diff --git a/model/gym-interface/py/ns3ai_gym_env/envs/ns3_environment.py b/model/gym-interface/py/ns3ai_gym_env/envs/ns3_environment.py
index cbbbe39..e50473e 100644
--- a/model/gym-interface/py/ns3ai_gym_env/envs/ns3_environment.py
+++ b/model/gym-interface/py/ns3ai_gym_env/envs/ns3_environment.py
@@ -1,8 +1,11 @@
-import numpy as np
+from pathlib import Path
+from typing import Any
+
 import gymnasium as gym
-from gymnasium import spaces
 import messages_pb2 as pb
 import ns3ai_gym_msg_py as py_binding
+import numpy as np
+from gymnasium import spaces
 from ns3ai_utils import Experiment
 
 
@@ -271,11 +274,18 @@ def get_state(self):
         extraInfo = {"info": self.get_extra_info()}
         return obs, reward, done, False, extraInfo
 
-    def __init__(self, targetName, ns3Path, ns3Settings=None, shmSize=4096):
+    def __init__(
+        self,
+        targetName: str | Path,
+        ns3Path: str,
+        ns3Settings: dict[str, Any] | None = None,
+        debug: bool = False,
+        shmSize=4096,
+    ):
         if self._created:
             raise Exception('Error: Ns3Env is singleton')
         self._created = True
-        self.exp = Experiment(targetName, ns3Path, py_binding, shmSize=shmSize)
+        self.exp = Experiment(targetName, ns3Path, py_binding, debug=debug, shmSize=shmSize)
         self.ns3Settings = ns3Settings
 
         self.newStateRx = False
diff --git a/python_utils/ns3ai_utils.py b/python_utils/ns3ai_utils.py
index efe605a..07fe5a8 100644
--- a/python_utils/ns3ai_utils.py
+++ b/python_utils/ns3ai_utils.py
@@ -18,43 +18,60 @@
 #         Muyuan Shen <muyuan_shen@hust.edu.cn>
 
 import os
+import signal
 import subprocess
-import psutil
 import time
-import signal
+from pathlib import Path
+from typing import Any
 
+import psutil
 
 SIMULATION_EARLY_ENDING = 0.5   # wait and see if the subprocess is running after creation
 
 
-def get_setting(setting_map):
-    ret = ''
+def get_setting(setting_map: dict[str, Any]) -> str:
+    ret = ""
     for key, value in setting_map.items():
-        ret += ' --{}={}'.format(key, value)
+        ret += f" --{key}"
+        if value:
+            ret += f"={value}"
     return ret
 
 
-def run_single_ns3(path, pname, setting=None, env=None, show_output=False):
+def run_single_ns3(
+    path,
+    pname: str | Path,
+    setting: dict[str, Any] | None = None,
+    env=None,
+    show_output=False,
+    debug=False,
+):
     if env is None:
         env = {}
     env.update(os.environ)
-    env['LD_LIBRARY_PATH'] = os.path.abspath(os.path.join(path, 'build', 'lib'))
-    # import pdb; pdb.set_trace()
-    exec_path = os.path.join(path, 'ns3')
-    if not setting:
-        cmd = '{} run {}'.format(exec_path, pname)
+    env["LD_LIBRARY_PATH"] = os.path.abspath(os.path.join(path, "build", "lib"))
+    if Path(pname).is_file():
+        cmd = pname
     else:
-        cmd = '{} run {} --{}'.format(exec_path, pname, get_setting(setting))
+        exec_path = os.path.join(path, "ns3")
+        cmd = f"{exec_path} run {pname} --"
+    if setting:
+        cmd += get_setting(setting)
+    if debug:
+        cmd = f"sleep infinity && {cmd}"
     if show_output:
-        proc = subprocess.Popen(cmd, shell=True, text=True, env=env,
-                                stdin=subprocess.PIPE,
-                                preexec_fn=os.setpgrp)
+        proc = subprocess.Popen(cmd, shell=True, text=True, env=env, stdin=subprocess.PIPE, preexec_fn=os.setpgrp)
     else:
-        proc = subprocess.Popen(cmd, shell=True, text=True, env=env,
-                                stdin=subprocess.PIPE,
-                                stdout=subprocess.PIPE,
-                                stderr=subprocess.PIPE,
-                                preexec_fn=os.setpgrp)
+        proc = subprocess.Popen(
+            cmd,
+            shell=True,
+            text=True,
+            env=env,
+            stdin=subprocess.PIPE,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+            preexec_fn=os.setpgrp,
+        )
 
     return cmd, proc
 
@@ -99,18 +116,26 @@ class Experiment:
     # \param[in] memSize : share memory size
     # \param[in] targetName : program name of ns3
     # \param[in] path : current working directory
-    def __init__(self, targetName, ns3Path, msgModule,
-                 handleFinish=False,
-                 useVector=False, vectorSize=None,
-                 shmSize=4096,
-                 segName="My Seg",
-                 cpp2pyMsgName="My Cpp to Python Msg",
-                 py2cppMsgName="My Python to Cpp Msg",
-                 lockableName="My Lockable"):
+    def __init__(
+        self,
+        targetName: str | Path,
+        ns3Path,
+        msgModule,
+        debug=False,
+        handleFinish=False,
+        useVector=False,
+        vectorSize=None,
+        shmSize=4096,
+        segName="My Seg",
+        cpp2pyMsgName="My Cpp to Python Msg",
+        py2cppMsgName="My Python to Cpp Msg",
+        lockableName="My Lockable",
+    ):
         if self._created:
             raise Exception('ns3ai_utils: Error: Experiment is singleton')
         self._created = True
-        self.targetName = targetName  # ns-3 target name, not file name
+        self.targetName = targetName  # ns-3 target name or file name
+        self.debug = debug
         os.chdir(ns3Path)
         self.msgModule = msgModule
         self.handleFinish = handleFinish
@@ -144,10 +169,15 @@ def __del__(self):
     # run ns3 script in cmd with the setting being input
     # \param[in] setting : ns3 script input parameters(default : None)
     # \param[in] show_output : whether to show output or not(default : False)
-    def run(self, setting=None, show_output=False):
+    def run(self, setting: dict[str, Any] | None = None, show_output=False):
         self.kill()
         self.simCmd, self.proc = run_single_ns3(
-            './', self.targetName, setting=setting, show_output=show_output)
+            "./",
+            self.targetName,
+            setting=setting,
+            show_output=show_output,
+            debug=self.debug,
+        )
         print("ns3ai_utils: Running ns-3 with: ", self.simCmd)
         # exit if an early error occurred, such as wrong target name
         time.sleep(SIMULATION_EARLY_ENDING)