diff --git a/src/commonMain/kotlin/com/infendro/cli/Execution.kt b/src/commonMain/kotlin/com/infendro/cli/Execution.kt
index b6eff1c..a4f8a5a 100644
--- a/src/commonMain/kotlin/com/infendro/cli/Execution.kt
+++ b/src/commonMain/kotlin/com/infendro/cli/Execution.kt
@@ -1,16 +1,30 @@
 package com.infendro.cli
 
 import com.infendro.cli.argument.Argument.*
+import com.infendro.cli.command.Command
 import kotlin.reflect.KProperty
 
 class Execution(
-    val arguments: List<Argument>,
+    val commands: List<Cmd>,
+    val arguments: List<Arg>,
 ) {
-    class Argument(
+    class Cmd(
+        val name: String,
+    )
+
+    class Arg(
         val name: String,
         val value: String?,
     )
 
+    operator fun Command.Key.getValue(
+        thisRef: Any?,
+        property: KProperty<*>,
+    ): String {
+        return commands[index]
+            .name
+    }
+
     operator fun <T> Single<T>.getValue(
         thisRef: Any?,
         property: KProperty<*>,
diff --git a/src/commonMain/kotlin/com/infendro/cli/argument/Argument.kt b/src/commonMain/kotlin/com/infendro/cli/argument/Argument.kt
index afc3792..4e0ce36 100644
--- a/src/commonMain/kotlin/com/infendro/cli/argument/Argument.kt
+++ b/src/commonMain/kotlin/com/infendro/cli/argument/Argument.kt
@@ -42,4 +42,10 @@ sealed class Argument<T> {
 
         abstract val parser: Parser<T>
     }
+
+    interface Parser<T> {
+        fun parse(
+            text: String?,
+        ): T
+    }
 }
diff --git a/src/commonMain/kotlin/com/infendro/cli/argument/Boolean.kt b/src/commonMain/kotlin/com/infendro/cli/argument/Boolean.kt
index 8db70b4..7343bad 100644
--- a/src/commonMain/kotlin/com/infendro/cli/argument/Boolean.kt
+++ b/src/commonMain/kotlin/com/infendro/cli/argument/Boolean.kt
@@ -1,8 +1,8 @@
 package com.infendro.cli.argument
 
-import com.infendro.cli.Command
+import com.infendro.cli.command.Command
 
-private object BooleanParser : Parser<Boolean> {
+private object BooleanParser : Argument.Parser<Boolean> {
     override fun parse(
         text: String?,
     ): Boolean {
diff --git a/src/commonMain/kotlin/com/infendro/cli/argument/Int.kt b/src/commonMain/kotlin/com/infendro/cli/argument/Int.kt
index 113d0ca..962e3cd 100644
--- a/src/commonMain/kotlin/com/infendro/cli/argument/Int.kt
+++ b/src/commonMain/kotlin/com/infendro/cli/argument/Int.kt
@@ -1,8 +1,8 @@
 package com.infendro.cli.argument
 
-import com.infendro.cli.Command
+import com.infendro.cli.command.Command
 
-private object IntParser : Parser<Int> {
+private object IntParser : Argument.Parser<Int> {
     override fun parse(
         text: String?,
     ): Int {
diff --git a/src/commonMain/kotlin/com/infendro/cli/argument/Parser.kt b/src/commonMain/kotlin/com/infendro/cli/argument/Parser.kt
deleted file mode 100644
index c93353e..0000000
--- a/src/commonMain/kotlin/com/infendro/cli/argument/Parser.kt
+++ /dev/null
@@ -1,7 +0,0 @@
-package com.infendro.cli.argument
-
-interface Parser<T> {
-    fun parse(
-        text: String?,
-    ): T
-}
diff --git a/src/commonMain/kotlin/com/infendro/cli/argument/String.kt b/src/commonMain/kotlin/com/infendro/cli/argument/String.kt
index 54c35f3..a2756e9 100644
--- a/src/commonMain/kotlin/com/infendro/cli/argument/String.kt
+++ b/src/commonMain/kotlin/com/infendro/cli/argument/String.kt
@@ -1,8 +1,8 @@
 package com.infendro.cli.argument
 
-import com.infendro.cli.Command
+import com.infendro.cli.command.Command
 
-private object StringParser : Parser<String> {
+private object StringParser : Argument.Parser<String> {
     override fun parse(
         text: String?,
     ): String {
diff --git a/src/commonMain/kotlin/com/infendro/cli/Command.kt b/src/commonMain/kotlin/com/infendro/cli/command/Command.kt
similarity index 65%
rename from src/commonMain/kotlin/com/infendro/cli/Command.kt
rename to src/commonMain/kotlin/com/infendro/cli/command/Command.kt
index c074e14..9159aa9 100644
--- a/src/commonMain/kotlin/com/infendro/cli/Command.kt
+++ b/src/commonMain/kotlin/com/infendro/cli/command/Command.kt
@@ -1,21 +1,26 @@
-package com.infendro.cli
+package com.infendro.cli.command
 
-import com.infendro.cli.Regex.ARGUMENT
-import com.infendro.cli.Regex.ARGUMENT_NAME
-import com.infendro.cli.Regex.COMMAND_NAME
+import com.infendro.cli.Execution
 import com.infendro.cli.argument.Argument
 import com.infendro.cli.exception.build.*
 import com.infendro.cli.exception.run.ArgumentCountException
 import com.infendro.cli.exception.run.InvalidArgumentException
 import com.infendro.cli.exception.run.UnknownArgumentException
 import com.infendro.cli.exception.run.UnknownCommandException
+import com.infendro.cli.util.Regex.ARGUMENT
+import com.infendro.cli.util.Regex.ARGUMENT_NAME
+import com.infendro.cli.util.Regex.COMMAND_NAME
 
 class Command private constructor(
-    private val name: String,
+    private val index: Int,
+    private val name: String?,
     private val commands: List<Command>,
     private val arguments: List<Argument<*>>,
     private val block: Execution.() -> Unit,
 ) {
+    private val nextIndex: Int
+        get() = index + 1
+
     fun run(
         args: Array<String>,
     ) {
@@ -24,11 +29,11 @@ class Command private constructor(
             .find { (_, value) -> value.startsWith("--") }
             ?.index ?: args.size
 
-        val c = args.slice(0..<index)
-        val a = args.slice(index..<args.size)
+        val cmd = args.slice(0..<index)
+        val arg = args.slice(index..<args.size)
 
         try {
-            run(c, a)
+            run(cmd, arg)
         } catch (e: UnknownCommandException) {
             println("""unknown command "${e.command}"""")
         } catch (e: InvalidArgumentException) {
@@ -45,33 +50,35 @@ class Command private constructor(
     }
 
     private fun run(
-        cmd: List<String>, args: List<String>,
+        cmd: List<String>,
+        arg: List<String>,
     ) {
-        if (cmd.isEmpty()) {
-            val arguments = parseArguments(args)
-            execute(arguments)
+        if (index == cmd.lastIndex) {
+            Execution(
+                parseCmd(cmd),
+                parseArg(arg),
+            ).block()
         } else {
-            val command = commands.find { it.name == cmd[0] }
-                ?: throw UnknownCommandException(cmd[0])
-            command.run(cmd.drop(1), args)
+            val command = commands.firstOrNull() { it.name == cmd[nextIndex] || it.name == null }
+                ?: throw UnknownCommandException(cmd[nextIndex])
+            command.run(cmd, arg)
         }
     }
 
-    private fun execute(
-        arguments: List<Execution.Argument>,
-    ) {
-        val execution = Execution(arguments)
-        execution.block()
+    private fun parseCmd(
+        cmd: List<String>,
+    ): List<Execution.Cmd> {
+        return cmd.map { Execution.Cmd(it) }
     }
 
-    private fun parseArguments(
-        args: List<String>,
-    ): List<Execution.Argument> {
-        val result = mutableListOf<Execution.Argument>()
+    private fun parseArg(
+        arg: List<String>,
+    ): List<Execution.Arg> {
+        val result = mutableListOf<Execution.Arg>()
 
-        for (arg in args) {
-            val match = ARGUMENT.matchEntire(arg)
-                ?: throw InvalidArgumentException(arg)
+        for (argument in arg) {
+            val match = ARGUMENT.matchEntire(argument)
+                ?: throw InvalidArgumentException(argument)
 
             val name = match.groups["name"]!!.value
             val value = match.groups["value"]?.value
@@ -79,7 +86,7 @@ class Command private constructor(
             if (arguments.none { it.name == name })
                 throw UnknownArgumentException(name)
 
-            result += Execution.Argument(name, value)
+            result += Execution.Arg(name, value)
         }
 
         arguments
@@ -92,26 +99,31 @@ class Command private constructor(
         return result
     }
 
-    class Builder(
-        private val name: String = "",
+    class Builder internal constructor(
+        private val index: Int,
+        private val name: String?,
     ) {
         private val commands = mutableListOf<Command>()
         private val arguments = mutableListOf<Argument<*>>()
         private lateinit var block: Execution.() -> Unit
 
+        private val nextIndex: Int
+            get() = index + 1
+
         fun command(
-            name: String,
-            block: Builder.() -> Unit,
+            name: String? = null,
+            block: Builder.(Key) -> Unit,
         ) {
-            if (!COMMAND_NAME.matches(name))
+            if (name != null && !COMMAND_NAME.matches(name))
                 throw IllegalCommandNameException(name)
 
             if (commands.any { it.name == name })
                 throw DuplicateCommandException(name)
 
-            val builder = Builder(name)
-            builder.block()
+            val builder = Builder(nextIndex, name)
+            builder.block(Key(nextIndex))
             val command = builder.build()
+
             commands.add(command)
         }
 
@@ -148,15 +160,19 @@ class Command private constructor(
             if (!this::block.isInitialized)
                 throw NoExecuteException()
 
-            return Command(name, commands, arguments, block)
+            return Command(index, name, commands, arguments, block)
         }
     }
+
+    class Key(
+        internal val index: Int,
+    )
 }
 
 fun cli(
     block: Command.Builder.() -> Unit,
 ): Command {
-    val builder = Command.Builder()
+    val builder = Command.Builder(-1, null)
     builder.block()
     return builder.build()
 }
diff --git a/src/commonMain/kotlin/com/infendro/cli/exception/build/DuplicateCommandException.kt b/src/commonMain/kotlin/com/infendro/cli/exception/build/DuplicateCommandException.kt
index 4a21135..c83df29 100644
--- a/src/commonMain/kotlin/com/infendro/cli/exception/build/DuplicateCommandException.kt
+++ b/src/commonMain/kotlin/com/infendro/cli/exception/build/DuplicateCommandException.kt
@@ -1,5 +1,5 @@
 package com.infendro.cli.exception.build
 
 class DuplicateCommandException(
-    val command: String,
+    val command: String?,
 ) : Exception()
diff --git a/src/commonMain/kotlin/com/infendro/cli/Regex.kt b/src/commonMain/kotlin/com/infendro/cli/util/Regex.kt
similarity index 88%
rename from src/commonMain/kotlin/com/infendro/cli/Regex.kt
rename to src/commonMain/kotlin/com/infendro/cli/util/Regex.kt
index a57d67c..f626669 100644
--- a/src/commonMain/kotlin/com/infendro/cli/Regex.kt
+++ b/src/commonMain/kotlin/com/infendro/cli/util/Regex.kt
@@ -1,7 +1,7 @@
-package com.infendro.cli
+package com.infendro.cli.util
 
 internal object Regex {
     val COMMAND_NAME = """[a-z]+(?:-[a-z]+)*""".toRegex()
     val ARGUMENT_NAME = """[a-z]+(?:[\-.][a-z]+)*""".toRegex()
     val ARGUMENT = """--(?<name>[a-z]+(?:[\-.][a-z]+)*)(?:=(?<value>.*))?""".toRegex()
-}
+}
\ No newline at end of file