diff --git a/backend/mirai-console/build.gradle.kts b/backend/mirai-console/build.gradle.kts
index a2e1294e5..07c94556c 100644
--- a/backend/mirai-console/build.gradle.kts
+++ b/backend/mirai-console/build.gradle.kts
@@ -20,8 +20,8 @@ kotlin {
 }
 
 dependencies {
-    compileAndTestRuntime(`mirai-core`)
-    compileAndTestRuntime(`kotlin-stdlib`)
+    compileAndTestRuntime(`mirai-core-api`)
+    compileAndTestRuntime(`mirai-core-utils`)
     compileAndTestRuntime(`kotlin-stdlib-jdk8`)
 
     compileAndTestRuntime(`kotlinx-atomicfu`)
@@ -35,7 +35,7 @@ dependencies {
     smartImplementation(`caller-finder`)
     smartApi(`kotlinx-coroutines-jdk8`)
 
-    testApi(`mirai-core-qqandroid`)
+    testApi(`mirai-core`)
     testApi(`kotlin-stdlib-jdk8`)
 }
 
diff --git a/backend/mirai-console/src/MiraiConsole.kt b/backend/mirai-console/src/MiraiConsole.kt
index 8360bd388..7c8cfb1e1 100644
--- a/backend/mirai-console/src/MiraiConsole.kt
+++ b/backend/mirai-console/src/MiraiConsole.kt
@@ -15,6 +15,7 @@ package net.mamoe.mirai.console
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Job
 import net.mamoe.mirai.Bot
+import net.mamoe.mirai.BotFactory
 import net.mamoe.mirai.console.MiraiConsole.INSTANCE
 import net.mamoe.mirai.console.MiraiConsoleImplementation.Companion.start
 import net.mamoe.mirai.console.extensions.BotConfigurationAlterer
@@ -30,7 +31,6 @@ import net.mamoe.mirai.console.util.ConsoleInternalApi
 import net.mamoe.mirai.console.util.CoroutineScopeUtils.childScopeContext
 import net.mamoe.mirai.console.util.SemVersion
 import net.mamoe.mirai.utils.BotConfiguration
-import net.mamoe.mirai.utils.DefaultLogger
 import net.mamoe.mirai.utils.MiraiLogger
 import java.io.File
 import java.nio.file.Path
@@ -142,7 +142,7 @@ public interface MiraiConsole : CoroutineScope {
                 fileBasedDeviceInfo()
                 redirectNetworkLogToDirectory()
                 this.botLoggerSupplier = {
-                    DefaultLogger("Bot.${it.id}")
+                    MiraiLogger.create("Bot.${it.id}")
                 }
                 parentCoroutineContext = MiraiConsole.childScopeContext("Bot $id")
 
@@ -157,8 +157,8 @@ public interface MiraiConsole : CoroutineScope {
             }
 
             return when (password) {
-                is ByteArray -> Bot(id, password, config)
-                is String -> Bot(id, password, config)
+                is ByteArray -> BotFactory.newBot(id, password, config)
+                is String -> BotFactory.newBot(id, password, config)
                 else -> throw IllegalArgumentException("Bad password type: `${password.javaClass.name}`. Require ByteArray or String")
             }
         }
diff --git a/backend/mirai-console/src/MiraiConsoleFrontEndDescription.kt b/backend/mirai-console/src/MiraiConsoleFrontEndDescription.kt
index a09d08b5d..cb042a1c1 100644
--- a/backend/mirai-console/src/MiraiConsoleFrontEndDescription.kt
+++ b/backend/mirai-console/src/MiraiConsoleFrontEndDescription.kt
@@ -12,7 +12,7 @@
 package net.mamoe.mirai.console
 
 import net.mamoe.mirai.console.util.SemVersion
-import net.mamoe.mirai.utils.MiraiExperimentalAPI
+import net.mamoe.mirai.utils.MiraiExperimentalApi
 
 
 /**
@@ -41,7 +41,7 @@ public interface MiraiConsoleFrontEndDescription {
      *
      * 返回 `null` 表示禁止 [MiraiConsole] 后端检查版本兼容性.
      */
-    @MiraiExperimentalAPI
+    @MiraiExperimentalApi
     public val compatibleBackendVersion: SemVersion? get() = null
 
     /**
diff --git a/backend/mirai-console/src/command/CommandSender.kt b/backend/mirai-console/src/command/CommandSender.kt
index 526e6675f..9088a9055 100644
--- a/backend/mirai-console/src/command/CommandSender.kt
+++ b/backend/mirai-console/src/command/CommandSender.kt
@@ -33,6 +33,7 @@ import net.mamoe.mirai.console.util.CoroutineScopeUtils.childScope
 import net.mamoe.mirai.console.util.CoroutineScopeUtils.childScopeContext
 import net.mamoe.mirai.console.util.MessageScope
 import net.mamoe.mirai.contact.*
+import net.mamoe.mirai.event.events.*
 import net.mamoe.mirai.message.*
 import net.mamoe.mirai.message.data.Message
 import net.mamoe.mirai.message.data.PlainText
diff --git a/backend/mirai-console/src/command/descriptor/CommandArgumentParserBuiltins.kt b/backend/mirai-console/src/command/descriptor/CommandArgumentParserBuiltins.kt
index e9f61a070..16bc5dff0 100644
--- a/backend/mirai-console/src/command/descriptor/CommandArgumentParserBuiltins.kt
+++ b/backend/mirai-console/src/command/descriptor/CommandArgumentParserBuiltins.kt
@@ -19,8 +19,6 @@ import net.mamoe.mirai.console.permission.AbstractPermitteeId
 import net.mamoe.mirai.console.permission.PermissionId
 import net.mamoe.mirai.console.permission.PermitteeId
 import net.mamoe.mirai.contact.*
-import net.mamoe.mirai.getFriendOrNull
-import net.mamoe.mirai.getGroupOrNull
 import net.mamoe.mirai.message.data.*
 
 
@@ -167,7 +165,7 @@ public object ExistingFriendValueArgumentParser : InternalCommandValueArgumentPa
     public override fun parse(raw: MessageContent, sender: CommandSender): Friend {
         if (raw is At) {
             checkArgument(sender is MemberCommandSender)
-            return sender.inferBotOrFail().getFriendOrNull(raw.target)
+            return sender.inferBotOrFail().getFriend(raw.target)
                 ?: illegalArgument("At 的对象 ${raw.target} 非 Bot 好友")
         } else {
             illegalArgument("无法解析 $raw 为好友")
@@ -329,7 +327,7 @@ public object ExistingMemberValueArgumentParser : InternalCommandValueArgumentPa
             if (raw.target == bot.id) {
                 return group.botAsMember
             }
-            group[raw.target]
+            group[raw.target] ?: illegalArgument("无法找到群员 ${raw.target}")
         } else {
             parse(raw.content, sender)
         }
@@ -374,20 +372,20 @@ internal abstract class InternalCommandValueArgumentParserExtensions<T : Any> :
     protected fun String.findBotOrFail(): Bot =
         Bot.getInstanceOrNull(this.parseToLongOrFail()) ?: illegalArgument("无法找到 Bot: $this")
 
-    protected fun Bot.findGroupOrFail(id: Long): Group = getGroupOrNull(id) ?: illegalArgument("无法找到群: $this")
+    protected fun Bot.findGroupOrFail(id: Long): Group = getGroup(id) ?: illegalArgument("无法找到群: $this")
 
     protected fun Bot.findGroupOrFail(id: String): Group =
-        getGroupOrNull(id.parseToLongOrFail()) ?: illegalArgument("无法找到群: $this")
+        getGroup(id.parseToLongOrFail()) ?: illegalArgument("无法找到群: $this")
 
     protected fun Bot.findFriendOrFail(id: String): Friend =
-        getFriendOrNull(id.parseToLongOrFail()) ?: illegalArgument("无法找到好友: $this")
+        getFriend(id.parseToLongOrFail()) ?: illegalArgument("无法找到好友: $this")
 
     protected fun Bot.findMemberOrFail(id: String): Friend =
-        getFriendOrNull(id.parseToLongOrFail()) ?: illegalArgument("无法找到群员: $this")
+        getFriend(id.parseToLongOrFail()) ?: illegalArgument("无法找到群员: $this")
 
     protected fun Group.findMemberOrFail(idOrCard: String): Member {
         if (idOrCard == "\$") return members.randomOrNull() ?: illegalArgument("当前语境下无法推断随机群员")
-        idOrCard.toLongOrNull()?.let { getOrNull(it) }?.let { return it }
+        idOrCard.toLongOrNull()?.let { get(it) }?.let { return it }
         this.members.singleOrNull { it.nameCardOrNick.contains(idOrCard) }?.let { return it }
         this.members.singleOrNull { it.nameCardOrNick.contains(idOrCard, ignoreCase = true) }?.let { return it }
 
@@ -410,7 +408,7 @@ internal abstract class InternalCommandValueArgumentParserExtensions<T : Any> :
 
     protected fun CommandSender.inferBotOrFail(): Bot =
         (this as? UserCommandSender)?.bot
-            ?: Bot.botInstancesSequence.singleOrNull()
+            ?: Bot.instancesSequence.singleOrNull()
             ?: illegalArgument("当前语境下无法推断目标 Bot, 因为目前有多个 Bot 在线.")
 
     protected fun CommandSender.inferGroupOrFail(): Group =
diff --git a/backend/mirai-console/src/data/AutoSavePluginData.kt b/backend/mirai-console/src/data/AutoSavePluginData.kt
index 36a1071c9..93b334337 100644
--- a/backend/mirai-console/src/data/AutoSavePluginData.kt
+++ b/backend/mirai-console/src/data/AutoSavePluginData.kt
@@ -39,11 +39,9 @@ public open class AutoSavePluginData private constructor(
     public final override val saveName: String
         get() = _saveName
 
-    private lateinit var _saveName: String
+    private var _saveName: String = saveName
 
-    public constructor(saveName: String) : this(null) {
-        _saveName = saveName
-    }
+    public constructor(saveName: String) : this(null)
 
     @ConsoleExperimentalApi
     override fun onInit(owner: PluginDataHolder, storage: PluginDataStorage) {
@@ -103,7 +101,7 @@ public open class AutoSavePluginData private constructor(
 
     private val updaterBlock: suspend CoroutineScope.() -> Unit = l@{
         if (::storage_.isInitialized) {
-            currentFirstStartTime_.updateWhen({ it == MAGIC_NUMBER_CFST_INIT }, { currentTimeMillis })
+            currentFirstStartTime_.updateWhen({ it == MAGIC_NUMBER_CFST_INIT }, { currentTimeMillis() })
             try {
                 delay(autoSaveIntervalMillis_.first.coerceAtLeast(1000)) // for safety
             } catch (e: CancellationException) {
@@ -117,7 +115,7 @@ public open class AutoSavePluginData private constructor(
                 }
             } else {
                 if (currentFirstStartTime_.updateWhen(
-                        { it != MAGIC_NUMBER_CFST_INIT && currentTimeMillis - it >= autoSaveIntervalMillis_.last },
+                        { it != MAGIC_NUMBER_CFST_INIT && currentTimeMillis() - it >= autoSaveIntervalMillis_.last },
                         { MAGIC_NUMBER_CFST_INIT })
                 ) {
                     withContext(owner_.coroutineContext) {
@@ -146,7 +144,7 @@ public open class AutoSavePluginData private constructor(
 }
 
 internal val debuggingLogger1 by lazy {
-    DefaultLogger("console.debug").withSwitch(false)
+    MiraiLogger.create("console.debug").withSwitch(false)
 }
 
 @Suppress("RESULT_CLASS_IN_RETURN_TYPE")
diff --git a/backend/mirai-console/src/internal/MiraiConsoleImplementationBridge.kt b/backend/mirai-console/src/internal/MiraiConsoleImplementationBridge.kt
index ffe63cf51..e1c7d62f1 100644
--- a/backend/mirai-console/src/internal/MiraiConsoleImplementationBridge.kt
+++ b/backend/mirai-console/src/internal/MiraiConsoleImplementationBridge.kt
@@ -96,7 +96,7 @@ internal object MiraiConsoleImplementationBridge : CoroutineScope, MiraiConsoleI
     override val loggerController: LoggerController by instance::loggerController
 
     init {
-        DefaultLogger = this::createLogger
+        MiraiLogger.setDefaultLoggerCreator(this::createLogger)
     }
 
 
@@ -134,7 +134,7 @@ internal object MiraiConsoleImplementationBridge : CoroutineScope, MiraiConsoleI
             }
 
             MiraiConsole.job.invokeOnCompletion {
-                Bot.botInstances.forEach { kotlin.runCatching { it.close() }.exceptionOrNull()?.let(mainLogger::error) }
+                Bot.instances.forEach { kotlin.runCatching { it.close() }.exceptionOrNull()?.let(mainLogger::error) }
             }
         }
 
diff --git a/build.gradle.kts b/build.gradle.kts
index f2faf5936..baa799d3d 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -56,14 +56,13 @@ val experimentalAnnotations = arrayOf(
     "kotlin.io.path.ExperimentalPathApi",
     "io.ktor.util.KtorExperimentalAPI",
 
-    "net.mamoe.mirai.utils.MiraiInternalAPI",
-    "net.mamoe.mirai.utils.MiraiExperimentalAPI",
+    "net.mamoe.mirai.utils.MiraiInternalApi",
+    "net.mamoe.mirai.utils.MiraiExperimentalApi",
     "net.mamoe.mirai.console.ConsoleFrontEndImplementation",
     "net.mamoe.mirai.console.util.ConsoleExperimentalApi",
     "net.mamoe.mirai.console.util.ConsoleInternalApi"
 )
 
-
 fun Project.configureJvmTarget() {
     tasks.withType(KotlinJvmCompile::class.java) {
         kotlinOptions.jvmTarget = "1.8"
diff --git a/buildSrc/src/main/kotlin/Versions.kt b/buildSrc/src/main/kotlin/Versions.kt
index 0aeb0bdc0..4dc97bb97 100644
--- a/buildSrc/src/main/kotlin/Versions.kt
+++ b/buildSrc/src/main/kotlin/Versions.kt
@@ -9,22 +9,24 @@
 
 @file:Suppress("MemberVisibilityCanBePrivate", "ObjectPropertyName", "unused")
 
+import org.gradle.api.attributes.Attribute
+
 object Versions {
-    const val core = "1.3.3"
+    const val core = "2.0-M1-dev-3"
     const val console = "1.1.0"
     const val consoleGraphical = "0.0.7"
     const val consoleTerminal = console
 
-    const val kotlinCompiler = "1.4.20"
-    const val kotlinStdlib = "1.4.20"
+    const val kotlinCompiler = "1.4.21"
+    const val kotlinStdlib = "1.4.21"
 
-    const val kotlinIntellijPlugin = "1.4.20-release-IJ2020.2-1" // keep to newest as kotlinCompiler
-    const val intellij = "2020.2.1" // don't update easily unless you want your disk space -= 500MB
+    const val kotlinIntellijPlugin = "203-1.4.21-release-IJ5981.133" // keep to newest as kotlinCompiler
+    const val intellij = "2020.3" // don't update easily unless you want your disk space -= 500MB
 
 
     const val coroutines = "1.4.0"
     const val serialization = "1.0.1"
-    const val ktor = "1.4.1"
+    const val ktor = "1.4.3"
     const val atomicFU = "0.14.4"
 
     const val androidGradle = "3.6.2"
@@ -56,9 +58,9 @@ const val `kotlinx-serialization-protobuf` = "org.jetbrains.kotlinx:kotlinx-seri
 
 const val `kotlinx-atomicfu` = "org.jetbrains.kotlinx:atomicfu:${Versions.atomicFU}"
 
-const val `mirai-core` = "net.mamoe:mirai-core:${Versions.core}"
-const val `mirai-core-qqandroid` = "net.mamoe:mirai-core-qqandroid:${Versions.core}"
 const val `mirai-core-api` = "net.mamoe:mirai-core-api:${Versions.core}"
+const val `mirai-core` = "net.mamoe:mirai-core:${Versions.core}"
+const val `mirai-core-utils` = "net.mamoe:mirai-core-utils:${Versions.core}"
 
 const val yamlkt = "net.mamoe.yamlkt:yamlkt:${Versions.yamlkt}"
 
@@ -66,3 +68,6 @@ const val `jetbrains-annotations` = "org.jetbrains:annotations:19.0.0"
 
 
 const val `caller-finder` = "io.github.karlatemp:caller:1.0.1"
+
+
+val ATTRIBUTE_MIRAI_TARGET_PLATFORM: Attribute<String> = Attribute.of("mirai.target.platform", String::class.java)
\ No newline at end of file
diff --git a/frontend/mirai-console-terminal/build.gradle.kts b/frontend/mirai-console-terminal/build.gradle.kts
index 23d378113..abc01a86a 100644
--- a/frontend/mirai-console-terminal/build.gradle.kts
+++ b/frontend/mirai-console-terminal/build.gradle.kts
@@ -6,41 +6,15 @@ plugins {
     id("com.jfrog.bintray")
 }
 
-kotlin {
-    target.compilations.all {
-        kotlinOptions {
-            jvmTarget = "1.8"
-            freeCompilerArgs = freeCompilerArgs + "-Xjvm-default=all"
-        }
-    }
-
-    sourceSets {
-        all {
-            languageSettings.enableLanguageFeature("InlineClasses")
-
-            languageSettings.useExperimentalAnnotation("kotlin.Experimental")
-            languageSettings.useExperimentalAnnotation("kotlin.RequiresOptIn")
-            languageSettings.progressiveMode = true
-            languageSettings.useExperimentalAnnotation("net.mamoe.mirai.utils.MiraiInternalAPI")
-            languageSettings.useExperimentalAnnotation("net.mamoe.mirai.utils.MiraiExperimentalAPI")
-            languageSettings.useExperimentalAnnotation("net.mamoe.mirai.console.util.ConsoleExperimentalApi")
-            languageSettings.useExperimentalAnnotation("net.mamoe.mirai.console.ConsoleFrontEndImplementation")
-            languageSettings.useExperimentalAnnotation("kotlin.ExperimentalUnsignedTypes")
-            languageSettings.useExperimentalAnnotation("kotlin.experimental.ExperimentalTypeInference")
-            languageSettings.useExperimentalAnnotation("kotlin.contracts.ExperimentalContracts")
-        }
-    }
-}
-
 dependencies {
     implementation("org.jline:jline:3.15.0")
     implementation("org.fusesource.jansi:jansi:1.18")
 
     compileAndTestRuntime(project(":mirai-console"))
-    compileAndTestRuntime("net.mamoe:mirai-core:${Versions.core}")
-    compileAndTestRuntime(kotlin("stdlib-jdk8", Versions.kotlinStdlib)) // embedded by core
+    compileAndTestRuntime(`mirai-core-api`)
+    compileAndTestRuntime(kotlin("stdlib-jdk8", Versions.kotlinStdlib)) // must specify `compileOnly` explicitly
 
-    testApi("net.mamoe:mirai-core-qqandroid:${Versions.core}")
+    testApi(`mirai-core`)
     testApi(project(":mirai-console"))
 }
 
diff --git a/frontend/mirai-console-terminal/src/ConsoleThread.kt b/frontend/mirai-console-terminal/src/ConsoleThread.kt
index 2756b7da9..76040ce96 100644
--- a/frontend/mirai-console-terminal/src/ConsoleThread.kt
+++ b/frontend/mirai-console-terminal/src/ConsoleThread.kt
@@ -26,14 +26,14 @@ import net.mamoe.mirai.console.util.ConsoleInternalApi
 import net.mamoe.mirai.console.util.cast
 import net.mamoe.mirai.console.util.requestInput
 import net.mamoe.mirai.console.util.safeCast
-import net.mamoe.mirai.utils.DefaultLogger
+import net.mamoe.mirai.utils.MiraiLogger
 import net.mamoe.mirai.utils.warning
 import org.jline.reader.EndOfFileException
 import org.jline.reader.UserInterruptException
 import kotlin.reflect.KClass
 import kotlin.reflect.full.isSubclassOf
 
-val consoleLogger by lazy { DefaultLogger("console") }
+val consoleLogger by lazy { MiraiLogger.create("console") }
 
 @OptIn(ConsoleInternalApi::class, ConsoleTerminalExperimentalApi::class, ExperimentalCommandDescriptors::class)
 internal fun startupConsoleThread() {
diff --git a/frontend/mirai-console-terminal/src/MiraiConsoleTerminalLoader.kt b/frontend/mirai-console-terminal/src/MiraiConsoleTerminalLoader.kt
index e54b68b2f..e22b89ad2 100644
--- a/frontend/mirai-console-terminal/src/MiraiConsoleTerminalLoader.kt
+++ b/frontend/mirai-console-terminal/src/MiraiConsoleTerminalLoader.kt
@@ -31,12 +31,12 @@ import net.mamoe.mirai.console.util.ConsoleExperimentalApi
 import net.mamoe.mirai.console.util.ConsoleInternalApi
 import net.mamoe.mirai.console.util.CoroutineScopeUtils.childScope
 import net.mamoe.mirai.message.data.Message
-import net.mamoe.mirai.utils.DefaultLogger
-import net.mamoe.mirai.utils.minutesToMillis
+import net.mamoe.mirai.utils.MiraiLogger
 import java.io.FileDescriptor
 import java.io.FileOutputStream
 import java.io.PrintStream
 import kotlin.system.exitProcess
+import kotlin.time.minutes
 
 /**
  * mirai-console-terminal CLI 入口点
@@ -159,7 +159,7 @@ object MiraiConsoleTerminalLoader {
 internal object ConsoleDataHolder : AutoSavePluginDataHolder,
     CoroutineScope by MiraiConsole.childScope("ConsoleDataHolder") {
     @ConsoleExperimentalApi
-    override val autoSaveIntervalMillis: LongRange = 1.minutesToMillis..10.minutesToMillis
+    override val autoSaveIntervalMillis: LongRange = 1.minutes.toLongMilliseconds()..10.minutes.toLongMilliseconds()
 
     @ConsoleExperimentalApi
     override val dataHolderName: String
@@ -170,7 +170,7 @@ internal fun overrideSTD() {
     System.setOut(
         PrintStream(
             BufferedOutputStream(
-                logger = DefaultLogger("stdout").run { ({ line: String? -> info(line) }) }
+                logger = MiraiLogger.create("stdout").run { ({ line: String? -> info(line) }) }
             ),
             false,
             "UTF-8"
@@ -179,7 +179,7 @@ internal fun overrideSTD() {
     System.setErr(
         PrintStream(
             BufferedOutputStream(
-                logger = DefaultLogger("stderr").run { ({ line: String? -> warning(line) }) }
+                logger = MiraiLogger.create("stderr").run { ({ line: String? -> warning(line) }) }
             ),
             false,
             "UTF-8"
diff --git a/tools/gradle-plugin/src/VersionConstants.kt b/tools/gradle-plugin/src/VersionConstants.kt
index 6c4e6233c..736796deb 100644
--- a/tools/gradle-plugin/src/VersionConstants.kt
+++ b/tools/gradle-plugin/src/VersionConstants.kt
@@ -10,6 +10,6 @@
 package net.mamoe.mirai.console.gradle
 
 internal object VersionConstants {
-    const val CONSOLE_VERSION = "1.1.0" // value is written here automatically during build
-    const val CORE_VERSION = "1.3.3" // value is written here automatically during build
+    const val CONSOLE_VERSION = "2.0-M1" // value is written here automatically during build
+    const val CORE_VERSION = "2.0-M1-dev-3" // value is written here automatically during build
 }
\ No newline at end of file
diff --git a/tools/intellij-plugin/build.gradle.kts b/tools/intellij-plugin/build.gradle.kts
index 168a5845b..fd562b309 100644
--- a/tools/intellij-plugin/build.gradle.kts
+++ b/tools/intellij-plugin/build.gradle.kts
@@ -23,7 +23,7 @@ intellij {
     updateSinceUntilBuild = false
 
     setPlugins(
-        "org.jetbrains.kotlin:${Versions.kotlinIntellijPlugin}@eap",
+        "org.jetbrains.kotlin:${Versions.kotlinIntellijPlugin}", // @eap
         "java"
     )
 }