diff --git a/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/Main.kt b/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/Main.kt
index d0518a5..0b1b878 100644
--- a/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/Main.kt
+++ b/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/Main.kt
@@ -2,24 +2,19 @@ package io.github.null2264.tsukumogami.bot
 
 import co.touchlab.kermit.Logger
 import io.github.null2264.tsukumogami.bot.core.di.appModule
-import io.github.null2264.tsukumogami.bot.core.module.DeveloperModule
-import io.github.null2264.tsukumogami.bot.core.module.GeneralModule
-import io.github.null2264.tsukumogami.bot.core.Bot
+import io.github.null2264.tsukumogami.bot.core.module.generalModule
+import io.github.null2264.tsukumogami.core.bot
 import org.koin.core.context.GlobalContext.startKoin
 
 suspend fun main() {
 
-    startKoin {
-        modules(appModule)
-    }
-
-    Bot {
+    bot {
         Logger.setTag("Tsukumogami")
 
         token = System.getenv("DISCORD_TOKEN")
 
         prefixes("src!", "mm!") // mm! for backwards compatibility
 
-        extensions(::DeveloperModule, ::GeneralModule)
+        modules(generalModule)
     }.start()
 }
diff --git a/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/core/Bot.kt b/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/core/Bot.kt
deleted file mode 100644
index 0645b7a..0000000
--- a/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/core/Bot.kt
+++ /dev/null
@@ -1,6 +0,0 @@
-package io.github.null2264.tsukumogami.bot.core
-
-import io.github.null2264.tsukumogami.core.AbstractBot
-import io.github.null2264.tsukumogami.core.BotConfigurator
-
-class Bot(block: BotConfigurator.() -> Unit = {}) : AbstractBot(block)
diff --git a/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/core/module/DeveloperModule.kt b/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/core/module/DeveloperModule.kt
index 95f82f9..b8952fd 100644
--- a/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/core/module/DeveloperModule.kt
+++ b/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/core/module/DeveloperModule.kt
@@ -1,17 +1,13 @@
 package io.github.null2264.tsukumogami.bot.core.module
 
-import io.github.null2264.tsukumogami.core.module.annotation.Command
-import io.github.null2264.tsukumogami.core.Context
-import io.github.null2264.tsukumogami.core.module.BotModule
-
-class DeveloperModule : BotModule("Developer", "Only for developers") {
-
-    @Command(
-        name="poweroff",
-        description="Turn the bot off",
-    )
-    private suspend fun shutdown(ctx: Context) {
-        ctx.reply("Shutting Down...", mentionsAuthor = true)
-        bot?.stop()
-    }
-}
+//class DeveloperModule : BotModule("Developer", "Only for developers") {
+//
+//    @Command(
+//        name="poweroff",
+//        description="Turn the bot off",
+//    )
+//    private suspend fun shutdown(ctx: Context) {
+//        ctx.reply("Shutting Down...", mentionsAuthor = true)
+//        bot?.stop()
+//    }
+//}
diff --git a/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/core/module/GeneralModule.kt b/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/core/module/GeneralModule.kt
index ce39762..3b0176e 100644
--- a/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/core/module/GeneralModule.kt
+++ b/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/core/module/GeneralModule.kt
@@ -1,23 +1,26 @@
 package io.github.null2264.tsukumogami.bot.core.module
 
-import dev.kord.core.entity.effectiveName
-import io.github.null2264.tsukumogami.core.module.annotation.Command
-import io.github.null2264.tsukumogami.core.Context
-import io.github.null2264.tsukumogami.core.module.BotModule
+import io.github.null2264.tsukumogami.bot.core.module.arguments.Test2Arguments
+import io.github.null2264.tsukumogami.bot.core.module.arguments.TestArguments
+import io.github.null2264.tsukumogami.core.module.api.botModules
 import kotlinx.datetime.Clock
 
-class GeneralModule : BotModule("General", "idk") {
-
-    @Command(description = "Ping the bot!")
-    private suspend fun ping(ctx: Context) {
+val generalModule = botModules("General") {
+    commands("ping", alias = setOf("p"), description = "Ping the bot!") { ctx ->
         val startTime = Clock.System.now()
         ctx.typing()
         val endTime = Clock.System.now()
         ctx.send("Pong! ${endTime.toEpochMilliseconds() - startTime.toEpochMilliseconds()}ms")
     }
 
-    @Command("test")
-    private suspend fun differentName(ctx: Context) {
-        ctx.send("Hello World! ${ctx.author?.effectiveName}")
+    groups("group") {
+        commands("test", arguments = ::Test2Arguments) { ctx, args -> ctx.reply("Hello world ${args.user}") }
+        groups("group") {
+            commands("test", alias = setOf("t")) { ctx ->
+                ctx.reply("Hello world ${ctx.command?.module?.name}")
+            }
+        }
     }
+
+    commands("test", arguments = ::TestArguments) { ctx, args -> ctx.send("Hello world ${args.test}") }
 }
diff --git a/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/core/module/arguments/TestArguments.kt b/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/core/module/arguments/TestArguments.kt
new file mode 100644
index 0000000..abc529f
--- /dev/null
+++ b/bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/core/module/arguments/TestArguments.kt
@@ -0,0 +1,15 @@
+package io.github.null2264.tsukumogami.bot.core.module.arguments
+
+import io.github.null2264.tsukumogami.core.commands.Arguments
+import io.github.null2264.tsukumogami.core.commands.ext.string
+import io.github.null2264.tsukumogami.core.commands.ext.user
+
+class TestArguments : Arguments() {
+    val test by string("Test") {
+        default("Lmao")
+    }
+}
+
+class Test2Arguments : Arguments() {
+    val user by user("User")
+}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/AbstractBot.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/AbstractBot.kt
deleted file mode 100644
index 604b054..0000000
--- a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/AbstractBot.kt
+++ /dev/null
@@ -1,108 +0,0 @@
-package io.github.null2264.tsukumogami.core
-
-import co.touchlab.kermit.Logger
-import dev.kord.core.Kord
-import dev.kord.core.entity.Message
-import dev.kord.core.event.gateway.ReadyEvent
-import dev.kord.core.event.message.MessageCreateEvent
-import dev.kord.core.on
-import dev.kord.gateway.Intent
-import dev.kord.gateway.PrivilegedIntent
-import io.github.null2264.tsukumogami.core.exceptions.CommandException
-import io.github.null2264.tsukumogami.core.exceptions.CommandNotFound
-import io.github.null2264.tsukumogami.core.module.BotModule
-import io.github.null2264.tsukumogami.core.module.Command
-import kotlin.reflect.full.callSuspend
-import kotlinx.coroutines.runBlocking
-
-abstract class AbstractBot(configurator: BotConfigurator.() -> Unit) {
-
-    private val commands: Map<String, Command>
-    private val extensions: Map<String, BotModule>
-    private val prefixes: List<String>
-    private val client: Kord
-
-    init {
-        val currentConfig = BotConfigurator()
-        currentConfig.apply(configurator)
-
-        extensions = mutableMapOf()
-        currentConfig.extensions.forEach {
-            val module = it.call()
-            module.setup()
-            module.install(this, currentConfig)
-            extensions[module.name] = module
-        }
-        commands = currentConfig.commands
-        prefixes = currentConfig.prefixes
-
-        client = runBlocking {
-            Kord(currentConfig.token).apply {
-                on<ReadyEvent> { onReady() }
-
-                on<MessageCreateEvent> { onMessage(this.message, this) }
-            }
-        }
-    }
-
-    open suspend fun start() {
-        client.login {
-            @OptIn(PrivilegedIntent::class)
-            intents += Intent.MessageContent
-        }
-    }
-
-    open suspend fun stop() {
-        client.shutdown()
-    }
-
-    fun getCommand(name: String) = commands[name]
-
-    private fun getContext(message: Message): Context {
-        val candidate = message.content.hasPrefix()
-        return Context(this, message, candidate?.first, candidate?.second)
-    }
-
-    open suspend fun onCommandError(context: Context, error: CommandException) {
-        context.send(error.message!!)
-    }
-
-    open suspend fun processCommand(message: Message) {
-        val ctx = getContext(message)
-
-        try {
-            ctx.command?.let {
-                it.callback.callSuspend(extensions[it.extension], ctx)
-            } ?: throw CommandNotFound()
-        } catch (e: CommandException) {
-            onCommandError(ctx, e)
-        } catch (e: Exception) {
-            Logger.e(e) { "Something went wrong while trying to process command '${ctx.command?.name}'" }
-        }
-    }
-
-    open suspend fun onMessage(message: Message, event: MessageCreateEvent) {
-        if (message.author?.isBot != false) return
-
-        processCommand(message)
-    }
-
-    open suspend fun onReady() {
-        Logger.i { "Online! ${client.getSelf().username}" }
-    }
-
-    fun String.hasPrefix(): Pair<String, String>? {
-        if (this.isBlank()) return null
-
-        var ret: Pair<String, String>? = null
-
-        prefixes.forEach {
-            if (this.substring(0, it.length) == it) {
-                ret = Pair(this.substring(0, it.length), this.substring(it.length).split(" ").first())
-                return@forEach
-            }
-        }
-
-        return ret
-    }
-}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/Bot.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/Bot.kt
new file mode 100644
index 0000000..82c03b8
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/Bot.kt
@@ -0,0 +1,127 @@
+package io.github.null2264.tsukumogami.core
+
+import co.touchlab.kermit.Logger
+import dev.kord.core.Kord
+import dev.kord.core.entity.Message
+import dev.kord.core.event.gateway.ReadyEvent
+import dev.kord.core.event.message.MessageCreateEvent
+import dev.kord.core.on
+import dev.kord.gateway.Intent
+import dev.kord.gateway.PrivilegedIntent
+import io.github.null2264.tsukumogami.core.commands.Command
+import io.github.null2264.tsukumogami.core.exceptions.CommandException
+import io.github.null2264.tsukumogami.core.exceptions.CommandNotFound
+import io.github.null2264.tsukumogami.core.module.BotModule
+import io.github.null2264.tsukumogami.core.commands.IGroup
+import io.github.null2264.tsukumogami.core.ext.parseCommandAndArguments
+import io.github.null2264.tsukumogami.core.koin.TsukumogamiKoinComponent
+import kotlin.reflect.full.callSuspend
+import kotlinx.coroutines.runBlocking
+import org.koin.core.component.inject
+
+open class Bot internal constructor(): IGroup, TsukumogamiKoinComponent {
+
+    val client: Kord by inject()
+    private val modules = mutableMapOf<String, BotModule>()
+    private val _prefixes = mutableListOf<String>()
+    val prefixes: List<String> get() = _prefixes.toList()
+    internal lateinit var token: String
+    override val allCommands: MutableMap<String, Command> = mutableMapOf()
+
+    fun addModule(module: BotModule) {
+        modules[module.name] = module.install(this)
+    }
+
+    fun addPrefix(prefix: String) {
+        _prefixes.add(prefix)
+    }
+
+    private fun addCommand(name: String, command: Command) {
+        if (allCommands.containsKey(name)) {
+            throw IllegalStateException("Duplicate command: '${command.name}'")
+        }
+        allCommands[command.name] = command
+    }
+
+    fun addCommand(command: Command) {
+        addCommand(command.name, command)
+        command.alias.forEach { addCommand(it, command) }
+    }
+
+    private fun removeCommand(name: String) {
+        if (!allCommands.containsKey(name)) {
+            throw IllegalStateException("Command not found: '${name}'")
+        }
+        allCommands.remove(name)
+    }
+
+    fun removeCommand(command: Command) {
+        removeCommand(command.name)
+        command.alias.forEach { removeCommand(it) }
+    }
+
+    open suspend fun start() {
+        client.login {
+            @OptIn(PrivilegedIntent::class)
+            intents += Intent.MessageContent
+        }
+    }
+
+    open suspend fun stop() {
+        client.shutdown()
+    }
+
+    fun getCommand(name: String?) = allCommands[name]
+
+    private fun getContext(message: Message): Context {
+        val parsed = message.content.parsePrefixAndCommand()
+        val context = Context(this, message, parsed?.first)
+        context.command = getCommand(parsed?.second)
+        if (context.command != null) context.invokedWith = parsed?.second
+        return context
+    }
+
+    open suspend fun onCommandError(context: Context, error: CommandException) {
+        context.send(error.message!!)
+    }
+
+    open suspend fun processCommand(message: Message) {
+        val ctx = getContext(message)
+
+        try {
+            ctx.command?.invoke(ctx) ?: throw CommandNotFound()
+        } catch (e: CommandException) {
+            onCommandError(ctx, e)
+        } catch (e: Exception) {
+            Logger.e(e) { "Something went wrong while trying to process command '${ctx.command?.name}'" }
+        }
+    }
+
+    open suspend fun onMessage(message: Message, event: MessageCreateEvent) {
+        if (message.author?.isBot != false) return
+
+        processCommand(message)
+    }
+
+    open suspend fun onReady() {
+        Logger.i { "Online! ${client.getSelf().username}" }
+    }
+
+    private fun String.parsePrefixAndCommand(): Pair<String, String>? {
+        if (this.isBlank()) return null
+
+        var ret: Pair<String, String>? = null
+
+        run {
+            prefixes.forEach { candidate ->
+                val prefix = this.substring(0, candidate.length)
+                if (prefix != candidate) { return@forEach }
+                val command = this.drop(candidate.length).substringBefore(' ')
+                ret = prefix to command
+                return@run
+            }
+        }
+
+        return ret
+    }
+}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/BotBuilder.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/BotBuilder.kt
new file mode 100644
index 0000000..51fc4f7
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/BotBuilder.kt
@@ -0,0 +1,52 @@
+package io.github.null2264.tsukumogami.core
+
+import dev.kord.core.Kord
+import dev.kord.core.event.gateway.ReadyEvent
+import dev.kord.core.event.message.MessageCreateEvent
+import dev.kord.core.on
+import io.github.null2264.tsukumogami.core.ext.loadModule
+import io.github.null2264.tsukumogami.core.koin.TsukumogamiKoinContext
+import io.github.null2264.tsukumogami.core.module.BotModule
+import kotlin.reflect.KFunction
+import kotlinx.coroutines.runBlocking
+import org.koin.dsl.bind
+
+class BotBuilder internal constructor(
+    val bot: Bot
+) {
+
+    var token: String = ""
+
+    var kordBuilder: suspend (String) -> Kord = { token ->
+        Kord(token).apply {
+            on<ReadyEvent> { bot.onReady() }
+            on<MessageCreateEvent> { bot.onMessage(this.message, this) }
+        }
+    }
+
+    fun modules(vararg modules: BotModule) {
+        modules.forEach(bot::addModule)
+    }
+
+    fun prefixes(vararg prefixes: String) {
+        prefixes.forEach(bot::addPrefix)
+    }
+}
+
+fun bot(clazz: KFunction<Bot> = ::Bot, declaration: BotBuilder.() -> Unit): Bot {
+    if (TsukumogamiKoinContext.getOrNull() == null)
+        TsukumogamiKoinContext.startKoin {
+        }
+
+    val bot = clazz.call()
+    val holder = BotBuilder(bot)
+    declaration(holder)
+
+    val kord = runBlocking {
+        holder.kordBuilder(holder.token)
+    }
+    loadModule { single { kord } bind Kord::class }
+    loadModule { single { bot } bind Bot::class }
+
+    return holder.bot
+}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/BotConfigurator.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/BotConfigurator.kt
deleted file mode 100644
index de98f03..0000000
--- a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/BotConfigurator.kt
+++ /dev/null
@@ -1,39 +0,0 @@
-package io.github.null2264.tsukumogami.core
-
-import io.github.null2264.tsukumogami.core.module.BotModule
-import io.github.null2264.tsukumogami.core.module.Command
-import kotlin.reflect.KClass
-import kotlin.reflect.KFunction
-import kotlin.reflect.full.isSubclassOf
-
-class BotConfigurator internal constructor() {
-
-    internal val commands = mutableMapOf<String, Command>()
-    internal val extensions = mutableListOf<KFunction<BotModule>>()
-    internal val prefixes = mutableListOf<String>()
-    var token: String = ""
-
-    internal fun isExists(name: String?) = this.commands.containsKey(name)
-
-    fun commands(command: Command, name: String? = null) {
-        this.commands[if (name.isNullOrEmpty()) command.name else name] = command
-    }
-
-    fun extensions(vararg extensions: KFunction<BotModule>) {
-        extensions.forEach {
-            val kClass = it.returnType.classifier as KClass<*>
-            if (!kClass.isSubclassOf(BotModule::class))
-                return
-
-            this.extensions.add(it)
-        }
-    }
-
-    fun prefixes(vararg prefixes: String) {
-        prefixes(prefixes.toList())
-    }
-
-    fun prefixes(prefixes: List<String>) {
-        this.prefixes.addAll(prefixes)
-    }
-}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/Context.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/Context.kt
index baed03d..bb71633 100644
--- a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/Context.kt
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/Context.kt
@@ -4,11 +4,33 @@ import dev.kord.core.behavior.channel.createMessage
 import dev.kord.core.entity.Message
 import dev.kord.rest.builder.message.AllowedMentionsBuilder
 import dev.kord.rest.builder.message.allowedMentions
+import io.github.null2264.tsukumogami.core.commands.Command
 
-class Context(private val bot: AbstractBot, private val message: Message, val prefix: String?, private val commandName: String?) {
+class Context(
+    val bot: Bot,
+    val message: Message,
+    /**
+     * The prefix that used to invoke the command
+     */
+    val prefix: String?,
+) {
 
+    /**
+     * The user that invoked the command
+     *
+     * Alias to [Message.author]
+     */
     val author get() = message.author
-    val command get() = commandName?.let { bot.getCommand(it) }
+
+    /**
+     * The text that invoked the command
+     */
+    var invokedWith: String? = null
+
+    /**
+     * The command that currently being invoked
+     */
+    var command: Command? = null
 
     suspend fun send(content: String) = message.channel.createMessage(content)
 
@@ -22,4 +44,15 @@ class Context(private val bot: AbstractBot, private val message: Message, val pr
     }
 
     suspend fun typing() = message.channel.type()
+
+    fun parseArguments(): MutableList<String>? =
+        if (prefix != null && invokedWith != null) {
+            message.content
+                .substringAfter("$prefix$invokedWith")
+                .trim()
+                .split(' ')
+                .toMutableList()
+        } else {
+            null
+        }
 }
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/annotation/TsukumogamiAnnotations.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/annotation/TsukumogamiAnnotations.kt
new file mode 100644
index 0000000..c0b0b38
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/annotation/TsukumogamiAnnotations.kt
@@ -0,0 +1,13 @@
+package io.github.null2264.tsukumogami.core.annotation
+
+@RequiresOptIn(message = "Intended for internal usage. External usage is strongly discouraged.", level = RequiresOptIn.Level.ERROR)
+@Retention(AnnotationRetention.BINARY)
+@Target(
+    AnnotationTarget.CLASS,
+    AnnotationTarget.TYPEALIAS,
+    AnnotationTarget.FUNCTION,
+    AnnotationTarget.PROPERTY,
+    AnnotationTarget.FIELD,
+    AnnotationTarget.CONSTRUCTOR,
+)
+annotation class TsukumogamiInternalApi
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/Argument.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/Argument.kt
new file mode 100644
index 0000000..bc85b9b
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/Argument.kt
@@ -0,0 +1,12 @@
+package io.github.null2264.tsukumogami.core.commands
+
+import io.github.null2264.tsukumogami.core.commands.converters.Converter
+
+data class Argument<T : Any?>(
+    val name: String,
+    val converter: Converter<T>,
+) {
+    init {
+        converter.argumentObj = this
+    }
+}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/Arguments.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/Arguments.kt
new file mode 100644
index 0000000..860e23e
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/Arguments.kt
@@ -0,0 +1,29 @@
+package io.github.null2264.tsukumogami.core.commands
+
+import io.github.null2264.tsukumogami.core.Context
+import io.github.null2264.tsukumogami.core.commands.converters.Converter
+
+abstract class Arguments {
+
+    val args = mutableListOf<Argument<*>>()
+
+    fun <R : Any> args(
+        name: String,
+        converter: Converter<R>
+    ): Converter<R> {
+        args.add(Argument(name, converter))
+
+        return converter
+    }
+
+    suspend fun parse(context: Context) {
+        val currentValues = context.parseArguments()
+
+        run {
+            args.forEach { arg ->
+                val value = currentValues?.removeFirstOrNull() ?: return@run
+                arg.converter.parse(context, value)
+            }
+        }
+    }
+}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/Command.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/Command.kt
new file mode 100644
index 0000000..d0e66dd
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/Command.kt
@@ -0,0 +1,36 @@
+package io.github.null2264.tsukumogami.core.commands
+
+import io.github.null2264.tsukumogami.core.Context
+import io.github.null2264.tsukumogami.core.module.BotModule
+import kotlin.reflect.KFunction
+
+open class Command(
+    val name: String,
+    val alias: Set<String>,
+    val description: String,
+    private val arguments: KFunction<Arguments>,
+    private val handler: suspend (Context, Arguments) -> Unit,
+) {
+
+    /**
+     * Return parent command if this command is a subcommand otherwise it returns null
+     */
+    var parent: Command? = null
+
+    /**
+     * The module this command belong to
+     */
+    var module: BotModule? = null
+        get() {
+            if (parent != null) {
+                field = parent?.module
+            }
+            return field
+        }
+
+    open suspend fun invoke(context: Context) {
+        val parsedArguments = arguments.call()
+        parsedArguments.parse(context)
+        handler.invoke(context, parsedArguments)
+    }
+}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/EmptyArguments.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/EmptyArguments.kt
new file mode 100644
index 0000000..92140a3
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/EmptyArguments.kt
@@ -0,0 +1,3 @@
+package io.github.null2264.tsukumogami.core.commands
+
+class EmptyArguments : Arguments()
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/Group.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/Group.kt
new file mode 100644
index 0000000..30cde51
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/Group.kt
@@ -0,0 +1,38 @@
+package io.github.null2264.tsukumogami.core.commands
+
+import io.github.null2264.tsukumogami.core.Context
+import io.github.null2264.tsukumogami.core.annotation.TsukumogamiInternalApi
+
+@OptIn(TsukumogamiInternalApi::class)
+class Group(
+    name: String,
+    alias: Set<String>,
+    description: String,
+) :
+    IGroup,
+    Command(
+        name,
+        alias,
+        description,
+        ::EmptyArguments,
+        { _, _ -> /* No handler for group to match the behaviour of Discord's slash command */ },
+    ) {
+
+    override val allCommands: MutableMap<String, Command> = mutableMapOf()
+
+    override fun _addCommand(command: Command) {
+        command.parent = this
+        super._addCommand(command)
+    }
+
+    override suspend fun invoke(context: Context) {
+        val subcommandName = context.message.content
+            .substringAfter("${context.prefix}${context.invokedWith}")
+            .trim()
+            .substringBefore(' ')
+        val command = allCommands[subcommandName] ?: return
+        context.invokedWith += " $subcommandName"
+        context.command = command
+        command.invoke(context)
+    }
+}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/IGroup.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/IGroup.kt
new file mode 100644
index 0000000..78d06c7
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/IGroup.kt
@@ -0,0 +1,49 @@
+package io.github.null2264.tsukumogami.core.commands
+
+import io.github.null2264.tsukumogami.core.Context
+import io.github.null2264.tsukumogami.core.annotation.TsukumogamiInternalApi
+import kotlin.reflect.KFunction
+
+@OptIn(TsukumogamiInternalApi::class)
+interface IGroup {
+
+    val allCommands: MutableMap<String, Command>
+
+    @TsukumogamiInternalApi
+    fun _addCommand(command: Command) {
+        allCommands[command.name] = command
+        command.alias.forEach { allCommands[it] = command }
+    }
+
+    fun commands(
+        name: String,
+        alias: Set<String> = setOf(),
+        description: String = "",
+        handler: suspend (Context) -> Unit,
+    ) {
+        val command = Command(name, alias, description, ::EmptyArguments) { ctx, _ -> handler(ctx) }
+        _addCommand(command)
+    }
+
+    fun <Args : Arguments> commands(
+        name: String,
+        alias: Set<String> = setOf(),
+        description: String = "",
+        arguments: KFunction<Args>,
+        handler: suspend (Context, Args) -> Unit,
+    ) {
+        val command = Command(name, alias, description, arguments) { ctx, args -> handler(ctx, args as Args) }
+        _addCommand(command)
+    }
+
+    fun groups(
+        name: String,
+        alias: Set<String> = setOf(),
+        description: String = "",
+        declaration: IGroup.() -> Unit,
+    ) {
+        val group = Group(name, alias, description)
+        declaration(group)
+        _addCommand(group)
+    }
+}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/module/annotation/Command.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/annotation/Command.kt
similarity index 85%
rename from core/src/main/kotlin/io/github/null2264/tsukumogami/core/module/annotation/Command.kt
rename to core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/annotation/Command.kt
index 9d6bf50..9756178 100644
--- a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/module/annotation/Command.kt
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/annotation/Command.kt
@@ -1,5 +1,4 @@
-package io.github.null2264.tsukumogami.core.module.annotation
-
+package io.github.null2264.tsukumogami.core.commands.annotation
 
 /**
  * Annotation to tag a function as command
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/converters/Converter.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/converters/Converter.kt
new file mode 100644
index 0000000..2824df3
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/converters/Converter.kt
@@ -0,0 +1,24 @@
+package io.github.null2264.tsukumogami.core.commands.converters
+
+import io.github.null2264.tsukumogami.core.Context
+import io.github.null2264.tsukumogami.core.commands.Argument
+import io.github.null2264.tsukumogami.core.commands.Arguments
+import kotlin.reflect.KProperty
+
+abstract class Converter<OutputType: Any?> {
+
+    lateinit var argumentObj: Argument<OutputType>
+
+    abstract var parsed: OutputType
+
+    abstract suspend fun parse(context: Context, input: String): OutputType
+
+    operator fun getValue(thisRef: Arguments, property: KProperty<*>): OutputType {
+        return this.parsed
+    }
+
+    fun default(defaultValue: OutputType): OutputType {
+        this.parsed = defaultValue
+        return this.parsed
+    }
+}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/converters/impl/StringConverter.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/converters/impl/StringConverter.kt
new file mode 100644
index 0000000..2a8a40d
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/converters/impl/StringConverter.kt
@@ -0,0 +1,14 @@
+package io.github.null2264.tsukumogami.core.commands.converters.impl
+
+import io.github.null2264.tsukumogami.core.Context
+import io.github.null2264.tsukumogami.core.commands.converters.Converter
+
+class StringConverter : Converter<String>() {
+
+    override var parsed: String = ""
+
+    override suspend fun parse(context: Context, input: String): String {
+        this.parsed = input
+        return input
+    }
+}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/converters/impl/UserConverter.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/converters/impl/UserConverter.kt
new file mode 100644
index 0000000..b88d27e
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/converters/impl/UserConverter.kt
@@ -0,0 +1,57 @@
+package io.github.null2264.tsukumogami.core.commands.converters.impl
+
+import dev.kord.common.entity.Snowflake
+import dev.kord.core.entity.User
+import io.github.null2264.tsukumogami.core.Context
+import io.github.null2264.tsukumogami.core.annotation.TsukumogamiInternalApi
+import io.github.null2264.tsukumogami.core.commands.converters.Converter
+import io.github.null2264.tsukumogami.core.exceptions.CommandException
+import io.github.null2264.tsukumogami.core.ext.users
+import kotlinx.coroutines.flow.firstOrNull
+
+class UserConverter : Converter<User>() {
+
+    override lateinit var parsed: User
+
+    override suspend fun parse(context: Context, input: String): User {
+        if (input.equals("me", true)) {
+            val user = context.author
+            if (user != null) {
+                this.parsed = user
+                return this.parsed
+            }
+        }
+        if (input.equals("you", true)) {
+            this.parsed = context.bot.client.getSelf()
+            return this.parsed
+        }
+
+        this.parsed = context.findUser(input) ?:
+            throw CommandException("User not found")
+
+        return this.parsed
+    }
+
+    private suspend fun Context.findUser(arg: String): User? =
+        if (arg.startsWith("<@") && arg.endsWith(">")) {
+            val id: String = arg.substring(2, arg.length - 1).replace("!", "")
+
+            try {
+                bot.client.getUser(Snowflake(id))
+            } catch (_: NumberFormatException) {
+                throw CommandException("Invalid user ID")
+            }
+        } else {
+            try {
+                bot.client.getUser(Snowflake(arg))
+            } catch (_: NumberFormatException) {
+                if (!arg.contains("#")) {
+                    null
+                } else {
+                    bot.client.users.firstOrNull { user ->
+                        user.tag.equals(arg, true)
+                    }
+                }
+            }
+        }
+}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/ext/ArgumentsExtensions.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/ext/ArgumentsExtensions.kt
new file mode 100644
index 0000000..c603b45
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/ext/ArgumentsExtensions.kt
@@ -0,0 +1,19 @@
+package io.github.null2264.tsukumogami.core.commands.ext
+
+import dev.kord.core.entity.User
+import io.github.null2264.tsukumogami.core.commands.Arguments
+import io.github.null2264.tsukumogami.core.commands.converters.Converter
+import io.github.null2264.tsukumogami.core.commands.converters.impl.StringConverter
+import io.github.null2264.tsukumogami.core.commands.converters.impl.UserConverter
+
+fun Arguments.string(name: String, declaration: Converter<String>.() -> Unit = {}): Converter<String> {
+    val converter = StringConverter()
+    declaration(converter)
+    return args(name, converter)
+}
+
+fun Arguments.user(name: String, declaration: Converter<User>.() -> Unit = {}): Converter<User> {
+    val converter = UserConverter()
+    declaration(converter)
+    return args(name, converter)
+}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/ext/KoinExtensions.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/ext/KoinExtensions.kt
new file mode 100644
index 0000000..b509a2b
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/ext/KoinExtensions.kt
@@ -0,0 +1,17 @@
+package io.github.null2264.tsukumogami.core.ext
+
+import io.github.null2264.tsukumogami.core.koin.TsukumogamiKoinContext
+import org.koin.core.module.Module
+import org.koin.dsl.ModuleDeclaration
+import org.koin.dsl.module
+
+fun loadModule(
+    createdAtStart: Boolean = false,
+    moduleDeclaration: ModuleDeclaration,
+): Module {
+    val moduleObj = module(createdAtStart, moduleDeclaration)
+
+    TsukumogamiKoinContext.loadKoinModules(moduleObj)
+
+    return moduleObj
+}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/ext/KordExtensions.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/ext/KordExtensions.kt
new file mode 100644
index 0000000..728b106
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/ext/KordExtensions.kt
@@ -0,0 +1,6 @@
+package io.github.null2264.tsukumogami.core.ext
+
+import dev.kord.core.Kord
+import dev.kord.core.supplier.EntitySupplyStrategy
+
+val Kord.users get() = with(EntitySupplyStrategy.cache).users
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/ext/StringExtensions.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/ext/StringExtensions.kt
new file mode 100644
index 0000000..2bc9b79
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/ext/StringExtensions.kt
@@ -0,0 +1,56 @@
+package io.github.null2264.tsukumogami.core.ext
+
+fun String.parseCommandAndArguments(): List<String> {
+    if (isBlank()) {
+        return emptyList()
+    }
+
+    val result = mutableListOf<String>()
+    val currentToken = StringBuilder()
+    var inQuotes = false
+
+    for (char in this) {
+        when (char) {
+            '"' -> {
+                if (inQuotes) {
+                    // Closing quote: add the accumulated token
+                    result.add(currentToken.toString())
+                    currentToken.clear()
+                    inQuotes = false
+                } else {
+                    // Opening quote:
+                    // If there's an existing token (e.g., word"another"), add it first
+                    if (currentToken.isNotEmpty()) {
+                        result.add(currentToken.toString())
+                        currentToken.clear()
+                    }
+                    inQuotes = true
+                }
+            }
+            ' ' -> {
+                if (inQuotes) {
+                    // Space inside quotes: append it
+                    currentToken.append(char)
+                } else {
+                    // Space outside quotes: separator
+                    if (currentToken.isNotEmpty()) {
+                        result.add(currentToken.toString())
+                        currentToken.clear()
+                    }
+                    // Ignore multiple spaces between tokens
+                }
+            }
+            else -> {
+                // Any other character: append it
+                currentToken.append(char)
+            }
+        }
+    }
+
+    // Add any remaining token after the loop (e.g., if the string doesn't end with a quote or space)
+    if (currentToken.isNotEmpty()) {
+        result.add(currentToken.toString())
+    }
+
+    return result
+}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/koin/TsukumogamiKoinComponent.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/koin/TsukumogamiKoinComponent.kt
new file mode 100644
index 0000000..525d75c
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/koin/TsukumogamiKoinComponent.kt
@@ -0,0 +1,8 @@
+package io.github.null2264.tsukumogami.core.koin
+
+import org.koin.core.Koin
+import org.koin.core.component.KoinComponent
+
+interface TsukumogamiKoinComponent : KoinComponent {
+    override fun getKoin(): Koin = TsukumogamiKoinContext.get()
+}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/koin/TsukumogamiKoinContext.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/koin/TsukumogamiKoinContext.kt
new file mode 100644
index 0000000..4ff3ad1
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/koin/TsukumogamiKoinContext.kt
@@ -0,0 +1,75 @@
+package io.github.null2264.tsukumogami.core.koin
+
+import org.koin.core.Koin
+import org.koin.core.KoinApplication
+import org.koin.core.context.KoinContext
+import org.koin.core.error.KoinApplicationAlreadyStartedException
+import org.koin.core.module.Module
+import org.koin.dsl.KoinAppDeclaration
+
+/**
+ * The [KoinContext] for Tsukumogami.
+ *
+ * To use this context, implement [TsukumogamiKoinComponent].
+ *
+ * @see org.koin.core.context.GlobalContext
+ */
+object TsukumogamiKoinContext : KoinContext {
+    /** The current [Koin] instance. */
+    private var koin: Koin? = null
+
+    /** The current [KoinApplication]. */
+    private var koinApp: KoinApplication? = null
+
+    override fun get(): Koin = koin ?: error("KoinApplication has not been started")
+    override fun getOrNull(): Koin? = koin
+    public fun getKoinApplicationOrNull(): KoinApplication? = koinApp
+
+    private fun register(koinApplication: KoinApplication) {
+        if (koin != null) {
+            throw KoinApplicationAlreadyStartedException("KoinApplication has already been started")
+        }
+
+        koinApp = koinApplication
+        koin = koinApplication.koin
+    }
+
+    override fun loadKoinModules(module: Module, createEagerInstances: Boolean) {
+        get().loadModules(listOf(module), createEagerInstances = createEagerInstances)
+    }
+
+    override fun loadKoinModules(modules: List<Module>, createEagerInstances: Boolean) {
+        get().loadModules(modules, createEagerInstances = createEagerInstances)
+    }
+
+    override fun startKoin(koinApplication: KoinApplication): KoinApplication = synchronized(this) {
+        register(koinApplication)
+        koinApplication.createEagerInstances()
+        koinApplication.allowOverride(true)
+
+        return koinApplication
+    }
+
+    override fun startKoin(appDeclaration: KoinAppDeclaration): KoinApplication  = synchronized(this) {
+        val koinApplication = KoinApplication.init()
+
+        register(koinApplication)
+        appDeclaration(koinApplication)
+        koinApplication.createEagerInstances()
+
+        return koinApplication
+    }
+
+    override fun stopKoin() {
+        koin?.close()
+        koin = null
+    }
+
+    override fun unloadKoinModules(module: Module) {
+        get().unloadModules(listOf(module))
+    }
+
+    override fun unloadKoinModules(modules: List<Module>) {
+        get().unloadModules(modules)
+    }
+}
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/module/BotModule.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/module/BotModule.kt
index 26fe1d5..bdf2b85 100644
--- a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/module/BotModule.kt
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/module/BotModule.kt
@@ -1,47 +1,27 @@
 package io.github.null2264.tsukumogami.core.module
 
-import co.touchlab.kermit.Logger
-import io.github.null2264.tsukumogami.core.AbstractBot
-import io.github.null2264.tsukumogami.core.module.annotation.Command as CommandAnnotation
-import io.github.null2264.tsukumogami.core.BotConfigurator
-import kotlin.reflect.jvm.isAccessible
-import kotlin.reflect.jvm.kotlinFunction
+import io.github.null2264.tsukumogami.core.Bot
+import io.github.null2264.tsukumogami.core.annotation.TsukumogamiInternalApi
+import io.github.null2264.tsukumogami.core.commands.Command
+import io.github.null2264.tsukumogami.core.commands.IGroup
 
-abstract class BotModule(val name: String, val description: String? = null) {
+@OptIn(TsukumogamiInternalApi::class)
+open class BotModule constructor(val name: String) : IGroup {
 
-    var bot: AbstractBot? = null
-        internal set
+    override val allCommands: MutableMap<String, Command> = mutableMapOf()
 
-    open fun setup() {}
+    override fun _addCommand(command: Command) {
+        command.module = this
+        super._addCommand(command)
+    }
 
-    internal fun install(bot: AbstractBot, configurator: BotConfigurator) {
-        this.bot = bot
+    internal fun install(bot: Bot): BotModule {
+        allCommands.values.distinctBy { it.name }.forEach(bot::addCommand)
+        return this
+    }
 
-        val methods = this::class.java.declaredMethods
-        for (method in methods) {
-            for (annotation in method.annotations) {
-                if (annotation !is CommandAnnotation)
-                    continue
-
-                configurator.apply {
-                    val kMethod = method.kotlinFunction
-                    if (isExists(kMethod?.name)) {
-                        Logger.e { "Command already exists" }
-                        return
-                    }
-                    kMethod?.let {
-                        it.isAccessible = true
-                        commands(
-                            Command(
-                                annotation.name.ifEmpty { it.name },
-                                name,
-                                it,
-                                annotation.description.ifEmpty { description },
-                            )
-                        )
-                    }
-                }
-            }
-        }
+    internal fun uninstall(bot: Bot): BotModule {
+        allCommands.values.distinctBy { it.name }.forEach(bot::removeCommand)
+        return this
     }
 }
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/module/Command.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/module/Command.kt
deleted file mode 100644
index c5d64ed..0000000
--- a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/module/Command.kt
+++ /dev/null
@@ -1,13 +0,0 @@
-package io.github.null2264.tsukumogami.core.module
-
-import kotlin.reflect.KFunction
-
-/**
- * Class holding information about a command
- */
-data class Command(
-    val name: String,
-    val extension: String,
-    val callback: KFunction<*>,
-    val description: String? = null,
-)
diff --git a/core/src/main/kotlin/io/github/null2264/tsukumogami/core/module/api/BotModuleApi.kt b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/module/api/BotModuleApi.kt
new file mode 100644
index 0000000..20f5f4e
--- /dev/null
+++ b/core/src/main/kotlin/io/github/null2264/tsukumogami/core/module/api/BotModuleApi.kt
@@ -0,0 +1,11 @@
+package io.github.null2264.tsukumogami.core.module.api
+
+import io.github.null2264.tsukumogami.core.module.BotModule
+
+typealias BotModuleDeclaration = BotModule.() -> Unit
+
+fun botModules(name: String, declaration: BotModuleDeclaration): BotModule {
+    val module = BotModule(name)
+    declaration(module)
+    return module
+}