diff --git a/src/Application.php b/src/Application.php
index 80ddd6b..b8c2685 100644
--- a/src/Application.php
+++ b/src/Application.php
@@ -29,6 +29,7 @@
 use function array_unshift;
 use function class_exists;
 use function implode;
+use function is_dir;
 use function is_object;
 use function is_string;
 use function str_replace;
@@ -405,6 +406,10 @@ public function commands(array $commands): void
      */
     public function registerCommands(string $namespace, string $basePath): static
     {
+        if (!is_dir($basePath)) {
+            return $this;
+        }
+
         $this->debugf('register commands from the namespace: %s', $namespace);
 
         $length = strlen($basePath) + 1;
@@ -430,6 +435,9 @@ public function registerCommands(string $namespace, string $basePath): static
      */
     public function registerGroups(string $namespace, string $basePath): self
     {
+        if (!is_dir($basePath)) {
+            return $this;
+        }
         $this->debugf('register groups from the namespace: %s', $namespace);
 
         $length = strlen($basePath) + 1;
diff --git a/src/Command.php b/src/Command.php
index 192677a..f13bcf8 100644
--- a/src/Command.php
+++ b/src/Command.php
@@ -40,6 +40,14 @@ abstract class Command extends AbstractHandler implements CommandInterface
     protected ?Controller $group = null;
 
     /**
+     * command argument rules
+     *
+     * eg:
+     *
+     *  [
+     *      'arg1' => 'type;desc',
+     *  ]
+     *
      * @return array
      */
     protected function getArguments(): array
@@ -63,7 +71,7 @@ protected function beforeInitFlagsParser(FlagsParser $fs): void
      */
     protected function afterInitFlagsParser(FlagsParser $fs): void
     {
-        $this->debugf('cmd: %s - load command flags configure', $this->getRealCName());
+        $this->debugf('cmd: %s - load command flags configure, class: %s', $this->getRealCName(), static::class);
         $this->configure();
         $this->configFlags($fs);
 
diff --git a/src/Decorate/AttachApplicationTrait.php b/src/Decorate/AttachApplicationTrait.php
index 83b7636..a28befc 100644
--- a/src/Decorate/AttachApplicationTrait.php
+++ b/src/Decorate/AttachApplicationTrait.php
@@ -45,14 +45,16 @@ public function getApp(): Application
     }
 
     /**
-     * @param Application $app
+     * @param Application|null $app
      */
-    public function setApp(Application $app): void
+    public function setApp(Application|null $app): void
     {
-        $this->app = $app;
+        if ($app !== null) {
+            $this->app = $app;
 
-        // auto setting $attached
-        $this->attached = true;
+            // auto setting $attached
+            $this->attached = true;
+        }
     }
 
     /**
@@ -168,29 +170,4 @@ public function log(int $level, string $message, array $extra = []): void
 
         Console::log($level, $message, $extra);
     }
-
-    /**************************************************************************
-     * wrap trigger events
-     **************************************************************************/
-
-    /**
-     * @param string $event
-     * @param mixed  ...$args
-     *
-     * @return bool
-     */
-    public function fire(string $event, ...$args): bool
-    {
-        $this->debugf("fire event: $event");
-
-        // if has application instance
-        if ($this->attached) {
-            $stop = $this->app->fire($event, ...$args);
-            if ($stop === false) {
-                return false;
-            }
-        }
-
-        return $this->parentFire($event, ...$args);
-    }
 }
diff --git a/src/Decorate/SubCommandsWareTrait.php b/src/Decorate/SubCommandsWareTrait.php
index ad961a3..e2ce58e 100644
--- a/src/Decorate/SubCommandsWareTrait.php
+++ b/src/Decorate/SubCommandsWareTrait.php
@@ -117,11 +117,12 @@ protected function subCommands(): array
     protected function dispatchSub(string $name, array $args): mixed
     {
         $subInfo = $this->commands[$name];
-        $this->debugf('cmd: %s - dispatch the attached subcommand: %s', $this->getRealName(), $name);
+        $this->debugf('cmd: %s - dispatch the subcommand: %s', $this->getRealName(), $name);
 
         // create and init sub-command
         $subCmd = $this->createSubCommand($subInfo);
         $subCmd->setParent($this);
+        $subCmd->setApp($this->getApp());
         $subCmd->setPath($this->path);
         $subCmd->setInputOutput($this->input, $this->output);
 
@@ -167,7 +168,7 @@ public function addSub(string $name, string|CommandInterface $handler = null, ar
             $name = $handler::getName();
         }
 
-        Assert::isFalse(!$name || !$handler, "Command 'name' and 'handler' cannot be empty! name: $name");
+        Assert::isFalse(!$name || !$handler, "Command 'name' and 'handler' cannot be empty! name: $name, handler: $handler");
         Assert::isFalse(isset($this->commands[$name]), "Command '$name' have been registered!");
 
         $this->validateName($name);
diff --git a/src/Handler/AbstractHandler.php b/src/Handler/AbstractHandler.php
index 1e7d3d2..af865c0 100644
--- a/src/Handler/AbstractHandler.php
+++ b/src/Handler/AbstractHandler.php
@@ -130,11 +130,12 @@ public static function aliases(): array
      */
     public function __construct(Input $input = null, Output $output = null)
     {
-        $this->input  = $input;
-        $this->output = $output;
+        // init io stream
+        $input && $this->setInput($input);
+        $output && $this->setOutput($output);
 
         // init an flags object
-        $this->flags = new SFlags();
+        $this->setFlags(new SFlags());
         $this->init();
     }
 
@@ -318,6 +319,8 @@ public function run(array $args): mixed
 
             return $this->doRun($args);
         } catch (Throwable $e) {
+            $this->log(Console::VERB_DEBUG, "cmd: $name - run error: " . $e->getMessage(), ['args' => $args]);
+
             if ($this->isDetached()) {
                 ErrorHandler::new()->handle($e);
             } else {
@@ -348,7 +351,7 @@ protected function doRun(array $args): mixed
         }
 
         // only fire for alone command run.
-        if ($this->isAlone()) {
+        if ($this->isAloneCmd()) {
             $this->fire(ConsoleEvent::COMMAND_RUN_BEFORE, $this);
         }
 
@@ -375,6 +378,8 @@ protected function doExecute(): mixed
      */
     public function coExecute(): int
     {
+        /** @noinspection PhpFullyQualifiedNameUsageInspection */
+        /** @noinspection PhpUndefinedNamespaceInspection */
         $cid = \Swoole\Coroutine\run(function (): void {
             $this->execute($this->input, $this->output);
         });
@@ -432,6 +437,7 @@ protected function prepare(): bool
             if (function_exists('cli_set_process_title')) {
                 cli_set_process_title($this->processTitle);
             } elseif (function_exists('setproctitle')) {
+                /** @noinspection PhpUndefinedFunctionInspection */
                 setproctitle($this->processTitle);
             }
 
@@ -444,6 +450,32 @@ protected function prepare(): bool
         return true;
     }
 
+    /**************************************************************************
+     * wrap trigger events
+     **************************************************************************/
+
+    /**
+     * @param string $event
+     * @param mixed  ...$args
+     *
+     * @return bool
+     */
+    public function fire(string $event, ...$args): bool
+    {
+        $this->debugf("fire event: $event");
+
+        // if has application instance
+        if ($this->attached) {
+            $stop = $this->app->fire($event, ...$args);
+            if ($stop === false) {
+                return false;
+            }
+        }
+        // TODO pop fire event to parent and app
+
+        return $this->parentFire($event, ...$args);
+    }
+
     /**************************************************************************
      * helper methods
      **************************************************************************/
@@ -496,7 +528,7 @@ public function loadRulesByDocblock(string $method, FlagsParser $fs): void
         $rftMth = PhpHelper::reflectMethod($this, $method);
 
         // parse doc for get flag rules
-        $dr = DocblockRules::newByDocblock($rftMth->getDocComment());
+        $dr = DocblockRules::newByDocblock((string)$rftMth->getDocComment());
         $dr->parse();
 
         $fs->addArgsByRules($dr->getArgRules());
@@ -582,11 +614,11 @@ public function getRealDesc(): string
     /**
      * @param bool $useReal
      *
-     * @return string
+     * @return string top:sub
      */
     public function getCommandId(bool $useReal = true): string
     {
-        return $useReal ? self::getName() : $this->commandName;
+        return $this->getPath(':');
     }
 
     /**