artistGenre.genre),
+        to: r.artist.id.through(r.artistGenre.artist),
+      }),
+      albums: r.many.album({
+        from: r.genre.id.through(r.albumGenre.genre),
+        to: r.album.id.through(r.albumGenre.album),
+      }),
+    },
+    artistGenre: {
+      artist: r.one.artist({
+        from: r.artistGenre.artist,
+        to: r.artist.id,
+      }),
+      genre: r.one.genre({
+        from: r.artistGenre.genre,
+        to: r.genre.id,
+      }),
+    },
+    platformImage: {
+      artistImages: r.many.artistImage(),
+      albumImages: r.many.albumImage(),
+      artists: r.many.artist({
+        from: r.platformImage.id.through(r.artistImage.image),
+        to: r.artist.id.through(r.artistImage.artist),
+      }),
+      albums: r.many.album({
+        from: r.platformImage.id.through(r.albumImage.image),
+        to: r.album.id.through(r.albumImage.album),
+      }),
+    },
+    artistImage: {
+      artist: r.one.artist({
+        from: r.artistImage.artist,
+        to: r.artist.id,
+      }),
+      image: r.one.platformImage({
+        from: r.artistImage.image,
+        to: r.platformImage.id,
+      }),
+    },
+    album: {
+      tracks: r.many.track(),
+      albumImages: r.many.albumImage(),
+      albumArtists: r.many.albumArtist(),
+      albumGenres: r.many.albumGenre(),
+      savedAlbums: r.many.savedAlbum(),
+      images: r.many.platformImage({
+        from: r.album.id.through(r.albumImage.album),
+        to: r.platformImage.id.through(r.albumImage.image),
+      }),
+      artists: r.many.artist({
+        from: r.album.id.through(r.albumArtist.album),
+        to: r.artist.id.through(r.albumArtist.artist),
+      }),
+      genres: r.many.genre({
+        from: r.album.id.through(r.albumGenre.album),
+        to: r.genre.id.through(r.albumGenre.genre),
+      }),
+    },
+    albumImage: {
+      album: r.one.album({
+        from: r.albumImage.album,
+        to: r.album.id,
+      }),
+      image: r.one.platformImage({
+        from: r.albumImage.image,
+        to: r.platformImage.id,
+      }),
+    },
+    albumArtist: {
+      album: r.one.album({
+        from: r.albumArtist.album,
+        to: r.album.id,
+      }),
+      artist: r.one.artist({
+        from: r.albumArtist.artist,
+        to: r.artist.id,
+      }),
+    },
+    albumGenre: {
+      album: r.one.album({
+        from: r.albumGenre.album,
+        to: r.album.id,
+      }),
+      genre: r.one.genre({
+        from: r.albumGenre.genre,
+        to: r.genre.id,
+      }),
+    },
+    track: {
+      album: r.one.album({
+        from: r.track.album,
+        to: r.album.id,
+      }),
+      trackArtists: r.many.trackArtist(),
+      topTracks: r.many.topTrack(),
+      savedTracks: r.many.savedTrack(),
+      playbackHistory: r.many.playbackHistory(),
+      artists: r.many.artist({
+        from: r.track.id.through(r.trackArtist.track),
+        to: r.artist.id.through(r.trackArtist.artist),
+      }),
+    },
+    trackArtist: {
+      track: r.one.track({
+        from: r.trackArtist.track,
+        to: r.track.id,
+      }),
+      artist: r.one.artist({
+        from: r.trackArtist.artist,
+        to: r.artist.id,
+      }),
+    },
+    topTrack: {
+      track: r.one.track({
+        from: r.topTrack.track,
+        to: r.track.id,
+      }),
+      user: r.one.user({
+        from: r.topTrack.user,
+        to: r.user.id,
+      }),
+    },
+    topArtist: {
+      artist: r.one.artist({
+        from: r.topArtist.artist,
+        to: r.artist.id,
+      }),
+      user: r.one.user({
+        from: r.topArtist.user,
+        to: r.user.id,
+      }),
+    },
+    savedAlbum: {
+      album: r.one.album({
+        from: r.savedAlbum.album,
+        to: r.album.id,
+      }),
+      user: r.one.user({
+        from: r.savedAlbum.user,
+        to: r.user.id,
+      }),
+    },
+    savedTrack: {
+      track: r.one.track({
+        from: r.savedTrack.track,
+        to: r.track.id,
+      }),
+      user: r.one.user({
+        from: r.savedTrack.user,
+        to: r.user.id,
+      }),
+    },
+    followedArtist: {
+      artist: r.one.artist({
+        from: r.followedArtist.artist,
+        to: r.artist.id,
+      }),
+      user: r.one.user({
+        from: r.followedArtist.user,
+        to: r.user.id,
+      }),
+    },
+    playbackHistory: {
+      track: r.one.track({
+        from: r.playbackHistory.track,
+        to: r.track.id,
+      }),
+      user: r.one.user({
+        from: r.playbackHistory.user,
+        to: r.user.id,
+      }),
+    },
+  }),
+);
diff --git a/api/src/db/spotify.ts b/api/src/db/spotify.ts
new file mode 100644
index 0000000..5616f42
--- /dev/null
+++ b/api/src/db/spotify.ts
@@ -0,0 +1,345 @@
+import type {
+  Album,
+  Artist,
+  FollowedArtists,
+  Image,
+  PlayHistory,
+  SavedAlbum,
+  SavedTrack,
+  SimplifiedAlbum,
+  SimplifiedArtist,
+  Track,
+} from "@spotify/web-api-ts-sdk";
+import { db } from ".";
+import {
+  album,
+  albumArtist,
+  albumGenre,
+  albumImage,
+  artist,
+  artistGenre,
+  artistImage,
+  followedArtist,
+  genre,
+  playbackHistory,
+  platformImage,
+  savedAlbum,
+  savedTrack,
+  topArtist,
+  topTrack,
+  track,
+  trackArtist,
+} from "./schema";
+import { and, eq, inArray } from "drizzle-orm";
+import { defaultSdk } from "../auth";
+
+export const PLATFORM_SPOTIFY = "spotify" as const;
+
+export async function upsertImages(images: Image[]) {
+  await db.insert(platformImage).values(
+    images.map(({ url, height, width }) => ({
+      platform: PLATFORM_SPOTIFY,
+      url,
+      height,
+      width,
+    })),
+  );
+}
+
+export async function upsertGenres(genres: string[]) {
+  await db.insert(genre).values(genres.map((name) => ({ name })));
+}
+
+export async function upsertArtists(artists: Artist[]) {
+  await db.insert(artist).values(
+    artists.map(({ id, name, images, genres, popularity, type }) => ({
+      platform: PLATFORM_SPOTIFY,
+      platform_id: id,
+      name,
+      popularity,
+      type,
+    })),
+  );
+  await upsertImages(artists.flatMap((a) => a.images));
+  await upsertGenres(artists.flatMap((a) => a.genres));
+  for (const spotifyArtist of artists) {
+    await db.insert(artistImage).select(
+      db
+        .select({
+          artist: artist.id,
+          image: platformImage.id,
+        })
+        .from(platformImage)
+        .where(
+          and(
+            eq(platformImage.platform, PLATFORM_SPOTIFY),
+            inArray(
+              platformImage.url,
+              spotifyArtist.images.map((t) => t.url),
+            ),
+          ),
+        )
+        .innerJoin(artist, eq(artist.platform_id, spotifyArtist.id)),
+    );
+    await db.insert(artistGenre).select(
+      db
+        .select({
+          artist: artist.id,
+          genre: genre.id,
+        })
+        .from(genre)
+        .where(inArray(genre.name, spotifyArtist.genres))
+        .innerJoin(artist, eq(artist.platform_id, spotifyArtist.id)),
+    );
+  }
+}
+
+async function getMissingArtists(artistIds: string[]) {
+  const existingArtists = await db
+    .select({ id: artist.id })
+    .from(artist)
+    .where(inArray(artist.platform_id, artistIds));
+  return artistIds.filter((id) => !existingArtists.some((a) => a.id === id));
+}
+
+async function lookupMissingArtists(artistIds: string[]) {
+  const missingArtistIds = await getMissingArtists(artistIds);
+  if (missingArtistIds.length === 0) return [];
+  const missingArtists = await defaultSdk.artists.get(missingArtistIds);
+  await upsertArtists(missingArtists);
+  return missingArtists;
+}
+
+function isFullArtistArray(
+  artists: Artist[] | SimplifiedArtist[],
+): artists is Artist[] {
+  return "images" in artists[0]!;
+}
+
+async function upsertMissingArtists(artists: SimplifiedArtist[] | Artist[]) {
+  if (artists.length === 0) return;
+  let missingArtists: Artist[];
+  if (isFullArtistArray(artists)) {
+    const missingArtistIds = await getMissingArtists(artists.map((t) => t.id));
+    if (missingArtistIds.length === 0) return;
+    missingArtists = artists.filter((a) => missingArtistIds.includes(a.id));
+  } else {
+    missingArtists = await lookupMissingArtists(artists.map((t) => t.id));
+  }
+  if (missingArtists.length === 0) return;
+  await upsertArtists(missingArtists);
+  return missingArtists;
+}
+
+async function getArtistIdMap(artistIds: string[]) {
+  if (artistIds.length === 0) return new Map<string, string>();
+  const rows = await db
+    .select({ id: artist.id, platform_id: artist.platform_id })
+    .from(artist)
+    .where(inArray(artist.platform_id, artistIds));
+  return new Map(rows.map((row) => [row.platform_id, row.id]));
+}
+
+async function getAlbumIdMap(albumIds: string[]) {
+  if (albumIds.length === 0) return new Map<string, string>();
+  const rows = await db
+    .select({ id: album.id, platform_id: album.platform_id })
+    .from(album)
+    .where(inArray(album.platform_id, albumIds));
+  return new Map(rows.map((row) => [row.platform_id ?? "", row.id]));
+}
+
+async function getTrackIdMap(trackIds: string[]) {
+  if (trackIds.length === 0) return new Map<string, string>();
+  const rows = await db
+    .select({ id: track.id, platform_id: track.platform_id })
+    .from(track)
+    .where(inArray(track.platform_id, trackIds));
+  return new Map(rows.map((row) => [row.platform_id ?? "", row.id]));
+}
+
+export async function upsertAlbums(albums: Album[] | SimplifiedAlbum[]) {
+  await upsertMissingArtists(albums.flatMap((a) => a.artists));
+  await db.insert(album).values(
+    albums.map(({ id, name, type, popularity, release_date, label }) => ({
+      platform: PLATFORM_SPOTIFY,
+      platform_id: id,
+      name,
+      type,
+      popularity,
+      release_date: new Date(release_date),
+      label,
+    })),
+  );
+  await upsertImages(albums.flatMap((a) => a.images));
+  await upsertGenres(albums.flatMap((a) => a.genres));
+  for (const spotifyAlbum of albums) {
+    await db.insert(albumImage).select(
+      db
+        .select({
+          album: album.id,
+          image: platformImage.id,
+        })
+        .from(platformImage)
+        .where(
+          and(
+            eq(platformImage.platform, PLATFORM_SPOTIFY),
+            inArray(
+              platformImage.url,
+              spotifyAlbum.images.map((t) => t.url),
+            ),
+          ),
+        )
+        .innerJoin(album, eq(album.platform_id, spotifyAlbum.id)),
+    );
+    await db.insert(albumArtist).select(
+      db
+        .select({
+          album: album.id,
+          artist: artist.id,
+        })
+        .from(artist)
+        .where(inArray(artist.platform_id, spotifyAlbum.artists.map((t) => t.id)))
+        .innerJoin(album, eq(album.platform_id, spotifyAlbum.id)),
+    );
+    await db.insert(albumGenre).select(
+      db
+        .select({
+          album: album.id,
+          genre: genre.id,
+        })
+        .from(genre)
+        .where(inArray(genre.name, spotifyAlbum.genres))
+        .innerJoin(album, eq(album.platform_id, spotifyAlbum.id)),
+    );
+  }
+}
+
+export async function upsertTracks(tracks: Track[]) {
+  if (tracks.length === 0) return;
+  await upsertAlbums(tracks.map((t) => t.album));
+  await upsertMissingArtists(tracks.flatMap((t) => t.artists));
+  const albumIdMap = await getAlbumIdMap(tracks.map((t) => t.album.id));
+  await db.insert(track).values(
+    tracks.map((spotifyTrack) => ({
+      album: albumIdMap.get(spotifyTrack.album.id)!,
+      name: spotifyTrack.name,
+      platform: PLATFORM_SPOTIFY,
+      platform_id: spotifyTrack.id,
+      popularity: spotifyTrack.popularity,
+      duration: spotifyTrack.duration_ms,
+      explicit: spotifyTrack.explicit,
+      disc_number: spotifyTrack.disc_number,
+      track_number: spotifyTrack.track_number,
+    })),
+  );
+  for (const spotifyTrack of tracks) {
+    await db.insert(trackArtist).select(
+      db
+        .select({
+          track: track.id,
+          artist: artist.id,
+        })
+        .from(artist)
+        .where(inArray(artist.platform_id, spotifyTrack.artists.map((t) => t.id)))
+        .innerJoin(track, eq(track.platform_id, spotifyTrack.id)),
+    );
+  }
+}
+
+export async function upsertTopArtists(
+  userId: string,
+  timeline: "short_term" | "medium_term" | "long_term",
+  artists: Artist[],
+) {
+  if (artists.length === 0) return;
+  await upsertArtists(artists);
+  const artistIdMap = await getArtistIdMap(artists.map((t) => t.id));
+  await db.insert(topArtist).values(
+    artists.map((spotifyArtist, index) => ({
+      artist: artistIdMap.get(spotifyArtist.id)!,
+      position: index + 1,
+      user: userId,
+      timeline,
+    })),
+  );
+}
+
+export async function upsertTopTracks(
+  userId: string,
+  timeline: "short_term" | "medium_term" | "long_term",
+  tracks: Track[],
+) {
+  if (tracks.length === 0) return;
+  await upsertTracks(tracks);
+  const trackIdMap = await getTrackIdMap(tracks.map((t) => t.id));
+  await db.insert(topTrack).values(
+    tracks.map((spotifyTrack, index) => ({
+      track: trackIdMap.get(spotifyTrack.id)!,
+      position: index + 1,
+      user: userId,
+      timeline,
+    })),
+  );
+}
+
+export async function upsertSavedAlbums(userId: string, saved: SavedAlbum[]) {
+  if (saved.length === 0) return;
+  const albums = saved.map((item) => item.album);
+  await upsertAlbums(albums);
+  const albumIdMap = await getAlbumIdMap(albums.map((t) => t.id));
+  await db.insert(savedAlbum).values(
+    saved.map((item) => ({
+      album: albumIdMap.get(item.album.id)!,
+      user: userId,
+      saved_at: new Date(item.added_at),
+    })),
+  );
+}
+
+export async function upsertSavedTracks(userId: string, saved: SavedTrack[]) {
+  if (saved.length === 0) return;
+  const tracks = saved.map((item) => item.track);
+  await upsertTracks(tracks);
+  const trackIdMap = await getTrackIdMap(tracks.map((t) => t.id));
+  await db.insert(savedTrack).values(
+    saved.map((item) => ({
+      track: trackIdMap.get(item.track.id)!,
+      user: userId,
+      saved_at: new Date(item.added_at),
+    })),
+  );
+}
+
+export async function upsertFollowedArtists(
+  userId: string,
+  followed: FollowedArtists,
+) {
+  const artists = followed.artists.items;
+  if (artists.length === 0) return;
+  await upsertArtists(artists);
+  const artistIdMap = await getArtistIdMap(artists.map((t) => t.id));
+  await db.insert(followedArtist).values(
+    artists.map((spotifyArtist) => ({
+      artist: artistIdMap.get(spotifyArtist.id)!,
+      user: userId,
+    })),
+  );
+}
+
+export async function upsertPlaybackHistory(
+  userId: string,
+  items: PlayHistory[],
+) {
+  if (items.length === 0) return;
+  const tracks = items.map((item) => item.track);
+  await upsertTracks(tracks);
+  const trackIdMap = await getTrackIdMap(tracks.map((t) => t.id));
+  await db.insert(playbackHistory).values(
+    items.map((item) => ({
+      track: trackIdMap.get(item.track.id)!,
+      user: userId,
+      played_at: new Date(item.played_at),
+    })),
+  );
+}
diff --git a/api/src/routes/sync.ts b/api/src/routes/sync.ts
index 0a8fa2d..a8ca0d4 100644
--- a/api/src/routes/sync.ts
+++ b/api/src/routes/sync.ts
@@ -1,6 +1,14 @@
 import Elysia from "elysia";
 import { auth, betterAuthElysia, SPOTIFY_CLIENT_ID } from "../auth";
 import { SpotifyApi } from "@spotify/web-api-ts-sdk";
+import {
+  upsertFollowedArtists,
+  upsertPlaybackHistory,
+  upsertSavedAlbums,
+  upsertSavedTracks,
+  upsertTopArtists,
+  upsertTopTracks,
+} from "../db/spotify";
 
 export const syncApp = new Elysia().use(betterAuthElysia).post(
   "/sync",
@@ -28,8 +36,25 @@ export const syncApp = new Elysia().use(betterAuthElysia).post(
         timeline,
         50,
       );
-      const topTracks = await sdk.currentUser.topItems("tracks", timeline, 50);
+      await upsertTopArtists(user.id, timeline, topArtists.items);
     }
+    for (const timeline of [
+      "short_term",
+      "medium_term",
+      "long_term",
+    ] as const) {
+      const topTracks = await sdk.currentUser.topItems("tracks", timeline, 50);
+      await upsertTopTracks(user.id, timeline, topTracks.items);
+    }
+    const followedArtists = await sdk.currentUser.followedArtists();
+    await upsertFollowedArtists(user.id, followedArtists);
+    const savedAlbums = await sdk.currentUser.albums.savedAlbums(50);
+    await upsertSavedAlbums(user.id, savedAlbums.items);
+    const savedTracks = await sdk.currentUser.tracks.savedTracks(50);
+    await upsertSavedTracks(user.id, savedTracks.items);
+    const recentlyPlayed = await sdk.player.getRecentlyPlayedTracks(50);
+    await upsertPlaybackHistory(user.id, recentlyPlayed.items);
+    return { ok: true };
   },
   {
     auth: true,