diff --git a/server/Database.js b/server/Database.js
index 7e119a99..be81f761 100644
--- a/server/Database.js
+++ b/server/Database.js
@@ -62,6 +62,10 @@ class Database {
     require('./models/PodcastTag')(this.sequelize)
     require('./models/Collection')(this.sequelize)
     require('./models/CollectionBook')(this.sequelize)
+    require('./models/Playlist')(this.sequelize)
+    require('./models/PlaylistMediaItem')(this.sequelize)
+    require('./models/Device')(this.sequelize)
+    require('./models/PlaybackSession')(this.sequelize)
 
     return this.sequelize.sync()
   }
diff --git a/server/models/AudioBookmark.js b/server/models/AudioBookmark.js
index 7cb3f9a7..c733a29e 100644
--- a/server/models/AudioBookmark.js
+++ b/server/models/AudioBookmark.js
@@ -52,20 +52,19 @@ module.exports = (sequelize) => {
   AudioBookmark.addHook('afterFind', findResult => {
     if (!Array.isArray(findResult)) findResult = [findResult]
     for (const instance of findResult) {
-      if (instance.mediaItemType === 'book' && instance.book !== undefined) {
-        instance.mediaItem = instance.book
-      } else if (instance.mediaItemType === 'podcastEpisode' && instance.podcastEpisode !== undefined) {
-        instance.mediaItem = instance.podcastEpisode
+      if (instance.mediaItemType === 'book' && instance.Book !== undefined) {
+        instance.MediaItem = instance.Book
+      } else if (instance.mediaItemType === 'podcastEpisode' && instance.PodcastEpisode !== undefined) {
+        instance.MediaItem = instance.PodcastEpisode
       }
       // To prevent mistakes:
-      delete instance.book
-      delete instance.dataValues.book
-      delete instance.podcastEpisode
-      delete instance.dataValues.podcastEpisode
+      delete instance.Book
+      delete instance.dataValues.Book
+      delete instance.PodcastEpisode
+      delete instance.dataValues.PodcastEpisode
     }
   })
 
-
   User.hasMany(AudioBookmark)
   AudioBookmark.belongsTo(User)
 
diff --git a/server/models/AudioTrack.js b/server/models/AudioTrack.js
index d4c5ea7b..9dbf05fa 100644
--- a/server/models/AudioTrack.js
+++ b/server/models/AudioTrack.js
@@ -51,16 +51,16 @@ module.exports = (sequelize) => {
   AudioTrack.addHook('afterFind', findResult => {
     if (!Array.isArray(findResult)) findResult = [findResult]
     for (const instance of findResult) {
-      if (instance.mediaItemType === 'book' && instance.book !== undefined) {
-        instance.mediaItem = instance.book
-      } else if (instance.mediaItemType === 'podcastEpisode' && instance.podcastEpisode !== undefined) {
-        instance.mediaItem = instance.podcastEpisode
+      if (instance.mediaItemType === 'book' && instance.Book !== undefined) {
+        instance.MediaItem = instance.Book
+      } else if (instance.mediaItemType === 'podcastEpisode' && instance.PodcastEpisode !== undefined) {
+        instance.MediaItem = instance.PodcastEpisode
       }
       // To prevent mistakes:
-      delete instance.book
-      delete instance.dataValues.book
-      delete instance.podcastEpisode
-      delete instance.dataValues.podcastEpisode
+      delete instance.Book
+      delete instance.dataValues.Book
+      delete instance.PodcastEpisode
+      delete instance.dataValues.PodcastEpisode
     }
   })
 
diff --git a/server/models/Device.js b/server/models/Device.js
new file mode 100644
index 00000000..4f5a180d
--- /dev/null
+++ b/server/models/Device.js
@@ -0,0 +1,29 @@
+const { DataTypes, Model } = require('sequelize')
+
+module.exports = (sequelize) => {
+  class Device extends Model { }
+
+  Device.init({
+    id: {
+      type: DataTypes.UUID,
+      defaultValue: DataTypes.UUIDV4,
+      primaryKey: true
+    },
+    identifier: DataTypes.STRING,
+    clientName: DataTypes.STRING, // e.g. Abs Web, Abs Android
+    clientVersion: DataTypes.STRING,
+    ipAddress: DataTypes.STRING,
+    deviceName: DataTypes.STRING, // e.g. Windows 10 Chrome, Google Pixel 6, Apple iPhone 10,3
+    deviceVersion: DataTypes.STRING // e.g. Browser version or Android SDK
+  }, {
+    sequelize,
+    modelName: 'Device'
+  })
+
+  const { User } = sequelize.models
+
+  User.hasMany(Device)
+  Device.belongsTo(User)
+
+  return Device
+}
\ No newline at end of file
diff --git a/server/models/MediaProgress.js b/server/models/MediaProgress.js
index 71cd4520..296f9338 100644
--- a/server/models/MediaProgress.js
+++ b/server/models/MediaProgress.js
@@ -55,16 +55,16 @@ module.exports = (sequelize) => {
   MediaProgress.addHook('afterFind', findResult => {
     if (!Array.isArray(findResult)) findResult = [findResult]
     for (const instance of findResult) {
-      if (instance.mediaItemType === 'book' && instance.book !== undefined) {
-        instance.mediaItem = instance.book
-      } else if (instance.mediaItemType === 'podcastEpisode' && instance.podcastEpisode !== undefined) {
-        instance.mediaItem = instance.podcastEpisode
+      if (instance.mediaItemType === 'book' && instance.Book !== undefined) {
+        instance.MediaItem = instance.Book
+      } else if (instance.mediaItemType === 'podcastEpisode' && instance.PodcastEpisode !== undefined) {
+        instance.MediaItem = instance.PodcastEpisode
       }
       // To prevent mistakes:
-      delete instance.book
-      delete instance.dataValues.book
-      delete instance.podcastEpisode
-      delete instance.dataValues.podcastEpisode
+      delete instance.Book
+      delete instance.dataValues.Book
+      delete instance.PodcastEpisode
+      delete instance.dataValues.PodcastEpisode
     }
   })
 
diff --git a/server/models/PlaybackSession.js b/server/models/PlaybackSession.js
new file mode 100644
index 00000000..2697c050
--- /dev/null
+++ b/server/models/PlaybackSession.js
@@ -0,0 +1,79 @@
+const { DataTypes, Model } = require('sequelize')
+
+const uppercaseFirst = str => `${str[0].toUpperCase()}${str.substr(1)}`
+
+module.exports = (sequelize) => {
+  class PlaybackSession extends Model {
+    getMediaItem(options) {
+      if (!this.mediaItemType) return Promise.resolve(null)
+      const mixinMethodName = `get${uppercaseFirst(this.mediaItemType)}`
+      return this[mixinMethodName](options)
+    }
+  }
+
+  PlaybackSession.init({
+    id: {
+      type: DataTypes.UUID,
+      defaultValue: DataTypes.UUIDV4,
+      primaryKey: true
+    },
+    mediaItemId: DataTypes.UUIDV4,
+    mediaItemType: DataTypes.STRING,
+    displayTitle: DataTypes.STRING,
+    displayAuthor: DataTypes.STRING,
+    duration: DataTypes.INTEGER,
+    playMethod: DataTypes.STRING,
+    mediaPlayer: DataTypes.STRING,
+    startTime: DataTypes.INTEGER,
+    currentTime: DataTypes.INTEGER,
+    timeListening: DataTypes.INTEGER,
+    serverVersion: DataTypes.STRING
+  }, {
+    sequelize,
+    modelName: 'PlaybackSession'
+  })
+
+  const { Book, PodcastEpisode, User, Device } = sequelize.models
+
+  Book.hasMany(PlaybackSession, {
+    foreignKey: 'mediaItemId',
+    constraints: false,
+    scope: {
+      mediaItemType: 'book'
+    }
+  })
+  PlaybackSession.belongsTo(Book, { foreignKey: 'mediaItemId', constraints: false })
+
+  PodcastEpisode.hasOne(PlaybackSession, {
+    foreignKey: 'mediaItemId',
+    constraints: false,
+    scope: {
+      mediaItemType: 'podcastEpisode'
+    }
+  })
+  PlaybackSession.belongsTo(PodcastEpisode, { foreignKey: 'mediaItemId', constraints: false })
+
+  PlaybackSession.addHook('afterFind', findResult => {
+    if (!Array.isArray(findResult)) findResult = [findResult]
+    for (const instance of findResult) {
+      if (instance.mediaItemType === 'book' && instance.Book !== undefined) {
+        instance.MediaItem = instance.Book
+      } else if (instance.mediaItemType === 'podcastEpisode' && instance.PodcastEpisode !== undefined) {
+        instance.MediaItem = instance.PodcastEpisode
+      }
+      // To prevent mistakes:
+      delete instance.Book
+      delete instance.dataValues.Book
+      delete instance.PodcastEpisode
+      delete instance.dataValues.PodcastEpisode
+    }
+  })
+
+  User.hasMany(PlaybackSession)
+  PlaybackSession.belongsTo(User)
+
+  Device.hasMany(PlaybackSession)
+  PlaybackSession.belongsTo(Device)
+
+  return PlaybackSession
+}
\ No newline at end of file
diff --git a/server/models/Playlist.js b/server/models/Playlist.js
new file mode 100644
index 00000000..6fa0b4a9
--- /dev/null
+++ b/server/models/Playlist.js
@@ -0,0 +1,27 @@
+const { DataTypes, Model } = require('sequelize')
+
+module.exports = (sequelize) => {
+  class Playlist extends Model { }
+
+  Playlist.init({
+    id: {
+      type: DataTypes.UUID,
+      defaultValue: DataTypes.UUIDV4,
+      primaryKey: true
+    },
+    name: DataTypes.STRING,
+    description: DataTypes.TEXT
+  }, {
+    sequelize,
+    modelName: 'Playlist'
+  })
+
+  const { Library, User } = sequelize.models
+  Library.hasMany(Playlist)
+  Playlist.belongsTo(Library)
+
+  User.hasMany(Playlist)
+  Playlist.belongsTo(User)
+
+  return Playlist
+}
\ No newline at end of file
diff --git a/server/models/PlaylistMediaItem.js b/server/models/PlaylistMediaItem.js
new file mode 100644
index 00000000..bbc8aa5d
--- /dev/null
+++ b/server/models/PlaylistMediaItem.js
@@ -0,0 +1,67 @@
+const { DataTypes, Model } = require('sequelize')
+
+const uppercaseFirst = str => `${str[0].toUpperCase()}${str.substr(1)}`
+
+module.exports = (sequelize) => {
+  class PlaylistMediaItem extends Model {
+    getMediaItem(options) {
+      if (!this.mediaItemType) return Promise.resolve(null)
+      const mixinMethodName = `get${uppercaseFirst(this.mediaItemType)}`
+      return this[mixinMethodName](options)
+    }
+  }
+
+  PlaylistMediaItem.init({
+    id: {
+      type: DataTypes.UUID,
+      defaultValue: DataTypes.UUIDV4,
+      primaryKey: true
+    },
+    mediaItemId: DataTypes.UUIDV4,
+    mediaItemType: DataTypes.STRING
+  }, {
+    sequelize,
+    modelName: 'PlaylistMediaItem'
+  })
+
+  const { Book, PodcastEpisode, Playlist } = sequelize.models
+
+  Book.hasMany(PlaylistMediaItem, {
+    foreignKey: 'mediaItemId',
+    constraints: false,
+    scope: {
+      mediaItemType: 'book'
+    }
+  })
+  PlaylistMediaItem.belongsTo(Book, { foreignKey: 'mediaItemId', constraints: false })
+
+  PodcastEpisode.hasOne(PlaylistMediaItem, {
+    foreignKey: 'mediaItemId',
+    constraints: false,
+    scope: {
+      mediaItemType: 'podcastEpisode'
+    }
+  })
+  PlaylistMediaItem.belongsTo(PodcastEpisode, { foreignKey: 'mediaItemId', constraints: false })
+
+  PlaylistMediaItem.addHook('afterFind', findResult => {
+    if (!Array.isArray(findResult)) findResult = [findResult]
+    for (const instance of findResult) {
+      if (instance.mediaItemType === 'book' && instance.Book !== undefined) {
+        instance.MediaItem = instance.Book
+      } else if (instance.mediaItemType === 'podcastEpisode' && instance.PodcastEpisode !== undefined) {
+        instance.MediaItem = instance.PodcastEpisode
+      }
+      // To prevent mistakes:
+      delete instance.Book
+      delete instance.dataValues.Book
+      delete instance.PodcastEpisode
+      delete instance.dataValues.PodcastEpisode
+    }
+  })
+
+  Playlist.hasMany(PlaylistMediaItem)
+  PlaylistMediaItem.belongsTo(Playlist)
+
+  return PlaylistMediaItem
+}
\ No newline at end of file
diff --git a/server/models/User.js b/server/models/User.js
index a15b77f6..0c4868ba 100644
--- a/server/models/User.js
+++ b/server/models/User.js
@@ -10,6 +10,7 @@ module.exports = (sequelize) => {
       primaryKey: true
     },
     username: DataTypes.STRING,
+    email: DataTypes.STRING,
     pash: DataTypes.STRING,
     type: DataTypes.STRING,
     token: DataTypes.STRING,