diff --git a/src/agentex/lib/cli/commands/agents.py b/src/agentex/lib/cli/commands/agents.py
index 18d7812a..10dab0d0 100644
--- a/src/agentex/lib/cli/commands/agents.py
+++ b/src/agentex/lib/cli/commands/agents.py
@@ -52,7 +52,7 @@ def get(
     client = Agentex()
     agent = client.agents.retrieve(agent_id=agent_id)
     logger.info(f"Agent retrieved: {agent}")
-    print_json(data=agent.to_dict())
+    print_json(data=agent.to_dict(), default=str)
 
 
 @agents.command()
@@ -64,7 +64,7 @@ def list():
     client = Agentex()
     agents = client.agents.list()
     logger.info(f"Agents retrieved: {agents}")
-    print_json(data=[agent.to_dict() for agent in agents])
+    print_json(data=[agent.to_dict() for agent in agents], default=str)
 
 
 @agents.command()
diff --git a/src/agentex/lib/cli/commands/tasks.py b/src/agentex/lib/cli/commands/tasks.py
index 189021f7..43d54894 100644
--- a/src/agentex/lib/cli/commands/tasks.py
+++ b/src/agentex/lib/cli/commands/tasks.py
@@ -25,7 +25,7 @@ def get(
     client = Agentex()
     task = client.tasks.retrieve(task_id=task_id)
     logger.info(f"Full Task {task_id}:")
-    print_json(data=task.to_dict())
+    print_json(data=task.to_dict(), default=str)
 
 
 @tasks.command()
@@ -35,7 +35,7 @@ def list():
     """
     client = Agentex()
     tasks = client.tasks.list()
-    print_json(data=[task.to_dict() for task in tasks])
+    print_json(data=[task.to_dict() for task in tasks], default=str)
 
 
 @tasks.command()
@@ -46,7 +46,10 @@ def list_running(
     List all currently running tasks for a specific agent.
     """
     client = Agentex()
-    all_tasks = client.tasks.list()
+    if agent_name:
+        all_tasks = client.tasks.list(agent_name=agent_name)
+    else:
+        all_tasks = client.tasks.list()
     running_tasks = [task for task in all_tasks if hasattr(task, "status") and task.status == "RUNNING"]
 
     if not running_tasks:
@@ -74,7 +77,7 @@ def list_running(
                 {"id": getattr(task, "id", "unknown"), "status": getattr(task, "status", "unknown")}
             )
 
-    print_json(data=serializable_tasks)
+    print_json(data=serializable_tasks, default=str)
 
 
 @tasks.command()
diff --git a/src/agentex/lib/cli/handlers/cleanup_handlers.py b/src/agentex/lib/cli/handlers/cleanup_handlers.py
index 4f4433d5..1d67b55e 100644
--- a/src/agentex/lib/cli/handlers/cleanup_handlers.py
+++ b/src/agentex/lib/cli/handlers/cleanup_handlers.py
@@ -59,7 +59,10 @@ def cleanup_agent_workflows(
         client = Agentex()
         
         # Get all running tasks
-        all_tasks = client.tasks.list()
+        if agent_name:
+            all_tasks = client.tasks.list(agent_name=agent_name)
+        else:
+            all_tasks = client.tasks.list()
         running_tasks = [task for task in all_tasks if hasattr(task, 'status') and task.status == "RUNNING"]
         
         if not running_tasks: