diff --git a/app/build.gradle b/app/build.gradle
index d581b1574..71d600d86 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -4,6 +4,7 @@ plugins {
     id 'com.android.application'
     id 'kotlin-android'
     id 'kotlin-kapt'
+    id 'kotlinx-serialization'
 }
 
 android {
@@ -107,10 +108,11 @@ dependencies {
     implementation libs.exoplayer.extension.mediasession
     implementation libs.exoplayer.dash
 
-    /* Retrofit and Jackson */
+    /* Retrofit and Kotlinx Serialization */
     implementation libs.square.retrofit
-    implementation libs.square.retrofit.converterJackson
-    implementation libs.jacksonAnnotations
+    implementation libs.kotlinx.serialization
+    implementation libs.kotlinx.datetime
+    implementation libs.kotlinx.serialization.retrofit
 
     /* Cronet and Coil */
     coreLibraryDesugaring libs.desugaring
diff --git a/app/proguard-rules.pro b/app/proguard-rules.pro
index db9143d05..c9ea8f734 100644
--- a/app/proguard-rules.pro
+++ b/app/proguard-rules.pro
@@ -29,3 +29,26 @@
 # Keep data classes used for Retrofit
 -keep class com.github.libretube.obj.** { *; }
 -keep class com.github.libretube.obj.update.** { *; }
+
+# Keep rules required by Kotlinx Serialization
+-if @kotlinx.serialization.Serializable class **
+-keepclassmembers class <1> {
+    static <1>$Companion Companion;
+}
+
+-if @kotlinx.serialization.Serializable class ** {
+    static **$* *;
+}
+-keepclassmembers class <2>$<3> {
+    kotlinx.serialization.KSerializer serializer(...);
+}
+
+-if @kotlinx.serialization.Serializable class ** {
+    public static ** INSTANCE;
+}
+-keepclassmembers class <1> {
+    public static <1> INSTANCE;
+    kotlinx.serialization.KSerializer serializer(...);
+}
+
+-keepattributes RuntimeVisibleAnnotations,AnnotationDefault
diff --git a/app/src/main/java/com/github/libretube/api/JsonHelper.kt b/app/src/main/java/com/github/libretube/api/JsonHelper.kt
new file mode 100644
index 000000000..bc44741c2
--- /dev/null
+++ b/app/src/main/java/com/github/libretube/api/JsonHelper.kt
@@ -0,0 +1,9 @@
+package com.github.libretube.api
+
+import kotlinx.serialization.json.Json
+
+object JsonHelper {
+    val json = Json {
+        ignoreUnknownKeys = true
+    }
+}
diff --git a/app/src/main/java/com/github/libretube/api/PipedApi.kt b/app/src/main/java/com/github/libretube/api/PipedApi.kt
index 53400a9f5..98e032389 100644
--- a/app/src/main/java/com/github/libretube/api/PipedApi.kt
+++ b/app/src/main/java/com/github/libretube/api/PipedApi.kt
@@ -15,6 +15,7 @@ import com.github.libretube.api.obj.SegmentData
 import com.github.libretube.api.obj.StreamItem
 import com.github.libretube.api.obj.Streams
 import com.github.libretube.api.obj.Subscribe
+import com.github.libretube.api.obj.Subscribed
 import com.github.libretube.api.obj.Subscription
 import com.github.libretube.api.obj.Token
 import retrofit2.http.Body
@@ -114,7 +115,7 @@ interface PipedApi {
     suspend fun isSubscribed(
         @Query("channelId") channelId: String,
         @Header("Authorization") token: String
-    ): com.github.libretube.api.obj.Subscribed
+    ): Subscribed
 
     @GET("subscriptions")
     suspend fun subscriptions(@Header("Authorization") token: String): List<Subscription>
diff --git a/app/src/main/java/com/github/libretube/api/PlaylistsHelper.kt b/app/src/main/java/com/github/libretube/api/PlaylistsHelper.kt
index add8856f9..2b1f58f8c 100644
--- a/app/src/main/java/com/github/libretube/api/PlaylistsHelper.kt
+++ b/app/src/main/java/com/github/libretube/api/PlaylistsHelper.kt
@@ -93,10 +93,7 @@ object PlaylistsHelper {
             }.last().playlist.id.toString()
         }
         val response = try {
-            RetrofitInstance.authApi.createPlaylist(
-                token,
-                Playlists(name = playlistName)
-            )
+            RetrofitInstance.authApi.createPlaylist(token, Playlists(name = playlistName))
         } catch (e: IOException) {
             appContext.toastFromMainThread(R.string.unknown_error)
             return null
@@ -107,7 +104,7 @@ object PlaylistsHelper {
         }
         if (response.playlistId != null) {
             appContext.toastFromMainThread(R.string.playlistCreated)
-            return response.playlistId!!
+            return response.playlistId
         }
         return null
     }
@@ -141,13 +138,8 @@ object PlaylistsHelper {
             return true
         }
 
-        return RetrofitInstance.authApi.addToPlaylist(
-            token,
-            PlaylistId(
-                playlistId = playlistId,
-                videoIds = videos.toList().map { it.url!!.toID() }
-            )
-        ).message == "ok"
+        val playlist = PlaylistId(playlistId, videoIds = videos.map { it.url!!.toID() })
+        return RetrofitInstance.authApi.addToPlaylist(token, playlist).message == "ok"
     }
 
     suspend fun renamePlaylist(playlistId: String, newName: String): Boolean {
@@ -164,10 +156,7 @@ object PlaylistsHelper {
 
         return RetrofitInstance.authApi.renamePlaylist(
             token,
-            PlaylistId(
-                playlistId = playlistId,
-                newName = newName
-            )
+            PlaylistId(playlistId, newName = newName)
         ).playlistId != null
     }
 
@@ -251,8 +240,8 @@ object PlaylistsHelper {
                             name = list.name,
                             type = "playlist",
                             visibility = "private",
-                            videos = list.relatedStreams.orEmpty().map {
-                                YOUTUBE_FRONTEND_URL + "/watch?v=" + it.url!!.toID()
+                            videos = list.relatedStreams.map {
+                                "$YOUTUBE_FRONTEND_URL/watch?v=${it.url!!.toID()}"
                             }
                         )
                     )
@@ -278,19 +267,13 @@ object PlaylistsHelper {
                 val newPlaylist = createPlaylist(playlist.name ?: "Unknown name", appContext)
                 newPlaylist ?: return@launch
 
-                addToPlaylist(
-                    newPlaylist,
-                    *playlist.relatedStreams.orEmpty().toTypedArray()
-                )
+                addToPlaylist(newPlaylist, *playlist.relatedStreams.toTypedArray())
 
                 var nextPage = playlist.nextpage
                 while (nextPage != null) {
                     nextPage = try {
                         RetrofitInstance.api.getPlaylistNextPage(playlistId, nextPage).apply {
-                            addToPlaylist(
-                                newPlaylist,
-                                *relatedStreams.orEmpty().toTypedArray()
-                            )
+                            addToPlaylist(newPlaylist, *relatedStreams.toTypedArray())
                         }.nextpage
                     } catch (e: Exception) {
                         return@launch
diff --git a/app/src/main/java/com/github/libretube/api/RetrofitInstance.kt b/app/src/main/java/com/github/libretube/api/RetrofitInstance.kt
index 03f69cee7..743280989 100644
--- a/app/src/main/java/com/github/libretube/api/RetrofitInstance.kt
+++ b/app/src/main/java/com/github/libretube/api/RetrofitInstance.kt
@@ -3,40 +3,43 @@ package com.github.libretube.api
 import com.github.libretube.constants.PIPED_API_URL
 import com.github.libretube.constants.PreferenceKeys
 import com.github.libretube.util.PreferenceHelper
+import com.jakewharton.retrofit2.converter.kotlinx.serialization.asConverterFactory
+import okhttp3.MediaType.Companion.toMediaType
 import retrofit2.Retrofit
-import retrofit2.converter.jackson.JacksonConverterFactory
+import retrofit2.create
 
 object RetrofitInstance {
     lateinit var url: String
     lateinit var authUrl: String
     val lazyMgr = resettableManager()
-    val jacksonConverterFactory = JacksonConverterFactory.create()
+    private val kotlinxConverterFactory = JsonHelper.json
+        .asConverterFactory("application/json".toMediaType())
 
-    val api: PipedApi by resettableLazy(lazyMgr) {
+    val api by resettableLazy(lazyMgr) {
         Retrofit.Builder()
             .baseUrl(url)
             .callFactory(CronetHelper.callFactory)
-            .addConverterFactory(jacksonConverterFactory)
+            .addConverterFactory(kotlinxConverterFactory)
             .build()
-            .create(PipedApi::class.java)
+            .create<PipedApi>()
     }
 
-    val authApi: PipedApi by resettableLazy(lazyMgr) {
+    val authApi by resettableLazy(lazyMgr) {
         Retrofit.Builder()
             .baseUrl(authUrl)
             .callFactory(CronetHelper.callFactory)
-            .addConverterFactory(jacksonConverterFactory)
+            .addConverterFactory(kotlinxConverterFactory)
             .build()
-            .create(PipedApi::class.java)
+            .create<PipedApi>()
     }
 
-    val externalApi: ExternalApi by resettableLazy(lazyMgr) {
+    val externalApi by resettableLazy(lazyMgr) {
         Retrofit.Builder()
             .baseUrl(url)
             .callFactory(CronetHelper.callFactory)
-            .addConverterFactory(jacksonConverterFactory)
+            .addConverterFactory(kotlinxConverterFactory)
             .build()
-            .create(ExternalApi::class.java)
+            .create<ExternalApi>()
     }
 
     /**
diff --git a/app/src/main/java/com/github/libretube/api/SubscriptionHelper.kt b/app/src/main/java/com/github/libretube/api/SubscriptionHelper.kt
index 61f1c6cc5..571d23572 100644
--- a/app/src/main/java/com/github/libretube/api/SubscriptionHelper.kt
+++ b/app/src/main/java/com/github/libretube/api/SubscriptionHelper.kt
@@ -4,6 +4,7 @@ import android.content.Context
 import android.util.Log
 import com.github.libretube.R
 import com.github.libretube.api.obj.StreamItem
+import com.github.libretube.api.obj.Subscribe
 import com.github.libretube.api.obj.Subscription
 import com.github.libretube.constants.PreferenceKeys
 import com.github.libretube.db.DatabaseHolder.Companion.Database
@@ -25,7 +26,7 @@ object SubscriptionHelper {
                 try {
                     RetrofitInstance.authApi.subscribe(
                         PreferenceHelper.getToken(),
-                        com.github.libretube.api.obj.Subscribe(channelId)
+                        Subscribe(channelId)
                     )
                 } catch (e: Exception) {
                     Log.e(TAG(), e.toString())
@@ -46,7 +47,7 @@ object SubscriptionHelper {
                 try {
                     RetrofitInstance.authApi.unsubscribe(
                         PreferenceHelper.getToken(),
-                        com.github.libretube.api.obj.Subscribe(channelId)
+                        Subscribe(channelId)
                     )
                 } catch (e: Exception) {
                     Log.e(TAG(), e.toString())
diff --git a/app/src/main/java/com/github/libretube/api/obj/Channel.kt b/app/src/main/java/com/github/libretube/api/obj/Channel.kt
index e1b261df4..5a227bea4 100644
--- a/app/src/main/java/com/github/libretube/api/obj/Channel.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/Channel.kt
@@ -1,17 +1,17 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class Channel(
-    var id: String? = null,
-    var name: String? = null,
-    var avatarUrl: String? = null,
-    var bannerUrl: String? = null,
-    var description: String? = null,
-    var nextpage: String? = null,
-    var subscriberCount: Long = 0,
-    var verified: Boolean = false,
-    var relatedStreams: List<StreamItem>? = listOf(),
-    var tabs: List<ChannelTab>? = listOf()
+    val id: String,
+    val name: String,
+    val avatarUrl: String,
+    val bannerUrl: String,
+    val description: String,
+    val nextpage: String? = null,
+    val subscriberCount: Long = 0,
+    val verified: Boolean = false,
+    val relatedStreams: List<StreamItem> = emptyList(),
+    val tabs: List<ChannelTab> = emptyList()
 )
diff --git a/app/src/main/java/com/github/libretube/api/obj/ChannelTab.kt b/app/src/main/java/com/github/libretube/api/obj/ChannelTab.kt
index c7e2d63de..14e0f86cf 100644
--- a/app/src/main/java/com/github/libretube/api/obj/ChannelTab.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/ChannelTab.kt
@@ -1,9 +1,9 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class ChannelTab(
-    val name: String? = null,
-    val data: String? = null
+    val name: String,
+    val data: String
 )
diff --git a/app/src/main/java/com/github/libretube/api/obj/ChannelTabResponse.kt b/app/src/main/java/com/github/libretube/api/obj/ChannelTabResponse.kt
index 6c6fd7bae..8208239a0 100644
--- a/app/src/main/java/com/github/libretube/api/obj/ChannelTabResponse.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/ChannelTabResponse.kt
@@ -1,6 +1,9 @@
 package com.github.libretube.api.obj
 
+import kotlinx.serialization.Serializable
+
+@Serializable
 data class ChannelTabResponse(
-    val content: List<ContentItem> = listOf(),
+    val content: List<ContentItem> = emptyList(),
     val nextpage: String? = null
 )
diff --git a/app/src/main/java/com/github/libretube/api/obj/ChapterSegment.kt b/app/src/main/java/com/github/libretube/api/obj/ChapterSegment.kt
index 6fbdfed00..c0fb3d7eb 100644
--- a/app/src/main/java/com/github/libretube/api/obj/ChapterSegment.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/ChapterSegment.kt
@@ -1,10 +1,10 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class ChapterSegment(
-    var title: String? = null,
-    var image: String? = null,
-    var start: Long? = null
+    val title: String? = null,
+    val image: String? = null,
+    val start: Long? = null
 )
diff --git a/app/src/main/java/com/github/libretube/api/obj/Comment.kt b/app/src/main/java/com/github/libretube/api/obj/Comment.kt
index ef8f6f9c4..d21018e88 100644
--- a/app/src/main/java/com/github/libretube/api/obj/Comment.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/Comment.kt
@@ -1,19 +1,19 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class Comment(
-    val author: String? = null,
-    val commentId: String? = null,
-    val commentText: String? = null,
-    val commentedTime: String? = null,
-    val commentorUrl: String? = null,
+    val author: String,
+    val commentId: String,
+    val commentText: String,
+    val commentedTime: String,
+    val commentorUrl: String,
     val repliesPage: String? = null,
-    val hearted: Boolean? = null,
-    val likeCount: Long? = null,
-    val pinned: Boolean? = null,
-    val thumbnail: String? = null,
-    val verified: Boolean? = null,
-    val replyCount: Long? = null
+    val hearted: Boolean,
+    val likeCount: Long,
+    val pinned: Boolean,
+    val thumbnail: String,
+    val verified: Boolean,
+    val replyCount: Long
 )
diff --git a/app/src/main/java/com/github/libretube/api/obj/CommentsPage.kt b/app/src/main/java/com/github/libretube/api/obj/CommentsPage.kt
index 88bb66a1b..3f8f83eec 100644
--- a/app/src/main/java/com/github/libretube/api/obj/CommentsPage.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/CommentsPage.kt
@@ -1,10 +1,10 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class CommentsPage(
-    var comments: MutableList<Comment> = arrayListOf(),
-    val disabled: Boolean? = null,
+    var comments: List<Comment> = emptyList(),
+    val disabled: Boolean = false,
     val nextpage: String? = null
 )
diff --git a/app/src/main/java/com/github/libretube/api/obj/ContentItem.kt b/app/src/main/java/com/github/libretube/api/obj/ContentItem.kt
index 9d6f33652..7d1492a66 100644
--- a/app/src/main/java/com/github/libretube/api/obj/ContentItem.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/ContentItem.kt
@@ -1,28 +1,28 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class ContentItem(
-    var url: String? = null,
-    val type: String? = null,
-    var thumbnail: String? = null,
-    var uploaderName: String? = null,
-    var uploaded: Long? = null,
-    var shortDescription: String? = null,
+    val url: String,
+    val type: String,
+    val thumbnail: String,
+    val uploaderName: String? = null,
+    val uploaded: Long? = null,
+    val shortDescription: String? = null,
     // Video only attributes
-    var title: String? = null,
-    var uploaderUrl: String? = null,
-    var uploaderAvatar: String? = null,
-    var uploadedDate: String? = null,
-    var duration: Long? = null,
-    var views: Long? = null,
-    var isShort: Boolean? = null,
-    var uploaderVerified: Boolean? = null,
+    val title: String? = null,
+    val uploaderUrl: String? = null,
+    val uploaderAvatar: String? = null,
+    val uploadedDate: String? = null,
+    val duration: Long = -1,
+    val views: Long = -1,
+    val isShort: Boolean? = null,
+    val uploaderVerified: Boolean? = null,
     // Channel and Playlist attributes
-    var name: String? = null,
-    var description: String? = null,
-    var subscribers: Long? = -1,
-    var videos: Long? = -1,
-    var verified: Boolean? = null
+    val name: String? = null,
+    val description: String? = null,
+    val subscribers: Long = -1,
+    val videos: Long = -1,
+    val verified: Boolean? = null
 )
diff --git a/app/src/main/java/com/github/libretube/api/obj/DeleteUserRequest.kt b/app/src/main/java/com/github/libretube/api/obj/DeleteUserRequest.kt
index e4a961836..7b5e6735e 100644
--- a/app/src/main/java/com/github/libretube/api/obj/DeleteUserRequest.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/DeleteUserRequest.kt
@@ -1,5 +1,6 @@
 package com.github.libretube.api.obj
 
-data class DeleteUserRequest(
-    var password: String? = null
-)
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class DeleteUserRequest(val password: String)
diff --git a/app/src/main/java/com/github/libretube/api/obj/Instances.kt b/app/src/main/java/com/github/libretube/api/obj/Instances.kt
index 053cb8b63..a25777be7 100644
--- a/app/src/main/java/com/github/libretube/api/obj/Instances.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/Instances.kt
@@ -1,15 +1,16 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class Instances(
-    var name: String? = null,
-    var api_url: String? = null,
-    var locations: String? = null,
-    var version: String? = null,
-    var up_to_date: Boolean? = null,
-    var cdn: Boolean? = null,
-    var registered: Long? = null,
-    var last_checked: Long? = null
+    val name: String,
+    @SerialName("api_url") val apiUrl: String,
+    val locations: String,
+    val version: String,
+    @SerialName("up_to_date") val upToDate: Boolean,
+    val cdn: Boolean,
+    val registered: Long,
+    @SerialName("last_checked") val lastChecked: Long
 )
diff --git a/app/src/main/java/com/github/libretube/api/obj/Login.kt b/app/src/main/java/com/github/libretube/api/obj/Login.kt
index 0636d72d9..eb8411491 100644
--- a/app/src/main/java/com/github/libretube/api/obj/Login.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/Login.kt
@@ -1,9 +1,9 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class Login(
-    val username: String? = null,
-    val password: String? = null
+    val username: String,
+    val password: String
 )
diff --git a/app/src/main/java/com/github/libretube/api/obj/Message.kt b/app/src/main/java/com/github/libretube/api/obj/Message.kt
index 93f063af0..70692071a 100644
--- a/app/src/main/java/com/github/libretube/api/obj/Message.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/Message.kt
@@ -1,5 +1,6 @@
 package com.github.libretube.api.obj
 
-data class Message(
-    var message: String? = null
-)
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class Message(val message: String? = null)
diff --git a/app/src/main/java/com/github/libretube/api/obj/PipedConfig.kt b/app/src/main/java/com/github/libretube/api/obj/PipedConfig.kt
index 1595b674f..e7f1c33ad 100644
--- a/app/src/main/java/com/github/libretube/api/obj/PipedConfig.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/PipedConfig.kt
@@ -1,5 +1,8 @@
 package com.github.libretube.api.obj
 
+import kotlinx.serialization.Serializable
+
+@Serializable
 data class PipedConfig(
     val donationUrl: String? = null,
     val statusPageUrl: String? = null,
diff --git a/app/src/main/java/com/github/libretube/api/obj/PipedStream.kt b/app/src/main/java/com/github/libretube/api/obj/PipedStream.kt
index 58de468e8..aadf7ed59 100644
--- a/app/src/main/java/com/github/libretube/api/obj/PipedStream.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/PipedStream.kt
@@ -1,23 +1,23 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class PipedStream(
-    var url: String? = null,
-    var format: String? = null,
-    var quality: String? = null,
-    var mimeType: String? = null,
-    var codec: String? = null,
-    var videoOnly: Boolean? = null,
-    var bitrate: Int? = null,
-    var initStart: Int? = null,
-    var initEnd: Int? = null,
-    var indexStart: Int? = null,
-    var indexEnd: Int? = null,
-    var width: Int? = null,
-    var height: Int? = null,
-    var fps: Int? = null,
+    val url: String? = null,
+    val format: String? = null,
+    val quality: String? = null,
+    val mimeType: String? = null,
+    val codec: String? = null,
+    val videoOnly: Boolean? = null,
+    val bitrate: Int? = null,
+    val initStart: Int? = null,
+    val initEnd: Int? = null,
+    val indexStart: Int? = null,
+    val indexEnd: Int? = null,
+    val width: Int? = null,
+    val height: Int? = null,
+    val fps: Int? = null,
     val audioTrackName: String? = null,
     val audioTrackId: String? = null
 )
diff --git a/app/src/main/java/com/github/libretube/api/obj/Playlist.kt b/app/src/main/java/com/github/libretube/api/obj/Playlist.kt
index 6530c04df..4933a91d8 100644
--- a/app/src/main/java/com/github/libretube/api/obj/Playlist.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/Playlist.kt
@@ -1,16 +1,16 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class Playlist(
-    var name: String? = null,
-    var thumbnailUrl: String? = null,
-    var bannerUrl: String? = null,
-    var nextpage: String? = null,
-    var uploader: String? = null,
-    var uploaderUrl: String? = null,
-    var uploaderAvatar: String? = null,
-    var videos: Int? = 0,
-    var relatedStreams: List<StreamItem>? = null
+    val name: String? = null,
+    val thumbnailUrl: String? = null,
+    val bannerUrl: String? = null,
+    val nextpage: String? = null,
+    val uploader: String? = null,
+    val uploaderUrl: String? = null,
+    val uploaderAvatar: String? = null,
+    val videos: Int = 0,
+    val relatedStreams: List<StreamItem> = emptyList()
 )
diff --git a/app/src/main/java/com/github/libretube/api/obj/PlaylistId.kt b/app/src/main/java/com/github/libretube/api/obj/PlaylistId.kt
index ea10202a4..3b083deff 100644
--- a/app/src/main/java/com/github/libretube/api/obj/PlaylistId.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/PlaylistId.kt
@@ -1,12 +1,12 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class PlaylistId(
-    var playlistId: String? = null,
-    var videoId: String? = null,
-    var videoIds: List<String>? = null,
-    var newName: String? = null,
-    var index: Int = -1
+    val playlistId: String? = null,
+    val videoId: String? = null,
+    val videoIds: List<String> = emptyList(),
+    val newName: String? = null,
+    val index: Int = -1
 )
diff --git a/app/src/main/java/com/github/libretube/api/obj/Playlists.kt b/app/src/main/java/com/github/libretube/api/obj/Playlists.kt
index 9bee35d0e..bf5c4faa2 100644
--- a/app/src/main/java/com/github/libretube/api/obj/Playlists.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/Playlists.kt
@@ -1,12 +1,12 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class Playlists(
-    var id: String? = null,
-    var name: String? = null,
-    var shortDescription: String? = null,
-    var thumbnail: String? = null,
-    var videos: Long? = null
+    val id: String? = null,
+    val name: String? = null,
+    val shortDescription: String? = null,
+    val thumbnail: String? = null,
+    val videos: Long = 0
 )
diff --git a/app/src/main/java/com/github/libretube/api/obj/PreviewFrames.kt b/app/src/main/java/com/github/libretube/api/obj/PreviewFrames.kt
index db7a051d4..48966998e 100644
--- a/app/src/main/java/com/github/libretube/api/obj/PreviewFrames.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/PreviewFrames.kt
@@ -1,8 +1,8 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class PreviewFrames(
     val urls: List<String>? = null,
     val frameWidth: Int? = null,
diff --git a/app/src/main/java/com/github/libretube/api/obj/SearchResult.kt b/app/src/main/java/com/github/libretube/api/obj/SearchResult.kt
index f923a6c7f..8cdb45d56 100644
--- a/app/src/main/java/com/github/libretube/api/obj/SearchResult.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/SearchResult.kt
@@ -1,11 +1,11 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class SearchResult(
-    val items: MutableList<ContentItem>? = arrayListOf(),
+    val items: List<ContentItem> = emptyList(),
     val nextpage: String? = null,
-    val suggestion: String? = "",
+    val suggestion: String? = null,
     val corrected: Boolean? = null
 )
diff --git a/app/src/main/java/com/github/libretube/api/obj/Segment.kt b/app/src/main/java/com/github/libretube/api/obj/Segment.kt
index 951a7b472..c1711e417 100644
--- a/app/src/main/java/com/github/libretube/api/obj/Segment.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/Segment.kt
@@ -1,8 +1,8 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class Segment(
     val UUID: String? = null,
     val actionType: String? = null,
diff --git a/app/src/main/java/com/github/libretube/api/obj/SegmentData.kt b/app/src/main/java/com/github/libretube/api/obj/SegmentData.kt
index a383cd801..4f65720af 100644
--- a/app/src/main/java/com/github/libretube/api/obj/SegmentData.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/SegmentData.kt
@@ -1,8 +1,8 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class SegmentData(
     val hash: String? = null,
     val segments: List<Segment> = listOf(),
diff --git a/app/src/main/java/com/github/libretube/api/obj/StreamItem.kt b/app/src/main/java/com/github/libretube/api/obj/StreamItem.kt
index 9363fbabd..60dadc0b7 100644
--- a/app/src/main/java/com/github/libretube/api/obj/StreamItem.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/StreamItem.kt
@@ -1,21 +1,21 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class StreamItem(
-    var url: String? = null,
+    val url: String? = null,
     val type: String? = null,
-    var title: String? = null,
-    var thumbnail: String? = null,
-    var uploaderName: String? = null,
-    var uploaderUrl: String? = null,
-    var uploaderAvatar: String? = null,
-    var uploadedDate: String? = null,
-    var duration: Long? = null,
-    var views: Long? = null,
-    var uploaderVerified: Boolean? = null,
-    var uploaded: Long? = null,
-    var shortDescription: String? = null,
+    val title: String? = null,
+    val thumbnail: String? = null,
+    val uploaderName: String? = null,
+    val uploaderUrl: String? = null,
+    val uploaderAvatar: String? = null,
+    val uploadedDate: String? = null,
+    val duration: Long? = null,
+    val views: Long? = null,
+    val uploaderVerified: Boolean? = null,
+    val uploaded: Long? = null,
+    val shortDescription: String? = null,
     val isShort: Boolean = false
 )
diff --git a/app/src/main/java/com/github/libretube/api/obj/Streams.kt b/app/src/main/java/com/github/libretube/api/obj/Streams.kt
index f4c561b22..6f4f8ce85 100644
--- a/app/src/main/java/com/github/libretube/api/obj/Streams.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/Streams.kt
@@ -1,31 +1,32 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.datetime.LocalDate
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class Streams(
-    val title: String? = null,
-    val description: String? = null,
-    val uploadDate: String? = null,
-    val uploader: String? = null,
-    val uploaderUrl: String? = null,
-    val uploaderAvatar: String? = null,
-    val thumbnailUrl: String? = null,
+    val title: String,
+    val description: String,
+    val uploadDate: LocalDate,
+    val uploader: String,
+    val uploaderUrl: String,
+    val uploaderAvatar: String,
+    val thumbnailUrl: String,
     val hls: String? = null,
     val dash: String? = null,
     val lbryId: String? = null,
-    val uploaderVerified: Boolean? = null,
-    val duration: Long? = null,
-    val views: Long? = null,
-    val likes: Long? = null,
-    val dislikes: Long? = null,
-    val audioStreams: List<PipedStream>? = null,
-    val videoStreams: List<PipedStream>? = null,
-    val relatedStreams: List<StreamItem>? = null,
-    val subtitles: List<Subtitle>? = null,
-    val livestream: Boolean? = null,
+    val uploaderVerified: Boolean,
+    val duration: Long,
+    val views: Long = 0,
+    val likes: Long = 0,
+    val dislikes: Long = 0,
+    val audioStreams: List<PipedStream> = emptyList(),
+    val videoStreams: List<PipedStream> = emptyList(),
+    val relatedStreams: List<StreamItem> = emptyList(),
+    val subtitles: List<Subtitle> = emptyList(),
+    val livestream: Boolean = false,
     val proxyUrl: String? = null,
-    val chapters: List<ChapterSegment>? = null,
-    val uploaderSubscriberCount: Long? = null,
-    val previewFrames: List<PreviewFrames>? = null
+    val chapters: List<ChapterSegment> = emptyList(),
+    val uploaderSubscriberCount: Long = 0,
+    val previewFrames: List<PreviewFrames> = emptyList()
 )
diff --git a/app/src/main/java/com/github/libretube/api/obj/Subscribe.kt b/app/src/main/java/com/github/libretube/api/obj/Subscribe.kt
index f474e129b..d268df2ca 100644
--- a/app/src/main/java/com/github/libretube/api/obj/Subscribe.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/Subscribe.kt
@@ -1,8 +1,6 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
-data class Subscribe(
-    var channelId: String? = null
-)
+@Serializable
+data class Subscribe(val channelId: String)
diff --git a/app/src/main/java/com/github/libretube/api/obj/Subscribed.kt b/app/src/main/java/com/github/libretube/api/obj/Subscribed.kt
index f20324e50..94986ec23 100644
--- a/app/src/main/java/com/github/libretube/api/obj/Subscribed.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/Subscribed.kt
@@ -1,8 +1,6 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
-data class Subscribed(
-    var subscribed: Boolean? = null
-)
+@Serializable
+data class Subscribed(val subscribed: Boolean? = null)
diff --git a/app/src/main/java/com/github/libretube/api/obj/Subscription.kt b/app/src/main/java/com/github/libretube/api/obj/Subscription.kt
index 5ddcf0861..b6dbf323b 100644
--- a/app/src/main/java/com/github/libretube/api/obj/Subscription.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/Subscription.kt
@@ -1,11 +1,11 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class Subscription(
-    var url: String? = null,
-    var name: String? = null,
-    var avatar: String? = null,
-    var verified: Boolean? = null
+    val url: String,
+    val name: String,
+    val avatar: String,
+    val verified: Boolean
 )
diff --git a/app/src/main/java/com/github/libretube/api/obj/Subtitle.kt b/app/src/main/java/com/github/libretube/api/obj/Subtitle.kt
index 74454e802..91b6760cd 100644
--- a/app/src/main/java/com/github/libretube/api/obj/Subtitle.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/Subtitle.kt
@@ -1,8 +1,8 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class Subtitle(
     val url: String? = null,
     val mimeType: String? = null,
diff --git a/app/src/main/java/com/github/libretube/api/obj/Token.kt b/app/src/main/java/com/github/libretube/api/obj/Token.kt
index 6f49ff7e8..a551dc727 100644
--- a/app/src/main/java/com/github/libretube/api/obj/Token.kt
+++ b/app/src/main/java/com/github/libretube/api/obj/Token.kt
@@ -1,9 +1,9 @@
 package com.github.libretube.api.obj
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class Token(
-    var token: String? = null,
-    var error: String? = null
+    val token: String? = null,
+    val error: String? = null
 )
diff --git a/app/src/main/java/com/github/libretube/db/DatabaseHelper.kt b/app/src/main/java/com/github/libretube/db/DatabaseHelper.kt
index c6fdf259f..cbaf5e6f4 100644
--- a/app/src/main/java/com/github/libretube/db/DatabaseHelper.kt
+++ b/app/src/main/java/com/github/libretube/db/DatabaseHelper.kt
@@ -16,9 +16,9 @@ object DatabaseHelper {
         val watchHistoryItem = WatchHistoryItem(
             videoId,
             streams.title,
-            streams.uploadDate,
+            streams.uploadDate.toString(),
             streams.uploader,
-            streams.uploaderUrl!!.toID(),
+            streams.uploaderUrl.toID(),
             streams.uploaderAvatar,
             streams.thumbnailUrl,
             streams.duration
diff --git a/app/src/main/java/com/github/libretube/db/obj/CustomInstance.kt b/app/src/main/java/com/github/libretube/db/obj/CustomInstance.kt
index 189b24a79..e2d9d9249 100644
--- a/app/src/main/java/com/github/libretube/db/obj/CustomInstance.kt
+++ b/app/src/main/java/com/github/libretube/db/obj/CustomInstance.kt
@@ -3,7 +3,9 @@ package com.github.libretube.db.obj
 import androidx.room.ColumnInfo
 import androidx.room.Entity
 import androidx.room.PrimaryKey
+import kotlinx.serialization.Serializable
 
+@Serializable
 @Entity(tableName = "customInstance")
 class CustomInstance(
     @PrimaryKey var name: String = "",
diff --git a/app/src/main/java/com/github/libretube/db/obj/LocalPlaylist.kt b/app/src/main/java/com/github/libretube/db/obj/LocalPlaylist.kt
index 5e027a953..3ef94118b 100644
--- a/app/src/main/java/com/github/libretube/db/obj/LocalPlaylist.kt
+++ b/app/src/main/java/com/github/libretube/db/obj/LocalPlaylist.kt
@@ -2,7 +2,9 @@ package com.github.libretube.db.obj
 
 import androidx.room.Entity
 import androidx.room.PrimaryKey
+import kotlinx.serialization.Serializable
 
+@Serializable
 @Entity
 data class LocalPlaylist(
     @PrimaryKey(autoGenerate = true)
diff --git a/app/src/main/java/com/github/libretube/db/obj/LocalPlaylistItem.kt b/app/src/main/java/com/github/libretube/db/obj/LocalPlaylistItem.kt
index c87db7b9c..f19effde5 100644
--- a/app/src/main/java/com/github/libretube/db/obj/LocalPlaylistItem.kt
+++ b/app/src/main/java/com/github/libretube/db/obj/LocalPlaylistItem.kt
@@ -3,7 +3,9 @@ package com.github.libretube.db.obj
 import androidx.room.ColumnInfo
 import androidx.room.Entity
 import androidx.room.PrimaryKey
+import kotlinx.serialization.Serializable
 
+@Serializable
 @Entity
 data class LocalPlaylistItem(
     @PrimaryKey(autoGenerate = true) val id: Int = 0,
diff --git a/app/src/main/java/com/github/libretube/db/obj/LocalPlaylistWithVideos.kt b/app/src/main/java/com/github/libretube/db/obj/LocalPlaylistWithVideos.kt
index 012617adf..671b477bd 100644
--- a/app/src/main/java/com/github/libretube/db/obj/LocalPlaylistWithVideos.kt
+++ b/app/src/main/java/com/github/libretube/db/obj/LocalPlaylistWithVideos.kt
@@ -2,7 +2,9 @@ package com.github.libretube.db.obj
 
 import androidx.room.Embedded
 import androidx.room.Relation
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class LocalPlaylistWithVideos(
     @Embedded val playlist: LocalPlaylist = LocalPlaylist(),
     @Relation(
diff --git a/app/src/main/java/com/github/libretube/db/obj/LocalSubscription.kt b/app/src/main/java/com/github/libretube/db/obj/LocalSubscription.kt
index 681779ad0..3fe2a1abb 100644
--- a/app/src/main/java/com/github/libretube/db/obj/LocalSubscription.kt
+++ b/app/src/main/java/com/github/libretube/db/obj/LocalSubscription.kt
@@ -2,7 +2,9 @@ package com.github.libretube.db.obj
 
 import androidx.room.Entity
 import androidx.room.PrimaryKey
+import kotlinx.serialization.Serializable
 
+@Serializable
 @Entity(tableName = "localSubscription")
 data class LocalSubscription(
     @PrimaryKey val channelId: String = ""
diff --git a/app/src/main/java/com/github/libretube/db/obj/PlaylistBookmark.kt b/app/src/main/java/com/github/libretube/db/obj/PlaylistBookmark.kt
index 328270830..b44e0f5b2 100644
--- a/app/src/main/java/com/github/libretube/db/obj/PlaylistBookmark.kt
+++ b/app/src/main/java/com/github/libretube/db/obj/PlaylistBookmark.kt
@@ -2,7 +2,9 @@ package com.github.libretube.db.obj
 
 import androidx.room.Entity
 import androidx.room.PrimaryKey
+import kotlinx.serialization.Serializable
 
+@Serializable
 @Entity(tableName = "playlistBookmark")
 data class PlaylistBookmark(
     @PrimaryKey
diff --git a/app/src/main/java/com/github/libretube/db/obj/SearchHistoryItem.kt b/app/src/main/java/com/github/libretube/db/obj/SearchHistoryItem.kt
index 6a7d0d3c2..d677d2dbc 100644
--- a/app/src/main/java/com/github/libretube/db/obj/SearchHistoryItem.kt
+++ b/app/src/main/java/com/github/libretube/db/obj/SearchHistoryItem.kt
@@ -2,7 +2,9 @@ package com.github.libretube.db.obj
 
 import androidx.room.Entity
 import androidx.room.PrimaryKey
+import kotlinx.serialization.Serializable
 
+@Serializable
 @Entity(tableName = "searchHistoryItem")
 data class SearchHistoryItem(
     @PrimaryKey val query: String = ""
diff --git a/app/src/main/java/com/github/libretube/db/obj/WatchHistoryItem.kt b/app/src/main/java/com/github/libretube/db/obj/WatchHistoryItem.kt
index 45da337df..01a8bdd74 100644
--- a/app/src/main/java/com/github/libretube/db/obj/WatchHistoryItem.kt
+++ b/app/src/main/java/com/github/libretube/db/obj/WatchHistoryItem.kt
@@ -3,7 +3,9 @@ package com.github.libretube.db.obj
 import androidx.room.ColumnInfo
 import androidx.room.Entity
 import androidx.room.PrimaryKey
+import kotlinx.serialization.Serializable
 
+@Serializable
 @Entity(tableName = "watchHistoryItem")
 data class WatchHistoryItem(
     @PrimaryKey val videoId: String = "",
diff --git a/app/src/main/java/com/github/libretube/db/obj/WatchPosition.kt b/app/src/main/java/com/github/libretube/db/obj/WatchPosition.kt
index bf6a77396..2f6f0e050 100644
--- a/app/src/main/java/com/github/libretube/db/obj/WatchPosition.kt
+++ b/app/src/main/java/com/github/libretube/db/obj/WatchPosition.kt
@@ -3,7 +3,9 @@ package com.github.libretube.db.obj
 import androidx.room.ColumnInfo
 import androidx.room.Entity
 import androidx.room.PrimaryKey
+import kotlinx.serialization.Serializable
 
+@Serializable
 @Entity(tableName = "watchPosition")
 data class WatchPosition(
     @PrimaryKey val videoId: String = "",
diff --git a/app/src/main/java/com/github/libretube/extensions/ToStreamItem.kt b/app/src/main/java/com/github/libretube/extensions/ToStreamItem.kt
index 2be7bbde4..7f1e718b7 100644
--- a/app/src/main/java/com/github/libretube/extensions/ToStreamItem.kt
+++ b/app/src/main/java/com/github/libretube/extensions/ToStreamItem.kt
@@ -13,7 +13,7 @@ fun Streams.toStreamItem(videoId: String): StreamItem {
         uploaderName = uploader,
         uploaderUrl = uploaderUrl,
         uploaderAvatar = uploaderAvatar,
-        uploadedDate = uploadDate,
+        uploadedDate = uploadDate.toString(),
         uploaded = null,
         duration = duration,
         views = views,
diff --git a/app/src/main/java/com/github/libretube/obj/BackupFile.kt b/app/src/main/java/com/github/libretube/obj/BackupFile.kt
index 82e8a75ec..958b04b64 100644
--- a/app/src/main/java/com/github/libretube/obj/BackupFile.kt
+++ b/app/src/main/java/com/github/libretube/obj/BackupFile.kt
@@ -7,14 +7,16 @@ import com.github.libretube.db.obj.PlaylistBookmark
 import com.github.libretube.db.obj.SearchHistoryItem
 import com.github.libretube.db.obj.WatchHistoryItem
 import com.github.libretube.db.obj.WatchPosition
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class BackupFile(
-    var watchHistory: List<WatchHistoryItem>? = null,
-    var watchPositions: List<WatchPosition>? = null,
-    var searchHistory: List<SearchHistoryItem>? = null,
-    var localSubscriptions: List<LocalSubscription>? = null,
-    var customInstances: List<CustomInstance>? = null,
-    var playlistBookmarks: List<PlaylistBookmark>? = null,
-    var localPlaylists: List<LocalPlaylistWithVideos>? = null,
-    var preferences: List<PreferenceItem>? = null
+    var watchHistory: List<WatchHistoryItem> = emptyList(),
+    var watchPositions: List<WatchPosition> = emptyList(),
+    var searchHistory: List<SearchHistoryItem> = emptyList(),
+    var localSubscriptions: List<LocalSubscription> = emptyList(),
+    var customInstances: List<CustomInstance> = emptyList(),
+    var playlistBookmarks: List<PlaylistBookmark> = emptyList(),
+    var localPlaylists: List<LocalPlaylistWithVideos> = emptyList(),
+    var preferences: List<PreferenceItem> = emptyList()
 )
diff --git a/app/src/main/java/com/github/libretube/obj/ImportPlaylist.kt b/app/src/main/java/com/github/libretube/obj/ImportPlaylist.kt
index a080dfa30..e31622d32 100644
--- a/app/src/main/java/com/github/libretube/obj/ImportPlaylist.kt
+++ b/app/src/main/java/com/github/libretube/obj/ImportPlaylist.kt
@@ -1,5 +1,8 @@
 package com.github.libretube.obj
 
+import kotlinx.serialization.Serializable
+
+@Serializable
 data class ImportPlaylist(
     var name: String? = null,
     val type: String? = null,
diff --git a/app/src/main/java/com/github/libretube/obj/ImportPlaylistFile.kt b/app/src/main/java/com/github/libretube/obj/ImportPlaylistFile.kt
index 43f9ff4a0..0693e2df6 100644
--- a/app/src/main/java/com/github/libretube/obj/ImportPlaylistFile.kt
+++ b/app/src/main/java/com/github/libretube/obj/ImportPlaylistFile.kt
@@ -1,7 +1,10 @@
 package com.github.libretube.obj
 
+import kotlinx.serialization.Serializable
+
+@Serializable
 data class ImportPlaylistFile(
-    val format: String? = null,
-    val version: Int? = null,
-    val playlists: List<ImportPlaylist>? = null
+    val format: String,
+    val version: Int,
+    val playlists: List<ImportPlaylist> = emptyList()
 )
diff --git a/app/src/main/java/com/github/libretube/obj/NewPipeSubscription.kt b/app/src/main/java/com/github/libretube/obj/NewPipeSubscription.kt
index 1db358271..c75befd6a 100644
--- a/app/src/main/java/com/github/libretube/obj/NewPipeSubscription.kt
+++ b/app/src/main/java/com/github/libretube/obj/NewPipeSubscription.kt
@@ -1,7 +1,11 @@
 package com.github.libretube.obj
 
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
 data class NewPipeSubscription(
-    val name: String? = null,
-    val service_id: Int? = null,
-    val url: String? = null
+    val name: String,
+    @SerialName("service_id") val serviceId: Int,
+    val url: String
 )
diff --git a/app/src/main/java/com/github/libretube/obj/NewPipeSubscriptions.kt b/app/src/main/java/com/github/libretube/obj/NewPipeSubscriptions.kt
index 9c19551d2..8309b5f27 100644
--- a/app/src/main/java/com/github/libretube/obj/NewPipeSubscriptions.kt
+++ b/app/src/main/java/com/github/libretube/obj/NewPipeSubscriptions.kt
@@ -1,7 +1,11 @@
 package com.github.libretube.obj
 
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
 data class NewPipeSubscriptions(
-    val app_version: String = "",
-    val app_version_int: Int = 0,
-    val subscriptions: List<NewPipeSubscription>? = null
+    @SerialName("app_version") val appVersion: String = "",
+    @SerialName("app_version_int") val appVersionInt: Int = 0,
+    val subscriptions: List<NewPipeSubscription> = emptyList()
 )
diff --git a/app/src/main/java/com/github/libretube/obj/PreferenceItem.kt b/app/src/main/java/com/github/libretube/obj/PreferenceItem.kt
index 7c547fea2..25bfd7ad4 100644
--- a/app/src/main/java/com/github/libretube/obj/PreferenceItem.kt
+++ b/app/src/main/java/com/github/libretube/obj/PreferenceItem.kt
@@ -1,6 +1,11 @@
 package com.github.libretube.obj
 
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.json.JsonNull
+import kotlinx.serialization.json.JsonPrimitive
+
+@Serializable
 data class PreferenceItem(
     val key: String? = null,
-    val value: Any? = null
+    val value: JsonPrimitive = JsonNull
 )
diff --git a/app/src/main/java/com/github/libretube/obj/update/Asset.kt b/app/src/main/java/com/github/libretube/obj/update/Asset.kt
index 1388df1c1..19102970f 100644
--- a/app/src/main/java/com/github/libretube/obj/update/Asset.kt
+++ b/app/src/main/java/com/github/libretube/obj/update/Asset.kt
@@ -1,20 +1,24 @@
 package com.github.libretube.obj.update
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.datetime.Instant
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.json.JsonElement
+import kotlinx.serialization.json.JsonNull
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class Asset(
-    val browser_download_url: String? = null,
-    val content_type: String? = null,
-    val created_at: String? = null,
-    val download_count: Int? = null,
-    val id: Int? = null,
-    val label: Any? = null,
-    val name: String? = null,
-    val node_id: String? = null,
-    val size: Int? = null,
-    val state: String? = null,
-    val updated_at: String? = null,
-    val uploader: Uploader? = null,
-    val url: String? = null
+    @SerialName("browser_download_url") val browserDownloadUrl: String,
+    @SerialName("content_type") val contentType: String,
+    @SerialName("created_at") val createdAt: Instant,
+    @SerialName("download_count") val downloadCount: Int,
+    val id: Int,
+    val label: JsonElement = JsonNull,
+    val name: String,
+    @SerialName("node_id") val nodeId: String,
+    val size: Int,
+    val state: String,
+    @SerialName("updated_at") val updatedAt: Instant,
+    val uploader: User,
+    val url: String
 )
diff --git a/app/src/main/java/com/github/libretube/obj/update/Author.kt b/app/src/main/java/com/github/libretube/obj/update/Author.kt
deleted file mode 100644
index ae61b7660..000000000
--- a/app/src/main/java/com/github/libretube/obj/update/Author.kt
+++ /dev/null
@@ -1,25 +0,0 @@
-package com.github.libretube.obj.update
-
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
-
-@JsonIgnoreProperties(ignoreUnknown = true)
-data class Author(
-    val avatar_url: String? = null,
-    val events_url: String? = null,
-    val followers_url: String? = null,
-    val following_url: String? = null,
-    val gists_url: String? = null,
-    val gravatar_id: String? = null,
-    val html_url: String? = null,
-    val id: Int? = null,
-    val login: String? = null,
-    val node_id: String? = null,
-    val organizations_url: String? = null,
-    val received_events_url: String? = null,
-    val repos_url: String? = null,
-    val site_admin: Boolean? = null,
-    val starred_url: String? = null,
-    val subscriptions_url: String? = null,
-    val type: String? = null,
-    val url: String? = null
-)
diff --git a/app/src/main/java/com/github/libretube/obj/update/Reactions.kt b/app/src/main/java/com/github/libretube/obj/update/Reactions.kt
index 0ec667860..01cfdc21e 100644
--- a/app/src/main/java/com/github/libretube/obj/update/Reactions.kt
+++ b/app/src/main/java/com/github/libretube/obj/update/Reactions.kt
@@ -1,15 +1,16 @@
 package com.github.libretube.obj.update
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class Reactions(
-    val confused: Int? = null,
-    val eyes: Int? = null,
-    val heart: Int? = null,
-    val hooray: Int? = null,
-    val laugh: Int? = null,
-    val rocket: Int? = null,
-    val total_count: Int? = null,
-    val url: String? = null
+    val confused: Int,
+    val eyes: Int,
+    val heart: Int,
+    val hooray: Int,
+    val laugh: Int,
+    val rocket: Int,
+    @SerialName("total_count") val totalCount: Int,
+    val url: String
 )
diff --git a/app/src/main/java/com/github/libretube/obj/update/UpdateInfo.kt b/app/src/main/java/com/github/libretube/obj/update/UpdateInfo.kt
index 8491dc734..6d166add7 100644
--- a/app/src/main/java/com/github/libretube/obj/update/UpdateInfo.kt
+++ b/app/src/main/java/com/github/libretube/obj/update/UpdateInfo.kt
@@ -1,27 +1,29 @@
 package com.github.libretube.obj.update
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
+import kotlinx.datetime.Instant
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 
-@JsonIgnoreProperties(ignoreUnknown = true)
+@Serializable
 data class UpdateInfo(
-    val assets: List<Asset>? = null,
-    val assets_url: String? = null,
-    val author: Author? = null,
-    val body: String? = null,
-    val created_at: String? = null,
-    val draft: Boolean? = null,
-    val html_url: String? = null,
-    val id: Int? = null,
-    val mentions_count: Int? = null,
-    val name: String? = null,
-    val node_id: String? = null,
-    val prerelease: Boolean? = null,
-    val published_at: String? = null,
-    val reactions: Reactions? = null,
-    val tag_name: String? = null,
-    val tarball_url: String? = null,
-    val target_commitish: String? = null,
-    val upload_url: String? = null,
-    val url: String? = null,
-    val zipball_url: String? = null
+    val assets: List<Asset> = emptyList(),
+    @SerialName("assets_url") val assetsUrl: String,
+    val author: User,
+    val body: String,
+    @SerialName("created_at") val createdAt: Instant,
+    val draft: Boolean,
+    @SerialName("html_url") val htmlUrl: String,
+    val id: Int,
+    @SerialName("mentions_count") val mentionsCount: Int,
+    val name: String,
+    @SerialName("node_id") val nodeId: String,
+    val prerelease: Boolean,
+    @SerialName("published_at") val publishedAt: Instant,
+    val reactions: Reactions,
+    @SerialName("tag_name") val tagName: String,
+    @SerialName("tarball_url") val tarballUrl: String,
+    @SerialName("target_commitish") val targetCommitish: String,
+    @SerialName("upload_url") val uploadUrl: String,
+    val url: String,
+    @SerialName("zipball_url") val zipballUrl: String
 )
diff --git a/app/src/main/java/com/github/libretube/obj/update/Uploader.kt b/app/src/main/java/com/github/libretube/obj/update/Uploader.kt
deleted file mode 100644
index 9dc63930b..000000000
--- a/app/src/main/java/com/github/libretube/obj/update/Uploader.kt
+++ /dev/null
@@ -1,25 +0,0 @@
-package com.github.libretube.obj.update
-
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties
-
-@JsonIgnoreProperties(ignoreUnknown = true)
-data class Uploader(
-    val avatar_url: String? = null,
-    val events_url: String? = null,
-    val followers_url: String? = null,
-    val following_url: String? = null,
-    val gists_url: String? = null,
-    val gravatar_id: String? = null,
-    val html_url: String? = null,
-    val id: Int? = null,
-    val login: String? = null,
-    val node_id: String? = null,
-    val organizations_url: String? = null,
-    val received_events_url: String? = null,
-    val repos_url: String? = null,
-    val site_admin: Boolean? = null,
-    val starred_url: String? = null,
-    val subscriptions_url: String? = null,
-    val type: String? = null,
-    val url: String? = null
-)
diff --git a/app/src/main/java/com/github/libretube/obj/update/User.kt b/app/src/main/java/com/github/libretube/obj/update/User.kt
new file mode 100644
index 000000000..b2103e904
--- /dev/null
+++ b/app/src/main/java/com/github/libretube/obj/update/User.kt
@@ -0,0 +1,26 @@
+package com.github.libretube.obj.update
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class User(
+    @SerialName("avatar_url") val avatarUrl: String,
+    @SerialName("events_url") val eventsUrl: String,
+    @SerialName("followers_url") val followersUrl: String,
+    @SerialName("following_url") val followingUrl: String,
+    @SerialName("gists_url") val gistsUrl: String,
+    @SerialName("gravatar_id") val gravatarId: String,
+    @SerialName("html_url") val htmlUrl: String,
+    val id: Int,
+    val login: String,
+    @SerialName("node_id") val nodeId: String,
+    @SerialName("organizations_url") val organizationsUrl: String,
+    @SerialName("received_events_url") val receivedEventsUrl: String,
+    @SerialName("repos_url") val reposUrl: String,
+    @SerialName("site_admin") val siteAdmin: Boolean,
+    @SerialName("starred_url") val starredUrl: String,
+    @SerialName("subscriptions_url") val subscriptionsUrl: String,
+    val type: String,
+    val url: String
+)
diff --git a/app/src/main/java/com/github/libretube/services/BackgroundMode.kt b/app/src/main/java/com/github/libretube/services/BackgroundMode.kt
index 8378e9128..d1413db69 100644
--- a/app/src/main/java/com/github/libretube/services/BackgroundMode.kt
+++ b/app/src/main/java/com/github/libretube/services/BackgroundMode.kt
@@ -13,8 +13,8 @@ import android.os.Looper
 import android.util.Log
 import android.widget.Toast
 import androidx.core.app.ServiceCompat
-import com.fasterxml.jackson.databind.ObjectMapper
 import com.github.libretube.R
+import com.github.libretube.api.JsonHelper
 import com.github.libretube.api.RetrofitInstance
 import com.github.libretube.api.obj.Segment
 import com.github.libretube.api.obj.SegmentData
@@ -40,6 +40,7 @@ import com.google.android.exoplayer2.Player
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
+import kotlinx.serialization.encodeToString
 
 /**
  * Loads the selected videos audio in background mode with a notification area.
@@ -318,11 +319,10 @@ class BackgroundMode : Service() {
             runCatching {
                 val categories = PlayerHelper.getSponsorBlockCategories()
                 if (categories.isEmpty()) return@runCatching
-                segmentData =
-                    RetrofitInstance.api.getSegments(
-                        videoId,
-                        ObjectMapper().writeValueAsString(categories)
-                    )
+                segmentData = RetrofitInstance.api.getSegments(
+                    videoId,
+                    JsonHelper.json.encodeToString(categories)
+                )
                 checkForSegments()
             }
         }
diff --git a/app/src/main/java/com/github/libretube/services/DownloadService.kt b/app/src/main/java/com/github/libretube/services/DownloadService.kt
index b35fae1a5..64a75c03a 100644
--- a/app/src/main/java/com/github/libretube/services/DownloadService.kt
+++ b/app/src/main/java/com/github/libretube/services/DownloadService.kt
@@ -102,21 +102,19 @@ class DownloadService : Service() {
                     Database.downloadDao().insertDownload(
                         Download(
                             videoId = videoId,
-                            title = streams.title ?: "",
+                            title = streams.title,
                             thumbnailPath = thumbnailTargetFile.absolutePath,
-                            description = streams.description ?: "",
-                            uploadDate = streams.uploadDate,
-                            uploader = streams.uploader ?: ""
+                            description = streams.description,
+                            uploadDate = streams.uploadDate.toString(),
+                            uploader = streams.uploader
                         )
                     )
                 }
-                streams.thumbnailUrl?.let { url ->
-                    ImageHelper.downloadImage(
-                        this@DownloadService,
-                        url,
-                        thumbnailTargetFile.absolutePath
-                    )
-                }
+                ImageHelper.downloadImage(
+                    this@DownloadService,
+                    streams.thumbnailUrl,
+                    thumbnailTargetFile.absolutePath
+                )
 
                 val downloadItems = streams.toDownloadItems(
                     videoId,
diff --git a/app/src/main/java/com/github/libretube/ui/adapters/CommentsAdapter.kt b/app/src/main/java/com/github/libretube/ui/adapters/CommentsAdapter.kt
index 73502253b..ec33f5cf5 100644
--- a/app/src/main/java/com/github/libretube/ui/adapters/CommentsAdapter.kt
+++ b/app/src/main/java/com/github/libretube/ui/adapters/CommentsAdapter.kt
@@ -66,22 +66,21 @@ class CommentsAdapter(
                 commentorImage.scaleY = REPLIES_ADAPTER_SCALE
             }
 
-            commentInfos.text =
-                comment.author.toString() + TextUtils.SEPARATOR + comment.commentedTime.toString()
+            commentInfos.text = comment.author + TextUtils.SEPARATOR + comment.commentedTime
             commentText.text = HtmlCompat.fromHtml(
-                comment.commentText.toString(),
+                comment.commentText,
                 HtmlCompat.FROM_HTML_MODE_LEGACY
             )
 
             ImageHelper.loadImage(comment.thumbnail, commentorImage)
             likesTextView.text = comment.likeCount.formatShort()
 
-            if (comment.verified == true) verifiedImageView.visibility = View.VISIBLE
-            if (comment.pinned == true) pinnedImageView.visibility = View.VISIBLE
-            if (comment.hearted == true) heartedImageView.visibility = View.VISIBLE
+            if (comment.verified) verifiedImageView.visibility = View.VISIBLE
+            if (comment.pinned) pinnedImageView.visibility = View.VISIBLE
+            if (comment.hearted) heartedImageView.visibility = View.VISIBLE
             if (comment.repliesPage != null) repliesAvailable.visibility = View.VISIBLE
-            if ((comment.replyCount ?: -1L) > 0L) {
-                repliesCount.text = comment.replyCount?.formatShort()
+            if (comment.replyCount > 0L) {
+                repliesCount.text = comment.replyCount.formatShort()
             }
 
             commentorImage.setOnClickListener {
@@ -99,7 +98,7 @@ class CommentsAdapter(
             }
 
             root.setOnLongClickListener {
-                ClipboardHelper(root.context).save(comment.commentText.toString())
+                ClipboardHelper(root.context).save(comment.commentText)
                 Toast.makeText(root.context, R.string.copied, Toast.LENGTH_SHORT).show()
                 true
             }
diff --git a/app/src/main/java/com/github/libretube/ui/adapters/SearchAdapter.kt b/app/src/main/java/com/github/libretube/ui/adapters/SearchAdapter.kt
index 6ffa9da7e..c99229616 100644
--- a/app/src/main/java/com/github/libretube/ui/adapters/SearchAdapter.kt
+++ b/app/src/main/java/com/github/libretube/ui/adapters/SearchAdapter.kt
@@ -83,13 +83,13 @@ class SearchAdapter(
     private fun bindWatch(item: ContentItem, binding: VideoRowBinding) {
         binding.apply {
             ImageHelper.loadImage(item.thumbnail, thumbnail)
-            thumbnailDuration.setFormattedDuration(item.duration!!, item.isShort)
+            thumbnailDuration.setFormattedDuration(item.duration, item.isShort)
             ImageHelper.loadImage(item.uploaderAvatar, channelImage)
             videoTitle.text = item.title
-            val viewsString = if (item.views?.toInt() != -1) item.views.formatShort() else ""
-            val uploadDate = if (item.uploadedDate != null) item.uploadedDate else ""
+            val viewsString = if (item.views != -1L) item.views.formatShort() else ""
+            val uploadDate = item.uploadedDate.orEmpty()
             videoInfo.text =
-                if (viewsString != "" && uploadDate != "") {
+                if (viewsString.isNotEmpty() && uploadDate.isNotEmpty()) {
                     "$viewsString • $uploadDate"
                 } else {
                     viewsString + uploadDate
@@ -98,7 +98,7 @@ class SearchAdapter(
             root.setOnClickListener {
                 NavigationHelper.navigateVideo(root.context, item.url)
             }
-            val videoId = item.url!!.toID()
+            val videoId = item.url.toID()
             val videoName = item.title!!
             root.setOnLongClickListener {
                 VideoOptionsBottomSheet(videoId, videoName)
@@ -111,7 +111,7 @@ class SearchAdapter(
             channelContainer.setOnClickListener {
                 NavigationHelper.navigateChannel(root.context, item.uploaderUrl)
             }
-            watchProgress.setWatchProgressLength(videoId, item.duration!!)
+            watchProgress.setWatchProgressLength(videoId, item.duration)
         }
     }
 
@@ -135,12 +135,12 @@ class SearchAdapter(
             }
 
             root.setOnLongClickListener {
-                ChannelOptionsBottomSheet(item.url!!.toID(), item.name)
+                ChannelOptionsBottomSheet(item.url.toID(), item.name)
                     .show((root.context as BaseActivity).supportFragmentManager)
                 true
             }
 
-            binding.searchSubButton.setupSubscriptionButton(item.url?.toID(), item.name?.toID())
+            binding.searchSubButton.setupSubscriptionButton(item.url.toID(), item.name?.toID())
         }
     }
 
@@ -150,7 +150,7 @@ class SearchAdapter(
     ) {
         binding.apply {
             ImageHelper.loadImage(item.thumbnail, playlistThumbnail)
-            if (item.videos?.toInt() != -1) videoCount.text = item.videos.toString()
+            if (item.videos != -1L) videoCount.text = item.videos.toString()
             playlistTitle.text = item.name
             playlistDescription.text = item.uploaderName
             root.setOnClickListener {
@@ -158,7 +158,7 @@ class SearchAdapter(
             }
             deletePlaylist.visibility = View.GONE
             root.setOnLongClickListener {
-                val playlistId = item.url!!.toID()
+                val playlistId = item.url.toID()
                 val playlistName = item.name!!
                 PlaylistOptionsBottomSheet(playlistId, playlistName, PlaylistType.PUBLIC)
                     .show(
diff --git a/app/src/main/java/com/github/libretube/ui/dialogs/BackupDialog.kt b/app/src/main/java/com/github/libretube/ui/dialogs/BackupDialog.kt
index 12e1ab34d..9518fbcc5 100644
--- a/app/src/main/java/com/github/libretube/ui/dialogs/BackupDialog.kt
+++ b/app/src/main/java/com/github/libretube/ui/dialogs/BackupDialog.kt
@@ -11,6 +11,8 @@ import com.github.libretube.obj.BackupFile
 import com.github.libretube.obj.PreferenceItem
 import com.github.libretube.util.PreferenceHelper
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
+import kotlinx.serialization.json.JsonNull
+import kotlinx.serialization.json.JsonPrimitive
 
 class BackupDialog(
     private val createBackupFile: (BackupFile) -> Unit
@@ -45,8 +47,14 @@ class BackupDialog(
         })
 
         object Preferences : BackupOption(R.string.preferences, onSelected = { file ->
-            file.preferences = PreferenceHelper.settings.all.map {
-                PreferenceItem(it.key, it.value)
+            file.preferences = PreferenceHelper.settings.all.map { (key, value) ->
+                val jsonValue = when (value) {
+                    is Number -> JsonPrimitive(value)
+                    is Boolean -> JsonPrimitive(value)
+                    is String -> JsonPrimitive(value)
+                    else -> JsonNull
+                }
+                PreferenceItem(key, jsonValue)
             }
         })
     }
diff --git a/app/src/main/java/com/github/libretube/ui/dialogs/DeleteAccountDialog.kt b/app/src/main/java/com/github/libretube/ui/dialogs/DeleteAccountDialog.kt
index 3613aabee..89d1e5ae1 100644
--- a/app/src/main/java/com/github/libretube/ui/dialogs/DeleteAccountDialog.kt
+++ b/app/src/main/java/com/github/libretube/ui/dialogs/DeleteAccountDialog.kt
@@ -8,6 +8,7 @@ import androidx.fragment.app.DialogFragment
 import androidx.lifecycle.lifecycleScope
 import com.github.libretube.R
 import com.github.libretube.api.RetrofitInstance
+import com.github.libretube.api.obj.DeleteUserRequest
 import com.github.libretube.databinding.DialogDeleteAccountBinding
 import com.github.libretube.extensions.TAG
 import com.github.libretube.util.PreferenceHelper
@@ -41,10 +42,7 @@ class DeleteAccountDialog : DialogFragment() {
             val token = PreferenceHelper.getToken()
 
             try {
-                RetrofitInstance.authApi.deleteAccount(
-                    token,
-                    com.github.libretube.api.obj.DeleteUserRequest(password)
-                )
+                RetrofitInstance.authApi.deleteAccount(token, DeleteUserRequest(password))
             } catch (e: Exception) {
                 Log.e(TAG(), e.toString())
                 Toast.makeText(context, R.string.unknown_error, Toast.LENGTH_SHORT).show()
diff --git a/app/src/main/java/com/github/libretube/ui/dialogs/DownloadDialog.kt b/app/src/main/java/com/github/libretube/ui/dialogs/DownloadDialog.kt
index 0a0ac45cf..e165e1f47 100644
--- a/app/src/main/java/com/github/libretube/ui/dialogs/DownloadDialog.kt
+++ b/app/src/main/java/com/github/libretube/ui/dialogs/DownloadDialog.kt
@@ -74,7 +74,7 @@ class DownloadDialog(
     }
 
     private fun initDownloadOptions(streams: Streams) {
-        binding.fileName.setText(streams.title.toString())
+        binding.fileName.setText(streams.title)
 
         val vidName = arrayListOf<String>()
 
@@ -82,7 +82,7 @@ class DownloadDialog(
         vidName.add(getString(R.string.no_video))
 
         // add all available video streams
-        for (vid in streams.videoStreams!!) {
+        for (vid in streams.videoStreams) {
             if (vid.url != null) {
                 val name = vid.quality + " " + vid.format
                 vidName.add(name)
@@ -95,7 +95,7 @@ class DownloadDialog(
         audioName.add(getString(R.string.no_audio))
 
         // add all available audio streams
-        for (audio in streams.audioStreams!!) {
+        for (audio in streams.audioStreams) {
             if (audio.url != null) {
                 val name = audio.quality + " " + audio.format
                 audioName.add(name)
@@ -108,7 +108,7 @@ class DownloadDialog(
         subtitleName.add(getString(R.string.no_subtitle))
 
         // add all available subtitles
-        for (subtitle in streams.subtitles!!) {
+        for (subtitle in streams.subtitles) {
             if (subtitle.url != null) {
                 subtitleName.add(subtitle.name.toString())
             }
diff --git a/app/src/main/java/com/github/libretube/ui/dialogs/LoginDialog.kt b/app/src/main/java/com/github/libretube/ui/dialogs/LoginDialog.kt
index d0306a2a8..b6287ce05 100644
--- a/app/src/main/java/com/github/libretube/ui/dialogs/LoginDialog.kt
+++ b/app/src/main/java/com/github/libretube/ui/dialogs/LoginDialog.kt
@@ -92,8 +92,8 @@ class LoginDialog : DialogFragment() {
                 Toast.LENGTH_SHORT
             ).show()
 
-            PreferenceHelper.setToken(response.token!!)
-            PreferenceHelper.setUsername(login.username!!)
+            PreferenceHelper.setToken(response.token)
+            PreferenceHelper.setUsername(login.username)
 
             dialog?.dismiss()
             activity?.recreate()
diff --git a/app/src/main/java/com/github/libretube/ui/dialogs/UpdateDialog.kt b/app/src/main/java/com/github/libretube/ui/dialogs/UpdateDialog.kt
index 88c1d636d..43c2acf51 100644
--- a/app/src/main/java/com/github/libretube/ui/dialogs/UpdateDialog.kt
+++ b/app/src/main/java/com/github/libretube/ui/dialogs/UpdateDialog.kt
@@ -29,7 +29,7 @@ class UpdateDialog(
                     intent.putExtra("downloadUrl", downloadUrl)
                     context?.startService(intent)
                 } else {
-                    val uri = Uri.parse(updateInfo.html_url)
+                    val uri = Uri.parse(updateInfo.htmlUrl)
                     val intent = Intent(Intent.ACTION_VIEW).setData(uri)
                     startActivity(intent)
                 }
@@ -40,8 +40,10 @@ class UpdateDialog(
     private fun getDownloadUrl(updateInfo: UpdateInfo): String? {
         val supportedArchitectures = Build.SUPPORTED_ABIS
         supportedArchitectures.forEach { arch ->
-            updateInfo.assets?.forEach { asset ->
-                if (asset.name?.contains(arch) == true) return asset.browser_download_url
+            updateInfo.assets.forEach { asset ->
+                if (asset.name.contains(arch)) {
+                    return asset.browserDownloadUrl
+                }
             }
         }
         return null
diff --git a/app/src/main/java/com/github/libretube/ui/fragments/ChannelFragment.kt b/app/src/main/java/com/github/libretube/ui/fragments/ChannelFragment.kt
index 3164fbafd..22c29884e 100644
--- a/app/src/main/java/com/github/libretube/ui/fragments/ChannelFragment.kt
+++ b/app/src/main/java/com/github/libretube/ui/fragments/ChannelFragment.kt
@@ -142,7 +142,7 @@ class ChannelFragment : BaseFragment() {
 
                 binding.channelShare.setOnClickListener {
                     val shareDialog = ShareDialog(
-                        response.id!!.toID(),
+                        response.id.toID(),
                         ShareObjectType.CHANNEL,
                         shareData
                     )
@@ -169,10 +169,10 @@ class ChannelFragment : BaseFragment() {
                     R.string.subscribers,
                     response.subscriberCount.formatShort()
                 )
-                if (response.description?.trim() == "") {
+                if (response.description.isBlank()) {
                     binding.channelDescription.visibility = View.GONE
                 } else {
-                    binding.channelDescription.text = response.description?.trim()
+                    binding.channelDescription.text = response.description.trim()
                 }
 
                 binding.channelDescription.setOnClickListener {
@@ -186,13 +186,13 @@ class ChannelFragment : BaseFragment() {
 
                 // recyclerview of the videos by the channel
                 channelAdapter = VideosAdapter(
-                    response.relatedStreams.orEmpty().toMutableList(),
+                    response.relatedStreams.toMutableList(),
                     forceMode = VideosAdapter.Companion.ForceMode.CHANNEL
                 )
                 binding.channelRecView.adapter = channelAdapter
             }
 
-            response.tabs?.let { setupTabs(it) }
+            setupTabs(response.tabs)
         }
     }
 
@@ -230,16 +230,13 @@ class ChannelFragment : BaseFragment() {
 
     private fun loadTab(tab: ChannelTab) {
         scope.launch {
-            tab.data ?: return@launch
             val response = try {
                 RetrofitInstance.api.getChannelTab(tab.data)
             } catch (e: Exception) {
                 return@launch
             }
 
-            val adapter = SearchAdapter(
-                response.content.toMutableList()
-            )
+            val adapter = SearchAdapter(response.content.toMutableList())
 
             runOnUiThread {
                 binding.channelRecView.adapter = adapter
@@ -275,7 +272,7 @@ class ChannelFragment : BaseFragment() {
                     return@launchWhenCreated
                 }
                 nextPage = response.nextpage
-                channelAdapter?.insertItems(response.relatedStreams.orEmpty())
+                channelAdapter?.insertItems(response.relatedStreams)
                 isLoading = false
                 binding.channelRefresh.isRefreshing = false
             }
@@ -291,9 +288,9 @@ class ChannelFragment : BaseFragment() {
     ) {
         scope.launch {
             val newContent = try {
-                RetrofitInstance.api.getChannelTab(tab.data ?: "", nextPage)
+                RetrofitInstance.api.getChannelTab(tab.data, nextPage)
             } catch (e: Exception) {
-                e.printStackTrace()
+                Log.e(TAG(), "Exception: $e")
                 null
             }
             onNewNextPage.invoke(newContent?.nextpage)
diff --git a/app/src/main/java/com/github/libretube/ui/fragments/PlayerFragment.kt b/app/src/main/java/com/github/libretube/ui/fragments/PlayerFragment.kt
index 3df84e776..fdd295f8a 100644
--- a/app/src/main/java/com/github/libretube/ui/fragments/PlayerFragment.kt
+++ b/app/src/main/java/com/github/libretube/ui/fragments/PlayerFragment.kt
@@ -37,9 +37,9 @@ import androidx.fragment.app.activityViewModels
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.lifecycleScope
 import androidx.recyclerview.widget.LinearLayoutManager
-import com.fasterxml.jackson.databind.ObjectMapper
 import com.github.libretube.R
 import com.github.libretube.api.CronetHelper
+import com.github.libretube.api.JsonHelper
 import com.github.libretube.api.RetrofitInstance
 import com.github.libretube.api.obj.ChapterSegment
 import com.github.libretube.api.obj.PipedStream
@@ -119,6 +119,8 @@ import kotlin.math.abs
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
+import kotlinx.datetime.LocalDate
+import kotlinx.serialization.encodeToString
 import org.chromium.net.CronetEngine
 import retrofit2.HttpException
 
@@ -685,9 +687,7 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
                     } else {
                         PlayingQueue.updateCurrent(streams.toStreamItem(videoId!!))
                         if (PlayerHelper.autoInsertRelatedVideos) {
-                            PlayingQueue.add(
-                                *streams.relatedStreams.orEmpty().toTypedArray()
-                            )
+                            PlayingQueue.add(*streams.relatedStreams.toTypedArray())
                         }
                     }
                 }
@@ -748,7 +748,7 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
                 segmentData =
                     RetrofitInstance.api.getSegments(
                         videoId!!,
-                        ObjectMapper().writeValueAsString(categories)
+                        JsonHelper.json.encodeToString(categories)
                     )
                 if (segmentData.segments.isEmpty()) return@runCatching
                 playerBinding.exoProgress.setSegments(segmentData.segments)
@@ -776,8 +776,7 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
             playerBinding.liveDiff.text = "-$diffText"
         }
         // call the function again after 100ms
-        handler
-            .postDelayed(this@PlayerFragment::refreshLiveStatus, 100)
+        handler.postDelayed(this@PlayerFragment::refreshLiveStatus, 100)
     }
 
     // seek to saved watch position if available
@@ -797,7 +796,7 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
             return
         }
         // position is almost the end of the video => don't seek, start from beginning
-        if (position != null && position < streams.duration!! * 1000 * 0.9) {
+        if (position != null && position < streams.duration * 1000 * 0.9) {
             exoPlayer.seekTo(position)
         }
     }
@@ -826,7 +825,7 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
         playerBinding.exoProgress.setPlayer(exoPlayer)
     }
 
-    private fun localizedDate(date: String?): String? {
+    private fun localizedDate(date: LocalDate): String {
         val locale = ConfigurationCompat.getLocales(resources.configuration)[0]!!
         return TextUtils.localizeDate(date, locale)
     }
@@ -870,12 +869,12 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
 
             playerChannelSubCount.text = context?.getString(
                 R.string.subscribers,
-                streams.uploaderSubscriberCount?.formatShort()
+                streams.uploaderSubscriberCount.formatShort()
             )
         }
 
         // duration that's not greater than 0 indicates that the video is live
-        if (streams.duration!! <= 0) {
+        if (streams.duration <= 0) {
             isLive = true
             handleLiveVideo()
         }
@@ -883,10 +882,8 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
         playerBinding.exoTitle.text = streams.title
 
         // init the chapters recyclerview
-        if (streams.chapters != null) {
-            chapters = streams.chapters.orEmpty()
-            initializeChapters()
-        }
+        chapters = streams.chapters
+        initializeChapters()
 
         // Listener for play and pause icon change
         exoPlayer.addListener(object : Player.Listener {
@@ -972,7 +969,7 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
         })
 
         binding.relPlayerDownload.setOnClickListener {
-            if (streams.duration!! <= 0) {
+            if (streams.duration <= 0) {
                 Toast.makeText(context, R.string.cannotDownload, Toast.LENGTH_SHORT).show()
             } else if (!DownloadService.IS_DOWNLOAD_RUNNING) {
                 val newFragment = DownloadDialog(videoId!!)
@@ -995,7 +992,7 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
         }
         initializeRelatedVideos(streams.relatedStreams)
         // set video description
-        val description = streams.description!!
+        val description = streams.description
 
         setupDescription(binding.playerDescription, description)
 
@@ -1009,7 +1006,7 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
 
         // update the subscribed state
         binding.playerSubscribe.setupSubscriptionButton(
-            this.streams.uploaderUrl?.toID(),
+            this.streams.uploaderUrl.toID(),
             this.streams.uploader
         )
 
@@ -1268,9 +1265,9 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
     private fun setResolutionAndSubtitles() {
         // create a list of subtitles
         subtitles = mutableListOf()
-        val subtitlesNamesList = mutableListOf(context?.getString(R.string.none)!!)
+        val subtitlesNamesList = mutableListOf(getString(R.string.none))
         val subtitleCodesList = mutableListOf("")
-        streams.subtitles.orEmpty().forEach {
+        streams.subtitles.forEach {
             subtitles.add(
                 SubtitleConfiguration.Builder(it.url!!.toUri())
                     .setMimeType(it.mimeType!!) // The correct MIME type (required).
@@ -1300,7 +1297,7 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
         if (defaultResolution != "") setPlayerResolution(defaultResolution.toInt())
 
         if (!PreferenceHelper.getBoolean(PreferenceKeys.USE_HLS_OVER_DASH, false) &&
-            streams.videoStreams.orEmpty().isNotEmpty()
+            streams.videoStreams.isNotEmpty()
         ) {
             val uri = let {
                 streams.dash?.toUri()
@@ -1377,16 +1374,14 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
     }
 
     override fun onCaptionsClicked() {
-        if (!this@PlayerFragment::streams.isInitialized ||
-            streams.subtitles.isNullOrEmpty()
-        ) {
+        if (!this@PlayerFragment::streams.isInitialized || streams.subtitles.isEmpty()) {
             Toast.makeText(context, R.string.no_subtitles_available, Toast.LENGTH_SHORT).show()
             return
         }
 
-        val subtitlesNamesList = mutableListOf(context?.getString(R.string.none)!!)
+        val subtitlesNamesList = mutableListOf(getString(R.string.none))
         val subtitleCodesList = mutableListOf("")
-        streams.subtitles!!.forEach {
+        streams.subtitles.forEach {
             subtitlesNamesList += it.name!!
             subtitleCodesList += it.code!!
         }
@@ -1515,9 +1510,9 @@ class PlayerFragment : BaseFragment(), OnlinePlayerOptions {
         playerBinding.seekbarPreview.visibility = View.GONE
         playerBinding.exoProgress.addListener(
             SeekbarPreviewListener(
-                streams.previewFrames.orEmpty(),
+                streams.previewFrames,
                 playerBinding.seekbarPreview,
-                streams.duration!! * 1000
+                streams.duration * 1000
             )
         )
     }
diff --git a/app/src/main/java/com/github/libretube/ui/fragments/PlaylistFragment.kt b/app/src/main/java/com/github/libretube/ui/fragments/PlaylistFragment.kt
index 39e5aca75..a5f8b476a 100644
--- a/app/src/main/java/com/github/libretube/ui/fragments/PlaylistFragment.kt
+++ b/app/src/main/java/com/github/libretube/ui/fragments/PlaylistFragment.kt
@@ -109,7 +109,7 @@ class PlaylistFragment : BaseFragment() {
                 Log.e(TAG(), e.toString())
                 return@launchWhenCreated
             }
-            playlistFeed = response.relatedStreams.orEmpty().toMutableList()
+            playlistFeed = response.relatedStreams.toMutableList()
             binding.playlistScrollview.visibility = View.VISIBLE
             nextPage = response.nextpage
             playlistName = response.name
@@ -140,7 +140,7 @@ class PlaylistFragment : BaseFragment() {
                     if (playlistFeed.isEmpty()) return@setOnClickListener
                     NavigationHelper.navigateVideo(
                         requireContext(),
-                        response.relatedStreams!!.first().url?.toID(),
+                        response.relatedStreams.first().url?.toID(),
                         playlistId
                     )
                 }
@@ -279,15 +279,9 @@ class PlaylistFragment : BaseFragment() {
             val response = try {
                 // load locally stored playlists with the auth api
                 if (playlistType == PlaylistType.PRIVATE) {
-                    RetrofitInstance.authApi.getPlaylistNextPage(
-                        playlistId!!,
-                        nextPage!!
-                    )
+                    RetrofitInstance.authApi.getPlaylistNextPage(playlistId!!, nextPage!!)
                 } else {
-                    RetrofitInstance.api.getPlaylistNextPage(
-                        playlistId!!,
-                        nextPage!!
-                    )
+                    RetrofitInstance.api.getPlaylistNextPage(playlistId!!, nextPage!!)
                 }
             } catch (e: Exception) {
                 Log.e(TAG(), e.toString())
@@ -295,7 +289,7 @@ class PlaylistFragment : BaseFragment() {
             }
 
             nextPage = response.nextpage
-            playlistAdapter?.updateItems(response.relatedStreams!!)
+            playlistAdapter?.updateItems(response.relatedStreams)
             isLoading = false
         }
     }
diff --git a/app/src/main/java/com/github/libretube/ui/fragments/SearchResultFragment.kt b/app/src/main/java/com/github/libretube/ui/fragments/SearchResultFragment.kt
index 4eefe16d2..54a84c9b8 100644
--- a/app/src/main/java/com/github/libretube/ui/fragments/SearchResultFragment.kt
+++ b/app/src/main/java/com/github/libretube/ui/fragments/SearchResultFragment.kt
@@ -5,6 +5,7 @@ import android.util.Log
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import androidx.core.view.isVisible
 import androidx.lifecycle.lifecycleScope
 import androidx.recyclerview.widget.LinearLayoutManager
 import com.github.libretube.R
@@ -94,13 +95,9 @@ class SearchResultFragment : BaseFragment() {
                 return@launchWhenCreated
             }
             runOnUiThread {
-                searchAdapter = SearchAdapter(response.items.orEmpty().toMutableList())
+                searchAdapter = SearchAdapter(response.items.toMutableList())
                 binding.searchRecycler.adapter = searchAdapter
-                binding.noSearchResult.visibility = if (response.items.orEmpty().isEmpty()) {
-                    View.VISIBLE
-                } else {
-                    View.GONE
-                }
+                binding.noSearchResult.isVisible = response.items.isEmpty()
             }
             nextPage = response.nextpage
         }
@@ -124,8 +121,8 @@ class SearchResultFragment : BaseFragment() {
             }
             nextPage = response.nextpage!!
             kotlin.runCatching {
-                if (response.items?.isNotEmpty() == true) {
-                    searchAdapter.updateItems(response.items.toMutableList())
+                if (response.items.isNotEmpty()) {
+                    searchAdapter.updateItems(response.items)
                 }
             }
         }
diff --git a/app/src/main/java/com/github/libretube/ui/models/CommentsViewModel.kt b/app/src/main/java/com/github/libretube/ui/models/CommentsViewModel.kt
index b8f4246b2..016b00ff0 100644
--- a/app/src/main/java/com/github/libretube/ui/models/CommentsViewModel.kt
+++ b/app/src/main/java/com/github/libretube/ui/models/CommentsViewModel.kt
@@ -48,7 +48,7 @@ class CommentsViewModel : ViewModel() {
                 return@launch
             }
             val updatedPage = commentsPage.value?.apply {
-                comments = comments.plus(response.comments).toMutableList()
+                comments += response.comments
             }
             nextPage = response.nextpage
             commentsPage.postValue(updatedPage)
diff --git a/app/src/main/java/com/github/libretube/ui/preferences/BackupRestoreSettings.kt b/app/src/main/java/com/github/libretube/ui/preferences/BackupRestoreSettings.kt
index 9aa6bb95e..0673081e7 100644
--- a/app/src/main/java/com/github/libretube/ui/preferences/BackupRestoreSettings.kt
+++ b/app/src/main/java/com/github/libretube/ui/preferences/BackupRestoreSettings.kt
@@ -68,7 +68,7 @@ class BackupRestoreSettings : BasePreferenceFragment() {
         createBackupFile = registerForActivityResult(
             CreateDocument("application/json")
         ) { uri: Uri? ->
-            BackupHelper(requireContext()).advancedBackup(uri, backupFile)
+            BackupHelper(requireContext()).createAdvancedBackup(uri, backupFile)
         }
 
         super.onCreate(savedInstanceState)
diff --git a/app/src/main/java/com/github/libretube/ui/preferences/InstanceSettings.kt b/app/src/main/java/com/github/libretube/ui/preferences/InstanceSettings.kt
index a7931a840..d42d7da5e 100644
--- a/app/src/main/java/com/github/libretube/ui/preferences/InstanceSettings.kt
+++ b/app/src/main/java/com/github/libretube/ui/preferences/InstanceSettings.kt
@@ -137,8 +137,8 @@ class InstanceSettings : BasePreferenceFragment() {
 
             response?.sortBy { it.name }
 
-            instanceNames.addAll(response.orEmpty().map { it.name ?: "" })
-            instanceValues.addAll(response.orEmpty().map { it.api_url ?: "" })
+            instanceNames.addAll(response.orEmpty().map { it.name })
+            instanceValues.addAll(response.orEmpty().map { it.apiUrl })
 
             customInstances.forEach { instance ->
                 instanceNames += instance.name
diff --git a/app/src/main/java/com/github/libretube/ui/sheets/ChannelOptionsBottomSheet.kt b/app/src/main/java/com/github/libretube/ui/sheets/ChannelOptionsBottomSheet.kt
index 987cfbf7a..f3edef523 100644
--- a/app/src/main/java/com/github/libretube/ui/sheets/ChannelOptionsBottomSheet.kt
+++ b/app/src/main/java/com/github/libretube/ui/sheets/ChannelOptionsBottomSheet.kt
@@ -20,7 +20,7 @@ import kotlinx.coroutines.runBlocking
  */
 class ChannelOptionsBottomSheet(
     private val channelId: String,
-    private val channelName: String?
+    channelName: String?
 ) : BaseBottomSheet() {
     private val shareData = ShareData(currentChannel = channelName)
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -44,7 +44,7 @@ class ChannelOptionsBottomSheet(
                         val channel = runBlocking {
                             RetrofitInstance.api.getChannel(channelId)
                         }
-                        channel.relatedStreams?.firstOrNull()?.url?.toID()?.let {
+                        channel.relatedStreams.firstOrNull()?.url?.toID()?.let {
                             NavigationHelper.navigateVideo(
                                 requireContext(),
                                 it,
@@ -60,7 +60,7 @@ class ChannelOptionsBottomSheet(
                         val channel = runBlocking {
                             RetrofitInstance.api.getChannel(channelId)
                         }
-                        channel.relatedStreams?.firstOrNull()?.url?.toID()?.let {
+                        channel.relatedStreams.firstOrNull()?.url?.toID()?.let {
                             BackgroundHelper.playOnBackground(
                                 requireContext(),
                                 videoId = it,
diff --git a/app/src/main/java/com/github/libretube/util/BackupHelper.kt b/app/src/main/java/com/github/libretube/util/BackupHelper.kt
index 036d867d4..51ff6a1b3 100644
--- a/app/src/main/java/com/github/libretube/util/BackupHelper.kt
+++ b/app/src/main/java/com/github/libretube/util/BackupHelper.kt
@@ -2,15 +2,22 @@ package com.github.libretube.util
 
 import android.content.Context
 import android.net.Uri
+import android.util.Log
 import androidx.core.content.edit
 import androidx.preference.PreferenceManager
-import com.fasterxml.jackson.databind.ObjectMapper
+import com.github.libretube.api.JsonHelper
 import com.github.libretube.constants.PreferenceKeys
 import com.github.libretube.db.DatabaseHolder.Companion.Database
+import com.github.libretube.extensions.TAG
 import com.github.libretube.extensions.query
 import com.github.libretube.obj.BackupFile
 import com.github.libretube.obj.PreferenceItem
-import java.io.FileOutputStream
+import kotlinx.serialization.json.booleanOrNull
+import kotlinx.serialization.json.decodeFromStream
+import kotlinx.serialization.json.encodeToStream
+import kotlinx.serialization.json.floatOrNull
+import kotlinx.serialization.json.intOrNull
+import kotlinx.serialization.json.longOrNull
 
 /**
  * Backup and restore the preferences
@@ -19,18 +26,15 @@ class BackupHelper(private val context: Context) {
     /**
      * Write a [BackupFile] containing the database content as well as the preferences
      */
-    fun advancedBackup(uri: Uri?, backupFile: BackupFile) {
-        if (uri == null) return
-        try {
-            context.contentResolver.openFileDescriptor(uri, "w")?.use {
-                FileOutputStream(it.fileDescriptor).use { fileOutputStream ->
-                    fileOutputStream.write(
-                        ObjectMapper().writeValueAsBytes(backupFile)
-                    )
+    fun createAdvancedBackup(uri: Uri?, backupFile: BackupFile) {
+        uri?.let {
+            try {
+                context.contentResolver.openOutputStream(it)?.use { outputStream ->
+                    JsonHelper.json.encodeToStream(backupFile, outputStream)
                 }
+            } catch (e: Exception) {
+                Log.e(TAG(), "Error while writing backup: $e")
             }
-        } catch (e: Exception) {
-            e.printStackTrace()
         }
     }
 
@@ -38,36 +42,33 @@ class BackupHelper(private val context: Context) {
      * Restore data from a [BackupFile]
      */
     fun restoreAdvancedBackup(uri: Uri?) {
-        if (uri == null) return
-
-        val mapper = ObjectMapper()
-        val json = context.contentResolver.openInputStream(uri)?.use {
-            it.bufferedReader().use { reader -> reader.readText() }
-        }.orEmpty()
-
-        val backupFile = mapper.readValue(json, BackupFile::class.java)
+        val backupFile = uri?.let {
+            context.contentResolver.openInputStream(it)?.use { inputStream ->
+                JsonHelper.json.decodeFromStream<BackupFile>(inputStream)
+            }
+        } ?: return
 
         query {
             Database.watchHistoryDao().insertAll(
-                *backupFile.watchHistory.orEmpty().toTypedArray()
+                *backupFile.watchHistory.toTypedArray()
             )
             Database.searchHistoryDao().insertAll(
-                *backupFile.searchHistory.orEmpty().toTypedArray()
+                *backupFile.searchHistory.toTypedArray()
             )
             Database.watchPositionDao().insertAll(
-                *backupFile.watchPositions.orEmpty().toTypedArray()
+                *backupFile.watchPositions.toTypedArray()
             )
             Database.localSubscriptionDao().insertAll(
-                *backupFile.localSubscriptions.orEmpty().toTypedArray()
+                *backupFile.localSubscriptions.toTypedArray()
             )
             Database.customInstanceDao().insertAll(
-                *backupFile.customInstances.orEmpty().toTypedArray()
+                *backupFile.customInstances.toTypedArray()
             )
             Database.playlistBookmarkDao().insertAll(
-                *backupFile.playlistBookmarks.orEmpty().toTypedArray()
+                *backupFile.playlistBookmarks.toTypedArray()
             )
 
-            backupFile.localPlaylists?.forEach {
+            backupFile.localPlaylists.forEach {
                 Database.localPlaylistsDao().createPlaylist(it.playlist)
                 val playlistId = Database.localPlaylistsDao().getAll().last().playlist.id
                 it.videos.forEach {
@@ -90,18 +91,26 @@ class BackupHelper(private val context: Context) {
             clear()
 
             // decide for each preference which type it is and save it to the preferences
-            preferences.forEach {
-                when (it.value) {
-                    is Boolean -> putBoolean(it.key, it.value)
-                    is Float -> putFloat(it.key, it.value)
-                    is Long -> putLong(it.key, it.value)
+            preferences.forEach { (key, jsonValue) ->
+                val value = if (jsonValue.isString) {
+                    jsonValue.content
+                } else {
+                    jsonValue.booleanOrNull
+                        ?: jsonValue.intOrNull
+                        ?: jsonValue.longOrNull
+                        ?: jsonValue.floatOrNull
+                }
+                when (value) {
+                    is Boolean -> putBoolean(key, value)
+                    is Float -> putFloat(key, value)
+                    is Long -> putLong(key, value)
                     is Int -> {
-                        when (it.key) {
-                            PreferenceKeys.START_FRAGMENT -> putInt(it.key, it.value)
-                            else -> putLong(it.key, it.value.toLong())
+                        when (key) {
+                            PreferenceKeys.START_FRAGMENT -> putInt(key, value)
+                            else -> putLong(key, value.toLong())
                         }
                     }
-                    is String -> putString(it.key, it.value)
+                    is String -> putString(key, value)
                 }
             }
         }
diff --git a/app/src/main/java/com/github/libretube/util/ImportHelper.kt b/app/src/main/java/com/github/libretube/util/ImportHelper.kt
index 0db3c1068..9560b7fca 100644
--- a/app/src/main/java/com/github/libretube/util/ImportHelper.kt
+++ b/app/src/main/java/com/github/libretube/util/ImportHelper.kt
@@ -4,8 +4,8 @@ import android.app.Activity
 import android.net.Uri
 import android.util.Log
 import android.widget.Toast
-import com.fasterxml.jackson.databind.ObjectMapper
 import com.github.libretube.R
+import com.github.libretube.api.JsonHelper
 import com.github.libretube.api.PlaylistsHelper
 import com.github.libretube.api.RetrofitInstance
 import com.github.libretube.api.SubscriptionHelper
@@ -15,11 +15,13 @@ import com.github.libretube.obj.ImportPlaylist
 import com.github.libretube.obj.ImportPlaylistFile
 import com.github.libretube.obj.NewPipeSubscription
 import com.github.libretube.obj.NewPipeSubscriptions
-import java.io.FileOutputStream
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.runBlocking
+import kotlinx.serialization.json.decodeFromStream
+import kotlinx.serialization.json.encodeToStream
+import okio.use
 
 class ImportHelper(
     private val activity: Activity
@@ -56,12 +58,11 @@ class ImportHelper(
         return when (val fileType = activity.contentResolver.getType(uri)) {
             "application/json", "application/*", "application/octet-stream" -> {
                 // NewPipe subscriptions format
-                val subscriptions = ObjectMapper().readValue(
-                    uri.readText(),
-                    NewPipeSubscriptions::class.java
-                )
-                subscriptions.subscriptions.orEmpty().map {
-                    it.url!!.replace("https://www.youtube.com/channel/", "")
+                val subscriptions = activity.contentResolver.openInputStream(uri)?.use {
+                    JsonHelper.json.decodeFromStream<NewPipeSubscriptions>(it)
+                }
+                subscriptions?.subscriptions.orEmpty().map {
+                    it.url.replace("https://www.youtube.com/channel/", "")
                 }
             }
             "text/csv", "text/comma-separated-values" -> {
@@ -91,20 +92,14 @@ class ImportHelper(
                     SubscriptionHelper.getFormattedLocalSubscriptions()
                 )
             }
-            val newPipeChannels = mutableListOf<NewPipeSubscription>()
-            subs.forEach {
-                newPipeChannels += NewPipeSubscription(
-                    name = it.name,
-                    service_id = 0,
-                    url = "https://www.youtube.com" + it.url
-                )
+            val newPipeChannels = subs.map {
+                NewPipeSubscription(it.name, 0, "https://www.youtube.com${it.url}")
             }
+            val newPipeSubscriptions = NewPipeSubscriptions(subscriptions = newPipeChannels)
 
-            val newPipeSubscriptions = NewPipeSubscriptions(
-                subscriptions = newPipeChannels
-            )
-
-            uri.write(newPipeSubscriptions)
+            activity.contentResolver.openOutputStream(uri)?.use {
+                JsonHelper.json.encodeToStream(newPipeSubscriptions, it)
+            }
 
             activity.toastFromMainThread(R.string.exportsuccess)
         }
@@ -134,11 +129,10 @@ class ImportHelper(
                 }
             }
             "application/json", "application/*", "application/octet-stream" -> {
-                val playlistFile = ObjectMapper().readValue(
-                    uri.readText(),
-                    ImportPlaylistFile::class.java
-                )
-                importPlaylists.addAll(playlistFile.playlists.orEmpty())
+                val playlistFile = activity.contentResolver.openInputStream(uri)?.use {
+                    JsonHelper.json.decodeFromStream<ImportPlaylistFile>(it)
+                }
+                importPlaylists.addAll(playlistFile?.playlists.orEmpty())
             }
             else -> {
                 activity.applicationContext.toastFromMainThread("Unsupported file type $fileType")
@@ -167,31 +161,13 @@ class ImportHelper(
 
         runBlocking {
             val playlists = PlaylistsHelper.exportPlaylists()
-            val playlistFile = ImportPlaylistFile(
-                format = "Piped",
-                version = 1,
-                playlists = playlists
-            )
+            val playlistFile = ImportPlaylistFile("Piped", 1, playlists)
 
-            uri.write(playlistFile)
+            activity.contentResolver.openOutputStream(uri)?.use {
+                JsonHelper.json.encodeToStream(playlistFile, it)
+            }
 
             activity.toastFromMainThread(R.string.exportsuccess)
         }
     }
-
-    private fun Uri.readText(): String {
-        return activity.contentResolver.openInputStream(this)?.use {
-            it.bufferedReader().use { reader -> reader.readText() }
-        }.orEmpty()
-    }
-
-    private fun Uri.write(text: Any) {
-        activity.contentResolver.openFileDescriptor(this, "w")?.use {
-            FileOutputStream(it.fileDescriptor).use { fileOutputStream ->
-                fileOutputStream.write(
-                    ObjectMapper().writeValueAsBytes(text)
-                )
-            }
-        }
-    }
 }
diff --git a/app/src/main/java/com/github/libretube/util/MetadataHelper.kt b/app/src/main/java/com/github/libretube/util/MetadataHelper.kt
deleted file mode 100644
index a2b46d13d..000000000
--- a/app/src/main/java/com/github/libretube/util/MetadataHelper.kt
+++ /dev/null
@@ -1,48 +0,0 @@
-package com.github.libretube.util
-
-import android.content.Context
-import android.net.Uri
-import com.fasterxml.jackson.databind.ObjectMapper
-import com.github.libretube.api.obj.Streams
-import java.io.File
-import java.io.FileOutputStream
-
-class MetadataHelper(
-    private val context: Context
-) {
-    private val mapper = ObjectMapper()
-    private val metadataDir = DownloadHelper.getDownloadDir(context, DownloadHelper.METADATA_DIR)
-
-    fun createMetadata(fileName: String, streams: Streams) {
-        val targetFile = File(metadataDir, fileName)
-        targetFile.createNewFile()
-
-        context.contentResolver.openFileDescriptor(
-            Uri.fromFile(targetFile),
-            "w"
-        )?.use {
-            FileOutputStream(it.fileDescriptor).use { fileOutputStream ->
-                fileOutputStream.write(
-                    mapper.writeValueAsBytes(
-                        streams
-                    )
-                )
-            }
-        }
-    }
-
-    fun getMetadata(fileName: String): Streams? {
-        val sourceFile = File(metadataDir, fileName)
-
-        return try {
-            val json = context.contentResolver.openInputStream(
-                Uri.fromFile(sourceFile)
-            )?.use {
-                it.bufferedReader().use { reader -> reader.readText() }
-            }
-            mapper.readValue(json, Streams::class.java)
-        } catch (e: Exception) {
-            return null
-        }
-    }
-}
diff --git a/app/src/main/java/com/github/libretube/util/PlayingQueue.kt b/app/src/main/java/com/github/libretube/util/PlayingQueue.kt
index 31769d384..99981aeda 100644
--- a/app/src/main/java/com/github/libretube/util/PlayingQueue.kt
+++ b/app/src/main/java/com/github/libretube/util/PlayingQueue.kt
@@ -147,7 +147,7 @@ object PlayingQueue {
         scope.launch {
             while (channelNextPage != null) {
                 RetrofitInstance.api.getChannelNextPage(channelId, nextPage!!).apply {
-                    add(*relatedStreams.orEmpty().toTypedArray())
+                    add(*relatedStreams.toTypedArray())
                     channelNextPage = this.nextpage
                 }
             }
@@ -158,7 +158,7 @@ object PlayingQueue {
         scope.launch {
             runCatching {
                 val channel = RetrofitInstance.api.getChannel(channelId)
-                add(*channel.relatedStreams.orEmpty().toTypedArray())
+                add(*channel.relatedStreams.toTypedArray())
                 updateCurrent(newCurrentStream)
                 if (channel.nextpage == null) return@launch
                 fetchMoreFromChannel(channelId, channel.nextpage)
diff --git a/app/src/main/java/com/github/libretube/util/TextUtils.kt b/app/src/main/java/com/github/libretube/util/TextUtils.kt
index 201a2957a..9bc33799b 100644
--- a/app/src/main/java/com/github/libretube/util/TextUtils.kt
+++ b/app/src/main/java/com/github/libretube/util/TextUtils.kt
@@ -2,10 +2,11 @@ package com.github.libretube.util
 
 import android.net.Uri
 import java.net.URL
-import java.time.LocalDate
 import java.time.format.DateTimeFormatter
 import java.time.format.FormatStyle
 import java.util.*
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.toJavaLocalDate
 
 object TextUtils {
     /**
@@ -42,16 +43,9 @@ object TextUtils {
      * @param locale The locale to use, otherwise uses system default
      * return Localized date string
      */
-    fun localizeDate(date: String?, locale: Locale): String? {
-        date ?: return null
-
-        // relative time span
-        if (!date.contains("-")) return date
-
-        val dateObj = LocalDate.parse(date)
-
+    fun localizeDate(date: LocalDate, locale: Locale): String {
         val formatter = DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(locale)
-        return dateObj.format(formatter)
+        return date.toJavaLocalDate().format(formatter)
     }
 
     /**
diff --git a/build.gradle b/build.gradle
index e3650b340..81dd9b027 100644
--- a/build.gradle
+++ b/build.gradle
@@ -5,13 +5,15 @@
 
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 buildscript {
+    ext.kotlin_version = '1.7.22'
     repositories {
         google()
         mavenCentral()
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:7.4.0'
-        classpath 'org.jetbrains.kotlin:kotlin-gradle-plugin:1.7.22'
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+        classpath "org.jetbrains.kotlin:kotlin-serialization:$kotlin_version"
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 799a499bf..01e43147d 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -11,13 +11,15 @@ espresso = "3.5.1"
 workRuntime = "2.7.1"
 exoplayer = "2.18.2"
 retrofit = "2.9.0"
-jacksonAnnotations = "2.13.4"
 desugaring = "2.0.0"
 cronetEmbedded = "108.5359.79"
 cronetOkHttp = "0.1.0"
 coil = "2.2.2"
 leakcanary = "2.10"
 room = "2.5.0"
+kotlinxSerialization = "1.4.1"
+kotlinxDatetime = "0.4.0"
+kotlinxRetrofit = "0.8.0"
 
 [libraries]
 androidx-appcompat = { group = "androidx.appcompat", name = "appcompat", version.ref = "appcompat" }
@@ -33,8 +35,6 @@ androidx-work-runtime = { group = "androidx.work", name="work-runtime-ktx", vers
 exoplayer = { group = "com.google.android.exoplayer", name = "exoplayer", version.ref = "exoplayer" }
 exoplayer-extension-mediasession = { group = "com.google.android.exoplayer", name = "extension-mediasession", version.ref = "exoplayer" }
 square-retrofit = { group = "com.squareup.retrofit2", name = "retrofit", version.ref = "retrofit" }
-square-retrofit-converterJackson = { group = "com.squareup.retrofit2", name = "converter-jackson", version.ref = "retrofit" }
-jacksonAnnotations = { group = "com.fasterxml.jackson.core", name = "jackson-annotations", version.ref = "jacksonAnnotations" }
 desugaring = { group = "com.android.tools", name = "desugar_jdk_libs", version.ref = "desugaring" }
 exoplayer-extension-cronet = { group = "com.google.android.exoplayer", name = "extension-cronet", version.ref = "exoplayer" }
 exoplayer-dash = { group = "com.google.android.exoplayer", name = "exoplayer-dash", version.ref = "exoplayer" }
@@ -46,4 +46,7 @@ lifecycle-viewmodel = { group = "androidx.lifecycle", name = "lifecycle-viewmode
 lifecycle-runtime = { group = "androidx.lifecycle", name = "lifecycle-runtime-ktx", version.ref = "lifecycle" }
 lifecycle-livedata = { group = "androidx.lifecycle", name = "lifecycle-livedata-ktx", version.ref = "lifecycle" }
 room = { group = "androidx.room", name="room-runtime", version.ref = "room" }
-room-compiler = { group = "androidx.room", name = "room-compiler", version.ref = "room" }
\ No newline at end of file
+room-compiler = { group = "androidx.room", name = "room-compiler", version.ref = "room" }
+kotlinx-serialization = { group = "org.jetbrains.kotlinx", name = "kotlinx-serialization-json", version.ref = "kotlinxSerialization" }
+kotlinx-datetime = { group = "org.jetbrains.kotlinx", name = "kotlinx-datetime", version.ref = "kotlinxDatetime" }
+kotlinx-serialization-retrofit = { group = "com.jakewharton.retrofit", name = "retrofit2-kotlinx-serialization-converter", version.ref = "kotlinxRetrofit" }
\ No newline at end of file